Modelling the melting of „shaft sludge” from shaft furnace dust removal in a short rotary kiln

Modelling the melting of „shaft sludge” from shaft furnace dust removal in a short rotary kiln | 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 Article Modelling the melting of „shaft sludge” from shaft furnace dust removal in a short rotary kiln Piotr Madej, Ryszard Prajsnar This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6509950/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 01 Aug, 2025 Read the published version in Scientific Reports → Version 1 posted 10 You are reading this latest preprint version Abstract Shaft sludge is a lead-bearing material produced by the wet dedusting of shaft furnace process gases generated during copper smelting from concentrates. It is a material with a high concentration of lead and hydrocarbon compounds, the melting of which in short rotary furnaces causes many problems. This paper presents the results of thermodynamic modelling of the melting process of shaft sludge and other lead-bearing materials. Computations were carried out using HSC 8 software by calculating thermodynamic equilibrium by minimising the free enthalpy of the system. Calculations showed that, as a result of the change in technology and the introduction of technical improvements, it is possible to increase the Pb recovery to raw lead from 55.4–70.7%, while maintaining a total Pb recovery of approximately 93%. The calculations presented in the article are realised within the framework of project No. POIR.01.01.01-00-1300/20 − 01 funded by the National Centre for Research and Development, entitled „Environmentally friendly technology for vitrification of lead-bearing slag by intensifying the work of a short rotary furnace with the dust and process gas conditioning system”. Physical sciences/Chemistry/Environmental chemistry/Pollution remediation Physical sciences/Engineering/Chemical engineering Physical sciences/Mathematics and computing/Computational science lead shaft sludge short rotary kiln recycling modelling 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 Figure 13 Figure 14 Figure 15 Figure 16 INTRODUCTION The copper ores exploited in Poland, located in the Sudetic and pre-Sudetic areas, were formed around 200 million years ago as a result of an upward flow of metal-bearing solutions through the rocks of the red claystone and zechstein contact (sandstone, shale and dolomite). The flow caused oxidation of the rocks and zonal distribution of metals. In the oxidised rocks, gold, silver and platinum are present, accompanied by iron oxides, while around the areas with oxidised formations, zones with mineralisation predominantly copper, lead, zinc and iron have formed successively [1]. The copper content in Polish chalcopyrite-bornite concentrates (Cu 2 S, Cu 5 FeS 4 ) produced at KGHM Polska Miedź S.A. is similar to that in chalcopyrite concentrates (20 ÷ 30 wt. %). On the other hand, their concentrations of sulphur and iron are several times lower: 9 ÷ 12 and 3 ÷ 6 wt. %, respectively.[2]. Furthermore, a characteristic property of Polish copper concentrates is the presence in them of organic carbon (6 ÷ 9 wt. %) of sapropel origin, mainly from marine organisms [3]. Polish copper concentrates also contain the following impurities: lead (1.5 ÷ 3.0 wt. %) and arsenic (0.05 ÷ 0.4 wt. %) [2] and are currently processed using two technologies: single-stage flash smelting proces at the Głogów I and II smelters and the shaft process at the Legnica smelter. The technology for copper production, based on the melting of briquetted copper concentrates in a shaft furnace, was implemented at the Legnica smelter in 1953 [4]. he process of obtaining copper in shaft furnaces includes the following technological operations [5]: charge preparation by weighing and averaging copper concentrates and dusty dizzy materials, mixing with a binder (sulphite lye) at 10 ÷ 11% and briquetting the mixture dried to approximately 4% H 2 O, melting of copper concentrate briquettes with the addition of converter slag and coke in a shaft furnace to produce so-called copper matte (an alloy of copper and iron sulphides). The slag obtained has a low copper content (0.3–0.5%) and is a waste material, converting copper matte to oxidise iron and sulphur and obtain blister copper (approx. 98% Cu), fire refining of blister copper in anode furnaces, electrorefining of anode copper. The advantage of the shaft process is the high-level elimination of the main impurities, i.e. Pb and As, already in the first stage of the pyrometallurgical process and their accumulation in the dust-gas phase, which is then wet dedusted. Between 30 and 40% of the lead and 40 to 50% of the arsenic contained in the concentrates goes into the wet dedusting sludge, which is the raw material for lead production, which is directed to short shaft furnaces [5]. The raw lead smelting process under Polish conditions is carried out in short shaft furnaces at the Łukasiewicz-IMN Legnica division. Lead production processes (using various technologies available worldwide) from waste materials are characterised by the formation (in addition to Pb) of lead slag (which is an inseparable mixture of sodium slag and Fe-Cu-Zn-Pb-S sulphides). These slags contain hazardous components: Pb, Zn, As and Cl making them unsuitable for further use and having to be stored (additional costs). To this day, no technology has been developed in the world to produce lead slag with properties that make it suitable for further economic use directly from the Pb recovery process. DESCRIPTION OF LEAD SMELTING TECHNOLOGY FROM SHAFT SLUDGE IN A SHORT ROTARY KILN Currently, the process of smelting lead from shaft sludge from copper concentrate smelting is carried out at the Łukasiewicz Research Network - Institute of Non-Ferrous Metals, Legnica division, in short rotary furnaces (so-called KPO furnaces) with a capacity of approximately 20 Mg charge and two furnaces with a capacity of 5 Mg charge. The furnaces are equipped with burners for natural gas and oxygen-enriched air up to 30% O 2 . The feedstock for the process is the so-called ‘base mix’ which is a mixture consisting of: 60% shaft sludge, 30% dust from the electric furnace of the Głogów smelter and 10% is dust from Łukasiewicz-IMN's own production, Legnica branch, as well as technological additives (anthracite and sodium carbonate) and iron scrap. The furnace charge is supplemented with the company's own metallic dross [6]. The composition of the charge is given in Table 1 , while the chemical composition of the base mix and turnbacks is given in Table 2 . Table 1 Mass composition of lead-bearing charge based on copper smelting materials for remelting in KPO2. Material Wet mass Moisture Dry mass [kg] [%] [kg] Mieszanka bazowa 3400 13,9 2928 Metallic dross 600 1,0 594 Iron scrap 450 0,0 450 Antracite 60 8,0 55 Sodium carbonate 90 1,5 89 Total 4450 - 3972 Table 2 Chemical composition of materials for modelling Pb smelting in KPO2. Component Content in the base mix [%] Metallic dross [%] Pb 44,0 30,2 Zn 5,40 3,00 As 3,20 1,20 Cu 0,78 1,00 Sn 0,63 0,50 Cd 0,21 Sb 0,10 0,2 K 2,10 6,20 Na 2,30 8,10 Fe 0,91 6,10 CaO 1,90 2,80 SiO2 1,56 25,6 Al2O3 0,43 2,83 MgO 0,33 5,80 S 9,12 3,50 Cog 9,84 2,00 Corg. 6,50 2,00 H 1,00 Cl 3,30 1,00 F 1,59 Other 4,30 0,00 The lead-bearing material-based charge from copper smelting is remelted over a period of 3.25 h at a final temperature of 1150°C in a short rotary furnace equipped with a burner for natural gas and oxygen-enriched air. The base mixture contains various chemical compounds such as: sulphides (PbS, ZnS, Cu 2 S) oxides (PbO, ZnO, As 2 O 5 ), sulphates (PbSO 4 , Na 2 SO 4 , K 2 SO 4 ), carbonates (Na 2 CO 3 , K 2 CO 3 ) and halides (halogens– PbCl 2 , NaCl, KCl, NaF, KF), as well as hydrocarbons. Metallic dross and slag are lead-bearing material separated during mechanical slag processing and contain curds of metallic lead, inclusions of Fe-As alloy, FeS–ZnS–PbS–Cu 2 S alloy (matte) andsilicate slag. As technological additives, iron scrap added separately and small amounts of sodium carbonate and anthracite are used [7]. The remelting process can be divided into three stages characterised by different physical and chemical parameters [7]: Stage I - evaporation of moisture and combustion of volatile hydrocarbons Stage II - heating of the charge and chemical reactions in the chargé Stage III - product heating and liquid phase separation During stage I of approx. 1 h, the charge is heated to approx. 500°C. During heating at a temperature slightly above 100°C with a slow temperature rise, the water in the charge is first evaporated over a period of about 15 minutes. During the evaporation of the water, the most volatile hydrocarbons are distilled from the feedstock. The distillation of hydrocarbons starts clearly at 130°C, reaching its highest rate at 250–300°C. Some of the bitumen substances (hydrocarbons) evaporated from the charge (introduced with the shaft sludge generated during the dedusting of process gases from the shaft furnaces during the smelting of copper concentrates) are burnt in the furnace in a stream of oxygen-enriched air supplied by the burner. Due to the low temperature of the process gases at this time (around 600°C), a significant amount of the bituminous substances are not burned off in the furnace. In stage II, the charge is heated from a temperature of about 500°C until the reduction of lead compounds is completed at a temperature of about 900°C in about 1 h. While the charge is being heated, heavy hydrocarbons are distilled with decreasing dynamics. As a result of the pyrolysis of the bituminous substances, carbon remains in the charge, which is consumed in the reduction reactions. In the temperature range of 600 ÷ 900°C, reactions take place to reduce lead compounds and other easily-reduced metals such as copper, antimony, arsenic and tin with the carbon and carbon monoxide formed in the Boudouard reaction. C (s) + CO 2(g) ⇔ 2 CO (g) 2 PbO + C ⇔ 2 Pb + CO 2 PbO + CO ⇔ Pb + CO 2 PbCl 2 + Na 2 CO 3 + CO ⇔ Pb + 2 NaCl + 2CO 2 ZnO + CO ⇔ Zn (g) + CO 2 As 2 O 3 + 3 CO ⇔ 2 As (g) + 3 CO 2 Sb 2 O 3 + 3 CO ⇔ 2 Sb + 3 CO 2 SnO 2 + 2 CO ⇔ Sn + 2 CO 2 CuO + CO ⇔ Cu + CO 2 Reduced Pb in liquid state, as well as other easily-reduced metals such as Ag, Bi Sb, Sn and Cu, form the raw lead phase, in which arsenic, partially reduced from gaseous form, is dissolved. Due to the presence in the charge of a significant amount of sulphides and, in lesser amounts, sulphates under reducing conditions, a alloy (matte) phase is formed containing sulphides of copper, lead, zinc and alkali metals according to the reaction: PbSO 4 + 4CO ⇔ PbS + 4 CO 2 K 2 SO 4 + 4 CO ⇔ K 2 S + 4 CO 2 Na 2 SO 4 + 4 CO ⇔ Na 2 S + 4 CO 2 2 Cu + MeS ⇔ Cu 2 S + Me Metallic iron introduced with the feedstock allows the reduction of PbS to metallic lead according to the reaction: PbS + Fe ⇔ Pb + FeS The matte phase obtained contains mainly FeS and ZnS, with PbS and Cu 2 S in lesser amounts. The presence of alkali metal sulphides Na 2 S, K 2 S in the matte reduces the solubility of metallic lead in the matte. The presence of free metallic iron in the feedstock creates conditions for the reduction of arsenic content in lead according to the reaction: Fe + 2 As ⇔ FeAs 2 Fe + As ⇔ Fe 2 As The formed intermetallic compounds of arsenic with iron (Fe 2 As and FeAs) and copper arsenide (Cu 3 As) dissolved in lead and unreacted iron are concentrated in a separate phase of Fe-As alloy with 20–25% As. Reduced to gaseous form, arsenic, cadmium and, in small