Gallium: Assessing the long term future extraction, supply, recycling and price of using WORLD7, in relation to future technology visions in the European Union

Gallium: Assessing the long term future extraction, supply, recycling and price of using WORLD7, in relation to future technology visions in the European Union | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Gallium: Assessing the long term future extraction, supply, recycling and price of using WORLD7, in relation to future technology visions in the European Union Harald Ulrik Sverdrup, Hördur Valdimar Haraldsson This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5390312/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 08 Jul, 2025 Read the published version in Biophysical Economics and Sustainability → Version 1 posted 10 You are reading this latest preprint version Abstract The gallium resources were assessed and used as input to long term simulations using the WORLD7 model. The content of gallium in different mother ores has been estimated to be about 14.7 million ton of gallium. Much of this is not accessible because of low extraction yields, about 610,000 ton gallium appear to be extractable (4%) with present practices. The gallium content in all source metal refining residuals is about 51,000 ton/yr, but only a production of 1,374 ton/yr appear as the maximum with present technology and conditions. The actual gallium production was about 450 ton/yr in 2023. The gallium price is very sensitive to increases in demand, and production is not very likely to be able to rapidly increase. The simulations show that soft gallium scarcity sets in after 2028 and physical scarcity will occur about 2060. Better gallium extraction and recycling yields may push the scarcity date forward to 2100. In the long term, only 60% of the gallium demand to photovoltaic technology can be satisfied. To really improve the situation and prevent scarcity, extractive access, gallium extraction yields and recycling yields must be significantly improved to better than 50%. At present the overall yields are 7-15%. Increasing both extraction yields and recycling yields can reduce the shortage. The long term sustainable extraction is under Business-as-Usual about 300 ton gallium per year, about 67% of the present production. Doubling present extraction and recycling yields may increase this to 460 ton per year. This poses a major challenge to future plans for an energy transition, where under Business-As-Usual (BAU), such a transition will remain a fair fantasy. The four EEA imaginaries, Ecotopia, The Great Decoupling, Unity in Adversity, and Technocracy for the Common Good, offer different policy pathways for managing future gallium scarcity through varying degrees of technological advancement, resource conservation, and avoidance strategy. WORLD7 gallium sustainability scarcity peak behaviour technology metals Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 1. Introduction Gallium is an important element for different photovoltaic technologies, semiconductors used in electronics and LED lighting technologies. The envisioned European energy transition towards renewable energy sources implies a large amount of photovoltaic electricity production, as well as more energy-efficient technologies helping to reduce energy use. At the same time, new electronics and semiconductors depend on a larger scale on different types of gallium and on gallium in combinations with other technology metals. All of that depends on having a sufficient supply of metals like gallium for these technologies. Gallium is a secondary product of zinc, copper, lead and bauxite mining. Other sources are being explored. In line with the long-term sustainability vision of the European Union, the European Green Deal stresses the importance of secure access to critical minerals that are essential for the functioning of the society in the future. To this end, the European Environment Agency (EEA) has developed four alternative imaginaries that depict different visions of a sustainable Europe by 2050 (SE2050), each with different policy approaches to resource use and management (EEA 2022, Sverdrup et al., 2024, Sverdrup). These are shaped as assumption scenarios that will need further substantiation and elaboration of details: Ecotopia: This scenario prioritises nature and sustainability, with a marked reduction in consumption and technological reliance. It is assumed that the public sector retracts, civil society and local communities play a collaborative role in driving decision-making and welfare systems. The Great Decoupling: In this scenario, it is assumed that technological innovations and social advancements have managed to decouple GDP growth from environmental degradation. Green growth is fuelled by competitive markets, with the bioeconomy at the forefront. Government interventions guide incentives, while EU cooperation remains pragmatic and focused. Unity in Adversity: In this scenario, Europe has come together under a unified constitution to respond to environmental, climate, and geopolitical challenges. Strict economic measures prioritise environmental sustainability, with significant investments made to address climate and ecological concerns. Technocracy for the Common Good: State control is central, with digitalisation used to monitor and manage social and ecological systems extensively. The EU functions as a cohesive alliance of strong governments, driving centralised economic activity, with a shift toward deglobalization and protectionist policies. Each of these imaginaries envisions a different role for metals and minerals, including gallium, and varies in the methods of their production, usage, and recycling. Policymakers can use these visions to craft strategies that align with the sustainability objectives of each imaginary, particularly in how critical metals like gallium can be reused and recycled (Haraldsson and Bonin, 2021; EEA 2022; Sverdrup et al., 2024). 1.2 Overview on gallium and what it is used for (put this together with introduction?) Gallium is used for many new technologies (computer semiconductors, LED lighting, photovoltaic solar energy collectors, screens, advanced sensors). The supply security of gallium depend on copper, zinc, lead and aluminium mining. Gallium are found in low concentrations in coal deposits, but a few deposits have significant amounts. Gallium is used in applications where there are no obvious good substitutes (Öhrlund 2011, Zuser and Rechberger 2011, Werner et al., 2017b, Panoussi et al., 2015). A eutectic alloy of gallium, tin and indium make an important non-toxic substitute for mercury in many of its applications. The global production in 2022 was small, only about 450 ton per year. The development of the production since 1945 to 2023 is shown in Figure 1a (USGS 2022 ds140). Figure 1b shows the development of the price during the same period (USGS 2022, ds140). Annual production in 2022 was somewhere between 560-650 ton per year, all depending on the source (USGS Minerals Commodities Summary 2022, Jaskula 2022, ds140-Gallium Mineral commodity Statistics USGS website, British Geological Survey: Idoine et al., 2022). Further increase in gallium demand in the near future is expected. The Covid epidemic and the Russian invasion of Ukraine caused global disturbances in the gallium market (Jaskula 2022). China was the largest gallium producer in 2019, it largely closed production 2020-2022, and restarted production in 2023. Time will show who else will enter the market to fill the growing demand. As demonstrated in the germanium and indium studies (Sverdrup et al., 2024a, 2024submitted), the future availability of critical minerals is closely connected to how the pathways towards these imaginaries are manifested in policy. In particular, the scarcity of metals such as germanium, indium, and gallium pose significant challenges to advanced technologies like photovoltaics and semiconductors. The management of these minerals, dependents on policy frameworks that prioritise innovation in recycling and extraction efficiencies to avoid shortages under the ‘business as usual’ scenario (BAU. 2. Objectives and scope The goal was to develop an integrated dynamic model for the global market for gallium. The gallium supply system will be explored using dynamic modelling and to asses if the supply is sustainable according to the Brundtland definition (…provide the needs for present and future generations”). The global industrial circulation in a is included, simulations cover 1850-2200. The model is tested respect to historical data for extraction rate and market price. The model was used to assess the long term risk for soft or hard scarcity of the gallium in the future. The results have two features. (1) the assembly of key data on resources, reserves, production rates and gallium prices. These are needed to initiate and parameterize the model. (2) The use of the model to assess the supply and production in the future. 3. Earlier work We have not found any serious sustainability assessment based on integrated assessment dynamic simulations for the gallium supply system and the development of the gallium supply system over time. No considerations of the cross-linking dependencies and feedbacks in the gallium system have been published earlier or included in any model. There is no earlier process-oriented systems dynamics model for gallium. No model have earlier integrated market supply and demand modelling in the gallium flow system. Some studies have touched upon the subject using simple mass balance approaches and burn-off estimates, but these are not really valid methods for a dependent secondary extracted metal like gallium. A preliminary study was presented by Sverdrup and Ragnarsdottir (2014) and Sverdrup et al., (2017). Lu et al., (2017) made a review of resources and extraction methods for gallium, stating that the gallium content in coal is about 10 million ton, that bauxite contain more than 1 million ton gallium, and that the gallium contents in zinc ores are significant. Lu et al., (2017) estimates that the gallium demand will increase from 325 ton/yr in 2017 to maybe as much as 5,000-5,500 ton/yr of gallium in 2030. Nobody really knows if that is possible or not, but absolutely needs to be found out. Frenzel et al., (2015) estimates the supply potential of gallium at 2,100 ton per year from bauxite refining, 85 ton per year from refining of sulfidic zinc ores, and potentially 590 ton per year from refining of coal combustion fly ash and slags (2,775 ton per year). 4. Methods and theory used 4.1. Overview The main tool employed is system dynamics modelling. For designing the system dynamics model, we use systems analysis. We analyse the system using stock-and-flow charts and causal loop diagrams. The mass balance expressed differential equations resulting from the flow charts and the causal loop diagrams were numerically solved using the STELLA ® Architect modelling environment (Senge 1990, Sverdrup et al. 2022). We use causal loop diagrams for mapping out where the causalities are, to find intervention points in the system, and to propose policy interventions. The Integrated Assessment Model WORLD7 was used for this study (Sverdrup and Olafsdottir 2019). The workflow was as follows: Estimate the available gallium resource that can be extracted using valid mining methods, considering the different yields and estimating the total geological deposit-to-supplied gallium approach. Use the WORLD7 integrated modelling framework to generate gallium demand from the production of consumer goods and technological infrastructures. Identify the available sources of technology elements and the estimate the available amounts that can be extracted from those deposits, considering extraction technologies and the cut-off caused by resource qualities and costs of extraction as related to the market price dynamics. Run the WORLD7 model to assess the supply sustainability from the first use of the technology metals to about 2200. Evaluate the model simulations with respect to result validity, and risk for future aspects of scarcity. Evaluate how future policies that would result from the EU Imaginaries would grip into the gallium system. The WORLD7 integrated assessment model was used for earlier assessments supply for silver (Sverdrup et al., 2014b), copper, zinc, lead (Sverdrup et al., 2015, 2019), aluminium (Sverdrup et al., (2015a), platinum group metals (Sverdrup and Ragnarsdottir 2016), wolfram (Sverdrup et al., 2017c), molybdenum and rhenium (Sverdrup et al., 2018b), tin (Olafsdottir and Sverdrup 2018), nickel (Olafsdottir and Sverdrup 2020), indium (Sverdrup et al., 2023). Further publications near completion after this are studies on tellurium, selenium, yttrium, antimony and bismuth, The source metal reserves and resources estimates for the relevant metals are based on geological estimates, the interpretation of geological data, and the allocation of extractable amounts according to ore quality, stratified with extraction costs, and as revised in our earlier studies for copper, zinc, lead, bauxite, nickel, molybdenum and wolfram (Phillips and Edwards 1976, Olafsdottir and Sverdrup 2018 (Sn), 2020 (Ni), Sverdrup and Olafsdottir 2019 (markets), Sverdrup et al., 2014a (Ag), 2015 (Al), 2017 (W), 2018 (Mo), 2019 (Ca,Zn,Pb), 2023 (In), 2024 (Ge).). 4.2. Resource estimations 4.2.1. Dependencies and cross-links Figure 2 shows how the different technology metals are almost all of them dependent on primary extraction of a major resource such as hydrocarbons, metals or phosphate. All the 10 big metals and the minor metals indicated with yellow colour have their own primary mines, for all those in blue colour, extraction is dominated by secondary extraction. This complicated system is contained inside the WORLD7 model. 4.2.2. Basis for estimating how much can be extracted from ore deposits Gallium is extracted mainly from Bayer Liquid from processing bauxite to alumina (about 60%) and zinc (about 40%) (Nassar et al., 2015). A few coal mines extract some gallium from coal and some production has been done from coal fly ash, and potentially, more is available. Gallium can be from secondary extraction during the refining process of primary metals like copper, zinc and lead. Recycled mother metals have very little content of gallium. Gallium is only available if the ore is hydrometallurgical processed and little technology metals come out with heap leaching methods. Only a few studies make detailed studies of the available resources of the technology metals. We have identified a few that were helpful for this study concerning: The size of the extractable gallium resource was discussed by Frenzel et al., (2016a,b, 2017), Lu et al., (2017), Paradis (2015), Panoussi et al., 2015, Wang et al., (2011) and Jaskula (2019). Statistics and data was supplied by USGS (2015, 2017, 2018, 2022). Aspects of the extraction methods and different degrees of recycling was discussed by Brown et al., (2014), Moskalyk (2003, 2004), Redlinger et al., (2015). No earlier studies on gallium involve any real feedbacks from market dynamics. Estimating the demand is particularly uncertain and was discussed by Goe and Gaustad (2014), Gibson and Hayes (2011), Dehnavi (2013), Weeks (1973) and Licht et al., (2015). The basic approach is to assume a certain percentage growth per year and let it expand exponentially. This is a fairly short term and naive approach and is generally not based in any fundamental system dynamics knowledge of the gallium system. Another approach was to let it expand with GDP. The more sophisticated approaches trace the demand back to specific technology needs, and derive estimates from that. 4.2.3. Extractability and yields One major source of difference between the available resource estimates in the literature are the differences (or lack of) assessment of actual industrial extractability. That a deposit has a certain amount of metal does not mean that it can all be extracted. The extraction pathway for a metal in general is shown in Figure 1. We have looked at many assessments to see if they seem to converge on a similar resource base for gallium (We reviewed Werner et al., 2017, Yellishetty et al., 2017, USGS 2022, Brown et al., 2015, Frenzel 2016, Mudd et al., 2014, 2017, Nassar et al., 2015, Sverdrup and Olafsdottir 2020, for gallium resource estimates). Yield is defined as being made of several components: Access yield: The part of the deposits that will be available for this kind of extraction. Some deposits lack physical or legal access, some have a composition that prevents extraction or the extraction operation do not have the infrastructure to extract the technology metal when the operation is running Reuter et al., (2013a,b); (Y A ). The substrate yield is the fraction of the potential in the source material that will be used for extraction, in many mines, the refining residuals are simply thrown away; (Y S ). When the gallium is taken out, first there is an extraction where gallium is separated from the other metals present (Y E ) and then it its refined and into pure gallium (Y R ), see Figure 3. Some methods, such as heap leach do not readily give such a secondary substrate that contains gallium or other metals that can be extracted. The refining yield is the fraction of the gallium recovered from the refining substrate; (Y R ) . Some bauxites have good gallium contents, but too much silica to be interesting for alumina production. Then gallium will not be extracted. Some coals goes straight to a use where the gallium will not be extracted from the ashes. The extraction cut-off is dependent on technology, extraction costs and the metal price at the time. 4.2.4. Resource and extractable amounts estimation. The recoverable resources are estimated (Krautkrämer 1988, Sverdrup and Olafsdottir 2019, 2020): Gallium resource = Mother metal resource * X Ga * Y (1) Gallium production = Mother metal production * X Ga * Y (2) X Ga is the fraction gallium in the material, and where the yield Y is the yield (Krautkrämer 1988, Sverdrup and Olafsdottir 2020, Sverdrup et al., 2023). This is defined as: Y= Y A * Y E * Y R (3) The refining yield Y R will be a function of the extractive efficiency when treating the ore shipped to the refinery. The material contained below the cut-off grade is lost with the waste (Krautkrämer 1988, Sverdrup and Olafsdottir 2020). The extraction yield Y E is: Y is the overall yield, the amount metal extracted divided by the total metal content in the original ore. The extraction cut-off is determined by the technology used for extraction, combined with several cost aspects of extraction. Gallium can be extracted from the waste liquid when bauxite is processed to alumina (Bayer process) and if the extraction plant has the necessary infrastructure for it. Some Russian and Chinese coal deposits are known to contain significant amounts of gallium. The different estimates come from different sources, not using the same background material, and they are thus not always consistent. For gallium extraction before 1950 was very small. Yields from refining residuals are far higher than the access yields and enrichment yields, suggesting that investment in technical ability for gallium extraction appear to be missing. Possibly because on the individual process step level, each process is difficult to make profitable, even if gallium is very important on the whole-system strategic level. 4.2.5 Long term sustainable supply of gallium. Sustainability is defined as “..sufficient for the needs of the present and future generations” according to the Brundtland definition. The future has many more generations than the present. If the time from invention of writing is counted, then that would be 5,000 years or about 150 generations. If we count from the invention of agriculture and the rise of cities, it is 10,000 years or 330 generations. If the industrial revolution started 1840, that is 180 years ago, then it is 6 generations. The total available resource must be estimated as follows: Available amount = extractable + recycled (5) This can be used to estimate the annual average supply for the time period assumed to be appropriate for length of the future. This way of estimating the long term average supply sets a final date for the resource, and after this time it will potentially no longer be available at all. Take note that “sufficient need” is not necessarily the same as “want” or “demand”. The results are reported later. 5. Dynamic simulation model description The dynamic model is best described by the system flow chart as described in Figure 4 and the causal loop diagram (CLD) shown in Figure 5. Figure 4 shows the flow chart for the part of the WORLD7 model dealing with gallium. The major gallium losses have been marked with red. In the model, tin was ignored as a source of gallium, as the contribution to the total supply is small. Figure 5 shows the causal loop diagram for the gallium sub-model. In certain aspects the CLD has been simplified in order to keep it readable. Market with blue is the extractive sector, in green is the recycling sector, in yellow is the market, red is the industry using gallium in commodities and turquoise is the use in society. The system feedbacks for system irreversible losses of gallium have not been shown. The system driving the preparation of gallium extraction substrate from coal ash, Bayer liquid and anode sludges from primary metal extraction have not been shown. R1, R2, R3 and R4 are reinforcing loops driving the gallium supply system. R1 is the extraction loop secondary to primary production of metals, and it is driven by profits. R2 is the extraction-investment loop, describing how increased extraction infrastructure increases extraction production and extraction profits. R3a and R3b are the loops for investing in recycling capacity. These links have been indicated in green. The investment decision is being taken based on profits and a supply capacity gap. These links have been indicated in blue. R4a-R4d are four different loop running over recycling to generate income and recycled gallium which is sold again to the market. R6 is the recycling-investment loop, describing how increased recycling infrastructure increases recycling production and recycling profits. B are different balancing loops, slowing the system down. B1-B4 are different balancing loops, slowing the system down. B1 is the balancing effect of a large supply to the market, which may press the market price down. B2 is the balancing effect of operation costs and capital cost of invested capital in infrastructure for first extraction of gallium from different substrates. B3 is the balancing effect of operation costs and capital cost of invested capital in infrastructure connected to recycling of gallium. B4a-B4d are the balancing effect of supply and demand in the system to deliver commodities with gallium to society. B5 is the balancing effect of closing the supply capacity gap by investing in more capacity. The small unnumbered B’s are stock depletion balancing loop in the system. The system involves a supply chain from extraction substrates and recycling substrates through extraction processes to the metal market, on to users of gallium for inclusion in commodities. The commodities flow to society and after use to scrap, where a part becomes a recycling substrate, closing the cycle. In the WORLD7 model, take from the market are driven by the modified demand, put gallium into society where it stays until scrapped or removed by wear and losses. Demand in the model is driven by population and metal use per person, but is adjusted up or down with price; this is the modified demand. The demand is estimated from average affluence, expressed as disposable income per person and global population, using outputs of the WORLD7 model (Sverdrup et al. 2019b, Sverdrup 2019). The basic driving mechanism of gallium extraction comes from profits of the extraction activity and availability of a extractable substrate used in the model. The price is determined by how much metal is available in the market in the same way as in our earlier metal models. This approach has been very successful in endogenously modelling the price (Sverdrup and Ragnarsdottir 2014, Sverdrup et al. 2017b, Sverdrup and Olafsdottir 2018, 2019). A high metal price will increase profits and promote larger supply to the market. High price leads to a reduction of demand in the model. More supply to the market will increase the amount available and lower the price. Figure 6 shows an overview of the WORLD7 integrated assessment model. The WORLD model was developed from 2012 and still ongoing in 2023. The WORLD7 model addresses a large number of metals, and they are all in some way all linked in their extraction. All modules in WORLD7 are interconnected. Every red line represents one or several feedback links. Every box contains one of several sub-models. The WORLD7 energy module supplies energy from fossil fuels, renewables and nuclear power, with a market price generated by supply and demand in the model. Energy for metal extraction is taken from this module (Sverdrup et al., 2019b). Table 1 shows average estimated for the use of technology metals, gram/unit; indium, gallium, antimony, selenium and silver for CIGS (CuInGaSe) photocell technology and other technologies. gram/unit. The copper, zinc, lead and silver production was derived in the WORLD7 model (Sverdrup et al., 2015a, 2019b, Sverdrup and Ragnarsdottir 2014b). The aluminium module in WORLD7 was used for the contribution from bauxite mining, integrated as a sub-module into the WORLD7 model (Sverdrup et al., 2015). Coal production and fly ash production rates were derived in the WORLD7 energy module. For gallium, the price has an effect on demand, but not any significant impact on the supply, as this is dependent on the source metal extraction rate. There is no feedback from gallium production and back to copper mining. The price has effect on demand in the model, but it does not have any significant impact on the supply, as this is dependent on the mother metal extraction rate. The mining cost depend on the energy price, other operating costs and financial costs. Table 1. The use of technology metals, gram/unit; indium, gallium, antimony, selenium and silver for CIGS (CuInGaSe) photocell technology and other technologies. gram/unit. Item Indium Gallium Antimony Selenium Silver Computers 0.040 0.002 0.770 0.050 0.250 LED TV 0.003 0.005 0.710 0.015 0.450 Mobile phones 0.0003 0.0005 0.071 0.002 0.045 CuInGaSe PhotoVoltaic 0.120 0.120 0 0.120 0.080 Cars 0.300 0.05 5 0.100 0.200 Handheld tools 0.002 - 0.140 0.005 0.010 The scrapping process for stock-in-use in society is driven by price (Dahmus and Gutowski 2007, Sverdrup and Olafsdottir 2019), after the metal has been scrapped, a high price will promote more recovery. Figure 7 shows the STELLA Architect code inside WORLD7 for the gallium module. 