amounts in this phase of the melt, zinc, are oxidised in the furnace atmosphere to form the dust phase. Readily evaporating substances such as Pb, PbO, PbS, PbCl 2 , ZnCl 2 and alkali metal chlorides and oxides also pass into the dust. The unreduced residue forms a slag phase, containing mainly silicates and oxides of sodium, potassium, iron, calcium, aluminium and up to 10% zinc oxide. In stage III, the products are heated to full liquidification at a temperature of 1000 ÷ 1110°C over a period of approximately 1 h. During this time, the reduction of zinc oxide from the slag with carbon monoxide takes place, as well as exchange reactions between the metal, matte and slag components, of which the reaction is the most significant: Fe + ZnS ⇔ Zn (g) + FeS The evaporated gaseous zinc oxidises in the furnace atmosphere and passes to the dusts as ZnO. Oxidised lead and arsenic vapours from the evaporation of the metallic phase, PbS evaporating from the matte phase oxidising in the gases to PbSO4, and alkali metal chlorides and oxides evaporating from the slag also move into the dust. After smelting, the lead and slag are ladled from the furnace into a ladle. After coagulation, the slag is crushed to separate metallic drosse, Fe-As alloy, matte and silicate slag. The gases are dedusted in a bag filter. The existing low-performance burner of 0.8 MW makes it impossible to achieve good technological parameters and smelting efficiency, as well as high rate in lead production with lead slag allowing its direct further use. Therefore, project work was undertaken to optimise the process. The research work began with the simulation of the currently implemented process in a short rotary kiln, the so-called KPO, with a working capacity of 5 Mg (the kiln which was assigned to carry out research on it under project POIR.01.01.01-00-1300/20 − 01) equipped with a 0.8 MW burner. This allowed a baseline to be established for the process improvements to be implemented. Then the process modelling was carried out for a 1.2 MW burner (the main technical improvement to achieve a liquid charge temperature of 1150°C with increased iron addition). THERMODYNAMIC MODEL Thermodynamic modelling of lead-bearing material melting with shaft sludge in KPO furnace with gas-phase oxidation (afterburning) was carried out using the HSC 8 programme. Thermodynamic equilibrium was calculated by minimising the free enthalpy of the system under current and new furnace firing conditions. For modelling, the dry mass of the materials according to Table 1 , the chemical composition of the lead-bearing materials according to Table 2 , firing recipes of the KPO furnace according to Table 3 i Table 4 , with natural gas Lw (composition: 83% CH4, 17% N2) and the following phases and substances in the system (at an elemental and compound activity factor of 1) were assumed: Gas: N 2 (g), O 2 (g), CO 2 (g), CO(g), H 2 (g), H 2 O(g), SO 2 (g), Cl 2 (g), F(g), Zn(g), As(g), PbS(g), ZnS(g), ZnCl 2 (g), Pb(g), PbCl 2 (g), Sb(g), SnO(g),Cd(g), KCl(g), NaCl(g), KF(g), NaF(g) Metal: Pb(l), Zn(l), Cu(l), Sb(l), As(l), Sn(l) Fe-As alloy: Fe, FeAs, Fe 2 As, FeAs 2 Matte: FeS(l), Cu 2 S(l), PbS(l), ZnS(l), As 2 S 3 (l), Na 2 S(l) Slag: PbO(l), PbSO 4 , ZnO(l), As 2 O 3 (l), Sb 2 O 3 (l), SnO 2 , Cu 2 O(l), CdO, Al 2 O 3 (l), MgO(l), CaO(l), K2O(l), Na 2 O(l), Na 2 O*SiO 2 (l), K 2 O*SiO 2 , CaSiO 3 (l), Al 2 SiO 5 (l), Mg 2 SiO 4 (l), FeO(l), Fe 3 O 4 (l), *2FeO*SiO 2 (l), SiO 2 (l), NaCl, KCl, KF, NaF, PbCl 2 , ZnCl 2 Table 3. Current KPO furnace firing recipe - natural gas burner Lw and oxygen-enriched air. Process stage Time [h] Natural gas [Nm 3 /h] Oxygen [Nm 3 /h] Air [Nm 3 /h] Total oxygen [Nm 3 /h] Free oxygen [Nm 3 /h] λ 1 0.25 50 60 300 123 40 1.48 2 1.00 60 150 400 234 134 2.35 3 2.00 100 110 500 215 49 1.30 Suma 3.25 273 385 1475 695 242 Table 4. New KPO furnace firing recipe - burner for natural gas Lw and oxygen. Process stage Time [h] Natural gas [Nm 3 /h] Total oxygen [Nm 3 /h] Free oxygen [Nm 3 /h] λ 1 0.25 50 123 40 1,48 2 1.00 60 234 134 2,35 3 2.00 100 215 49 1,30 Suma 3.25 273 695 242 Thermodynamic modelling of the reductive remelting of the lead-bearing material in KPO furnace included two separate processes: reduction remelting of lead-bearing material at 1150°C with variable iron use as the main additive affecting lead yields, oxidation of gas phase (CO, H2) and metal vapours at 600°C with variable O 2 consumption, It was assumed that the free oxygen (unused for the combustion of natural gas) in an amount of 242 Nm 3 /charge, would be used 90% for the afterburning of hydrocarbon vapours in the gas space of the furnace, and 10% would react with the feedstock, mainly in the combustion of coal. The gas oxidation temperature assumed is based on three considerations: is approximately the average temperature of the gases in the post-combustion, cooling and dedusting system of the KPO furnaces at Łukasiewicz-IMN, vapour pressures of substances at this temperature are relatively low, reaction kinetics are fast enough. The modelling results are presented below in the form of graphs of changes in elements and compounds in the individual products (metal, dross, matte, slag and gases) with increasing Fe addition in the process and with increasing O2 consumption in the oxidation process (gas phase afterburning). In Table 5 do Table 10 show the masses and chemical compositions of the products and the elemental yield in the products. Figure 1 and Fig. 2 how the change in the amount of metals in the raw lead with increasing Fe consumption in the melting of the lead-bearing material in KPO furnace for the current and new furnace firingrecipes, respectively. Figure 3 and Fig. 4 show the change in the amount of components in the Fe-As alloy with increasing Fe consumption in the melting of the lead-bearing material in KPO furnace for the current and new furnace firing recipes, respectively. Figure 5 and Fig. 6 show the change in the amount of components in the matte (sulphide alloy) with increasing Fe consumption in the remelting of the lead-bearing material in KPO furnace for the current and new furnace firing recipes, respectively. Figure 7 and Fig. 8 show the change in the amount of components in the silicate slag with increasing Fe consumption in the remelting of the lead-bearing material in KPO furnace for the current and new furnace firing recipes, respectively. Figure 9 and Fig. 10 show the change in the amount of components in the gas phase with increasing Fe consumption in the remelting of the lead-bearing material in KPO furnace for the current and new furnace firing recipes, respectively. Figure 11 and Fig. 12 show the change in the amount of components in the dust obtained in the oxidation (afterburning) of the process gases with increasing O 2 consumption in the proces of melting of the lead-bearing material in KPO furnace for the current and new furnace firing recipes, respectively. Figure 13 and Fig. 14 show the change in the amount of components in the gases obtained in the oxidation (afterburning) of the gases with increasing O 2 consumption in the proces of melting of the lead-bearing material in KPO furnace for the current and new furnace firing recipes, respectively. Figure 15 anf Fig. 16 show the change in the composition of the gases obtained in the oxidation (afterburning) gas process with the increase in O 2 consumption in the proces of melting of the lead-bearing material in KPO furnace for the current and new furnace firing recipes, respectively. Table 5 i Table 6 show the calculated amount of products per charge and their percentage contribution to the dry weight of the lead-bearing material charge (base mix, drosse and process additives) for the current and new furnace firing recipes, respectively, with optimal process parameters - an addition of 760 kg of iron to the charge for both firing recipes variants and oxygen for gas post-combustion (770 Nm 3 for the current firing recipes and 700 Nm 3 for the new firing recipes). Table 7 i Table 8 give the calculated chemical composition of the process products of the lead-bearing material charge in KPO furnace for the current and new furnace firing recipes, respectively, for optimum conditions. Table 9 i Table 10 give the elemental yields in the products of the process for the current and new furnace firing recipes, respectively, for optimum conditions Table 5 Mass and proportion of base mix melt products in KPO for the current burner (0.8 MW power) obtained by calculation. Produkt Masa Udział [kg] [%] Ołów 857 24,3 Szpejza 461 13,1 Kamień 747 21,2 Żużel 678 19,2 Pyły 1059 30,1 Table 6 Mass and proportion of base mix melt products in KPO for the new burner (1.2 MW power) obtained by calculation. Produkt Masa Udział [kg] [%] Ołów 1084 30,8 Szpejza 449 12,7 Kamień 804 22,8 Żużel 723 20,5 Pyły 693 19,7 Table 7 Chemical composition of products from base mix remelting modelling at KPO for the current burner (0,8 MW). Chemical composition [%] Pb Zn Cu As Sb Sn Cd S Cl F Fe Na K CaO MgO Al 2 O 3 SiO 2 Raw lead 94.9 0.007 2.04 0.06 0.47 2.48 Fe-As alloy 21.8 78.2 Matte 12.3 6.76 1.52 32.5 46.8 0.12 Slag 0.05 0.14 0.01 3.14 4.92 16.8 13.2 3.69 10.7 6.52 4.36 29.3 Dust 52.2 11.7 0.01 0.01 0.58 3.59 1.24 2.40 6.92 Table 8 Chemical composition of products from base mix remelting modelling at KPO for the new burner (1.2 MW). Chemical composition [%] Pb Zn Cu As Sb Sn Cd S Cl F Fe Na K CaO MgO Al 2 O 3 SiO 2 Raw lead 95.7 0.09 1.79 0.06 0.38 1.97 Fe-As alloy 22.3 77.7 Matte 12.2 9.06 1.16 32.4 45.0 0.12 Slag 0.05 0.19 5.21 5.40 15.6 13.5 5.64 10.0 6.11 4.09 27.6 Dust 47.0 14.5 0.01 0.88 3.78 4.87 1.08 2.48 8.29 Table 9 Elemental yields in products from base mix remelting modelling at KPO for the current burner (0.8 MW). Produkt Yield [%] Pb Zn Cu As Sn Sb S Cl F Na K Fe Raw lead 55.4 0.3 60.7 0.5 99.4 98.4 Fe-As alloy 99.5 43.8 Matte 6.3 28.7 39.4 84.3 0.8 42.4 Slag 0.6 0.0 0.0 0.2 0.0 0.0 20.7 71.7 77.2 25.4 13.8 Dust 38.3 70.5 0.0 0.4 1.6 15.5 79.3 28.3 22.0 74.6 Table 10 Elemental yields in products from base mix remelting modelling at KPO for the new burner (1.2 MW). Produkt Yield [%] Pb Zn Cu As Sn Sb S Cl F Na K Fe Raw lead 70.7 0.6 67.6 0.6 99.6 99.3 Fe-As alloy 99.4 42.4 Matte 6.7 41.5 32.5 90.8 0.8 44.0 Slag 0.0 0.8 0.0 0.0 0.1 0.0 0.0 36.7 83.9 84.3 41.5 13.7 Dust 22.6 57.3 0.0 0.2 0.7 9.0 63.2 16.2 14.9 58.5 The addition of metallic iron to the lead-bearing feedstock based on shaft furnance slurry has a major influence on the melting results at the assumed temperature of 1150°C. With an increase in iron addition, there is an increase in the amount of metallic lead obtained due to its reduction (from lead sulphide) with a decrease in the amount of PbS and an increase in the amount of FeS in the matte (metal sulphide alloy FeS, ZnS, PbS, Cu 2 S). The associated metals (Cu, Sb, Sn, As) dissolve into the raw lead as a result of oxide reduction. With an increase in iron addition, the amount of arsenic in the raw lead decreases strongly due to its binding in the Fe-As alloy in the form of the intermetallic compound FeAs. Unreacted iron is also dissolved in the Fe-As alloy. The slag concentrates unreduced metal oxides (CaO, MgO, Al 2 O 3 , FeO, SiO 2 ) forming a solution with SiO 2 in the form of silicates. The slag also contains sodium and potassium chlorides and fluorides. The gases emitted from the charge contain, in addition to the usual components (N 2 H 2 O and CO 2 ), large amounts of CO and H 2 , as well as metal vapours (Pb, Zn, Cd) and vaporised chemical compounds (PbS, NaCl, KCl, NaF, KF). The gases emitted from the feedstock