6. Results 6.1. Resource and production estimates Table 2 shows the recoverable resources of source metals in million ton of metal, this was used as input data to the WORLD7 model (Sverdrup and Ragnarsdottir 2014, Sverdrup et al., 2017a,b,c and Sverdrup and Olafsdottir 2018, 2019). The data has been stratified with respect to ore metal content and relative extraction cost (Phillips and Edwards 1976, Sverdrup and Olafsdottir 2019, 2020). For the content in coal two approaches to estimating the content was used, both resulting in about the same amount. The gallium content in coal is low, but it remains in the ashes and gets concentrated there 20-30 times. The given yields and the resource gallium content are very approximate estimates by the authors, derived from unpublished industrial sources and in some parts from the scientific literature. Note how the yields are very low. Of a geological presence of 15 million ton gallium, only 0.6 million ton is estimated to be obtainable for use (4%). This makes it clear that it is as important to improve yields as it is to find more gallium in deposits. Table 2. Resource estimates for gallium. There are no primary mines for gallium. All extraction is secondary. Numbers in italics for coal grades (136,000 ton) are parallel estimates to the bulk estimate on coal combustion ashes content (139,000 ton or 136,000 ton). Take note that the yields are very low for most pathways. Source Resource mill ton Rich High Low Ultra Ga content, ton Y A Y E Y R Y Extractable Ga, ton ppm Yield, Fraction Zinc 2,676 60 30 20 10 107,000 0.5 0.2 0.9 0.090 9,633 Copper 4,020 40 20 10 5 80,400 0.5 0.2 0.9 0.090 7,236 Tin 120 30 15 7 1,800 0.4 0.2 0.7 0.140 252 Lead 3,015 50 30 20 5 60,300 0.5 0.2 0.9 0.090 5,427 Silver 2.4 50 30 120 0.6 0.2 0.95 0.110 14 Coal 420,000 500,000 530,000 8 6 4 3,360,000 3,000,000 2,120,000 0.1 0.1 0.1 0.2 0.2 0.2 0.8 0.8 0.8 0.016 0.016 0.016 54,000 48,000 34,000 1,450,000 8 6 4 8,480,000 0.016 136,000 Coal ash 58,000 200 150 100 - 8,700,000 0.1 0.2 0.8 0.016 139,000 Bauxite 112,000 80 50 25 5 6,000,000 0.5 0.2 0.8 0.080 448,000 Sum 14,949,000 0.04 609,592 Table 3. Extraction rate estimates for gallium, assuming presently (2023) applicable substrate access and supply chain yields. There are no primary mines for gallium, everything is secondary extraction. Source Mining mill ton/yr Rich High Low Ultra Gallium content ton/yr Y A Y E Y R Y Extractable gallium ton/yr ppm Fraction Zinc 17 60 30 20 10 340 0.5 0.4 0.9 0.090 62 Copper 22 40 20 10 5 220 0.5 0.2 0.9 0.090 20 Tin 0.4 30 15 7 - 6 0.4 0.2 0.7 0.140 0.8 Lead 3 50 30 20 5 60 0.5 0.2 0.9 0.090 5.4 Silver 0.027 - - 50 30 2 0.6 0.2 0.95 0.110 0.2 Coal 4,200 8 6 4 - 25,200 0.1 0.2 0.8 0.016 403 Fly ash 118 200 150 100 - 17,700 0.1 0.2 0.8 0.016 283 Bauxite 350 80 50 25 5 17,500 0.5 0.2 0.8 0.080 600 Sum - - - - - 61,028 0.026 1,374 Table 3 shows the extraction rate estimates for gallium, assuming presently applicable substrate access and extraction yields. Gallium occur on the average as 50 ppm in bauxite (aluminium ore), and can be extracted when the bauxite is processed to alumina, the raw material used for aluminium production (Figure 2 and see Foley and Jaskula 2013, USGS 2018). The refining yield is estimated to be at best 40% (Jaskula 2014). In reality, the real industrial yields end up far below that so far. The content in zinc ores vary from 8 ppm to 320 ppm (Butcher and Brown 2014). Our own estimate of the of bauxite resource is 112,500 million ton (Sverdrup and Ragnarsdottir 2016). At 50 ppm gallium content (50 g/ton), that corresponds to a geological resource of 6 million ton gallium (Table 1). But assuming that to be all present in geological deposits to be fully extractable is wrong. The different access and extraction yields must be considered, and at present, with best available technology, about 450,000 ton of gallium would be extractable. Most of the gallium supplied in 2023 comes from Bayer liquid from processing bauxite to alumina, see Tables 3 and 4 (Ronguo et al., 2016, Lokanc et al., 2015). Table 4. Extraction rate estimates for gallium, but assuming better yields than at present (2022). Still, they are quite low. The technical extraction yield in 2022 was about 25%. Only 13% of the potential was extracted. Source Mining rate Gallium content Y A Y E Y R Y Extractable gallium Extraction 2023 Mill ton/yr ton/yr Assumed future yields, as fraction of total content present ton/yr Zinc 17 340 0.6 0.65 0.9 0.35 119 60 Copper 22 220 0.6 0.65 0.9 0.35 77 30 Tin 0.4 6 0.6 0.65 0.9 0.35 2 - Lead 3 60 0.6 0.65 0.9 0.35 21 3 Silver 0.027 2 0.6 0.5 0.9 0.27 1 - Coal 4,200 25,200 0.15 0.5 0.9 0.07 1,764 20 Fly ash 118 17,700 0.15 0.5 0.9 0.07 819 50 Bauxite 150 7,500 0.5 0.5 0.9 0.23 1,679 287 Sum - 51,028 0.09 4,482 450 Table 4 shows approximate extraction rate estimates for gallium, but assuming better yields than at present (2022). With gallium, the main issue is not the size of the resource, but (1) the access to the flow of substrate for extraction from mother metals, (2) dependence on the suitability of the bauxite for alumina production (It must have a low silica content), and (3) if the infrastructure for extracting gallium is present at the site where the secondary residual material is produced. Production at present is far below the potential available (Ronguo et al., 2016). The yield in the refining step is 75-80% (Hoang et al., 2015). The different yields given in the literature are not at all consistent. The yields indicated by the USGS (Foley et al., 2017) are in the range of 10% access, about 20-30% yield in the first steps of extraction and 80% yield in the final refining to pure gallium, resulting in a total yield of about 5-10%. The low yields are a major challenge in the extraction of gallium, but it seems that they may be slowly improving. It can be seen from the Table 3 that the potential is 51,000 ton/year of gallium, but that because of low yields under business-as-usual, the real extraction potential is 1,340 ton per year. There is a significant potential source of gallium in coal, and that could be extracted from the ash after combustion, the ash is about 5-20% of the coal, thus gallium is enriched 5-20 times in the ash as compared to the raw coal. Earlier estimates are in the same order of magnitude as we have indicated in Tables 2 and 3. The total extraction potential is about 4,500 ton per year of gallium according to Table 3. The average reserve content were adapted from unofficial information found in company websites, confidential information from consulting companies and using industrial information. These is are independent sources from USGS and similar literature (USGS 2011-2022, BGS 2022), but the estimates are of the same order of magnitude as in Table 4 (Sverdrup et al., 2017a). Table 5 shows the present production and capacities for gallium production. The available estimates are not internally consistent and the numbers are approximate estimates made by the authors. The final column shows a very approximate estimate of the extraction potential, and this can be compared to the present production of gallium. The gallium potential without China is about 1,540 ton/year, or three times the present production. China supplies 84% of the global supply, followed by United States at 7%, and all the rest with only marginal contributions. The present global gallium technical production capacity (800 ton/yr) is far larger than the actual gallium production (450 ton/yr) in 2023, and far less than the gallium extraction potential (3,450 ton/yr). Table 6 shows a comparison of gallium resources estimates for anode sludge residuals and potential gallium production, at different yields for recycling and extraction from anode sludges, mostly from sulphide ores. Anode sludge arise when the mother metal is refined using electrolysis. Table 7 shows a comparison of gallium resources in coal ash and potential gallium production (ton/yr), at different yields. Present yield from anode slimes is in the range 10-15% (Table 1). Present yields for gallium extraction from coal and coal ashes is in the range 2-4% (Table 1), gallium recycling from urban scrap is at present very low, less than 10% (Data extracted from Dahmus and Gutowski 2007, Reuter et al., 2013a,b). Table 5. Present production and capacities for gallium production in 2023. Amounts are in ton gallium per year. The final column shows an estimate of the potential. ? implies no data was found. Country Primary gallium production 2023, ton/yr Estimated primary gallium production capacity, ton/yr High purity gallium refining capacity, ton/yr Alumina primary production, million ton/yr Zinc primary production, million ton/yr Gallium approximate potential assuming 50 ppm content and 50% yield, ton/yr China 380 650 ? 76 4.3 2,000 Australia ? ? ? 20 1.3 525 Brazil ? ? ? 11 0.2 302 India ? ? ? 7.4 0.8 410 Peru ? ? ? 0 1.6 40 USA 30 150 320 4.3 0.8 125 Bolivia 0 0 0 - 0.8 20 Mexico 0 0 0 - 0.7 18 Ukraine 4 5 - ? 0.1 Russia 5 5 5 0.6 0.3 22 Belgium 0 10 3 - - Japan 0 10 3 - - Slovakia 0 10 3 - + South Korea 0 5 2 - - Germany 0 5 5 ? + Other ? ? 59 2.0 2.0 100 Sum 450 800 400 120.0 14.0 3,540 Table 6. Comparison of gallium resource (ton) estimates for anode sludge residuals and potential gallium production (ton/yr), at different yields. Item Extraction or recycling under different scenarios for yield (Y) as fraction Y=0.04 Y=0.1 Y=0.2 Y=0.3 Y=0.4 Probable resource, ton (Table 1) 94,000 470,000 940,000 1,410,000 1,880,000 Production, ton/yr (Table 5) 350 875 1,750 2,625 3,500 Table 7. Comparison of gallium resource (ton) in coal ash and potential gallium production (ton/yr), at different yields. The yields marked in italics are probably out of reach. Item Extraction or recycling yields (Y), expressed as fraction Y=0.02 Y=0.1 Y=0.2 Y=0.3 Y=0.4 Probable resource, ton (Table 5) 140,000 870,000 1,740,000 2,610,000 3,480,000 Production, ton/yr (Table 2) 500 2,500 5,000 7,500 10,000 Table 8. Summary of gallium production (ton) at different yields for extraction from all sources and including recycling with different yields. Item Extraction or recycling yields (Y), expressed as fraction Y=0.02 Y=0.04 Y=0.1 Y=0.2 Y=0.3 Y=0.4 Extraction from anode slime, ton/yr 160 350 875 1,750 2,625 3,500 Supply from coal ash, ton/yr 500 1,000 2,500 2,500 2,500 2,500 Supply from bauxite, ton/yr 150 300 750 1500 2.250 3,000 Sum 810 1,650 4,277 5,750 6,875 9,000 Recycling yields R=0.02 R=0.04 R=0.1 R=0.2 R=0.3 R=0.4 Recycling, ton/yr 16 69 475 1,438 2,946 13,500 sum 826 1,719 4,752 7,188 9,821 22,500 Table 8 shows a summary of gallium resource (ton) and potential gallium production (ton/yr), at different yields for extraction and recycling. Tables 5-7 shows that increasing yields in both the extraction supply chain for gallium and for the recycling recovery chain has a large effect on the gallium supply, at constant substrate use (anode slimes and coal ashes). Table 8 shows that the gallium challenge is very difficult, but probably not impossible to solve. If extraction and recycling yields can be raised to 30% instead of the 4%, gallium supply could increase from the present maximum potential of 1,375 ton/yr to about 9,821 ton/yr. For extraction from anode slimes, this is probably feasible, but at a significant energy cost, but for extraction from coal and bauxite, a yield more than 10% appears to be very challenging. 6.2. WORLD7 simulations The production rate for gallium is shown in Figure 8a shows the production and the contribution from bauxite refining to alumina, 75% of the gallium and from zinc production, 25% of the gallium as compared to the recorded mining history (USGS 2014, 2022). At present, gallium is mostly produced during bauxite processing in China, a preparation for aluminium production, but other sources like refining residuals from zinc and silver are becoming more important with time. Demand is driven by electronics and solar photovoltaic panels production, coming from the energy module in WORLD7. Figure 8a shows the simulated production rate of gallium, together with the demand, price modified demand, the supply, extraction and recycling. After 2125, hard scarcity becomes apparent. Before 2010, gallium demand was modest, but that increases sharply after 2010. Figure 8b shows the extraction rate from different metal ores. The gallium supply from zinc, copper and lead has a maximum capacity in 2055. Technological development has been assumed from 2025 to increase yields. Figure 8c shows the source of the gallium extracted. Figure 8d shows the stocks in use in photovoltaics, semiconductors, other use and as waste. Figure 8e shows the simulation of the price and the amount gallium in the market. After 2055, the market is nearly empty and the price shoots up. Gallium is then in hard scarcity. If extraction access and refining yields cannot be significantly improved, it will stay like that. If overall total yields are improved to better than 50%, then there will be probably no scarcity for gallium. Figure 8f shows the cumulative amounts for demand, supply, extracted and recycled gallium. It can be seen that demand given by Line 1, far exceeds the supply Line 2. It can be seen that demand given by Line 1 far exceeds the supply given by Line 2. The simulations suggest a long term running average shortfall of 33% of the demand for gallium, thus only a 67% satisfaction of demand. In the long term simulations, recycling reached only 13-15% when based on market mechanisms alone. For demand to be met in the long run, the long term recycling flow back into the system will have to be at least 55% of the gallium supply to the market. This would require something more that just market mechanisms (e.g. gallium price) to promote recycling. Figure 9a shows the fraction of the supply as recycled gallium. The recycling has been modelled as a function of price (Dahmus and Gutowski 2007, Gutowski et al., 2016). Figure 9b shows the simulated yields for the production of gallium in the model. At present, gallium overall yields are at about 10-15%. In the simulation, dynamic recycling is used, depending on price. However, yields for recycling are also far too low, and must be improved for recycling to be important. Figure 9c shows the gallium supply and stocks-in-use is predicted to increase steadily until 2400 when it peaks. Figure 9d shows the cumulative amounts of gallium extracted from different sources over time. Extraction from zinc anode slimes is dominating at the moment, but we expect that bauxite may become the dominant source in the next decades. 6.3. Testing the model The model has been tested against the recorded mining data derived from the USGS (2022, Foley et al., 2017) databases (Figure 10a-c). The results of the test can be seen throughout the results section and in the comparisons with the data. The general trend was reproduce, but some of the short term variations less well. But no systematic bias builds up over time, as can be seen from Figure 10b. The model does reproduce the observed mining rates satisfactory when the model is driven by market demand and price dynamics. The metal market price is well simulated for gallium as can be seen in Figure 10c. This suggests that the model reconstructs the historical pattern reasonably well and that it is safe to use the model for exploring future scenarios. 7. Discussion 7.1. Uncertainties The major uncertainties in the simulations come from the following aspects: Uncertainties in future demand. Most of what is out there has been naive guesses by market economists based on growing future GDP. A few technical assessments of future gallium needs based on energy needs are available, but these are only partial. Uncertainties in gallium content in mother ores and fly ash on a global scale Uncertainties in extraction yields (substrate access, technical yields) at present and in the future For the contents of gallium in different substrates, there is no earlier in-depth assessment. We have found numbers for gallium contents in different references, but these will give approximate estimates. The situation is similar for access and extraction yields, we have some reports of gallium yields, but no assessment for the whole industry. The values found show a wide range. Thus, the yield estimates are very approximate. The gallium reserve and resource estimates were made by the authors pieced together from corporate reports and ephemeral internet sites. Little information is available on reserves and resources on a global level. It is known that for gallium, the content potential in bauxite is not fully used. The present recycling rate for gallium is not really known, but most earlier studies agree that it is a low fraction of the total supply. The estimated gallium supply rates are much lower that the potential as a result of poor recycling rates used in the simulations. These recycling rates represents the observed level 2028-2023. Many demand estimates found in the internet or in some publications are naive estimates based on a belief in constant annual growth of GDP or purely guesses about monotonous economic growth. These are normally not so useful and have been ignored. All of this is rounded off in the test on field data. The model does appear to reconstruct the past reasonably well. This indicates that the uncertainties have been kept under control and that the sum of all of it remains small. 7.2. On scarcity The gallium may fast run into physical scarcity because the price has no feedback on the extraction rate of the source metals, such as on copper and zinc. The extraction rate can only be expanded if less than the potential is extracted or by improving extraction yields. But these increases will in most cases be marginal, and there is no room for substantial increases. For the extraction from bauxite, the economic feedback on bauxite mining rates are absent in the system. The value of the gallium per ton bauxite is rather insignificant, and for the producer of alumina from bauxite, the extra value of the gallium obtained will be marginal, For the extraction from coal or coal ash, the drivers are strategic as much as it is an issue of profitability and operable access to an interesting substrate. At many places where coal is used, there are no conditions for extracting gallium. It is important to consider that when the commodity is still relatively cheap, it may for that reason be unnecessarily wasted, when it would in retrospect have been relatively easy to induce better use efficiency and recycling. To wait until there is severe scarcity would be too late for optimal mitigation as unnecessary resources would already have been wasted by then. Supply per person and year reflects the amount available to compensate for continuous losses and any surplus available for growth in the stock-in-use as shown in Figure 9. Stock-in-use per person is an indicator of the utility gained from the resource, and a decline in stock-in-use suggests a decline in service provision from that resource. Stocks-in-use is the amount providing utility. The supply is to maintain the stock, replace losses and any surplus will cause growth, a deficit a decrease in utility. The production of gallium is limited to some extent by the fact that only a fraction of the metal refineries are technically equipped for efficient recovery of gallium from Bayer liquid or from anode slimes from Cu-Zn-Pb-Ag electrolytic refining. Significant investments would be needed in order to increase gallium production. Light Emitting Diode (LED) lighting technology is rapidly spreading as mass products in consumer lighting devices uses gallium. Making variations with these allow gallium to be almost sufficient to physically scarce before 2060. The simulations show that significant improvements in yields, access and recycling will be very important for avoiding supply problems with gallium. The present status of these conditions at present are very unsatisfactory. 7.3. On the pathways of gallium through the world Figure 11 shows a flow chart for the flow of gallium through the Chinese and Rest-of-the-World (RoW) systems. Chine is a large producer and exporter of gallium, but this occurs to a large degree from mother metal refining and mother metal refining residuals source from the Rest of the World, more than Chinese domestic resources. China has had a successful strategy for securing the raw materials for making gallium, and to prioritize to supply its own manufacturing industry, and then supply the global market with those products (Han et al., 2015, Hayes-Labruto et al., 2013, Su 2009). In the continuation, a lot of scrap is flowed back from the Rest of the World to China for recycling, just like as illustrated in Figure 11. If the authorities in China were to restrict the export of gallium metal, that would limit gallium availability in the rest of the world. It not really matter for global supply situation, if the gallium withheld gets incorporated into products anyway and those products would be recycled outside of China. Then there would only be a delay. But that is not the situation at the moment. It appears that a very substantial part of the value chain has been located to China. The reasons for this are many, as the policy to do so has in the past been promoted both by Chinese and European governments and policies. For China, this puts them in a very good business position with strategic strength, as well as a political will to use strong control. Figure 19b shows the cumulative amounts of demand, supply, extraction and recycling. It can be seen that the demand is far larger than the supply. Increasing recycling to 80% by 2030 would decrease the gap, but cannot close it. The amounts of gallium extracted 1850-2250, gives an indication of what eventually will be the total available amount. Figure 11 shows the flows through RoW and China and the market dominance. 