are oxidised (post-combusted) both in the gas space of the furnace by the excess oxygen introduced into the burner and also by the additional oxygen introduced into the post-combustion chamber. As a result of the oxidation of the gases and their temperature drop, solid dusts are formed in the dedusting system containing: PbO, PbSO 4 , PbCl 2 , ZnO, K 2 SO 4 , Na 2 SO 4 , KCl, NaCl, KF, NaF and CdO, adopted gases containing N 2 , CO 2 , H 2 O and O 2 . The results of modelling the smelting of the lead-bearing feed in KPO furnace are close to the real results in terms of the amount of products, their chemical composition and Pb yield [8]. At the current iron addition of 450 kg per melt, 600 ÷ 700 kg of raw lead is obtained, while the model predicts the production of 660 kg of raw lead. With the current firing recipe of KPO furnace (with a power output of 0.8 MW), increasing the iron addition to 760 kg per melt should, according to the model, increase the raw lead production to 857 kg with a Pb yield of 55.4%. The low Pb yield in raw lead is mainly due to the evaporation of metallic lead and PbS into a large amount of gas phase containing a high amount of N 2 . With the new natural gas and oxygen burner (with a power of 1.2 MW), the amount of gases will decrease significantly due to the elimination of N2 introduced with air, resulting in a significant reduction in the evaporation of metallic lead and PbS and an increase in the recovery of Pb in raw lead. For the new KPO furnace firing recipe, the amount of lead produced will increase to 1084 kg per melt with a Pb recovery of 70.7%. The non-recoverable losses of Pb in matte and slag with the new furnace firing recipe will be 6.7%, which means that with a dust return for remelting (10% addition to the base mix), the total recovery of Pb in raw lead will be approximately 93%. CONCLUSIONS Thermodynamic equilibrium calculations carried out by minimising the free enthalpy of the system concluded that the use of a 1.2MW burner (instead of the 0.8MW burner currently used) would allow the Pb- to raw lead yield to be increased from 55.4–70.7%. Calculations have shown that the total Pb recovery rate will drop from 93.7% (for the 0.8MW burner) to 93.3%. However, the distribution of lead in the products will change completely (lead will mainly go to the metallic phase) which is desirable. The use of a gas-oxygen burner will reduce the total volume of process gases generated (elimination of N 2 ), which will contribute to reducing the lead content in process dust and obtaining a lower mass of dust (reduced evaporation of metallic lead and PbS) which, from the point of view of the need to return them to the furnace, will improve material circulation in the process. The results of these calculations allowed further work to be undertaken on the project involving the installation of a new burner and the implementation of shaft slurry-based lead-bearing material remelting tests using a short rotary kiln (KPO ) with a capacity of 5 Mg. Declarations Author Contribution P.M. obtained funding for the research, wrote the article, carried out the analysis of the results obtained, prepared the results, managed the research workR. P. performed the calculations Acknowledgement The research was funded by the National Centre for Research and Development under grant no. POIR.01.01.01-00-1300/20-01. Data Availability The datasets generated and/or analysed during the current study are not publicly available as these data belong to the Lukasiewicz Research Network - Institute of Non-ferrous Metals, but are available from the author responding to a reasonable request after obtaining permission from the management of the Lukasiewicz Research Network - Institute of Non-ferrous Metals. Requests for data sharing should be addressed to Mr. Grzegorz Krawiec at: [email protected] . References https://www.pgi.gov.pl/psg-1/psg-2/informacja-i-szkolenia/wiadomosci-surowcowe/9795-miedz-i-srebro.html J. Czernecki, Z. Śmieszek, S. Gizicki, J. Dobrzański, i M. Warmuz, „Problems with elimination of the main impurities in the KGHM Polsa Miedż S.A. copper concentrates from copper productio cycle”, Polska Metalurgia w latach 2006-2010, Cracow: Scientific Publishers „AKAPIT”, 2010, pp. 315–343. Monografia KGHM Polska Miedź S.A. Lubin, 2007 https://kghm.com/pl/o-nas/historia Z. Śmieszek, T. Sak, i P. Madej; Metalurgia Metali Nieżelaznych w Polsce; Ores And Non-Ferrous Metals; vol. 1; no. 6; pp. 7–16, 2017; doi: 10.15199/67.2017.6.1. P. Madej, et al; Report nr 8115/21 Environmentally friendly technology for vitrification of lead-bearing slag by intensifying the work of a short rotary furnace with the dust and process gas conditioning system Phase 1; Łukasiewicz Research Network – Institute of Non-Ferrous Metals; Gliwice; 2021. Final report on the implementation of the project no. 6 ZR7 2005 C/06597 Intensyfikacja produkcji ołowiu surowego z półproduktów hutnictwa miedzi w piecach obrotowych z zastosowaniem palnika gazowo-tlenowego wraz z ekologiczną utylizacją powstających półproduktów – żużla, pyłów Pb-Zn i gazów procesowych; Institute of Non-Ferrous Metals Gliwice; 2005. P. Madej, et al.; Report nr 8115/III/2023 Environmentally friendly technology for vitrification of lead-bearing slag by intensifying the work of a short rotary furnace with the dust and process gas conditioning system Phase 3”, Łukasiewicz Research Network – Institute of Non-Ferrous Metals; Gliwice; 2021. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 01 Aug, 2025 Read the published version in Scientific Reports → Version 1 posted Editorial decision: Revision requested 02 Jun, 2025 Reviews received at journal 29 May, 2025 Reviews received at journal 16 May, 2025 Reviewers agreed at journal 16 May, 2025 Reviewers agreed at journal 14 May, 2025 Reviewers invited by journal 14 May, 2025 Editor assigned by journal 13 May, 2025 Editor invited by journal 06 May, 2025 Submission checks completed at journal 05 May, 2025 First submitted to journal 23 Apr, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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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-6509950","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":456390693,"identity":"82b73cb8-12ca-437f-a22e-a23be7086cf4","order_by":0,"name":"Piotr Madej","email":"data:image/png;base64,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","orcid":"","institution":"Łukasiewicz Research Network– Institute of Non-Ferrous Metals","correspondingAuthor":true,"prefix":"","firstName":"Piotr","middleName":"","lastName":"Madej","suffix":""},{"id":456390694,"identity":"449bb0c8-0427-4fb3-a883-9de952cb5dfc","order_by":1,"name":"Ryszard Prajsnar","email":"","orcid":"","institution":"Łukasiewicz Research Network– Institute of Non-Ferrous Metals","correspondingAuthor":false,"prefix":"","firstName":"Ryszard","middleName":"","lastName":"Prajsnar","suffix":""}],"badges":[],"createdAt":"2025-04-23 07:23:33","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6509950/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6509950/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41598-025-12808-8","type":"published","date":"2025-08-01T16:29:09+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":82882775,"identity":"36b3b3bf-a94c-4f6b-bca6-a6c08552da6a","added_by":"auto","created_at":"2025-05-16 11:12:26","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":60217,"visible":true,"origin":"","legend":"\u003cp\u003eInfluence of Fe addition on the amount of metals in raw lead for the current KPO firing recipe.\u003c/p\u003e","description":"","filename":"image1.png","url":"https://assets-eu.researchsquare.com/files/rs-6509950/v1/235355445ed1e428a60e5fb3.png"},{"id":82882761,"identity":"ab86b3a4-b62a-4b8a-a59a-630eff51162c","added_by":"auto","created_at":"2025-05-16 11:12:25","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":64043,"visible":true,"origin":"","legend":"\u003cp\u003eInfluence of Fe addition on the amount of metals in raw lead for new KPO firing recipe.\u003c/p\u003e","description":"","filename":"image2.png","url":"https://assets-eu.researchsquare.com/files/rs-6509950/v1/fd3f43628656390b44cadc42.png"},{"id":82882760,"identity":"a8bb13fa-6c91-41c8-ae1c-3e0ef6636a6b","added_by":"auto","created_at":"2025-05-16 11:12:25","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":58790,"visible":true,"origin":"","legend":"\u003cp\u003eInfluence of Fe addition on the amount of components in the Fe-As alloy for current KPO firing recipe.\u003c/p\u003e","description":"","filename":"image3.png","url":"https://assets-eu.researchsquare.com/files/rs-6509950/v1/065578cae65518c2675eea03.png"},{"id":82883906,"identity":"34abad25-d146-44cd-87ed-5e9cdda1bc5c","added_by":"auto","created_at":"2025-05-16 11:28:25","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":57953,"visible":true,"origin":"","legend":"\u003cp\u003eInfluence of Fe addition on the amount of components in the Fe-As alloy for new KPO firing recipe.\u003c/p\u003e","description":"","filename":"image4.png","url":"https://assets-eu.researchsquare.com/files/rs-6509950/v1/8132b4d9ca91181e0a49fa84.png"},{"id":82882759,"identity":"ff44fce5-83f2-455f-9af8-d93ac361d9b5","added_by":"auto","created_at":"2025-05-16 11:12:25","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":72385,"visible":true,"origin":"","legend":"\u003cp\u003eInfluence of Fe addition on the amount of components in the matte for current KPO firing recipe.\u003c/p\u003e","description":"","filename":"image5.png","url":"https://assets-eu.researchsquare.com/files/rs-6509950/v1/a0c62288d27045388a32cce1.png"},{"id":82883086,"identity":"ca525843-d2d5-45c3-a0d7-da0db327a017","added_by":"auto","created_at":"2025-05-16 11:20:25","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":71123,"visible":true,"origin":"","legend":"\u003cp\u003eInfluence of Fe addition on the amount of components in the matte for new KPO firing recipe.\u003c/p\u003e","description":"","filename":"image6.png","url":"https://assets-eu.researchsquare.com/files/rs-6509950/v1/f471789b1bafe9272c4b8eb0.png"},{"id":82883090,"identity":"4f185e35-eac4-4346-b675-aa578adc2ea3","added_by":"auto","created_at":"2025-05-16 11:20:26","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":67837,"visible":true,"origin":"","legend":"\u003cp\u003eInfluence of Fe addition on the amount of components in the slag for the current KPO firing recipe.\u003c/p\u003e","description":"","filename":"image7.png","url":"https://assets-eu.researchsquare.com/files/rs-6509950/v1/1745a594f38bcf2199a19785.png"},{"id":82883082,"identity":"7af48cec-76b5-4764-aae9-68687a7c11fd","added_by":"auto","created_at":"2025-05-16 11:20:25","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":67402,"visible":true,"origin":"","legend":"\u003cp\u003eInfluence of Fe addition on the amount of components in the slag for new KPO firing recipe.\u003c/p\u003e","description":"","filename":"image8.png","url":"https://assets-eu.researchsquare.com/files/rs-6509950/v1/a0149d76ca1414c35bc3f0ba.png"},{"id":82883914,"identity":"81bd4b8d-575a-49a2-a85a-5f05bf6c5dea","added_by":"auto","created_at":"2025-05-16 11:28:26","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":73153,"visible":true,"origin":"","legend":"\u003cp\u003eInfluence of Fe addition on the amount of components in the gases for the current KPO firing recipe.\u003c/p\u003e","description":"","filename":"image9.png","url":"https://assets-eu.researchsquare.com/files/rs-6509950/v1/5b394af36caa8340010f4efa.png"},{"id":82882769,"identity":"17ce48a2-d4ad-4e75-a0fc-0b2bb96e703c","added_by":"auto","created_at":"2025-05-16 11:12:25","extension":"png","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":66856,"visible":true,"origin":"","legend":"\u003cp\u003eInfluence of Fe addition on the amount of components in the gases for new KPO firing recipe.\u003c/p\u003e","description":"","filename":"image10.png","url":"https://assets-eu.researchsquare.com/files/rs-6509950/v1/af225ccb093091e9adbd8fd8.png"},{"id":82882788,"identity":"b955dab6-bc93-48d9-a43a-d8ecf841f7e3","added_by":"auto","created_at":"2025-05-16 11:12:26","extension":"png","order_by":11,"title":"Figure 11","display":"","copyAsset":false,"role":"figure","size":70400,"visible":true,"origin":"","legend":"\u003cp\u003eInfluence of O\u003csub\u003e2\u003c/sub\u003e consumption ion the amount of components in the dust during gas oxidation for current KPO firing recipe.\u003c/p\u003e","description":"","filename":"image11.png","url":"https://assets-eu.researchsquare.com/files/rs-6509950/v1/9129a27805fcae662a599a4f.png"},{"id":82883085,"identity":"8651509d-474e-446c-afb3-d3150277be01","added_by":"auto","created_at":"2025-05-16 11:20:25","extension":"png","order_by":12,"title":"Figure 12","display":"","copyAsset":false,"role":"figure","size":65513,"visible":true,"origin":"","legend":"\u003cp\u003eInfluence of O2 consumption on the amount of components in the dust during gas oxidation for new KPO firing recipe.\u003c/p\u003e","description":"","filename":"image12.png","url":"https://assets-eu.researchsquare.com/files/rs-6509950/v1/77ae55e3b54886da8fd46329.png"},{"id":82883096,"identity":"bbb1c145-1f2d-47a9-91d0-a48f33718e13","added_by":"auto","created_at":"2025-05-16 11:20:26","extension":"png","order_by":13,"title":"Figure 13","display":"","copyAsset":false,"role":"figure","size":74985,"visible":true,"origin":"","legend":"\u003cp\u003eInfluence of O\u003csub\u003e2\u003c/sub\u003e consumption on the amount of components in the gasses during oxidation of gases for the current KPO firing recipe.\u003c/p\u003e","description":"","filename":"image13.png","url":"https://assets-eu.researchsquare.com/files/rs-6509950/v1/03d989662aa8ae94a3859198.png"},{"id":82882789,"identity":"d4cd90d0-5a24-4f36-8951-8334815dd6d8","added_by":"auto","created_at":"2025-05-16 11:12:26","extension":"png","order_by":14,"title":"Figure 14","display":"","copyAsset":false,"role":"figure","size":67349,"visible":true,"origin":"","legend":"\u003cp\u003eInfluence of O\u003csub\u003e2\u003c/sub\u003e consumption on the amount of components in the gasses during oxidation of gases for the mew KPO firing recipe.\u003c/p\u003e","description":"","filename":"image14.png","url":"https://assets-eu.researchsquare.com/files/rs-6509950/v1/6f9504f1f01b27c80149c91a.png"},{"id":82883101,"identity":"5a8a2043-6ce9-4a88-beb9-93e3cb855db8","added_by":"auto","created_at":"2025-05-16 11:20:26","extension":"png","order_by":15,"title":"Figure 15","display":"","copyAsset":false,"role":"figure","size":69712,"visible":true,"origin":"","legend":"\u003cp\u003eInfluence of O\u003csub\u003e2\u003c/sub\u003e consumption on the composition of the gases in the gas oxidation process for the current KPO firing recipe.\u003c/p\u003e","description":"","filename":"image15.png","url":"https://assets-eu.researchsquare.com/files/rs-6509950/v1/61723291edc755ed72e6e980.png"},{"id":82882791,"identity":"7c213979-fc88-4448-9150-5d3bf38a06a5","added_by":"auto","created_at":"2025-05-16 11:12:26","extension":"png","order_by":16,"title":"Figure 16","display":"","copyAsset":false,"role":"figure","size":73629,"visible":true,"origin":"","legend":"\u003cp\u003eInfluence of O\u003csub\u003e2\u003c/sub\u003e consumption on the composition of the gases in the gas oxidation process for the new KPO firing recipe.\u003c/p\u003e","description":"","filename":"image16.png","url":"https://assets-eu.researchsquare.com/files/rs-6509950/v1/d0f22248f03023558674c573.png"},{"id":88268493,"identity":"44a154c6-8b30-46c1-9345-28a8682d17d8","added_by":"auto","created_at":"2025-08-04 16:52:15","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2052766,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6509950/v1/f86d5792-4337-49a7-a905-c8999eac6ee5.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Modelling the melting of „shaft sludge” from shaft furnace dust removal in a short rotary kiln","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eThe copper ores exploited in Poland, located in the Sudetic and pre-Sudetic areas, were formed around 200\u0026nbsp;million years ago as a result of an upward flow of metal-bearing solutions through the rocks of the red claystone and zechstein contact (sandstone, shale and dolomite). The flow caused oxidation of the rocks and zonal distribution of metals. In the oxidised rocks, gold, silver and platinum are present, accompanied by iron oxides, while around the areas with oxidised formations, zones with mineralisation predominantly copper, lead, zinc and iron have formed successively [1].\u003c/p\u003e \u003cp\u003eThe copper content in Polish chalcopyrite-bornite concentrates (Cu\u003csub\u003e2\u003c/sub\u003eS, Cu\u003csub\u003e5\u003c/sub\u003eFeS\u003csub\u003e4\u003c/sub\u003e) produced at KGHM Polska Miedź S.A. is similar to that in chalcopyrite concentrates (20\u0026thinsp;\u0026divide;\u0026thinsp;30 wt. %). On the other hand, their concentrations of sulphur and iron are several times lower: 9\u0026thinsp;\u0026divide;\u0026thinsp;12 and 3\u0026thinsp;\u0026divide;\u0026thinsp;6 wt. %, respectively.[2]. Furthermore, a characteristic property of Polish copper concentrates is the presence in them of organic carbon (6\u0026thinsp;\u0026divide;\u0026thinsp;9 wt. %) of sapropel origin, mainly from marine organisms [3]. Polish copper concentrates also contain the following impurities: lead (1.5\u0026thinsp;\u0026divide;\u0026thinsp;3.0 wt. %) and arsenic (0.05\u0026thinsp;\u0026divide;\u0026thinsp;0.4 wt. %) [2] and are currently processed using two technologies: single-stage flash smelting proces at the Głog\u0026oacute;w I and II smelters and the shaft process at the Legnica smelter.\u003c/p\u003e \u003cp\u003eThe technology for copper production, based on the melting of briquetted copper concentrates in a shaft furnace, was implemented at the Legnica smelter in 1953 [4]. he process of obtaining copper in shaft furnaces includes the following technological operations [5]:\u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003echarge preparation by weighing and averaging copper concentrates and dusty dizzy materials, mixing with a binder (sulphite lye) at 10\u0026thinsp;\u0026divide;\u0026thinsp;11% and briquetting the mixture dried to approximately 4% H\u003csub\u003e2\u003c/sub\u003eO,\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003emelting of copper concentrate briquettes with the addition of converter slag and coke in a shaft furnace to produce so-called copper matte (an alloy of copper and iron sulphides). The slag obtained has a low copper content (0.3\u0026ndash;0.5%) and is a waste material,\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003econverting copper matte to oxidise iron and sulphur and obtain blister copper (approx. 98% Cu),\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003efire refining of blister copper in anode furnaces,\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eelectrorefining of anode copper.\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003cp\u003eThe advantage of the shaft process is the high-level elimination of the main impurities, i.e. Pb and As, already in the first stage of the pyrometallurgical process and their accumulation in the dust-gas phase, which is then wet dedusted. Between 30 and 40% of the lead and 40 to 50% of the arsenic contained in the concentrates goes into the wet dedusting sludge, which is the raw material for lead production, which is directed to short shaft furnaces [5].\u003c/p\u003e \u003cp\u003eThe raw lead smelting process under Polish conditions is carried out in short shaft furnaces at the Łukasiewicz-IMN Legnica division.\u003c/p\u003e \u003cp\u003eLead production processes (using various technologies available worldwide) from waste materials are characterised by the formation (in addition to Pb) of lead slag (which is an inseparable mixture of sodium slag and Fe-Cu-Zn-Pb-S sulphides). These slags contain hazardous components: Pb, Zn, As and Cl making them unsuitable for further use and having to be stored (additional costs). To this day, no technology has been developed in the world to produce lead slag with properties that make it suitable for further economic use directly from the Pb recovery process.\u003c/p\u003e"},{"header":"DESCRIPTION OF LEAD SMELTING TECHNOLOGY FROM SHAFT SLUDGE IN A SHORT ROTARY KILN","content":"\u003cp\u003eCurrently, the process of smelting lead from shaft sludge from copper concentrate smelting is carried out at the Łukasiewicz Research Network - Institute of Non-Ferrous Metals, Legnica division, in short rotary furnaces (so-called KPO furnaces) with a capacity of approximately 20 Mg charge and two furnaces with a capacity of 5 Mg charge. The furnaces are equipped with burners for natural gas and oxygen-enriched air up to 30% O\u003csub\u003e2\u003c/sub\u003e.\u003c/p\u003e \u003cp\u003eThe feedstock for the process is the so-called \u0026lsquo;base mix\u0026rsquo; which is a mixture consisting of: 60% shaft sludge, 30% dust from the electric furnace of the Głog\u0026oacute;w smelter and 10% is dust from Łukasiewicz-IMN's own production, Legnica branch, as well as technological additives (anthracite and sodium carbonate) and iron scrap. The furnace charge is supplemented with the company's own metallic dross [6]. The composition of the charge is given in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, while the chemical composition of the base mix and turnbacks is given in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMass composition of lead-bearing charge based on copper smelting materials for remelting in KPO2.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eMaterial\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eWet mass\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMoisture\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eDry mass\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e[kg]\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e[%]\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e[kg]\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMieszanka bazowa\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3400\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13,9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2928\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMetallic dross\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e600\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1,0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e594\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIron scrap\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e450\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0,0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e450\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAntracite\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8,0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e55\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSodium carbonate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1,5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e89\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e4450\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3972\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eChemical composition of materials for modelling Pb smelting in KPO2.