7.4. From problems to industrial opportunity An number of problems have been discussed with respect to gallium extraction and supply to industry (and to society). For the international mining and extraction industry, these problems lead to a number of challenges, which when taken on, will lead to good business opportunities. The Rest-of-the World has a second chance to capture gallium as it is recycled from the products, however with a delay. To do that, a strategy for capturing gallium-containing scrap and recycling it will be necessary. China does not have the world’s largest geological deposits of gallium, and thus, China only have an apparent near monopoly on gallium at the present time, because the rest of the world allows them to have it. If the gallium was produced where the deposits are and where the scrap is appearing, then the situation would be a very different one. There are some industrial capacity to do gallium extraction and recycling in Europe at present, but it would have to be significantly expanded in the near future. The EU has discussed that they should have such a strategy, many discussions are being held, but as of 2024 there is nothing real in place beside general visions and goals, and a worked out strategy is still missing. The creation of favourable conditions for recycling businesses in Europe is not yet implemented. This would have to include proper incentives as well as protection against unfair competition and the effects of state sponsored competition from outside countries. Low yields in most industrial gallium transactions are a problem at present. With research into modern separation methods these can surely be improved, leading to improved extraction yields. Such improvements often translated straight down to the operating profit of a refinery. The poor recycling rates at present are partly linked to low yields when extracting from source substrates with low content. Another challenge is one of creating a circular value chains for gallium, where the system issues of collecting and refining the scrap contain gallium. The large producing countries of alumina from raw bauxite and the major producers of zinc have been listed in Table 4. Of these countries, only China and the United States have a substantial capacity for producing gallium. Every country with a large alumina production or substantial zinc production, but no primary gallium production, is potentially an business opportunity overlooked. China has at present a very dominating position in the gallium supply chain and market because of a long term strategy and having taken their opportunities seriously. Because of large scale outsourcing of industrial production to China from Europe and North America, it is also one of the major users of gallium for photovoltaic technologies and LED lighting products. In the past, Chinese strategies on Rare Earth Element supply is well known, and this should considered when the global dependence on China for gallium supply is strategically evaluated for the future. 7.5. On future resource policies Figures 12 shows the gallium system with examples of generic policy interventions included towards the non-predetermined future imaginary path, as well as policy intervention in realising pathways towards the different imaginaries. A systemic approach is required and necessary when planning policies for complex systems. The gallium system is a very complicated system with significant delays inside where linear or short-term thinking does not work, especially when understanding different policy choices and their influence towards different imaginaries pathways. Planning toward sustainability without a predetermined future state (non-imaginary) results in a policy that is perceived as sustainable but without a future state. The purpose of the imaginary analysis, in this context, is to be able to frame the vision of the future and connect to the contemporary policy gap in relation to current “failed” policies. This is demonstrated in the study by the authors on indium, cadmium and germanium (Sverdrup et al 2023, 2024a, 2024). There are ways to increase the gallium availability for society, and push the gallium supply peak further into the future by a significant amount. The following statements can be made for different policy options that may appear as possible: What does not really work that well as problem solution More mining : Increasing the rate of gallium extraction to satisfy demand, will be great in the short term relieving short term problems, but will not solve the root cause of the problem. More extraction from primary sources of gallium will make the gallium supply peak time appear earlier and aggravate scarcity later. Many geological surveys and mining companies are focused on this approach, mostly for short term profits and lack of long term impact assessment. For future generations, this is consuming the potential resources for future generations now before they are born. That is in conflict with the Brundtland and UN definition of sustainability. Secure key resource potentials anywhere in order to secure national supply exclusively . This will foster increased risk for resource conflicts and promote the use of non-democratic methods and favour the rule of the strong to abuse the less powerful. May cause short term local benefits, but will create other problems a bit later. This solution appears to have some similarity with policies of colonial approaches. Gallium substitution in key technologies may be a policy to consider, but with care. Substitution of gallium may appear as challenging, many of the proposed substitutes are other scarce technology metals, and do not improve the overall technology metal supply challenges at all. Only when gallium is substituted with a resource in a significantly larger supply than gallium, and when this metal is not stressed by a demand in significant overshoot of the supply, will substitution make sense. What constitute parts of a solution: Improve extraction supply chain yield : Increasing gallium secondary extraction yield is a component of a working policy. It allows for more gallium to be taken from the same amount of extraction substrate. This shifts gallium from potential loss to potential use. Improve recycling recovery chain yield : Increasing recycling yield is a policy component. It allows more gallium to be taken from the same amount of scrap. Increasing gallium recycling yield may have demands for how technologies (Photovoltaic technologies) using gallium are designed and that they may have to be prepared for recovery (Sverdrup et al., 2023). This shifts gallium from potential loss to potential use. Improve both extraction yield and recycling yield Increasing recycling yield is a policy component. It allows for far more gallium to be supplied from the same amount of secondary substrate and ores, while reducing systems losses. Significant investment in research would be needed. Increasing access yield, to extract more gallium from streams that have not extraction, will convent a loss flux to an available flux, without shifting the depletion date forward. This shifts gallium from potential loss to potential use. Adaptive management of the global demand by reducing total demand and increasing use efficiency in society (less losses, longer use time, making less gallium do the same job as more would do earlier) would contribute to the results of policy and help push the supply peak to a later date. Could possible reduce use to sustainable levels. Would need strong incentives and an active policy with some global agreements For an effective solution, a combinations of policies would be required, by combining policy 3: Improve both extraction yield, policy 4: increasing recycling yield, with policy 5: Adaptive management of the global demand. To further plan for sustainable management within the bounds of sustainability, the use of integrated assessment modelling will be required and WORLD7 is such a model. Further research is needed to make policy impact assessment using biophysically consistent Integrated Assessment Models, to check if proposed policy packages actually deliver the goals intended and that adverse side-effects stay under control and withing socially acceptable boundaries. Proceeding with policy proposals without doing proper and valid impact assessments is unprofessional and potentially damaging governance. Integrated models that are mass and energy consistent would be needed. Present econometric economic model that are not thermodynamically compliant will not do. Statistical interpolations will not do for the same reasons. In present policies, no consideration of future generations are taken seriously, even if it gets long speeches and beautiful works in working documents. Table 8. Estimation of critical extraction and global critical supply for gallium based a long term perspective of 165 or 330 generations. Present yields are in the range 10%. for recycling and extraction yield, whereas yield from coal ash is less than 5% As a comparison, the supply in 2023 was 430 ton/yr. Item Extraction or recycling yields (Y), expressed as fraction Y=0.04 Y=0.1 Y=0.2 Y=0.3 Y=0.4 Probable resource, anode slime, ton 94,000 470,000 940,000 1,410,000 1,880,000 Probable resource coal 280,000 870,000 870,000 870,000 870,000 Probable resource bauxite 120,000 240,000 480,000 720,000 960,000 Sum available resources 494,000 1,580,000 2,290,000 3,000,000 3,710,000 Critical extraction, 330 generations 100 316 458 600 742 Critical extraction, 165 generations 200 632 916 1,200 1,484 7.6. Long term sustainable supply of gallium. Sustainability includes both the present and future generations. Table 8 shows the estimation of critical extraction for gallium based a long term perspective of 165 generations (5,000 years) and 330 generations (10,000 years). Under business as usual, the sustainable supply of gallium is about 100-200 ton/yr. Significantly improving access yields, mining yields, extraction yields and recycling yields may potentially increase sustainable gallium supply to approximately 600-900 ton/yr. In the assessment, we have assumed that the “sufficient need” is the same as the “demand”. As indicated in figure 13, under BAU, resource extraction and technological development follow the current trends without significant changes in policy intervention. This means moderate innovation in recycling and extraction yields, but a heavy reliance on continued extraction of primary metals as a part of a sustainable strategy. As the demand for critical metals like gallium increases, BAU is at risk for resource shortages due to insufficient rate in advances in recycling, efficiency and avoidance. Profit-driven incentives dominate and risk creating lagged and response-driven approach to long-term sustainability planning, which runs closer to resource depletion and price volatility, where market forces struggle to cope with scarcity. The implications towards the different imaginaries where the imaginaries contrast sharply with BAU, where Ecotopia minimizes reliance on metals by reducing overall technological demand and avoidance/substitution approach. The Great Decoupling scenario embraces technological growth, promoting a bioeconomy-driven market approach and progress through improved recycling and extraction efficiency. In Unity in Adversity, environmental and geopolitical challenges are addressed by securing domestic supply chains and investing heavily in recycling and sustainable extraction of gallium. Emphasis is on coordinated environmental regulations and protectionist policies to safeguard gallium resources. Going step further, the Technocracy for the Common Good, Gallium and other critical metals are tightly controlled through monitoring of extraction, recycling, and use. Government managed resource allocation prioritizes efficiency, with centralized economic activity and protectionism securing strategic resources within the EU. Each of the imaginaries envisions a different role for critical minerals, and varies in the methods of their production, usage, and recycling. Policymakers can use these imaginaries to develop strategies that align with the sustainability objectives of each imaginary, particularly in how critical metals like gallium can be reused and recycled (Haraldsson and Bonin, 2021; EEA 2022; Sverdrup et al., 2024, 2024 submitted). 7.7. Needs for further research Some of the tables shown in this study have a lot of question marks. This illustrates that there is a need for a better mapping of geological occurrence, extraction potentials, technical capabilities and recycling yields. Some scenarios not explored here are the outcomes of different global population scenarios. If the global population does not start to significantly decline after 2100, the World will be very soon in a very unsustainable situation with supply of about everything. To assess such scenarios are a major undertaking and would have to wait for a later time with good funding. A better understanding of what is real need that meets the minimum requirement versus “want” or “demand” is needed. The gallium use yield must also be analysed and assessed whether improvements are possible. A full scenario-analysis exploring the outcome from different policy proposal are needed. The Integrated Assessment Model WORLD7 could be used for developing a multi-goal, multi component policy that is optimized towards sustainability criteria derived from formal definitions and set goals. The Imaginaries are policy proposals that have yet to be embodied with action plans and explored with systems analysis (Causal loop mapping, integrated flow charts, integrated energy charts). Such a process is required and necessary for the Imaginaries to have a foundation in reality. 8. Conclusion The model was used and there was found a significant risk for technology metal scarcity under business as usual scenario. The WORLD7 model was used to simulate the extraction rates, ore grade decline and approximate metal price levels for gallium. We need to carefully distinguish between the primary production from mines and total supply to the market. The rate of recycling is far too low, and the supply situation may be significantly improved if the recycling rates can be increased substantially. The introduction of extraction methods like heap leaching and subsequent electrowinning for many of the source metals (copper, zinc, lead) yield less of the technology metals and is a real threat to the long term supply of these metals. These methods are preferred for low and ultralow ores grades and have become more frequent in mining. Market mechanisms have not been able to have sufficient effect, and it appears that governmental interventions are unavoidable. The conclusion show that there is not an immediate risk for scarcity but it builds up in the longer run (after 2030), scarcity manifested as rising metal prices should be expected and prepared for. Our analysis suggests that pressing for more mining to reduce the demand-supply gap, will make short term improvements at the cost of severe shortage later. A combination of improving extraction yields and improving recycling yields combined with demand reduction may improve the supply situation and push the supply peak beyond 2100. In relation to the EEA imaginaries, each EEA imaginary offers a distinct approach to mitigating gallium scarcity, ranging from conservation focused strategies to technologically driven solutions. These imaginaries highlight the necessity of tailored policy interventions to achieve the desired future state and avoid critical shortages. They emphasize the importance of understanding and addressing the unique challenges posed by gallium shortages. 9. Declarations 9.1. Who did what? Harald Ulrik Sverdrup developed the gallium module for the WORLD7 model. Harald Sverdrup and Anna Hulda Olafsdottir developed the WORLD7 model as it stands today. Harald Sverdrup wrote up the manuscript draft and did the simulation runs. Harald Sverdrup, Ole van Allen and Hördur Haraldsson cooperated on finalizing the manuscript, doing revisions and corrections. Hördur Haraldsson worked on the policy implications and future assessments. 9.2. Declaration of no conflict of interests We declare that we have no conflict of interest with in the field of gallium, nor any vested interests. 9.3. Research ethics This work is original research done by the authors. No artificial intelligence or large language models like ChatGPT were used in any of our work. All text herein come from the hands of the authors. 9.4. Funding This study contributed to the SIMRESS project (Models, potential and long-term scenarios for resource efficiency), funded by the German Federal Ministry for Environment and the German Environmental Protection Agency (FKZ 3712 93 102), the SIMRESSS Aufstockungsauftrag (FKZ 3712 93 102) and the SIMRESS Climate Impact Analysis project (FKZ 3716 32 100 0). This study contributed to EU H2020 LOCOMOTION project, funded by EU Horizon 2020 program under grant agreement 821105/H2020-LC-CLA-2018-2. 9.5. Acknowledgement of earlier significant efforts. Dr. Deniz Koca and Dr. Anna Hulda Olafsdottir, participated in developing WORLD4, WORLD5 and WORLD6 as originally derivatives of World3. Dr. Anna Hulda Olafsdottir and Harald Sverdrup developed WORLD7 from WORLD6. Anna Hulda Olafsdottir and Harald Sverdrup did several earlier and simpler approaches for gallium (Sverdrup and Olafsdottir 2020). References van Allen, O., Sverdrup, H. U., Olafsdottir, A.H., 2022. Global resource use and the future: Any room for the circular economy? H. Lehmann, C. Hinske, V. de Margerie, A. Slaveikova Nikolova (Eds). The Impossibilities of the Circular Economy Separating Aspirations from Reality. Pages 217-232. Routledge, Taylor and Francis, London and New York. DOI: 10.4324/9781003244196-24. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5390312","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":376170753,"identity":"7d0124b8-f810-48d4-86df-b309b044fdbf","order_by":0,"name":"Harald Ulrik Sverdrup","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA4ElEQVRIiWNgGAWjYBACAxDxgA3CkQBiOTaitCQgaTEmXUtiAyEt5uxnH35IKGOwNzje+/B2Zdud9D7p3gPMBRW4tVj2pBtLJJxjSNxw5rix5dm2Z7ltMucSmGecweOwA2kMEoltDAmSM9LYJBvbDue2SeQYMPO24dFy/hnzD6AWe8n5z8Ba0tkIarmRxgayhbFfgg2sJYEILc/YLBLOSST286QxWzace2YIcthhHnx+OZ/GfONDmY09G/sxxpsNZXfk5WfkGD7mwRNiUCABYxxAIokEJCkeBaNgFIyCEQIAKLxKu6xYkiYAAAAASUVORK5CYII=","orcid":"","institution":"System Dynamics, Inland Norway University","correspondingAuthor":true,"prefix":"","firstName":"Harald","middleName":"Ulrik","lastName":"Sverdrup","suffix":""},{"id":376170754,"identity":"b7fbe4c0-3488-4e29-9979-3f8a43a8bd70","order_by":1,"name":"Hördur Valdimar Haraldsson","email":"","orcid":"","institution":"System Dynamics, Inland Norway University","correspondingAuthor":false,"prefix":"","firstName":"Hördur","middleName":"Valdimar","lastName":"Haraldsson","suffix":""}],"badges":[],"createdAt":"2024-11-04 18:53:20","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5390312/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5390312/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s41247-025-00125-7","type":"published","date":"2025-07-08T15:57:59+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":69811810,"identity":"8b434f40-a45e-42dc-b696-96de9f2b771b","added_by":"auto","created_at":"2024-11-25 12:53:06","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":103754,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eThe global production of gallium (a). The production was historically very small (100 ton/year), but has increased strongly in the last years to about 400 ton/year. China is the dominant producer at the moment. The market price inflation-adjusted to 2020 is shown in (b). Data from USGS (2022) and additional data as assembled from different internet sources by the authors.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5390312/v1/4818019f4dbcb5fd690d1d8b.jpg"},{"id":69811805,"identity":"866a839f-e592-4d2c-bd6c-cfd8aa0a45fd","added_by":"auto","created_at":"2024-11-25 12:53:06","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":80320,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eThe technology metals are almost all of them dependent on primary extraction of a major resource such as hydrocarbons, metals or phosphate. All metals or minerals indicated with colour have their own primary mines, all those without colour, all extraction is dominated by secondary extraction. This complicated system is contained inside the WORLD7 model.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5390312/v1/8e8d54e792acf365ff6da0fc.jpg"},{"id":69811807,"identity":"10d85aea-6602-4fd6-8f08-864a14c65f3d","added_by":"auto","created_at":"2024-11-25 12:53:06","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":50762,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003ePathway to extract gallium from bauxite and zinc ores. This is the main supply of gallium in 2022. There are other sources, but they are not really used at the moment (copper, lead, coal combustion ashes, see Tables 1 and 2).\u003c/em\u003e\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5390312/v1/8742bc569e06f1089ed0f067.jpg"},{"id":69811806,"identity":"577694dd-d1d8-4257-8d2f-a53e8eee60b2","added_by":"auto","created_at":"2024-11-25 12:53:06","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":70422,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eFlowchart for the submodule of the WORLD7 model dealing with gallium. The major gallium loss flows have been marked with red.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5390312/v1/4d62eea3d0bd2c05f4b75458.jpg"},{"id":69813169,"identity":"ccea01b8-3c65-45a8-9303-51f64d29df1d","added_by":"auto","created_at":"2024-11-25 13:01:06","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":116097,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eCausal loop for the gallium sub-model. R1, R2 and R3 are reinforcing loops driving the system. R1 is the extraction loop, driven by profits, R2 is the extraction-investment loop, describing how increased infrastructure increases production and profits. R3 are four different loop running over recycling to generate income and recycled gallium which is sold again to the market.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5390312/v1/076328ec702098daae38f934.jpg"},{"id":69811809,"identity":"495df645-4ab0-4cb8-926b-c6fae215dcb1","added_by":"auto","created_at":"2024-11-25 12:53:06","extension":"jpg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":584112,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eAn overview of the WORLD7 system. Every box has a sub-model, every red line is one or several feedbacks or information links in the model. The gallium module contains the model shown in Figures 4-5 and as STELLA Software code in Figure 6.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"6.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5390312/v1/f1cde88ed6cf4125e31545ac.jpg"},{"id":69811812,"identity":"82ccab7c-feeb-456a-9070-9b2f3e2fdcad","added_by":"auto","created_at":"2024-11-25 12:53:06","extension":"jpg","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":366913,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eThe STELLA Architect code inside WORLD7 for the gallium module.