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eComponent\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eContent in the base mix [%]\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMetallic dross [%]\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e44,0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e30,2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eZn\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e5,40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e3,00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3,20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1,20\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCu\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0,78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1,00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSn\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0,63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0,50\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0,21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0,10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0,2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eK\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2,10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6,20\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNa\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2,30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e8,10\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFe\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0,91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6,10\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCaO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1,90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2,80\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSiO2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1,56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e25,6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAl2O3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0,43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2,83\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMgO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0,33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e5,80\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9,12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e3,50\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCog\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9,84\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2,00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCorg.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e6,50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2,00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1,00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3,30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1,00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1,59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOther\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e4,30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0,00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe lead-bearing material-based charge from copper smelting is remelted over a period of 3.25 h at a final temperature of 1150\u0026deg;C in a short rotary furnace equipped with a burner for natural gas and oxygen-enriched air.\u003c/p\u003e \u003cp\u003eThe base mixture contains various chemical compounds such as: sulphides (PbS, ZnS, Cu\u003csub\u003e2\u003c/sub\u003eS) oxides (PbO, ZnO, As\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e), sulphates (PbSO\u003csub\u003e4\u003c/sub\u003e, Na\u003csub\u003e2\u003c/sub\u003eSO\u003csub\u003e4\u003c/sub\u003e, K\u003csub\u003e2\u003c/sub\u003eSO\u003csub\u003e4\u003c/sub\u003e), carbonates (Na\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e, K\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e) and halides (halogens\u0026ndash; PbCl\u003csub\u003e2\u003c/sub\u003e, NaCl, KCl, NaF, KF), as well as hydrocarbons.\u003c/p\u003e \u003cp\u003eMetallic dross and slag are lead-bearing material separated during mechanical slag processing and contain curds of metallic lead, inclusions of Fe-As alloy, FeS\u0026ndash;ZnS\u0026ndash;PbS\u0026ndash;Cu\u003csub\u003e2\u003c/sub\u003eS alloy (matte) andsilicate slag. As technological additives, iron scrap added separately and small amounts of sodium carbonate and anthracite are used [7].\u003c/p\u003e \u003cp\u003eThe remelting process can be divided into three stages characterised by different physical and chemical parameters [7]:\u003c/p\u003e \u003cp\u003eStage I - evaporation of moisture and combustion of volatile hydrocarbons\u003c/p\u003e \u003cp\u003eStage II - heating of the charge and chemical reactions in the charg\u0026eacute;\u003c/p\u003e \u003cp\u003eStage III - product heating and liquid phase separation\u003c/p\u003e \u003cp\u003eDuring stage I of approx. 1 h, the charge is heated to approx. 500\u0026deg;C. During heating at a temperature slightly above 100\u0026deg;C with a slow temperature rise, the water in the charge is first evaporated over a period of about 15 minutes. During the evaporation of the water, the most volatile hydrocarbons are distilled from the feedstock. The distillation of hydrocarbons starts clearly at 130\u0026deg;C, reaching its highest rate at 250\u0026ndash;300\u0026deg;C. Some of the bitumen substances (hydrocarbons) evaporated from the charge (introduced with the shaft sludge generated during the dedusting of process gases from the shaft furnaces during the smelting of copper concentrates) are burnt in the furnace in a stream of oxygen-enriched air supplied by the burner. Due to the low temperature of the process gases at this time (around 600\u0026deg;C), a significant amount of the bituminous substances are not burned off in the furnace.\u003c/p\u003e \u003cp\u003eIn stage II, the charge is heated from a temperature of about 500\u0026deg;C until the reduction of lead compounds is completed at a temperature of about 900\u0026deg;C in about 1 h. While the charge is being heated, heavy hydrocarbons are distilled with decreasing dynamics. As a result of the pyrolysis of the bituminous substances, carbon remains in the charge, which is consumed in the reduction reactions.\u003c/p\u003e \u003cp\u003eIn the temperature range of 600\u0026thinsp;\u0026divide;\u0026thinsp;900\u0026deg;C, reactions take place to reduce lead compounds and other easily-reduced metals such as copper, antimony, arsenic and tin with the carbon and carbon monoxide formed in the Boudouard reaction.\u003c/p\u003e \u003cp\u003eC\u003csub\u003e(s)\u003c/sub\u003e\u0026thinsp;+\u0026thinsp;CO\u003csub\u003e2(g)\u003c/sub\u003e \u0026hArr; 2 CO\u003csub\u003e(g)\u003c/sub\u003e\u003c/p\u003e \u003cp\u003e2 PbO\u0026thinsp;+\u0026thinsp;C \u0026hArr; 2 Pb\u0026thinsp;+\u0026thinsp;CO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003cp\u003ePbO\u0026thinsp;+\u0026thinsp;CO \u0026hArr; Pb\u0026thinsp;+\u0026thinsp;CO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003cp\u003ePbCl\u003csub\u003e2\u003c/sub\u003e\u0026thinsp;+\u0026thinsp;Na\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e\u0026thinsp;+\u0026thinsp;CO \u0026hArr; Pb\u0026thinsp;+\u0026thinsp;2 NaCl\u0026thinsp;+\u0026thinsp;2CO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003cp\u003eZnO\u0026thinsp;+\u0026thinsp;CO \u0026hArr; Zn\u003csub\u003e(g)\u003c/sub\u003e\u0026thinsp;+\u0026thinsp;CO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003cp\u003eAs\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e\u0026thinsp;+\u0026thinsp;3 CO \u0026hArr; 2 As\u003csub\u003e(g)\u003c/sub\u003e\u0026thinsp;+\u0026thinsp;3 CO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003cp\u003eSb\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e\u0026thinsp;+\u0026thinsp;3 CO \u0026hArr; 2 Sb\u0026thinsp;+\u0026thinsp;3 CO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003cp\u003eSnO\u003csub\u003e2\u003c/sub\u003e\u0026thinsp;+\u0026thinsp;2 CO \u0026hArr; Sn\u0026thinsp;+\u0026thinsp;2 CO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003cp\u003eCuO\u0026thinsp;+\u0026thinsp;CO \u0026hArr; Cu\u0026thinsp;+\u0026thinsp;CO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003cp\u003eReduced Pb in liquid state, as well as other easily-reduced metals such as Ag, Bi Sb, Sn and Cu, form the raw lead phase, in which arsenic, partially reduced from gaseous form, is dissolved. Due to the presence in the charge of a significant amount of sulphides and, in lesser amounts, sulphates under reducing conditions, a alloy (matte) phase is formed containing sulphides of copper, lead, zinc and alkali metals according to the reaction:\u003c/p\u003e \u003cp\u003ePbSO\u003csub\u003e4\u003c/sub\u003e\u0026thinsp;+\u0026thinsp;4CO \u0026hArr; PbS\u0026thinsp;+\u0026thinsp;4 CO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eK\u003csub\u003e2\u003c/sub\u003eSO\u003csub\u003e4\u003c/sub\u003e\u0026thinsp;+\u0026thinsp;4 CO \u0026hArr; K\u003csub\u003e2\u003c/sub\u003eS\u0026thinsp;+\u0026thinsp;4 CO\u003csub\u003e2\u003c/sub\u003e\u003c/h2\u003e \u003cp\u003eNa\u003csub\u003e2\u003c/sub\u003eSO\u003csub\u003e4\u003c/sub\u003e\u0026thinsp;+\u0026thinsp;4 CO \u0026hArr; Na\u003csub\u003e2\u003c/sub\u003eS\u0026thinsp;+\u0026thinsp;4 CO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003cp\u003e2 Cu\u0026thinsp;+\u0026thinsp;MeS \u0026hArr; Cu\u003csub\u003e2\u003c/sub\u003eS\u0026thinsp;+\u0026thinsp;Me\u003c/p\u003e \u003cp\u003eMetallic iron introduced with the feedstock allows the reduction of PbS to metallic lead according to the reaction:\u003c/p\u003e \u003cp\u003ePbS\u0026thinsp;+\u0026thinsp;Fe \u0026hArr; Pb\u0026thinsp;+\u0026thinsp;FeS\u003c/p\u003e \u003cp\u003eThe matte phase obtained contains mainly FeS and ZnS, with PbS and Cu\u003csub\u003e2\u003c/sub\u003eS in lesser amounts. The presence of alkali metal sulphides Na\u003csub\u003e2\u003c/sub\u003eS, K\u003csub\u003e2\u003c/sub\u003eS in the matte reduces the solubility of metallic lead in the matte. The presence of free metallic iron in the feedstock creates conditions for the reduction of arsenic content in lead according to the reaction:\u003c/p\u003e \u003cp\u003eFe\u0026thinsp;+\u0026thinsp;2 As \u0026hArr; FeAs\u003c/p\u003e \u003cp\u003e2 Fe\u0026thinsp;+\u0026thinsp;As \u0026hArr; Fe\u003csub\u003e2\u003c/sub\u003eAs\u003c/p\u003e \u003cp\u003eThe formed intermetallic compounds of arsenic with iron (Fe\u003csub\u003e2\u003c/sub\u003eAs and FeAs) and copper arsenide (Cu\u003csub\u003e3\u003c/sub\u003eAs) dissolved in lead and unreacted iron are concentrated in a separate phase of Fe-As alloy with 20\u0026ndash;25% As. Reduced to gaseous form, arsenic, cadmium and, in small amounts in this phase of the melt, zinc, are oxidised in the furnace atmosphere to form the dust phase. Readily evaporating substances such as Pb, PbO, PbS, PbCl\u003csub\u003e2\u003c/sub\u003e, ZnCl\u003csub\u003e2\u003c/sub\u003e and alkali metal chlorides and oxides also pass into the dust. The unreduced residue forms a slag phase, containing mainly silicates and oxides of sodium, potassium, iron, calcium, aluminium and up to 10% zinc oxide.\u003c/p\u003e \u003cp\u003eIn stage III, the products are heated to full liquidification at a temperature of 1000\u0026thinsp;\u0026divide;\u0026thinsp;1110\u0026deg;C over a period of approximately 1 h. During this time, the reduction of zinc oxide from the slag with carbon monoxide takes place, as well as exchange reactions between the metal, matte and slag components, of which the reaction is the most significant:\u003c/p\u003e \u003cp\u003eFe\u0026thinsp;+\u0026thinsp;ZnS \u0026hArr; Zn\u003csub\u003e(g)\u003c/sub\u003e\u0026thinsp;+\u0026thinsp;FeS\u003c/p\u003e \u003cp\u003eThe evaporated gaseous zinc oxidises in the furnace atmosphere and passes to the dusts as ZnO. Oxidised lead and arsenic vapours from the evaporation of the metallic phase, PbS evaporating from the matte phase oxidising in the gases to PbSO4, and alkali metal chlorides and oxides evaporating from the slag also move into the dust.\u003c/p\u003e \u003cp\u003eAfter smelting, the lead and slag are ladled from the furnace into a ladle. After coagulation, the slag is crushed to separate metallic drosse, Fe-As alloy, matte and silicate slag. The gases are dedusted in a bag filter.\u003c/p\u003e \u003cp\u003eThe existing low-performance burner of 0.8 MW makes it impossible to achieve good technological parameters and smelting efficiency, as well as high rate in lead production with lead slag allowing its direct further use. Therefore, project work was undertaken to optimise the process.\u003c/p\u003e \u003cp\u003eThe research work began with the simulation of the currently implemented process in a short rotary kiln, the so-called KPO, with a working capacity of 5 Mg (the kiln which was assigned to carry out research on it under project POIR.01.01.01-00-1300/20\u0026thinsp;\u0026minus;\u0026thinsp;01) equipped with a 0.8 MW burner. This allowed a baseline to be established for the process improvements to be implemented. Then the process modelling was carried out for a 1.2 MW burner (the main technical improvement to achieve a liquid charge temperature of 1150\u0026deg;C with increased iron addition).\u003c/p\u003e \u003c/div\u003e"},{"header":"THERMODYNAMIC MODEL","content":"\u003cp\u003eThermodynamic modelling of lead-bearing material melting with shaft sludge in KPO furnace with gas-phase oxidation (afterburning) was carried out using the HSC 8 programme. Thermodynamic equilibrium was calculated by minimising the free enthalpy of the system under current and new furnace firing conditions.\u003c/p\u003e \u003cp\u003eFor modelling, the dry mass of the materials according to Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, the chemical composition of the lead-bearing materials according to Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, firing recipes of the KPO furnace according to Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003ei Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e, with natural gas Lw (composition: 83% CH4, 17% N2) and the following phases and substances in the system (at an elemental and compound activity factor of 1) were assumed:\u003c/p\u003e \u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003eGas:\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 448px;\"\u003e\n \u003cp\u003eN\u003csub\u003e2\u003c/sub\u003e(g), O\u003csub\u003e2\u003c/sub\u003e(g), CO\u003csub\u003e2\u003c/sub\u003e(g), CO(g), H\u003csub\u003e2\u003c/sub\u003e(g), H\u003csub\u003e2\u003c/sub\u003eO(g), SO\u003csub\u003e2\u003c/sub\u003e(g), Cl\u003csub\u003e2\u003c/sub\u003e(g), F(g), Zn(g), As(g), PbS(g), ZnS(g), ZnCl\u003csub\u003e2\u003c/sub\u003e(g), Pb(g), PbCl\u003csub\u003e2\u003c/sub\u003e(g), Sb(g), SnO(g),Cd(g), KCl(g), NaCl(g), KF(g), NaF(g)\u003c/p\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: 103px;\"\u003e\n \u003cp\u003eMetal:\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 448px;\"\u003e\n \u003cp\u003ePb(l), Zn(l), Cu(l), Sb(l), As(l), Sn(l)\u003c/p\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: 103px;\"\u003e\n \u003cp\u003eFe-As alloy:\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 448px;\"\u003e\n \u003cp\u003eFe, FeAs, Fe\u003csub\u003e2\u003c/sub\u003eAs, FeAs\u003csub\u003e2\u003c/sub\u003e\u003c/p\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: 103px;\"\u003e\n \u003cp\u003eMatte:\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 448px;\"\u003e\n \u003cp\u003eFeS(l), Cu\u003csub\u003e2\u003c/sub\u003eS(l), PbS(l), ZnS(l), As\u003csub\u003e2\u003c/sub\u003eS\u003csub\u003e3\u003c/sub\u003e(l), Na\u003csub\u003e2\u003c/sub\u003eS(l)\u003c/p\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: 103px;\"\u003e\n \u003cp\u003eSlag:\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 448px;\"\u003e\n \u003cp\u003ePbO(l), PbSO\u003csub\u003e4\u003c/sub\u003e, ZnO(l), As\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e(l), Sb\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e(l), SnO\u003csub\u003e2\u003c/sub\u003e, Cu\u003csub\u003e2\u003c/sub\u003eO(l), CdO, Al\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e(l), MgO(l), CaO(l), K2O(l), Na\u003csub\u003e2\u003c/sub\u003eO(l), Na\u003csub\u003e2\u003c/sub\u003eO*SiO\u003csub\u003e2\u003c/sub\u003e(l), K\u003csub\u003e2\u003c/sub\u003eO*SiO\u003csub\u003e2\u003c/sub\u003e, CaSiO\u003csub\u003e3\u003c/sub\u003e(l), Al\u003csub\u003e2\u003c/sub\u003eSiO\u003csub\u003e5\u003c/sub\u003e(l), Mg\u003csub\u003e2\u003c/sub\u003eSiO\u003csub\u003e4\u003c/sub\u003e(l), FeO(l), Fe\u003csub\u003e3\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e(l), *2FeO*SiO\u003csub\u003e2\u003c/sub\u003e(l), SiO\u003csub\u003e2\u003c/sub\u003e(l), NaCl, KCl, KF, NaF, PbCl\u003csub\u003e2\u003c/sub\u003e, ZnCl\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eTable 3. Current KPO furnace firing recipe - natural gas burner Lw and oxygen-enriched air.\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003eProcess stage\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003eTime [h]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003eNatural gas [Nm\u003csup\u003e3\u003c/sup\u003e/h]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003eOxygen [Nm\u003csup\u003e3\u003c/sup\u003e/h]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003eAir [Nm\u003csup\u003e3\u003c/sup\u003e/h]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 89px;\"\u003e\n \u003cp\u003eTotal oxygen [Nm\u003csup\u003e3\u003c/sup\u003e/h]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003eFree oxygen [Nm\u003csup\u003e3\u003c/sup\u003e/h]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003e\u0026lambda;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003e0.25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e300\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 89px;\"\u003e\n \u003cp\u003e123\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003e1.48\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003e1.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e150\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e400\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 89px;\"\u003e\n \u003cp\u003e234\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e134\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003e2.35\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003e2.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e110\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e500\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 89px;\"\u003e\n \u003cp\u003e215\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003e1.30\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003eSuma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003e3.25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e273\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e385\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e1475\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 89px;\"\u003e\n \u003cp\u003e695\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e242\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003e\u0026nbsp;\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\u003cp\u003eTable\u0026nbsp;4. New KPO furnace firing recipe - burner for natural gas Lw and oxygen.\u003c/p\u003e\n\u003cdiv\u003e\n \u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"586\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003eProcess stage\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003eTime [h]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 109px;\"\u003e\n \u003cp\u003eNatural gas [Nm\u003csup\u003e3\u003c/sup\u003e/h]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 109px;\"\u003e\n \u003cp\u003eTotal oxygen [Nm\u003csup\u003e3\u003c/sup\u003e/h]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 154px;\"\u003e\n \u003cp\u003eFree oxygen [Nm\u003csup\u003e3\u003c/sup\u003e/h]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 82px;\"\u003e\n \u003cp\u003e\u0026lambda;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e0.25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 109px;\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 109px;\"\u003e\n \u003cp\u003e123\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 154px;\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 82px;\"\u003e\n \u003cp\u003e1,48\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e1.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 109px;\"\u003e\n \u003cp\u003e60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 109px;\"\u003e\n \u003cp\u003e234\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 154px;\"\u003e\n \u003cp\u003e134\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 82px;\"\u003e\n \u003cp\u003e2,35\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e2.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 109px;\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 109px;\"\u003e\n \u003cp\u003e215\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 154px;\"\u003e\n \u003cp\u003e49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 82px;\"\u003e\n \u003cp\u003e1,30\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003eSuma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e3.25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 109px;\"\u003e\n \u003cp\u003e273\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 109px;\"\u003e\n \u003cp\u003e695\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 154px;\"\u003e\n \u003cp\u003e242\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 82px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003eThermodynamic modelling of the reductive remelting of the lead-bearing material in KPO furnace included two separate processes:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\n \u003cp\u003ereduction remelting of lead-bearing material at 1150\u0026deg;C with variable iron use as the main additive affecting lead yields,\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003eoxidation of gas phase (CO, H2) and metal vapours at 600\u0026deg;C with variable O\u003csub\u003e2\u003c/sub\u003e consumption,\u003c/p\u003e\n \u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eIt was assumed that the free oxygen (unused for the combustion of natural gas) in an amount of 242 Nm\u003csup\u003e3\u003c/sup\u003e/charge, would be used 90% for the afterburning of hydrocarbon vapours in the gas space of the furnace, and 10% would react with the feedstock, mainly in the combustion of coal.\u003c/p\u003e\n\u003cp\u003eThe gas oxidation temperature assumed is based on three considerations:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\n \u003cp\u003eis approximately the average temperature of the gases in the post-combustion, cooling and dedusting system of the KPO furnaces at Łukasiewicz-IMN,\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003evapour pressures of substances at this temperature are relatively low,\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003ereaction kinetics are fast enough.