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"7.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5390312/v1/3f8002130f0037d5d5afaae4.jpg"},{"id":69814366,"identity":"d5cc89d1-7ccb-4853-a385-e04d2a78a274","added_by":"auto","created_at":"2024-11-25 13:09:06","extension":"jpg","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":231889,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003e(a) The simulated production rate of gallium, together with the demand (D), price modified demand (M), the supply (S), extraction (E) and recycling (R). After 2125, a small hard scarcity becomes apparent. (b) shows the simulated extraction from different mother metal ores. (c) shows the comparison of demand and actual supply for photovoltaic technologies, semiconductors and other uses. (d) shows the stocks in use in photovoltaics, semiconductors, other use and as waste. (e) shows the simulation of the price and the amount gallium in the market. (f) shows the cumulative amounts for demand, supply, extracted and recycled gallium\u003c/em\u003e\u003c/p\u003e","description":"","filename":"8.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5390312/v1/30cd7364d50ec6e62e260dca.jpg"},{"id":69813171,"identity":"d548f44b-9213-4485-9f77-b9e70b89d3ab","added_by":"auto","created_at":"2024-11-25 13:01:06","extension":"jpg","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":102635,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003e(a) Fraction of the supply as recycled gallium (b) effective yields simulated in the model. (c) Gallium supply and stocks-in-use per person and year. (d) Cumulative amounts of gallium extracted from different sources over time.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"9.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5390312/v1/916bacb3b3c2f6cc01630598.jpg"},{"id":69811816,"identity":"55b65fb3-5b7a-4a91-bc57-9136162ee38b","added_by":"auto","created_at":"2024-11-25 12:53:06","extension":"jpg","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":107573,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003e(a) is the simulated rate of gallium extraction as compared to the observed. (b) shows the cumulative amount observed and simulated. (c) shows the simulated price as compared to the available data. (d) The flows through RoW and China and the market dominance. By 2050, the Chinese dominance over the market may have disappeared.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"10.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5390312/v1/ad43fc46882f86a6252290f3.jpg"},{"id":69813170,"identity":"1044e36a-87c8-4766-a2b9-ed9f07713c75","added_by":"auto","created_at":"2024-11-25 13:01:06","extension":"jpg","order_by":11,"title":"Figure 11","display":"","copyAsset":false,"role":"figure","size":47524,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eThe flow chart shows the flow of gallium through the Chinese and Rest-of-the-World (RoW) systems. For long term stability, the net primary input must amount to the growth plus the irreversible losses in the system (The red arrows). The thickness of the arrows indicate how much flows in different ways.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"11.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5390312/v1/5b2cf02aa0dd46f2062770e5.jpg"},{"id":69813172,"identity":"cfcf479b-95fa-46c7-9d6f-c8af17023364","added_by":"auto","created_at":"2024-11-25 13:01:06","extension":"jpg","order_by":12,"title":"Figure 12","display":"","copyAsset":false,"role":"figure","size":136352,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eThe gallium system with policy interventions including connection to the EEA imaginaries. A systemic approach is required and necessary when planning policies for complex systems. The gallium system is a very complicated system with significant delays inside where linear or short term thinking is useless.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"12.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5390312/v1/e5694ec4789d5d804e1b13ed.jpg"},{"id":86700080,"identity":"7db074b3-b31c-42c5-aec1-fab24ced1a16","added_by":"auto","created_at":"2025-07-14 16:11:28","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":4345133,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5390312/v1/fefb0c66-5f02-4350-8720-e530a6dabadb.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Gallium: Assessing the long term future extraction, supply, recycling and price of using WORLD7, in relation to future technology visions in the European Union","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eGallium is an important element for different photovoltaic technologies, semiconductors used in electronics and LED lighting technologies. The envisioned European energy transition towards renewable energy sources implies a large amount of photovoltaic electricity production, as well as more energy-efficient technologies helping to reduce energy use. At the same time, new electronics and semiconductors depend on a larger scale on different types of gallium and on gallium in combinations with other technology metals. All of that depends on having a sufficient supply of metals like gallium for these technologies. Gallium is a secondary product of zinc, copper, lead and bauxite mining. Other sources are being explored.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn line with the long-term sustainability vision of the European Union, the European Green Deal stresses the importance of secure access to critical minerals that are essential for the functioning of the society in the future. To this end, the European Environment Agency (EEA) has developed four alternative imaginaries that depict different visions of a sustainable Europe by 2050 (SE2050), each with different policy approaches to resource use and management (EEA 2022, Sverdrup et al., 2024, Sverdrup). These are shaped as assumption scenarios that will need further substantiation and elaboration of details:\u003c/p\u003e\n\u003col\u003e\n \u003cli\u003e\u003cstrong\u003eEcotopia:\u003c/strong\u003e This scenario prioritises nature and sustainability, with a marked reduction in consumption and technological reliance. It is assumed that the public sector retracts, civil society and local communities play a collaborative role in driving decision-making and welfare systems.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eThe Great Decoupling:\u003c/strong\u003e In this scenario, it is assumed that technological innovations and social advancements have managed to decouple GDP growth from environmental degradation. Green growth is fuelled by competitive markets, with the bioeconomy at the forefront. Government interventions guide incentives, while EU cooperation remains pragmatic and focused.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eUnity in Adversity:\u003c/strong\u003e In this scenario, Europe has come together under a unified constitution to respond to environmental, climate, and geopolitical challenges. Strict economic measures prioritise environmental sustainability, with significant investments made to address climate \u0026nbsp;and ecological concerns.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eTechnocracy for the Common Good:\u003c/strong\u003e State control is central, with digitalisation used to monitor and manage social and ecological systems extensively. The EU functions as a cohesive alliance of strong governments, driving centralised economic activity, with a shift toward deglobalization and protectionist policies.\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003eEach of these imaginaries envisions a different role for metals and minerals, including gallium, and varies in the methods of their production, usage, and recycling. Policymakers can use these visions to craft strategies that align with the sustainability objectives of each imaginary, particularly in how critical metals like gallium can be reused and recycled (Haraldsson and Bonin, 2021; EEA 2022; Sverdrup et al., 2024).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1.2 Overview on gallium and what it is used for (put this together with introduction?)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eGallium is used for many new technologies (computer semiconductors, LED lighting, photovoltaic solar energy collectors, screens, advanced sensors). The supply security of gallium depend on copper, zinc, lead and aluminium mining. Gallium are found in low concentrations in coal deposits, but a few deposits have significant amounts. Gallium is used in applications where there are no obvious good substitutes (\u0026Ouml;hrlund 2011, Zuser and Rechberger 2011, Werner et al., 2017b, Panoussi et al., 2015). A eutectic alloy of gallium, tin and indium make an important non-toxic substitute for mercury in many of its applications. The global production in 2022 was small, only about 450 ton per year. The development of the production since 1945 to 2023 is shown in Figure 1a (USGS 2022 ds140). Figure 1b shows the development of the price during the same period (USGS 2022, ds140). Annual production in 2022 was somewhere between 560-650 ton per year, all depending on the source (USGS Minerals Commodities Summary 2022, Jaskula 2022, ds140-Gallium Mineral commodity Statistics USGS website, British Geological Survey: Idoine et al., 2022). Further increase in gallium demand in the near future is expected. The Covid epidemic and the Russian invasion of Ukraine caused global disturbances in the gallium market (Jaskula 2022). China was the largest gallium producer in 2019, it largely closed production 2020-2022, and restarted production in 2023. Time will show who else will enter the market to fill the growing demand. As demonstrated in the germanium and indium studies (Sverdrup et al., 2024a, 2024submitted), the future availability of critical minerals is closely connected to how the pathways towards these imaginaries are manifested in policy. In particular, the scarcity of metals such as germanium, indium, and gallium pose significant challenges to advanced technologies like photovoltaics and semiconductors. The management of these minerals, dependents on policy frameworks that prioritise innovation in recycling and extraction efficiencies to avoid shortages under the \u0026lsquo;business as usual\u0026rsquo; scenario (BAU.\u003c/p\u003e"},{"header":"2. Objectives and scope ","content":"\u003cp\u003eThe goal was to develop an integrated dynamic model for the global market for gallium. The gallium supply system will be explored using dynamic modelling and to asses if the supply is sustainable according to the Brundtland definition (\u0026hellip;provide the needs for present and future generations\u0026rdquo;). The global industrial circulation in a is included, simulations cover 1850-2200. The model is tested respect to historical data for extraction rate and market price. The model was used to assess the long term risk for soft or hard scarcity of the gallium in the future. The results have two features. (1) the assembly of key data on resources, reserves, production rates and gallium prices. These are needed to initiate and parameterize the model. (2) The use of the model to assess the supply and production in the future.\u003c/p\u003e"},{"header":"3. Earlier work","content":"\u003cp\u003eWe have not found any serious sustainability assessment based on integrated assessment dynamic simulations for the gallium supply system and the development of the gallium supply system over time. No considerations of the cross-linking dependencies and feedbacks in the gallium system have been published earlier or included in any model. There is no earlier process-oriented systems dynamics model for gallium. No model have earlier integrated market supply and demand modelling in the gallium flow system. Some studies have touched upon the subject using simple mass balance approaches and burn-off estimates, but these are not really valid methods for a dependent secondary extracted metal like gallium. A preliminary study was presented by Sverdrup and Ragnarsdottir (2014) and Sverdrup et al., (2017). Lu et al., (2017) made a review of resources and extraction methods for gallium, stating that the gallium content in coal is about 10 million ton, that bauxite contain more than 1 million ton gallium, and that the gallium contents in zinc ores are significant. Lu et al., (2017) estimates that the gallium demand will increase from 325 ton/yr in 2017 to maybe as much as 5,000-5,500 ton/yr of gallium in 2030. Nobody really knows if that is possible or not, but absolutely needs to be found out. Frenzel et al., (2015) estimates the supply potential of gallium at 2,100 ton per year from bauxite refining, 85 ton per year from refining of sulfidic zinc ores, and potentially 590 ton per year from refining of coal combustion fly ash and slags (2,775 ton per year).\u003c/p\u003e"},{"header":"4. Methods and theory used ","content":"\u003cp\u003e\u003cstrong\u003e4.1. Overview\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe main tool employed is system dynamics modelling. For designing the system dynamics model, we use systems analysis.\u0026nbsp;We analyse the system using stock-and-flow charts and causal loop diagrams. The\u0026nbsp;mass balance expressed differential equations resulting from the flow charts and the causal loop diagrams were numerically solved using the STELLA\u003csup\u003e\u0026reg;\u003c/sup\u003e Architect modelling environment (Senge 1990, Sverdrup et al. 2022). We use causal loop diagrams for mapping out where the causalities are, to find intervention points in the system, and to propose policy interventions. The Integrated Assessment Model WORLD7 was used for this study (Sverdrup and Olafsdottir 2019). The workflow was as follows: \u0026nbsp;\u003c/p\u003e\n\u003col\u003e\n \u003cli\u003eEstimate the available gallium resource that can be extracted using valid mining methods, considering the different yields and estimating the total geological deposit-to-supplied gallium approach.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eUse the WORLD7 integrated modelling framework to generate gallium demand from the production of consumer goods and technological infrastructures.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eIdentify the available sources of technology elements and the estimate the available \u0026nbsp;amounts that can be extracted from those deposits, considering extraction technologies and the cut-off caused by resource qualities and costs of extraction as related to the market price dynamics.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eRun the WORLD7 model to assess the supply sustainability from the first use of the technology metals to about 2200.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eEvaluate the model simulations with respect to result validity, and risk for future aspects of scarcity.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eEvaluate how future policies that would result from the EU Imaginaries would grip into the gallium system.\u0026nbsp;\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003eThe WORLD7 integrated assessment model was used for earlier assessments supply for silver (Sverdrup et al., 2014b), copper, zinc, lead (Sverdrup et al., 2015, 2019), aluminium (Sverdrup et al., (2015a), platinum group metals (Sverdrup and Ragnarsdottir 2016), wolfram (Sverdrup et al., 2017c), molybdenum and rhenium (Sverdrup et al., 2018b), tin (Olafsdottir and Sverdrup 2018), nickel (Olafsdottir and Sverdrup 2020), indium (Sverdrup et al., 2023). Further publications near completion after this are studies on tellurium, selenium, yttrium, antimony and bismuth, The source metal reserves and resources estimates for the relevant metals are based on geological estimates, the interpretation of geological data, and the allocation of extractable amounts\u003cem\u003e\u0026nbsp;\u003c/em\u003eaccording to ore quality, stratified with extraction costs, and as revised in our earlier studies for copper, zinc, lead, bauxite, nickel, molybdenum and wolfram (Phillips and Edwards 1976, Olafsdottir and Sverdrup 2018 (Sn), 2020 (Ni), Sverdrup and Olafsdottir 2019 (markets), Sverdrup et al., 2014a (Ag), 2015 (Al), 2017 (W), 2018 (Mo), 2019 (Ca,Zn,Pb), 2023 (In), 2024 (Ge).).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e4.2. Resource estimations\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e4.2.1. Dependencies and cross-links\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFigure 2 shows how the different technology metals are almost all of them dependent on primary extraction of a major resource such as hydrocarbons, metals or phosphate. All the 10 big metals and the minor metals \u0026nbsp;indicated with yellow colour have their own primary mines, for all those in blue colour, extraction is dominated by secondary extraction. This complicated system is contained inside the WORLD7 model.\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e4.2.2. Basis for estimating how much can be extracted from ore deposits\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eGallium is extracted mainly from Bayer Liquid from processing bauxite to alumina (about 60%) and zinc (about 40%) (Nassar et al., 2015). A few coal mines extract some gallium from coal and some production has been done from coal fly ash, and potentially, more is available. Gallium can be from secondary extraction during the refining process of primary metals like copper, zinc and lead. Recycled mother metals have very little content of gallium. Gallium is only available if the ore is hydrometallurgical processed and little technology metals come out with heap leaching methods. Only a few studies make detailed studies of the available resources of the technology metals. We have identified a few that were helpful for this study concerning: The size of the extractable gallium resource was discussed by Frenzel et al., (2016a,b, 2017), Lu et al., (2017), Paradis (2015), Panoussi et al., 2015, Wang et al., (2011) and Jaskula (2019). Statistics and data was supplied by USGS (2015, 2017, 2018, 2022). Aspects of the extraction methods and different degrees of recycling was discussed by Brown et al., (2014),\u0026nbsp;Moskalyk (2003, 2004),\u0026nbsp;Redlinger et al., (2015). No earlier studies on gallium involve any real feedbacks from market dynamics.\u003c/p\u003e\n\u003cp\u003eEstimating the demand is particularly uncertain and was discussed by Goe and Gaustad (2014), \u0026nbsp;Gibson and Hayes (2011), Dehnavi (2013), Weeks (1973) and Licht et al., (2015). The basic approach is to assume a certain percentage growth per year and let it expand exponentially. This is a fairly short term and naive approach and is generally not based in any fundamental system dynamics knowledge of the gallium system. Another approach was to let it expand with GDP. The more sophisticated approaches trace the demand back to specific technology needs, and derive estimates from that.\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e4.2.3. Extractability and yields\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOne major source of difference between the available resource estimates in the literature are the differences (or lack of) assessment of actual industrial extractability. That a deposit has a certain amount of metal does not mean that it can all be extracted. The extraction pathway for a metal in general is shown in Figure 1. We have looked at many assessments to see if they seem to converge on a similar resource base for gallium (We reviewed Werner et al., 2017, Yellishetty et al., 2017, USGS 2022, Brown et al., 2015, Frenzel 2016, Mudd et al., 2014, 2017, Nassar et al., 2015, Sverdrup and Olafsdottir 2020, \u0026nbsp;for gallium resource estimates). Yield is defined as being made of several components: Access yield: The part of the deposits that will be available for this kind of extraction.\u003c/p\u003e\n\u003cp\u003eSome deposits lack physical or legal access, some have a composition that prevents extraction or the extraction operation do not have the infrastructure to extract the technology metal when the operation is running Reuter et al., (2013a,b); (Y\u003csub\u003eA\u003c/sub\u003e). The substrate yield is the fraction of the potential in the source material that will be used for extraction, in many mines, the refining residuals are simply thrown away; (Y\u003csub\u003eS\u003c/sub\u003e). When the gallium is taken out, first there is an extraction where gallium is separated from the other metals present (Y\u003csub\u003eE\u003c/sub\u003e) and then it its refined and into pure gallium (Y\u003csub\u003eR\u003c/sub\u003e), see Figure 3. Some methods, such as heap leach do not readily give such a secondary substrate that contains gallium or other metals that can be extracted. The refining yield is the fraction of the gallium recovered from the refining substrate; (Y\u003csub\u003eR\u003c/sub\u003e)\u003csub\u003e.\u0026nbsp;\u003c/sub\u003eSome bauxites have good gallium contents, but too much silica to be interesting for alumina production. Then gallium will not be extracted. Some coals goes straight to a use where the gallium will not be extracted from the ashes. The extraction cut-off is dependent on technology, extraction costs and the metal price at the time.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e4.2.4. Resource and extractable amounts estimation.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe recoverable resources are estimated (Krautkr\u0026auml;mer 1988, Sverdrup and Olafsdottir 2019, 2020): \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eGallium resource \u0026nbsp; \u0026nbsp; \u0026nbsp; = Mother metal resource \u0026nbsp; \u0026nbsp; \u0026nbsp;* X\u003csub\u003eGa\u003c/sub\u003e\u0026nbsp; * Y \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; (1)\u003c/p\u003e\n\u003cp\u003eGallium production \u0026nbsp; = Mother metal production \u0026nbsp; * X\u003csub\u003eGa\u003c/sub\u003e * Y \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; (2)\u003c/p\u003e\n\u003cp\u003eX\u003csub\u003eGa\u003c/sub\u003e is the fraction gallium in the material, and where the yield Y is the yield (Krautkr\u0026auml;mer 1988, Sverdrup and Olafsdottir 2020, Sverdrup et al., 2023). This is defined as:\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; Y= Y\u003csub\u003eA\u0026nbsp;\u003c/sub\u003e* Y\u003csub\u003eE\u0026nbsp;\u003c/sub\u003e* Y\u003csub\u003eR \u0026nbsp;\u0026nbsp;\u003c/sub\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u003csub\u003e\u0026nbsp; \u0026nbsp;\u003c/sub\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;(3)\u003c/p\u003e\n\u003cp\u003eThe refining yield Y\u003csub\u003eR\u003c/sub\u003e will be a function of the extractive efficiency when treating the ore shipped to the refinery. The material contained below the cut-off grade is lost with the waste (Krautkr\u0026auml;mer 1988, Sverdrup and Olafsdottir 2020). The extraction yield Y\u003csub\u003eE\u003c/sub\u003e is:\u003c/p\u003e\n\u003cp\u003e\u003cimg src=\"data:image/png;base64,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\" width=\"547\" height=\"52\"\u003e\u003c/p\u003e\n\u003cp\u003eY is the overall yield, the amount metal extracted divided by the total metal content in the original ore. The extraction cut-off is determined by the technology used for extraction, combined with several cost aspects of extraction. Gallium can be extracted from the waste liquid when bauxite is processed to alumina (Bayer process) and if the extraction plant has the necessary infrastructure for it. Some Russian and Chinese coal deposits are known to contain significant amounts of gallium. The different estimates come from different sources, not using the same background material, and they are thus not always consistent. \u0026nbsp;For gallium extraction before 1950 was very small. Yields from refining residuals are far higher than the access yields and enrichment yields, suggesting that investment in technical ability for gallium extraction appear to be missing. Possibly because on the individual process step level, each process is difficult to make profitable, even if gallium is very important on the whole-system strategic level. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e4.2.5 Long term sustainable supply of gallium.\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSustainability is defined as \u0026ldquo;..sufficient for the needs of the present and future generations\u0026rdquo; according to the Brundtland definition. The future has many more generations than the present. If the time from invention of writing is counted, then that would be 5,000 years or about 150 generations. If we count from the invention of agriculture and the rise of cities, it is 10,000 years or 330 generations. If the industrial revolution started 1840, that is 180 years ago, then it is 6 generations. The total available resource must be estimated as follows:\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Available amount = extractable + recycled \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;(5)\u003c/p\u003e\n\u003cp\u003eThis can be used to estimate the annual average supply for the time period assumed to be appropriate for length of the future.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cimg src=\"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAXUAAAA3CAYAAADzGtobAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAA0nSURBVHhe7Z3Lq1bVG8e3v3k3beygGhQKhpwMohoIZamEYGU4CCEwTkWTqLxFBF28N0orCiIo0wobpHaBBhVBWqJgNMmIiEaW1T9w2p/V/p7zuM5+3/Ne9uvPs8/3A4t33W/n7Gev/Txr7T1voqQwxhjTCv5X/RpjjGkBFurGGNMiLNSNMaZFWKgbY0yLsFA3xpgWYaFujDEtwkLdGGNahIW6Mca0CAt1Y4xpERbqxhjTIizUzcDcddddyTUJ9e3cuTP5H3nkkWLevHmT4W5s3bq1a9733nsvpTfdX2MuNSzUzUD8/PPPxfHjx4tPP/20+OOPP6rYZtm3b18xNjZWhbrzwgsvFCtWrKhC03nggQeKLVu2VKF2E2+MZu5hoW4G4s0330xC96qrrio+//zzKnZ4Pvnkk+Kpp56qQkWxYMGCyjc8V1xxReVrNz/99FPlM3MRC3UzEJ999lla/eI++uijKnZKDTJ//vyk8oCbbropxaFOAeKvu+66FMcvq37oRd3y9ddfp5Wo2jh69GiVMgXlSYt9qIMnDPqvujq1Sz7VSd6owtE46IfqIp0ymgvynD59uipRJL/mhDoZt552VB/jhHxOYntKoy6Vx3/27Nni6aefTmlWN81BePWuMf1w5MiRifHx8eQ/cODARLlaT35B2rp166rQxMRXX301sWLFiuR/9dVXU9q5c+cmSuEzce21107s2LEjpQH5OoVPnTqV8lOO8tSjegE/6bQHlONfnPwK5/nVF+omr8pGyKM+kJ7nI0xdtKN6COOnbvq0ZcuWlJcw86UweQhrPjvVH+cktoejPPMq8vxmbuGVuumbt99+u3j44YeT/4477ijOnz9/wYp59erVxcGDBydXj++++27x+OOPJz/lWD2jVrnmmmvSyrNXlixZklQLlKP80qVLq5QpSgFc3HrrrckvNQ66/xyeDrAHbN68OdVF3aWgLL755psqxxT0V3Wp7pxt27alfqme5cuXJz91M8bvv/8+5UNVxXxhAwDybNq0qesTRR1qD7ds2bLi77//rlLMXMdC3fQFghqBfeONN6bH+6uvvjrFf/zxx+kXVq5cWZSr0yTAyH/ixIkUB4RRJUiFgmDtB4QfZVFboGLIqdOb//rrr5Vvit9//z39ahzqyxdffJHiI9wAUHVIZTIMdX0BBL0xTWChbvrigw8+SLtIyqe8SVc++k9babJiRtdO/ieeeKKKLYpnnnmmeP/999PK/dy5c113rOTQBsJ1w4YNxXfffVfs2LGjSqlHTwqLFy9Ov5HLLrss/Z49e/aCsWCozbnzzjuLP//8s3j55ZdTnmHQTUd9E9wEQf0aBozXZu5ioW76YteuXcXdd99dhf5j0aJFaaUp4x7cf//9aUV/+PDhZEAUrHoRkqzcf/zxxyTcouqgLixY5SL8VN/JkyenCcfXX3990vC6d+/eJOBuvvnmFI71ovagrt27d0/W8dprr9WqQRD8Dz74YFK9kE6d//zzT0pTWYUh71MEdRVwcwP6Sp83btyYwvQLfvjhh/RLexL40Km9ODbUMZqbTsZf02LKlYcxPVEKl2SE4xcDH/CreAx2ioexsbFpBjsZVnH4Sacsfox9+HHUg/EwhmNbGBplVJSREeMhdSgP7as/1K+6ZFQkjTLE0Z9OxkXaIo/GTRmNFSOqyoPGoPTYLn7A0BznTEZToTnppz0c6UA7pKu8mVv4w9PGGNMgPF299dZbtaq8CE9Sjz76aHoKlM2pCRpTv/DojREpPoKb/sn3JRtjZg9cv19++WWtQI9nGVC7sTOKGwCbDDjT0BSNCXW2rZWPfMWxY8eqGDMI/RyNN8ZcOiC0EdZcwzkI+2effTatylGOsBVVkB/7U1ML4kaEOo8RnDB86aWXUufMcHAHN8bMLhDa7MzK4ambbb2s3jupWZ5//vnkmqARoc5+5CeffDJZ9tkpoCPR/OpYM3t8gccN9hjjSOeGUHdUmzTCxMd6uJvJqq/0/Cg0jzJKk1Me6tJ+Y+qMh2YiMR9O/Y/9gFxdonTq1V5s4qgPYv66I/WROAfa8UE+wjjVaYz5/8IKnW222t0kkFXbt28vnnvuua6LNXYsNfZyPAylw8IuA44rAxZ37S4A4mkmWuGx5usYNH4s+nVHtbW7QbsDqJs48mungvKojHY/0C51Ur92R+iItsqSlzDxOZRTu/RLuw3y9oCw6qQuwpTHj2N+cAJ/3JmgXR7qB2VVHzslSMvnL85xhDTyd3Ox78aY4eE6lYyIaPcT1zPXPP547UeaujaHFup0DiErEIRRgAFhCUiErdI7CfxcYM9EnAzKUoeIYW31inSaSMZEOd2shPoUyxBWnyFPl2AWcYygG4HK5On8E0iI6yYxauiPXbudaY5c7gjikTnIAND1yzWdw9+kThb1y9Dql0OHDiU9ulQCL774YnoM0QEQ4EShdO3xhGE/R7Uj1I0ao+7YNif2eNcHeXiUoa4rr7wypXF4hUMyaktl69738corryRjRjn5SY0yjKrj8ssvr3z1zKRD52DKG2+8kfy88va+++5L/lFS/m/YtdyZiwOqFenSudZRxZSLxRQeBUML9f3796fj3vGfpbwzXfCO7ahr54i49MP9HNWOdDu2fe+99yZBjOO9JAh0BDQg8ImPbeHi+7sFk49VmrEh3NeuXZviBznG/dtvv1W+euINsA7GxI2S+eP04UMPPVSlTEd6/G7O206NaRZeRVH34jgtMiPxNPAoGEqoY7TjLpSvNInjeLggfd26dUkwxveAzHRUOz+KLbgJdDq2zZMAK1kJbNLVP91caAOolxV/nVDFQEk8ZeknNxGY6Ri3YIsn0MaePXvS+CPc3DQuxs8Y9AbAfLzcVMbHx9P8sWrP5zvCDTHesOpcpzcNGmMG4/rrr09agPzaleFUGymQKcgDrueIZNANN9yQfoeivMgHIh5/jsec8SteBkqQIQGdUgR9Oroo8pMedcmEiS+FZhXzH2qDeJUnL37pr6MjXynMU1nSCSteuq4c9Un5dMQb6KPi8/aBtFge/XwcN2no1TQ+/CoroylOcYCujfz5/BljLg24jqOcEMgY0rimuYa5xvPrmHLIhSYYWKhfqiBA84llQuPNYtTwx+tm8OCP129/GNPFHINufE0YbvqFsdJ2U//kEG/mM9WrG2tT891P22b2IuE9CPx/NHWtNbJP/VICg2x8ZzV6aB6LFi5cWMWMlvzxq45e8giMweTnka2bLr1pvv3228o3eng0jWcNsLmUT2NVaHh4tF21alXx4YcfFuXTTxU7BW3r8RiaPNU7U9t15P0xswOMoVyvqHT7gfyoZ5tSi7ZOqJervKSvllFQemgZZ0eNXvN6zz33pN8c/oAYPfnAQy87ashLnRiFu+nSm+ZitvXLL79UvinqPnYxKNplhT0Elxvi6z7U3NT4Z2q7Dn84evbCguD222+/YJHSCRZryCW+FKYvYTVCtWI3Zhr8e8RHQtQiUY2Q2wFQV+DQG0YbA+CXXjG6ujigHtqgTdWHvxOxb/xKdUK7isfl6o+8faXzSx25/UagE0XVRxp9U3uRurZz1Q79VhrU9WemMjGMn/4Qhl76adqFhbrpCIJAQp3fGEZQSKgAfgQY6QgSwuQRUaCge6QuGa/JG+sC8kZBTl3UX4f6Rr0gIaeySu8Eabmw03gQzIwHP8JVaHykkYc6NDeRurbz9vLx1/VnpjJxvphXtdlrP017aJ36xYwGtmiWwmFS7/fYY49N+74oai7SUV3w4eW//vqrSvnvG5y33HJL8usghlQTnWBrrNRmbGFlO2od9K0UXpP1UoYwn9MbBsaDyoTxMHZtO+OXsffy0eqLieaLLbDltX3J9tOMFgt10xMIiHhy+LbbbkvxvR5kKleRk69l1kvU+jnI1e1UroRtTrypDEvU8Q96EvpiM1v6aZrFQt30BCdzx8fH0wowul4t9ryWmdPHCBY+On3gwIG0cgS9xmFQKF+3oyi+s7ob3HD6YdCT0GKm9urS++0jDNtPMzuxUDe15EJyzZo16fSsVuasjuOOIvLHjx/jj3WgAuBULkKF3R2x7NKlS1Mc+fUFmFgXdDtaTd/YJaSTyPSRFen69etTuNPJZIHaIv9Qc5530I9W17Wt9qDuSaeuPzOVyecb+umnaRHlRWbMNDAM8u9RrhCrmCljHPEY4LQbhDdIEocjTgY5nN4uWbfLRYY/8tMedWPok6ETJ2On2sXoV0fsG3WpHMT4OshLHtLpi3abENdpPMQxB8oXjZiRurYx6BKPo23Kkkd9zvsD3crE/kVjLvTaT9Me/OFpM3JYWfJVl3feeWdy/zd6dQ7l+N/PmGax+sWMHHZboF6RCgNVwJkzZ2pfhGaMGQ4LdTNyeL3B2NhYchhKeSUy+mGOzhtjmsXqF2OMaRFeqRtjTIuwUDfGmBZhoW6MMS3CQt0YY1qEhboxxrQIC3VjjGkRFurGGNMiLNSNMaZFWKgbY0xrKIp/AcC5heRtBXCYAAAAAElFTkSuQmCC\" width=\"373\" height=\"55\"\u003e\u003c/p\u003e\n\u003cp\u003eThis way of estimating the long term average supply sets a final date for the resource, and after this time it will potentially no longer be available at all. Take note that \u0026ldquo;sufficient need\u0026rdquo; is not necessarily the same as \u0026ldquo;want\u0026rdquo; or \u0026ldquo;demand\u0026rdquo;. The results are reported later.\u003c/p\u003e"},{"header":"5. Dynamic simulation model description","content":"\u003cp\u003eThe dynamic model is best described by the system flow chart as described in Figure 4 and the causal loop diagram (CLD) shown in Figure 5. Figure 4 shows the flow chart for the part of the WORLD7 model dealing with gallium. The major gallium losses have been marked with red. In the model, tin was ignored as a source of gallium, as the contribution to the total supply is small. \u0026nbsp;Figure 5 shows the causal loop diagram for the gallium sub-model. In certain aspects the CLD has been simplified in order to keep it readable. \u0026nbsp;Market with blue is the extractive sector, in green is the recycling sector, in yellow is the market, red is the industry using gallium in commodities and turquoise is the use in society.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe system feedbacks for system irreversible losses of gallium have not been shown. The system driving the preparation of gallium extraction substrate from coal ash, Bayer liquid and anode sludges from primary metal extraction have not been shown. R1, R2, R3 and R4 are reinforcing loops driving the gallium supply system. R1 is the extraction loop secondary to primary production of metals, and it is driven by profits. R2 is the extraction-investment loop, describing how increased extraction infrastructure increases extraction production and extraction profits. R3a and R3b are the loops for investing in recycling capacity. These links have been indicated in green. The investment decision is being taken based on profits and a supply capacity gap. These links have been indicated in blue. R4a-R4d are four different loop running over recycling to generate income and recycled gallium which is sold again to the market. R6 is the recycling-investment loop, describing how increased recycling infrastructure increases recycling production and recycling profits.\u003c/p\u003e\n\u003cp\u003eB are different balancing loops, slowing the system down. B1-B4 are different balancing loops, slowing the system down. B1 is the balancing effect of a large supply to the market, which may press the market price down. B2 is the balancing effect of operation costs and capital cost of invested capital in infrastructure for first extraction of gallium from different substrates. B3 is the balancing effect of operation costs and capital cost of invested capital in infrastructure connected to recycling of gallium. B4a-B4d are the balancing effect of supply and demand in the system to deliver commodities with gallium to society. B5 is the balancing effect of closing the supply capacity gap by investing in more capacity. The small unnumbered B\u0026rsquo;s are stock depletion balancing loop in the system. The system involves a supply chain from extraction substrates and recycling substrates through extraction processes to the metal market, on to users of gallium for inclusion in commodities. The commodities flow to society and after use to scrap, where a part becomes a recycling substrate, closing the cycle.\u003c/p\u003e\n\u003cp\u003eIn the WORLD7 model, take from the market are driven by the modified demand, put gallium into society where it stays until scrapped or removed by wear and losses. Demand in the model is driven by population and metal use per person, but is adjusted up or down with price; this is the modified demand. The demand is estimated from average affluence, expressed as disposable income per person and global population, using outputs of the WORLD7\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003emodel (Sverdrup et al. 2019b, Sverdrup 2019).\u0026nbsp;The basic driving mechanism of gallium extraction comes from profits of the extraction activity and availability of a extractable substrate used in the model.\u0026nbsp;The price is determined by how much metal is available in the market in the same way as in our earlier metal models. This approach has been very successful in endogenously modelling the price (Sverdrup and Ragnarsdottir 2014, Sverdrup et al. 2017b, Sverdrup and Olafsdottir 2018, 2019). A high metal price will increase profits and promote larger supply to the market. High price leads to a reduction of demand in the model. More supply to the market will increase the amount available and lower the price.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFigure 6 shows an overview of the WORLD7 integrated assessment model. The WORLD \u0026nbsp;model was developed from 2012 and still ongoing in 2023. The WORLD7 model addresses a large number of metals, and they are all in some way all linked in their extraction. All modules in WORLD7 are interconnected. Every red line represents one or several feedback links. Every box contains one of several sub-models. The WORLD7 energy module supplies energy from fossil fuels, renewables and nuclear power, with a market price generated by supply and demand in the model. Energy for metal extraction is taken from this module (Sverdrup et al., 2019b).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTable 1 shows average estimated for the use of technology metals, gram/unit; indium, gallium, antimony, selenium and silver for CIGS (CuInGaSe) photocell technology and other technologies. gram/unit.\u0026nbsp;The copper, zinc, lead and silver production was derived in the WORLD7 model (Sverdrup et al., 2015a, 2019b, Sverdrup and Ragnarsdottir 2014b). The aluminium module in WORLD7 was used for the contribution from bauxite mining, integrated as a sub-module into the WORLD7 model (Sverdrup et al., 2015). Coal production and fly ash production rates were derived in the WORLD7 energy module. For gallium, the price has an effect on demand, but not any significant impact on the supply, as this is dependent on the source metal extraction rate. There is no feedback from gallium production and back to copper mining. The price has effect on demand in the model, but it does not have any significant impact on the supply, as this is dependent on the mother metal extraction rate. The mining cost depend on the energy price, other operating costs and financial costs.\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n\u003cdiv align=\"center\"\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"6\" valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eTable 1. The use of technology metals, gram/unit; indium, gallium, antimony, selenium and silver for CIGS (CuInGaSe) photocell technology and other technologies. gram/unit.\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eItem\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eIndium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eGallium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAntimony\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSelenium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSilver\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eComputers\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.040\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.002\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.770\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.050\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.250\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eLED TV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.003\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.005\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.710\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.015\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.450\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eMobile phones\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.0003\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.0005\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.071\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.002\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.045\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCuInGaSe PhotoVoltaic\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.120\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.120\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.120\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.080\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCars\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.300\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.200\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eHandheld tools\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.002\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.140\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.005\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.010\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003eThe scrapping process for stock-in-use in society is driven by price (Dahmus and Gutowski 2007, Sverdrup and Olafsdottir 2019),\u003cem\u003e\u0026nbsp;\u003c/em\u003eafter the metal has been scrapped, a high price will promote more recovery. \u0026nbsp; Figure 7 shows the STELLA Architect code inside WORLD7 for the gallium module.\u0026nbsp;\u003c/p\u003e"},{"header":"6. Results","content":"\u003cp\u003e\u003cstrong\u003e6.1. Resource and production estimates\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTable 2 shows the recoverable resources of source metals \u0026nbsp;in million ton of metal, this was used as input data to the WORLD7 model (Sverdrup and Ragnarsdottir 2014, Sverdrup et al., 2017a,b,c and Sverdrup and Olafsdottir 2018, 2019). The data has been stratified with respect to ore metal content and relative extraction cost (Phillips and Edwards 1976, Sverdrup and Olafsdottir 2019, 2020). For the content in coal two approaches to estimating the content was used, both resulting in about the same amount. The gallium content in coal is low, but it remains in the ashes and gets concentrated there 20-30 times. The given yields and the resource gallium content are very approximate estimates by the authors, derived from unpublished industrial sources and in some parts from the scientific literature. Note how the yields are very low. Of a geological presence of 15 million ton gallium, only 0.6 million ton is estimated to be obtainable for use (4%). This makes it clear that it is as important to improve yields as it is to find more gallium in deposits.\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"12\" valign=\"top\" style=\"width: 604px;\"\u003e\n \u003cp\u003e\u003cem\u003eTable 2. Resource estimates for gallium. There are no primary mines for gallium. All extraction is secondary. Numbers in italics for coal grades (136,000 ton) are parallel estimates to the bulk estimate on coal combustion ashes content \u0026nbsp;(139,000 ton or 136,000 ton). Take note that the yields are very low for most pathways.\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 59px;\"\u003e\n \u003cp\u003eSource\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003eResource\u003c/p\u003e\n \u003cp\u003emill ton\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 42px;\"\u003e\n \u003cp\u003eRich\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003eHigh\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 41px;\"\u003e\n \u003cp\u003eLow\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003eUltra\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 78px;\"\u003e\n \u003cp\u003eGa content, ton\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 33px;\"\u003e\n \u003cp\u003eY\u003csub\u003eA\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 37px;\"\u003e\n \u003cp\u003eY\u003csub\u003eE\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 39px;\"\u003e\n \u003cp\u003eY\u003csub\u003eR\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 46px;\"\u003e\n \u003cp\u003eY\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 75px;\"\u003e\n \u003cp\u003eExtractable Ga, ton\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\" style=\"width: 169px;\"\u003e\n \u003cp\u003eppm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"4\" style=\"width: 156px;\"\u003e\n \u003cp\u003eYield, Fraction\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 59px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 42px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 41px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 33px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 37px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 39px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 46px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 59px;\"\u003e\n \u003cp\u003eZinc\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e2,676\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 42px;\"\u003e\n \u003cp\u003e60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 41px;\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e107,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 33px;\"\u003e\n \u003cp\u003e0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 37px;\"\u003e\n \u003cp\u003e0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 39px;\"\u003e\n \u003cp\u003e0.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 46px;\"\u003e\n \u003cp\u003e0.090\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e9,633\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 59px;\"\u003e\n \u003cp\u003eCopper\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e4,020\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 42px;\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 41px;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e80,400\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 33px;\"\u003e\n \u003cp\u003e0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 37px;\"\u003e\n \u003cp\u003e0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 39px;\"\u003e\n \u003cp\u003e0.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 46px;\"\u003e\n \u003cp\u003e0.090\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e7,236\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 59px;\"\u003e\n \u003cp\u003eTin\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e120\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 42px;\"\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 41px;\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e1,800\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 33px;\"\u003e\n \u003cp\u003e0.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 37px;\"\u003e\n \u003cp\u003e0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 39px;\"\u003e\n \u003cp\u003e0.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 46px;\"\u003e\n \u003cp\u003e0.140\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e252\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 59px;\"\u003e\n \u003cp\u003eLead\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e3,015\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 42px;\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 41px;\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e60,300\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 33px;\"\u003e\n \u003cp\u003e0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 37px;\"\u003e\n \u003cp\u003e0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 39px;\"\u003e\n \u003cp\u003e0.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 46px;\"\u003e\n \u003cp\u003e0.090\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e5,427\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 59px;\"\u003e\n \u003cp\u003eSilver\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e2.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 42px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 41px;\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e120\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 33px;\"\u003e\n \u003cp\u003e0.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 37px;\"\u003e\n \u003cp\u003e0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 39px;\"\u003e\n \u003cp\u003e0.95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 46px;\"\u003e\n \u003cp\u003e0.110\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e14\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 59px;\"\u003e\n \u003cp\u003e\u003cem\u003eCoal\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e\u003cem\u003e420,000\u003c/em\u003e\u003c/p\u003e\n \u003cp\u003e\u003cem\u003e500,000\u003c/em\u003e\u003c/p\u003e\n \u003cp\u003e\u003cem\u003e530,000\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 42px;\"\u003e\n \u003cp\u003e\u003cem\u003e8\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n \u003cp\u003e\u003cem\u003e6\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 41px;\"\u003e\n \u003cp\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n \u003cp\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n \u003cp\u003e\u003cem\u003e4\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cem\u003e3,360,000\u003c/em\u003e\u003c/p\u003e\n \u003cp\u003e\u003cem\u003e3,000,000\u003c/em\u003e\u003c/p\u003e\n \u003cp\u003e\u003cem\u003e2,120,000\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 33px;\"\u003e\n \u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n \u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n \u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 37px;\"\u003e\n \u003cp\u003e\u003cem\u003e0.2\u003c/em\u003e\u003c/p\u003e\n \u003cp\u003e\u003cem\u003e0.2\u003c/em\u003e\u003c/p\u003e\n \u003cp\u003e\u003cem\u003e0.2\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 39px;\"\u003e\n \u003cp\u003e\u003cem\u003e0.8\u003c/em\u003e\u003c/p\u003e\n \u003cp\u003e\u003cem\u003e0.8\u003c/em\u003e\u003c/p\u003e\n \u003cp\u003e\u003cem\u003e0.8\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 46px;\"\u003e\n \u003cp\u003e\u003cem\u003e0.016\u003c/em\u003e\u003c/p\u003e\n \u003cp\u003e\u003cem\u003e0.016\u003c/em\u003e\u003c/p\u003e\n \u003cp\u003e\u003cem\u003e0.016\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e\u003cem\u003e54,000\u003c/em\u003e\u003c/p\u003e\n \u003cp\u003e\u003cem\u003e48,000\u003c/em\u003e\u003c/p\u003e\n \u003cp\u003e\u003cem\u003e34,000\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e\u003cem\u003e1,450,000\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 42px;\"\u003e\n \u003cp\u003e\u003cem\u003e8\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e\u003cem\u003e6\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 41px;\"\u003e\n \u003cp\u003e\u003cem\u003e4\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cem\u003e8,480,000\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 33px;\"\u003e\n \u003cp\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 37px;\"\u003e\n \u003cp\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 39px;\"\u003e\n \u003cp\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 46px;\"\u003e\n \u003cp\u003e\u003cem\u003e0.016\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e\u003cem\u003e136,000\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 59px;\"\u003e\n \u003cp\u003eCoal ash\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e58,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 42px;\"\u003e\n \u003cp\u003e200\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e150\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 41px;\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u0026nbsp;8,700,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 33px;\"\u003e\n \u003cp\u003e0.