\u003c/p\u003e\n \u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eThe modelling results are presented below in the form of graphs of changes in elements and compounds in the individual products (metal, dross, matte, slag and gases) with increasing Fe addition in the process and with increasing O2 consumption in the oxidation process (gas phase afterburning). In Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e do Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e10\u003c/span\u003e show the masses and chemical compositions of the products and the elemental yield in the products.\u003c/p\u003e\n\u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e and Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e how the change in the amount of metals in the raw lead with increasing Fe consumption in the melting of the lead-bearing material in KPO furnace for the current and new furnace firingrecipes, respectively.\u003c/p\u003e\n\u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e and Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e show the change in the amount of components in the Fe-As alloy with increasing Fe consumption in the melting of the lead-bearing material in KPO furnace for the current and new furnace firing recipes, respectively.\u003c/p\u003e\n\u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e and Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e6\u003c/span\u003e show the change in the amount of components in the matte (sulphide alloy) with increasing Fe consumption in the remelting of the lead-bearing material in KPO furnace for the current and new furnace firing recipes, respectively.\u003c/p\u003e\n\u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e7\u003c/span\u003e and Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e8\u003c/span\u003e show the change in the amount of components in the silicate slag with increasing Fe consumption in the remelting of the lead-bearing material in KPO furnace for the current and new furnace firing recipes, respectively.\u003c/p\u003e\n\u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e9\u003c/span\u003e and Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e10\u003c/span\u003e show the change in the amount of components in the gas phase with increasing Fe consumption in the remelting of the lead-bearing material in KPO furnace for the current and new furnace firing recipes, respectively.\u003c/p\u003e\n\u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e11\u003c/span\u003e and Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e12\u003c/span\u003e show the change in the amount of components in the dust obtained in the oxidation (afterburning) of the process gases with increasing O\u003csub\u003e2\u003c/sub\u003e consumption in the proces of melting of the lead-bearing material in KPO furnace for the current and new furnace firing recipes, respectively.\u003c/p\u003e\n\u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e13\u003c/span\u003e and Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e14\u003c/span\u003e show the change in the amount of components in the gases obtained in the oxidation (afterburning) of the gases with increasing O\u003csub\u003e2\u003c/sub\u003e consumption in the proces of melting of the lead-bearing material in KPO furnace for the current and new furnace firing recipes, respectively.\u003c/p\u003e\n\u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e15\u003c/span\u003e anf Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e16\u003c/span\u003e show the change in the composition of the gases obtained in the oxidation (afterburning) gas process with the increase in O\u003csub\u003e2\u003c/sub\u003e consumption in the proces of melting of the lead-bearing material in KPO furnace for the current and new furnace firing recipes, respectively.\u003c/p\u003e\n\u003cp\u003eTable\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003ei Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e6\u003c/span\u003e show the calculated amount of products per charge and their percentage contribution to the dry weight of the lead-bearing material charge (base mix, drosse and process additives) for the current and new furnace firing recipes, respectively, with optimal process parameters - an addition of 760 kg of iron to the charge for both firing recipes variants and oxygen for gas post-combustion (770 Nm\u003csup\u003e3\u003c/sup\u003e for the current firing recipes and 700 Nm\u003csup\u003e3\u003c/sup\u003e for the new firing recipes).\u003c/p\u003e\n\u003cp\u003eTable \u003cspan class=\"InternalRef\"\u003e7\u003c/span\u003ei Table \u003cspan class=\"InternalRef\"\u003e8\u003c/span\u003e give the calculated chemical composition of the process products of the lead-bearing material charge in KPO furnace for the current and new furnace firing recipes, respectively, for optimum conditions.\u003c/p\u003e\n\u003cp\u003eTable \u003cspan class=\"InternalRef\"\u003e9\u003c/span\u003ei Table \u003cspan class=\"InternalRef\"\u003e10\u003c/span\u003e give the elemental yields in the products of the process for the current and new furnace firing recipes, respectively, for optimum conditions\u0026nbsp;\u003c/p\u003e\n\u003ctable id=\"Tab5\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eMass and proportion of base mix melt products in KPO for the current burner (0.8 MW power) obtained by calculation.\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\" rowspan=\"2\"\u003e\n \u003cp\u003eProdukt\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eMasa\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eUdział\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e[kg]\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e[%]\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eOł\u0026oacute;w\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e857\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e24,3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSzpejza\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e461\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e13,1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eKamień\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e747\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e21,2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eŻużel\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e678\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e19,2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePyły\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1059\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e30,1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u003ctable id=\"Tab6\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 6\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eMass and proportion of base mix melt products in KPO for the new burner (1.2 MW power) obtained by calculation.\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\" rowspan=\"2\"\u003e\n \u003cp\u003eProdukt\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eMasa\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eUdział\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e[kg]\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e[%]\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eOł\u0026oacute;w\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1084\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e30,8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSzpejza\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e449\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e12,7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eKamień\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e804\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e22,8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eŻużel\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e723\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e20,5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePyły\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e693\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e19,7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u003ctable id=\"Tab7\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 7\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eChemical composition of products from base mix remelting modelling at KPO for the current burner (0,8 MW).\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\" colspan=\"17\"\u003e\n \u003cp\u003eChemical composition [%]\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ePb\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eZn\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCu\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eAs\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSb\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSn\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCd\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eS\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCl\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eF\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eFe\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eNa\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eK\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCaO\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eMgO\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eAl\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSiO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eRaw lead\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e94.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.007\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.47\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.48\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eFe-As alloy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e21.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e78.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMatte\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e12.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.76\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.52\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e32.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e46.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSlag\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3.14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e4.92\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e16.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e13.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3.69\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e10.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.52\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e4.36\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e29.3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDust\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e52.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e11.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.58\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3.59\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.92\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u003ctable id=\"Tab8\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 8\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eChemical composition of products from base mix remelting modelling at KPO for the new burner (1.2 MW).