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 37px;\"\u003e\n \u003cp\u003e0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 39px;\"\u003e\n \u003cp\u003e0.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 46px;\"\u003e\n \u003cp\u003e0.016\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e139,000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 59px;\"\u003e\n \u003cp\u003eBauxite\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e112,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 42px;\"\u003e\n \u003cp\u003e80\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 41px;\"\u003e\n \u003cp\u003e25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e6,000,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 33px;\"\u003e\n \u003cp\u003e0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 37px;\"\u003e\n \u003cp\u003e0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 39px;\"\u003e\n \u003cp\u003e0.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 46px;\"\u003e\n \u003cp\u003e0.080\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e448,000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 59px;\"\u003e\n \u003cp\u003eSum\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 42px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 41px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e14,949,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"4\" valign=\"top\" style=\"width: 156px;\"\u003e\n \u003cp\u003e0.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e609,592\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"12\" valign=\"top\" style=\"width: 604px;\"\u003e\n \u003cp\u003e\u003cem\u003eTable 3. Extraction rate estimates for gallium, assuming presently (2023) applicable substrate access and supply chain yields. There are no primary mines for gallium, everything is secondary extraction.\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 56px;\"\u003e\n \u003cp\u003eSource\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 67px;\"\u003e\n \u003cp\u003eMining\u0026nbsp;\u003c/p\u003e\n \u003cp\u003emill ton/yr\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003eRich\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 44px;\"\u003e\n \u003cp\u003eHigh\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 44px;\"\u003e\n \u003cp\u003eLow\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003eUltra\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003eGallium content\u003c/p\u003e\n \u003cp\u003eton/yr\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 38px;\"\u003e\n \u003cp\u003eY\u003csub\u003eA\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 34px;\"\u003e\n \u003cp\u003eY\u003csub\u003eE\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 39px;\"\u003e\n \u003cp\u003eY\u003csub\u003eR\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003eY\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003eExtractable gallium\u003c/p\u003e\n \u003cp\u003eton/yr\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\" style=\"width: 179px;\"\u003e\n \u003cp\u003eppm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"4\" style=\"width: 159px;\"\u003e\n \u003cp\u003eFraction\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003eZinc\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67px;\"\u003e\n \u003cp\u003e17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 44px;\"\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 44px;\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e340\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 38px;\"\u003e\n \u003cp\u003e0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 34px;\"\u003e\n \u003cp\u003e0.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 39px;\"\u003e\n \u003cp\u003e0.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e0.090\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e62\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003eCopper\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67px;\"\u003e\n \u003cp\u003e22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 44px;\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 44px;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e220\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 38px;\"\u003e\n \u003cp\u003e0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 34px;\"\u003e\n \u003cp\u003e0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 39px;\"\u003e\n \u003cp\u003e0.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e0.090\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003eTin\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67px;\"\u003e\n \u003cp\u003e0.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 44px;\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 44px;\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 38px;\"\u003e\n \u003cp\u003e0.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 34px;\"\u003e\n \u003cp\u003e0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 39px;\"\u003e\n \u003cp\u003e0.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e0.140\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003eLead\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 44px;\"\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 44px;\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 38px;\"\u003e\n \u003cp\u003e0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 34px;\"\u003e\n \u003cp\u003e0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 39px;\"\u003e\n \u003cp\u003e0.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e0.090\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e5.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003eSilver\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67px;\"\u003e\n \u003cp\u003e0.027\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 44px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 44px;\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 38px;\"\u003e\n \u003cp\u003e0.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 34px;\"\u003e\n \u003cp\u003e0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 39px;\"\u003e\n \u003cp\u003e0.95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e0.110\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003eCoal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67px;\"\u003e\n \u003cp\u003e4,200\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 44px;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 44px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e25,200\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 38px;\"\u003e\n \u003cp\u003e0.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 34px;\"\u003e\n \u003cp\u003e0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 39px;\"\u003e\n \u003cp\u003e0.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e0.016\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e403\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003eFly ash\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67px;\"\u003e\n \u003cp\u003e118\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e200\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 44px;\"\u003e\n \u003cp\u003e150\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 44px;\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e17,700\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 38px;\"\u003e\n \u003cp\u003e0.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 34px;\"\u003e\n \u003cp\u003e0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 39px;\"\u003e\n \u003cp\u003e0.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e0.016\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e283\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003eBauxite\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67px;\"\u003e\n \u003cp\u003e350\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e80\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 44px;\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 44px;\"\u003e\n \u003cp\u003e25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e17,500\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 38px;\"\u003e\n \u003cp\u003e0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 34px;\"\u003e\n \u003cp\u003e0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 39px;\"\u003e\n \u003cp\u003e0.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e0.080\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e600\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003eSum\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 44px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 44px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e61,028\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"4\" style=\"width: 159px;\"\u003e\n \u003cp\u003e0.026\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e1,374\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eTable 3 shows the extraction rate estimates for gallium, assuming presently applicable substrate access and extraction yields.\u003cem\u003e\u0026nbsp;\u003c/em\u003eGallium occur on the average as 50 ppm in bauxite (aluminium ore), and can be extracted when the bauxite is processed to alumina, the raw material used for aluminium production (Figure 2 and see Foley and Jaskula 2013, USGS 2018). The refining yield is estimated to be at best 40% (Jaskula 2014). In reality, the real industrial yields end up far below that so far. The content in zinc ores vary from 8 ppm to 320 ppm (Butcher and Brown 2014). Our own estimate of the of bauxite resource is 112,500 million ton (Sverdrup and Ragnarsdottir 2016). At 50 ppm gallium content (50 g/ton), that corresponds to a geological resource of 6 million ton gallium (Table 1). But assuming that to be all present in geological deposits to be fully extractable is wrong. The different access and extraction yields must be considered, and at present, with best available technology, about 450,000 ton of gallium would be extractable. Most of the gallium supplied in 2023 comes from Bayer liquid from processing bauxite to alumina, see Tables 3 and 4 (Ronguo et al., 2016, Lokanc et al., 2015).\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"9\" valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eTable 4. Extraction rate estimates for gallium, but assuming better yields than at present (2022). Still, they are quite low. The technical extraction yield in 2022 was about 25%. Only 13% of the potential was extracted.\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\"\u003e\n \u003cp\u003eSource\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eMining rate\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eGallium content\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eY\u003csub\u003eA\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eY\u003csub\u003eE\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eY\u003csub\u003eR\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eY\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eExtractable gallium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eExtraction 2023\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eMill ton/yr\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eton/yr\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"4\"\u003e\n \u003cp\u003eAssumed future yields, as fraction of total content present\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eton/yr\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eZinc\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e340\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.65\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e119\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e60\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCopper\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e220\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.65\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e77\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eTin\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.65\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eLead\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.65\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSilver\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.027\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCoal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e4,200\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e25,200\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1,764\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eFly ash\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e118\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e17,700\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e819\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eBauxite\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e150\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e7,500\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1,679\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e287\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSum\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e51,028\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"4\" valign=\"top\"\u003e\n \u003cp\u003e0.09\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e4,482\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e450\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eTable 4 shows approximate extraction rate estimates for gallium, but assuming better yields than at present (2022). With gallium, the main issue is not the size of the resource, but (1) the access to the flow of substrate for extraction from mother metals, (2) dependence on the suitability of the bauxite for alumina production (It must have a low silica content), and (3) if the infrastructure for extracting gallium is present at the site where the secondary residual material is produced. Production at present is far below the potential available (Ronguo et al., 2016). The yield in the refining step is 75-80% (Hoang et al., 2015). The different yields given in the literature are not at all consistent. The yields indicated by the USGS (Foley et al., 2017) are in the range of 10% access, about 20-30% yield in the first steps of extraction and 80% yield in the final refining to pure gallium, resulting in a total yield of about 5-10%. The low yields are a major challenge in the extraction of gallium, but it seems that they may be slowly improving. It can be seen from the Table 3 that the potential is 51,000 ton/year of gallium, but that because of low yields under business-as-usual, the real extraction potential is 1,340 ton per year. There is a significant potential source of gallium in coal, and that could be extracted from the ash after combustion, the ash is about 5-20% of the coal, thus gallium is enriched 5-20 times in the ash as compared to the raw coal. Earlier estimates are in the same order of magnitude as we have indicated in Tables 2 and 3. The total extraction potential is about 4,500 ton per year of gallium according to Table 3. The average reserve content were adapted from unofficial information found in company websites, confidential information from consulting companies and using industrial information. These is are independent sources from USGS and similar literature (USGS 2011-2022, BGS 2022), but the estimates are of the same order of magnitude as in Table 4 (Sverdrup et al., 2017a).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTable 5 shows the present production and capacities for gallium production. The available estimates are not internally consistent and the numbers are approximate estimates made by the authors. The final column shows a very approximate estimate of the extraction potential, and this can be compared to the present production of gallium. The gallium potential without China is about 1,540 ton/year, or three times the present production.\u003cem\u003e\u0026nbsp;\u003c/em\u003eChina supplies 84% of the global supply, followed by United States at 7%, and all the rest with only marginal contributions. The present global gallium technical production capacity (800 ton/yr) is far larger than the actual gallium production (450 ton/yr) in 2023, and far less than the gallium extraction potential (3,450 ton/yr).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTable 6 shows a comparison of gallium resources estimates for anode sludge residuals and potential gallium production, at different yields for recycling and extraction from anode sludges, mostly from sulphide ores. Anode sludge arise when the mother metal is refined using electrolysis.\u003c/p\u003e\n\u003cp\u003eTable 7 shows a comparison of gallium resources in coal ash and potential gallium production (ton/yr), at different yields. Present yield from anode slimes is in the range 10-15% (Table 1). Present yields for gallium extraction from coal and coal ashes is in the range 2-4% (Table 1), gallium recycling from urban scrap is at present very low, less than 10% (Data extracted from Dahmus and Gutowski 2007, Reuter et al., 2013a,b). \u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"7\" valign=\"top\" style=\"width: 100%;\"\u003e\n \u003cp\u003e\u003cem\u003eTable 5. Present production and capacities for gallium production in 2023. Amounts are in ton gallium per year. The final column shows an estimate of the potential. ? implies no data was found.\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003eCountry\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003ePrimary gallium production 2023, ton/yr\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003eEstimated primary gallium production capacity,\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;ton/yr\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003eHigh purity gallium refining capacity, ton/yr\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003eAlumina primary production, million ton/yr\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003eZinc\u003c/p\u003e\n \u003cp\u003eprimary production, million ton/yr\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.543%;\"\u003e\n \u003cp\u003eGallium approximate potential assuming 50 ppm content and 50% yield, ton/yr\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003eChina\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e380\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003e650\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e?\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e76\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e4.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.543%;\"\u003e\n \u003cp\u003e2,000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003eAustralia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e?\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003e?\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e?\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e1.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.543%;\"\u003e\n \u003cp\u003e525\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003eBrazil\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e?\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003e?\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e?\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.543%;\"\u003e\n \u003cp\u003e302\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003eIndia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e?\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003e?\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e?\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e7.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e0.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.543%;\"\u003e\n \u003cp\u003e410\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003ePeru\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e?\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003e?\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e?\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e1.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.543%;\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003eUSA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003e150\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e320\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e4.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e0.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.543%;\"\u003e\n \u003cp\u003e125\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003eBolivia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e0.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.543%;\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003eMexico\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e0.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.543%;\"\u003e\n \u003cp\u003e18\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003eUkraine\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e?\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e0.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.543%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003eRussia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e0.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e0.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.543%;\"\u003e\n \u003cp\u003e22\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003eBelgium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.543%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003eJapan\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.543%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003eSlovakia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e+\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.543%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003eSouth Korea\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.543%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003eGermany\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e?\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e+\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.543%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003eOther\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e?\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003e?\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e59\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e2.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e2.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.543%;\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003eSum\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e450\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.5629%;\"\u003e\n \u003cp\u003e800\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e400\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e120.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12.5828%;\"\u003e\n \u003cp\u003e14.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.543%;\"\u003e\n \u003cp\u003e3,540\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"6\" valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eTable 6. Comparison of gallium resource (ton) estimates for \u003cstrong\u003eanode sludge\u003c/strong\u003e residuals and potential gallium production (ton/yr), at different yields.\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 191px;\"\u003e\n \u003cp\u003eItem\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"5\" valign=\"top\" style=\"width: 412px;\"\u003e\n \u003cp\u003eExtraction or recycling under different scenarios for yield (Y) as fraction\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eY=0.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eY=0.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eY=0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eY=0.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eY=0.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eProbable resource, ton (Table 1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e94,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e470,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e940,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1,410,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1,880,000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eProduction, ton/yr (Table 5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e350\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e875\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1,750\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2,625\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3,500\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"6\" valign=\"top\" style=\"width: 604px;\"\u003e\n \u003cp\u003e\u003cem\u003eTable 7. Comparison of gallium resource (ton) in \u003cstrong\u003ecoal ash\u003c/strong\u003e and potential gallium production (ton/yr), at different yields. The yields marked in italics are probably out of reach.\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 208px;\"\u003e\n \u003cp\u003eItem\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"5\" valign=\"top\" style=\"width: 396px;\"\u003e\n \u003cp\u003eExtraction or recycling yields (Y), expressed as fraction\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003eY=0.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003eY=0.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cem\u003eY=0.2\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cem\u003eY=0.3\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e\u003cem\u003eY=0.4\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 208px;\"\u003e\n \u003cp\u003eProbable resource, ton (Table 5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e140,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e870,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cem\u003e1,740,000\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cem\u003e2,610,000\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e\u003cem\u003e3,480,000\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 208px;\"\u003e\n \u003cp\u003eProduction, ton/yr (Table 2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e500\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e2,500\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cem\u003e5,000\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cem\u003e7,500\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e\u003cem\u003e10,000\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"7\" valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eTable 8. Summary of gallium production (ton) at different yields for extraction from all sources \u0026nbsp;and including recycling with different yields.\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 261px;\"\u003e\n \u003cp\u003eItem\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"6\" valign=\"top\" style=\"width: 343px;\"\u003e\n \u003cp\u003eExtraction or recycling yields (Y), expressed as fraction\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eY=0.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eY=0.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eY=0.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eY=0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eY=0.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eY=0.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eExtraction from anode slime, ton/yr\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e160\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e350\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e875\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1,750\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2,625\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3,500\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSupply from coal ash, ton/yr\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e500\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2,500\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003e2,500\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003e2,500\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003e2,500\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSupply from bauxite, ton/yr\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e150\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e300\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e750\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1500\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2.250\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3,000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSum\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e810\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1,650\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e4,277\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e5,750\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e6,875\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e9,000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eRecycling yields\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eR=0.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eR=0.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eR=0.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eR=0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eR=0.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eR=0.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eRecycling, ton/yr\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e69\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e475\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1,438\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2,946\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e13,500\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003esum\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e826\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1,719\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e4,752\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e7,188\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e9,821\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e22,500\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\u003cp\u003eTable 8 shows a summary of gallium resource (ton) and potential gallium production (ton/yr), at different yields for extraction and recycling. Tables 5-7 shows that increasing yields in both the extraction supply chain for gallium and for the recycling recovery chain has a large effect on the gallium supply, at constant substrate use (anode slimes and coal ashes). Table 8 shows that the gallium challenge is very difficult, but probably not impossible to solve. If extraction and recycling yields can be raised to 30% instead of the 4%, gallium supply could increase from the present maximum potential of 1,375 ton/yr to about 9,821 ton/yr. For extraction from anode slimes, this is probably feasible, but at a significant energy cost, but for extraction from coal and bauxite, a yield more than 10% appears to be very challenging.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e6.2. WORLD7 simulations\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe production rate for gallium is shown in Figure 8a shows the production and the contribution from bauxite refining to alumina, 75% of the gallium and from zinc production, 25% of the gallium as compared to the recorded mining history (USGS 2014, 2022). At present, gallium is mostly produced during bauxite processing in China, a preparation for aluminium production, but other sources like refining residuals from zinc and silver are becoming more important with time. Demand is driven by electronics and solar photovoltaic panels production, coming from the energy module in WORLD7. \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Figure 8a shows the simulated production rate of gallium, together with the demand, price modified demand, the supply, extraction and recycling. After 2125, hard scarcity becomes apparent. Before 2010, gallium demand was modest, but that increases sharply after 2010. Figure 8b shows the extraction rate from different metal ores. The gallium supply from zinc, copper and lead has a maximum capacity in 2055. Technological development has been assumed from 2025 to increase yields. Figure 8c shows the source of the gallium extracted. Figure 8d shows the stocks in use in photovoltaics, semiconductors, other use and as waste. Figure 8e shows the simulation of the price and the amount gallium in the market. After 2055, the market is nearly empty and the price shoots up. Gallium is then in hard scarcity. If extraction access and refining yields cannot be significantly improved, it will stay like that. If overall total yields are improved to better than 50%, then there will be probably no scarcity for gallium. Figure 8f shows the cumulative amounts for demand, supply, extracted and recycled gallium. It can be seen that demand given by Line 1, far exceeds the supply Line 2. It can be seen that demand given by Line 1 far exceeds the supply given by Line 2. The simulations suggest a long term running average shortfall of 33% of the demand for gallium, thus only a 67% satisfaction of demand. In the long term simulations, recycling reached only 13-15% when based on market mechanisms alone. For demand to be met in the long run, the long term recycling flow back into the system will have to be at least 55% of the gallium supply to the market. This would require something more that just market mechanisms (e.g. gallium price) \u0026nbsp; to promote recycling.\u003c/p\u003e\n\u003cp\u003eFigure 9a shows the fraction of the supply as recycled gallium. The recycling has been modelled as a function of price (Dahmus and Gutowski 2007, Gutowski et al., 2016).\u003cem\u003e\u0026nbsp;\u003c/em\u003eFigure 9b shows the simulated yields for the production of gallium in the model. At\u0026nbsp;present, gallium overall yields are at about 10-15%. In the simulation, dynamic recycling is used, depending on price. However, yields for recycling are also far too low, and must be improved for recycling to be important.\u0026nbsp;Figure 9c shows the gallium supply and stocks-in-use is predicted to increase steadily until 2400 when it peaks. Figure 9d shows the cumulative amounts of gallium extracted from different sources over time. Extraction from zinc anode slimes is dominating at the moment, but we expect that bauxite may become the dominant source in the next decades.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e6.3. Testing the model\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe model has been tested against the recorded mining data derived from the USGS (2022, Foley et al., 2017) databases (Figure 10a-c). The results of the test can be seen throughout the results section and in the comparisons with the data. The general trend was reproduce, but some of the short term variations less well. But no systematic bias builds up over time, as can be seen from Figure 10b. The model does reproduce the observed mining rates satisfactory when the model is driven by market demand and price dynamics. The metal market price is well simulated for gallium as can be seen in Figure 10c. This suggests that the model reconstructs the historical pattern reasonably well and that it is safe to use the model for exploring future scenarios.\u003c/p\u003e"},{"header":"7. Discussion","content":"\u003cp\u003e\u003cstrong\u003e7.1. Uncertainties\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe major uncertainties in the simulations come from the following aspects:\u0026nbsp;\u003c/p\u003e\n\u003col\u003e\n \u003cli\u003eUncertainties in future demand. Most of what is out there has been naive guesses by market economists based on growing future GDP. A few technical assessments of future gallium needs based on energy needs are available, but these are only partial.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eUncertainties in gallium content in mother ores and fly ash on a global scale\u003c/li\u003e\n \u003cli\u003eUncertainties in extraction yields (substrate access, technical yields) at present and in the future\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003eFor the contents of gallium in different substrates, there is no earlier in-depth assessment. We have found numbers for gallium contents in different references, but these will give approximate estimates. The situation is similar for access and extraction yields, we have some reports of gallium yields, but no assessment for the whole industry. The values found show a wide range. Thus, the yield estimates are very approximate. The gallium reserve and resource estimates were made by the authors pieced together from corporate reports and ephemeral internet sites. Little information is available on reserves and resources on a global level. It is known that for gallium, the content potential in bauxite is not fully used. The present recycling rate for gallium is not really known, but most earlier studies agree that it is a low fraction of the total supply. The estimated gallium supply rates are much lower that the potential as a result of \u0026nbsp;poor recycling rates used in the simulations. These recycling rates represents the observed level 2028-2023. Many demand estimates found in the internet or in some publications are naive estimates based on a belief in constant annual growth of GDP or purely guesses about monotonous economic growth. These are normally not so useful and have been ignored. All of this is rounded off in the test on field data. The model does appear to reconstruct the past reasonably well. This indicates that the uncertainties have been kept under control and that the sum of all of it remains small.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e7.2. On scarcity\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe gallium may fast run into physical scarcity because the price has no feedback on the extraction rate of the source metals, such as on copper and zinc. The extraction rate can only be expanded if less than the potential is extracted or by improving extraction yields. But these increases will in most cases be marginal, and there is no room for substantial increases. For the extraction from bauxite, the economic feedback on bauxite mining rates are absent in the system. The value of the gallium per ton bauxite is rather insignificant, and for the producer of alumina from bauxite, the extra value of the gallium obtained will be marginal, For the extraction from coal or coal ash, the drivers are strategic as much as it is an issue of profitability and operable access to an interesting substrate. At many places where coal is used, there are no conditions for extracting gallium. It is important to consider that when the commodity is still relatively cheap, it may for that reason be unnecessarily wasted, when it would in retrospect have been relatively easy to induce better use efficiency and recycling. To wait until there is severe scarcity would be too late for optimal mitigation as unnecessary resources would already have been wasted by then.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSupply per person and year reflects the amount available to compensate for continuous losses and any surplus available for growth in the stock-in-use as shown in Figure 9. Stock-in-use per person is an indicator of the utility gained from the resource, and a decline in stock-in-use suggests a decline in service provision from that resource. Stocks-in-use is the amount providing utility. The supply is to maintain the stock, replace losses and any surplus will cause growth, a deficit a decrease in utility.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe production of gallium is limited to some extent by the fact that only a fraction of the metal refineries are technically equipped for efficient recovery of gallium from Bayer liquid or from anode slimes from Cu-Zn-Pb-Ag electrolytic refining. Significant investments would be needed in order to increase gallium production. Light Emitting Diode (LED) lighting technology is rapidly spreading as mass products in consumer lighting devices uses gallium. Making variations with these allow gallium to be almost sufficient to physically scarce before 2060. The simulations show that significant improvements in yields, access and recycling will be very important for avoiding supply problems with gallium. The present status of these conditions at present are very unsatisfactory.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e7.3. On the pathways of gallium through the world\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFigure 11 shows a flow chart for the flow of gallium through the Chinese and Rest-of-the-World (RoW) systems. Chine is a large producer and exporter of gallium, but this occurs to a large degree from mother metal refining and mother metal refining residuals source from the Rest of the World, more than Chinese domestic resources. China has had a successful strategy for securing the raw materials for making gallium, and to prioritize to supply its own manufacturing industry, and then supply the global market with those products (Han et al., 2015, Hayes-Labruto et al., 2013, Su 2009). In the continuation, a lot of scrap is flowed back from the Rest of the World to China for recycling, just like as illustrated in Figure 11. If the authorities in China were to restrict the export of gallium metal, that would limit gallium availability in the rest of the world. It not really matter for global supply situation, if the gallium withheld gets incorporated into products anyway and those products would be recycled outside of China. Then there would only be a delay. But that is not the situation at the moment. It appears that a very substantial part of the value chain has been located to China. The reasons for this are many, as the policy to do so has in the past been promoted both by Chinese and European governments and policies. For China, this puts them in a very good business position with strategic strength, as well as a political will to use strong control. Figure 19b shows the cumulative amounts of demand, supply, extraction and recycling. It can be seen that the demand is far larger than the supply. Increasing recycling to 80% by 2030 would decrease the gap, but cannot close it. The amounts of gallium extracted 1850-2250, gives an indication of what eventually will be the total available amount. Figure 11 shows the flows through RoW and China and the market dominance.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e7.4. From problems to industrial opportunity\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAn number of problems have been discussed with respect to gallium extraction and supply to industry (and to society). \u0026nbsp;For the international mining and extraction industry, these problems lead to a number of challenges, which when taken on, will lead to good business opportunities. The Rest-of-the World has a second chance to capture gallium as it is recycled from the products, however with a delay. To do that, a strategy for capturing gallium-containing scrap and recycling it will be necessary. China does not have the world\u0026rsquo;s largest geological deposits of gallium, and thus, China only have an apparent near monopoly on gallium at the present time, because the rest of the world allows them to have it. If the gallium was produced where the deposits are and where the scrap is appearing, then the situation would be a very different one. There are some industrial capacity to do gallium extraction and recycling in Europe at present, but it would have to be significantly expanded in the near future. The EU has discussed that they should have such a strategy, many discussions are being held, but as of 2024 there is nothing real in place beside general visions and goals, and a worked out strategy is still missing. \u0026nbsp;The creation of favourable conditions for recycling businesses in Europe is not yet implemented. This would have to include proper incentives as well as protection against unfair competition and the effects of state sponsored competition from outside countries.\u003c/p\u003e\n\u003cp\u003eLow yields in most industrial gallium transactions are a problem at present. With research into modern separation methods these can surely be improved, leading to improved extraction yields. Such improvements often translated straight down to the operating profit of a refinery. The poor recycling rates at present are partly linked to low yields when extracting from source substrates with low content. Another challenge is one of creating a circular value chains for gallium, where the system issues of collecting and refining the scrap contain gallium. The large producing countries of alumina from raw bauxite and the major producers of zinc have been listed in Table 4. Of these countries, only China and the United States have a substantial capacity for producing gallium. Every country with a large alumina production or substantial zinc production, but no primary gallium production, is potentially an business opportunity overlooked. China has at present a very dominating position in the gallium supply chain and market because of a long term strategy and having taken their opportunities seriously. Because of large scale outsourcing of industrial production to China from Europe and North America, it is also one of the major users of gallium for photovoltaic technologies and LED lighting products. In the past, Chinese strategies on Rare Earth Element supply is well known, and this should considered when the global dependence on China for gallium supply is strategically evaluated for the future. \u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e7.5. On future resource policies\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFigures 12 shows the gallium system with examples of generic policy interventions included towards the non-predetermined future imaginary path, as well as policy intervention in realising pathways towards the different imaginaries. A systemic approach is required and necessary when planning policies for complex systems. The gallium system is a very complicated system with significant delays inside where linear or short-term thinking does not work, especially when understanding different policy choices and their influence towards different imaginaries pathways. Planning toward sustainability without a predetermined future state (non-imaginary) results in a policy that is perceived as sustainable but without a future state. The purpose of the imaginary analysis, in this context, is to be able to frame the vision of the future and connect to the contemporary policy gap in relation to current \u0026ldquo;failed\u0026rdquo; policies. This is demonstrated in the study by the authors on indium, cadmium and germanium (Sverdrup et al 2023, 2024a, 2024).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;There are ways to increase the gallium availability for society, and push the gallium supply peak further into the future by a significant amount. The following statements can be made for different policy options that may appear as possible:\u0026nbsp;\u003c/p\u003e\n\u003col\u003e\n \u003cli\u003e\u003cstrong\u003eWhat does not really work that well as problem solution\u003c/strong\u003e\n \u003col style=\"list-style-type: lower-alpha;\"\u003e\n \u003cli\u003e\u003cstrong\u003eMore mining\u003c/strong\u003e: Increasing the rate of gallium extraction to satisfy demand, will be great in the short term relieving short term problems, but will not solve the root cause of the problem. More extraction from primary sources of gallium will make the gallium supply peak time appear earlier and aggravate scarcity later. Many geological surveys and mining companies are focused on this approach, mostly for short term profits and lack of long term impact assessment. For future generations, this is consuming the potential resources for future generations now before they are born. That is in conflict with the Brundtland and UN definition of sustainability.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eSecure key resource potentials anywhere in order to secure national supply exclusively\u003c/strong\u003e. This will foster increased risk for resource conflicts and promote the use of non-democratic methods and favour the rule of the strong to abuse the less powerful. May cause short term local benefits, but will create other problems a bit later. This solution appears to have some similarity with policies of colonial approaches.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eGallium substitution\u003c/strong\u003e in key technologies may be a policy to consider, but with care. Substitution of gallium may appear as challenging, many of the proposed substitutes are other scarce technology metals, and do not improve the overall technology metal supply challenges at all. Only when gallium is substituted with a resource in a significantly larger supply than gallium, and when this metal is not stressed by a demand in significant overshoot of the supply, will substitution make sense.\u003c/li\u003e\n \u003c/ol\u003e\n \u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eWhat constitute parts of a solution:\u003c/strong\u003e\n \u003col style=\"list-style-type: lower-alpha;\"\u003e\n \u003cli\u003e\u003cstrong\u003eImprove extraction supply chain yield\u003c/strong\u003e: Increasing gallium secondary extraction yield is a component of a working policy. It allows for more gallium to be taken from the same amount of extraction substrate. This shifts gallium from potential loss to potential use.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eImprove recycling recovery chain yield\u003c/strong\u003e: Increasing recycling yield is a policy component. It allows more gallium to be taken from the same amount of scrap. Increasing gallium recycling yield may have demands for how technologies (Photovoltaic technologies) using gallium are designed and that they may have to be prepared for recovery (Sverdrup et al., 2023). This shifts gallium from potential loss to potential use.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eImprove both extraction yield and recycling yield\u003c/strong\u003e Increasing recycling yield is a policy component. It allows for far more gallium to be supplied from the same amount of secondary substrate and ores, while reducing systems losses. Significant investment in research would be needed. Increasing access yield, to extract more gallium from streams that have not extraction, will convent a loss flux to an available flux, without shifting the depletion date forward. This shifts gallium from potential loss to potential use.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eAdaptive management of the global demand\u003c/strong\u003e by reducing total demand and increasing use efficiency in society (less losses, longer use time, making less gallium do the same job as more would do earlier) would contribute to the results of policy and help push the supply peak to a later date. Could possible reduce use to sustainable levels. Would need strong incentives and an active policy with some global agreements\u003c/li\u003e\n \u003c/ol\u003e\n \u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003eFor an effective solution, a combinations of policies would be required, by combining policy 3: \u0026nbsp;\u003cstrong\u003eImprove both extraction yield,\u0026nbsp;\u003c/strong\u003epolicy 4:\u003cstrong\u003e\u0026nbsp;increasing recycling yield,\u0026nbsp;\u003c/strong\u003ewith policy 5:\u003cstrong\u003e\u0026nbsp;Adaptive management of the global demand.\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo further plan for sustainable management within the bounds of sustainability, the use of integrated assessment modelling will be required and WORLD7 is such a model.\u0026nbsp;Further research is needed to make policy impact assessment using biophysically consistent Integrated Assessment Models, to check if proposed policy packages actually deliver the goals intended and that adverse side-effects stay under control and withing socially acceptable boundaries. Proceeding with policy proposals without doing proper and valid impact assessments is unprofessional and potentially damaging governance. Integrated models that are mass and energy consistent would be needed. Present econometric economic model that are not thermodynamically compliant will not do. Statistical interpolations will not do for the same reasons. In present policies, no consideration of future generations are taken seriously, even if it gets long speeches and beautiful works in working documents.\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"6\" valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eTable 8. Estimation of critical extraction and global critical supply for gallium based a long term perspective of 165 or 330 generations. Present yields are in the range 10%. for recycling and extraction yield, whereas yield from coal ash is less than 5% \u0026nbsp;As a comparison, the supply in 2023 was 430 ton/yr.\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 209px;\"\u003e\n \u003cp\u003eItem\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"5\" valign=\"top\" style=\"width: 395px;\"\u003e\n \u003cp\u003eExtraction or recycling yields (Y), expressed as fraction\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;Y=0.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eY=0.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eY=0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eY=0.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eY=0.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eProbable resource, anode slime, ton\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e94,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e470,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e940,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1,410,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1,880,000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eProbable resource coal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e280,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e870,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e870,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e870,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e870,000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eProbable resource bauxite\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e120,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e240,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e480,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e720,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e960,000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSum available resources\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e494,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1,580,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2,290,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3,000,000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3,710,000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCritical extraction, 330 generations\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e316\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e458\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e600\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e742\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCritical extraction, 165 generations\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e200\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e632\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e916\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1,200\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1,484\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e7.6. Long term sustainable supply of gallium.\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSustainability includes both the present and future generations. Table 8 shows the estimation of critical extraction for gallium based a long term perspective of 165 generations (5,000 years) and 330 generations (10,000 years). Under business as usual, the sustainable supply of gallium is about 100-200 ton/yr. Significantly improving access yields, mining yields, extraction yields and recycling yields may potentially increase sustainable gallium supply to approximately 600-900 ton/yr. In the assessment, we have assumed that the \u0026ldquo;sufficient need\u0026rdquo; is the same as the \u0026ldquo;demand\u0026rdquo;. \u0026nbsp;As indicated in figure 13, under BAU, resource extraction and technological development follow the current trends without significant changes in policy intervention. This means moderate innovation in recycling and extraction yields, but a heavy reliance on continued extraction of primary metals as a part of a sustainable strategy. As the demand for critical metals like gallium increases, BAU is at risk for resource shortages due to insufficient rate in advances in recycling, efficiency and avoidance. Profit-driven incentives dominate and risk creating lagged and response-driven approach to long-term sustainability planning, which runs closer to resource depletion and price volatility, where market forces struggle to cope with scarcity.\u003c/p\u003e\n\u003cp\u003eThe implications towards the different imaginaries where the imaginaries contrast sharply with BAU, where Ecotopia minimizes reliance on metals by reducing overall technological demand and avoidance/substitution approach. The Great Decoupling scenario embraces technological growth, promoting a bioeconomy-driven market approach and progress through improved recycling and extraction efficiency. In Unity in Adversity, environmental and geopolitical challenges are addressed by securing domestic supply chains and investing heavily in recycling and sustainable extraction of gallium. Emphasis is on coordinated environmental regulations and protectionist policies to safeguard gallium resources. Going step further, the Technocracy for the Common Good, Gallium and other critical metals are tightly controlled through monitoring of extraction, recycling, and use. Government managed resource allocation prioritizes efficiency, with centralized economic activity and protectionism securing strategic resources within the EU.\u0026nbsp;Each of the imaginaries envisions a different role for critical minerals, and varies in the methods of their production, usage, and recycling. Policymakers can use these imaginaries to develop strategies that align with the sustainability objectives of each imaginary, particularly in how critical metals like gallium can be reused and recycled (Haraldsson and Bonin, 2021; EEA 2022; Sverdrup et al., 2024, 2024 submitted).\u003cem\u003e\u003c/em\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e7.7. Needs for further research\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSome of the tables shown in this study have a lot of question marks. This illustrates that there is a need for a better mapping of geological occurrence, extraction potentials, technical capabilities and recycling yields. Some scenarios not explored here are the outcomes of different global population scenarios. If the global population does not start to significantly decline after 2100, the World will be very soon in a very unsustainable situation with supply of about everything. To assess such scenarios are a major undertaking and would have to wait for a later time with good funding. A better understanding of what is real need that meets the minimum requirement versus \u0026ldquo;want\u0026rdquo; or \u0026ldquo;demand\u0026rdquo; is needed. The gallium use yield must also be analysed and assessed whether improvements are possible. A full scenario-analysis exploring the outcome from different policy proposal are needed. The Integrated Assessment Model WORLD7 could be used for developing a multi-goal, multi component policy that is optimized towards sustainability criteria derived from formal definitions and set goals.\u003c/p\u003e\n\u003cp\u003eThe Imaginaries are policy proposals that have yet to be embodied with action plans and explored with systems analysis (Causal loop mapping, integrated flow charts, integrated energy charts). Such a process is required and necessary for the Imaginaries to have a foundation in reality.\u003c/p\u003e"},{"header":"8. Conclusion","content":"\u003cp\u003eThe model was used and there was found a significant risk for technology metal scarcity under business as usual scenario. The WORLD7 model was used to simulate the extraction rates, ore grade decline and approximate metal price levels for gallium. We need to carefully distinguish between the primary production from mines and total supply to the market. The rate of recycling is far too low, and the supply situation may be significantly improved if the recycling rates can be increased substantially. The introduction of extraction methods like heap leaching and subsequent electrowinning for many of the source metals (copper, zinc, lead) yield less of the technology metals and is a real threat to the long term supply of these metals. These methods are preferred for low and ultralow ores grades and have become more frequent in mining. Market mechanisms have not been able to have sufficient effect, and it appears that governmental interventions are unavoidable. The conclusion show that there is not an immediate risk for scarcity but it builds up in the longer run (after 2030), scarcity manifested as rising metal prices should be expected and prepared for. Our analysis suggests that pressing for more mining to reduce the demand-supply gap, will make short term improvements at the cost of severe shortage later. A combination of improving extraction yields and improving recycling yields combined with demand reduction may improve the supply situation and push the supply peak beyond 2100. In relation to the EEA imaginaries, each EEA imaginary offers a distinct approach to mitigating gallium scarcity, ranging from conservation focused strategies to technologically driven solutions. These imaginaries highlight the necessity of tailored policy interventions to achieve the desired future state and avoid critical shortages. They emphasize the importance of understanding and addressing the unique challenges posed by gallium shortages.\u0026nbsp;\u003c/p\u003e"},{"header":"9. Declarations","content":"\u003cp\u003e\u003cstrong\u003e9.1. Who did what?\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eHarald Ulrik Sverdrup developed the gallium module for the WORLD7 model. Harald Sverdrup and Anna Hulda Olafsdottir developed the WORLD7 model as it stands today. Harald Sverdrup wrote up the manuscript draft and did the simulation runs. Harald Sverdrup, Ole van Allen and Hördur Haraldsson cooperated on finalizing the manuscript, doing revisions and corrections. Hördur Haraldsson worked on the policy implications and future assessments.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e9.2. Declaration of no conflict of interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe declare that we have no conflict of interest with in the field of gallium, nor any vested interests.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e9.3. Research ethics\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work is original research done by the authors. No artificial intelligence or large language models like ChatGPT were used in any of our work. All text herein come from the hands of the authors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e9.4. Funding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study contributed to the SIMRESS project (Models, potential and long-term scenarios for resource efficiency), funded by the German Federal Ministry for Environment and the German Environmental Protection Agency (FKZ 3712 93 102), the SIMRESSS Aufstockungsauftrag (FKZ 3712 93 102) and the SIMRESS Climate Impact Analysis project\u0026nbsp;\u0026nbsp;(FKZ 3716 32 100 0). This study contributed to EU H2020 LOCOMOTION project,\u0026nbsp;funded\u0026nbsp;by\u0026nbsp;EU Horizon 2020 program under grant agreement 821105/H2020-LC-CLA-2018-2.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e9.5. Acknowledgement of earlier significant efforts.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDr. Deniz Koca and Dr. Anna Hulda Olafsdottir, participated in developing WORLD4, WORLD5 and WORLD6 as originally derivatives of World3. Dr. Anna Hulda Olafsdottir and Harald Sverdrup developed WORLD7 from WORLD6. Anna Hulda Olafsdottir and Harald Sverdrup did several earlier and simpler approaches for gallium (Sverdrup and Olafsdottir 2020).\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003evan Allen, O., Sverdrup, H. U., Olafsdottir, A.H., 2022. Global resource use and the future: Any room for the circular economy? H. Lehmann, C. Hinske, V. de Margerie, A. 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Future metal demand from photovoltaic cells and wind turbines - investigating the potential risk of disabling a shift to renewable energy systems. \u003cstrong\u003eScience and Technology Options Assessment (STOA), \u003c/strong\u003eEuropean Parliament.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"biophysical-economics-and-sustainability","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"berq","sideBox":"Learn more about [Biophysical Economics and Sustainability](http://link.springer.com/journal/41247)","snPcode":"41247","submissionUrl":"https://submission.nature.com/new-submission/41247/3","title":"Biophysical Economics and Sustainability","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"WORLD7, gallium, sustainability, scarcity, peak behaviour, technology metals","lastPublishedDoi":"10.21203/rs.3.rs-5390312/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5390312/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"The gallium resources were assessed and used as input to long term simulations using the WORLD7 model. The content of gallium in different mother ores has been estimated to be about 14.7 million ton of gallium. Much of this is not accessible because of low extraction yields, about 610,000 ton gallium appear to be extractable (4%) with present practices. The gallium content in all source metal refining residuals is about 51,000 ton/yr, but only a production of 1,374 ton/yr appear as the maximum with present technology and conditions. The actual gallium production was about 450 ton/yr in 2023. The gallium price is very sensitive to increases in demand, and production is not very likely to be able to rapidly increase. The simulations show that soft gallium scarcity sets in after 2028 and physical scarcity will occur about 2060. Better gallium extraction and recycling yields may push the scarcity date forward to 2100. In the long term, only 60% of the gallium demand to photovoltaic technology can be satisfied. To really improve the situation and prevent scarcity, extractive access, gallium extraction yields and recycling yields must be significantly improved to better than 50%. At present the overall yields are 7-15%. Increasing both extraction yields and recycling yields can reduce the shortage. The long term sustainable extraction is under Business-as-Usual about 300 ton gallium per year, about 67% of the present production. Doubling present extraction and recycling yields may increase this to 460 ton per year. This poses a major challenge to future plans for an energy transition, where under Business-As-Usual (BAU), such a transition will remain a fair fantasy. The four EEA imaginaries, Ecotopia, The Great Decoupling, Unity in Adversity, and Technocracy for the Common Good, offer different policy pathways for managing future gallium scarcity through varying degrees of technological advancement, resource conservation, and avoidance strategy.","manuscriptTitle":"Gallium: Assessing the long term future extraction, supply, recycling and price of using WORLD7, in relation to future technology visions in the European Union","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-11-25 12:53:01","doi":"10.21203/rs.3.rs-5390312/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-03-05T01:52:25+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-03-02T18:40:44+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-02-04T04:08:08+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"193118720481494520081610884806120971249","date":"2025-01-13T11:00:03+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"271258896805907918899274249779486580883","date":"2025-01-09T06:41:48+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"280038539459303318476631066666841390815","date":"2024-11-10T04:18:18+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-11-07T05:31:53+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-11-07T03:05:37+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-11-07T03:05:07+00:00","index":"","fulltext":""},{"type":"submitted","content":"Biophysical Economics and Sustainability","date":"2024-11-04T18:44:57+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"biophysical-economics-and-sustainability","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"berq","sideBox":"Learn more about [Biophysical Economics and Sustainability](http://link.springer.com/journal/41247)","snPcode":"41247","submissionUrl":"https://submission.nature.com/new-submission/41247/3","title":"Biophysical Economics and Sustainability","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"6cea4d75-a6d0-4a83-8777-d99059441a9f","owner":[],"postedDate":"November 25th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-07-14T16:09:52+00:00","versionOfRecord":{"articleIdentity":"rs-5390312","link":"https://doi.org/10.1007/s41247-025-00125-7","journal":{"identity":"biophysical-economics-and-sustainability","isVorOnly":false,"title":"Biophysical Economics and Sustainability"},"publishedOn":"2025-07-08 15:57:59","publishedOnDateReadable":"July 8th, 2025"},"versionCreatedAt":"2024-11-25 12:53:01","video":"","vorDoi":"10.1007/s41247-025-00125-7","vorDoiUrl":"https://doi.org/10.1007/s41247-025-00125-7","workflowStages":[]},"version":"v1","identity":"rs-5390312","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5390312","identity":"rs-5390312","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}