\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\" colspan=\"18\"\u003e\n \u003cp\u003eChemical composition [%]\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ePb\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eZn\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCu\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eAs\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSb\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSn\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCd\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eS\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCl\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eF\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eFe\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eNa\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eK\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCaO\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eMgO\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eAl\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSiO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"1\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eRaw lead\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e95.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.09\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.79\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.38\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.97\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"1\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eFe-As alloy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e22.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e77.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"1\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMatte\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e12.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e9.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e32.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e45.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"1\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSlag\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.19\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e5.21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e5.40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e15.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e13.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e5.64\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e10.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e4.09\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e27.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"1\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDust\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e47.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e14.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.88\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3.78\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e4.87\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.48\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e8.29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"1\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u003ctable id=\"Tab9\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 9\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eElemental yields in products from base mix remelting modelling at KPO for the current burner (0.8 MW).\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\" rowspan=\"2\"\u003e\n \u003cp\u003eProdukt\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"12\"\u003e\n \u003cp\u003eYield [%]\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ePb\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eZn\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCu\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eAs\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSn\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSb\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eS\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCl\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eF\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eNa\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eK\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eFe\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eRaw lead\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e55.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e60.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e99.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e98.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eFe-As alloy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e99.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e43.8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMatte\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e28.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e39.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e84.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e42.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSlag\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e20.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e71.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e77.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e25.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e13.8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDust\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e38.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e70.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e15.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e79.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e28.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e22.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e74.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u003ctable id=\"Tab10\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 10\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eElemental yields in products from base mix remelting modelling at KPO for the new burner (1.2 MW).\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\" rowspan=\"2\"\u003e\n \u003cp\u003eProdukt\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"12\"\u003e\n \u003cp\u003eYield [%]\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ePb\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eZn\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCu\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eAs\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSn\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSb\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eS\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCl\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eF\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eNa\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eK\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eFe\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eRaw lead\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e70.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e67.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e99.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e99.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eFe-As alloy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e99.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e42.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMatte\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e41.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e32.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e90.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e44.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSlag\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e36.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e83.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e84.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e41.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e13.7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDust\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e22.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e57.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e9.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e63.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e16.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e14.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e58.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp\u003eThe addition of metallic iron to the lead-bearing feedstock based on shaft furnance slurry has a major influence on the melting results at the assumed temperature of 1150\u0026deg;C. With an increase in iron addition, there is an increase in the amount of metallic lead obtained due to its reduction (from lead sulphide) with a decrease in the amount of PbS and an increase in the amount of FeS in the matte (metal sulphide alloy FeS, ZnS, PbS, Cu\u003csub\u003e2\u003c/sub\u003eS).\u003c/p\u003e\n\u003cp\u003eThe associated metals (Cu, Sb, Sn, As) dissolve into the raw lead as a result of oxide reduction. With an increase in iron addition, the amount of arsenic in the raw lead decreases strongly due to its binding in the Fe-As alloy in the form of the intermetallic compound FeAs. Unreacted iron is also dissolved in the Fe-As alloy.\u003c/p\u003e\n\u003cp\u003eThe slag concentrates unreduced metal oxides (CaO, MgO, Al\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e, FeO, SiO\u003csub\u003e2\u003c/sub\u003e) forming a solution with SiO\u003csub\u003e2\u003c/sub\u003e in the form of silicates. The slag also contains sodium and potassium chlorides and fluorides.\u003c/p\u003e\n\u003cp\u003eThe gases emitted from the charge contain, in addition to the usual components (N\u003csub\u003e2\u003c/sub\u003e H\u003csub\u003e2\u003c/sub\u003eO and CO\u003csub\u003e2\u003c/sub\u003e), large amounts of CO and H\u003csub\u003e2\u003c/sub\u003e, as well as metal vapours (Pb, Zn, Cd) and vaporised chemical compounds (PbS, NaCl, KCl, NaF, KF). The gases emitted from the feedstock are oxidised (post-combusted) both in the gas space of the furnace by the excess oxygen introduced into the burner and also by the additional oxygen introduced into the post-combustion chamber. As a result of the oxidation of the gases and their temperature drop, solid dusts are formed in the dedusting system containing: PbO, PbSO\u003csub\u003e4\u003c/sub\u003e, PbCl\u003csub\u003e2\u003c/sub\u003e, ZnO, K\u003csub\u003e2\u003c/sub\u003eSO\u003csub\u003e4\u003c/sub\u003e, Na\u003csub\u003e2\u003c/sub\u003eSO\u003csub\u003e4\u003c/sub\u003e, KCl, NaCl, KF, NaF and CdO, adopted gases containing N\u003csub\u003e2\u003c/sub\u003e, CO\u003csub\u003e2\u003c/sub\u003e, H\u003csub\u003e2\u003c/sub\u003eO and O\u003csub\u003e2\u003c/sub\u003e.\u003c/p\u003e\n\u003cp\u003eThe results of modelling the smelting of the lead-bearing feed in KPO furnace are close to the real results in terms of the amount of products, their chemical composition and Pb yield [8]. At the current iron addition of 450 kg per melt, 600\u0026thinsp;\u0026divide;\u0026thinsp;700 kg of raw lead is obtained, while the model predicts the production of 660 kg of raw lead.\u003c/p\u003e\n\u003cp\u003eWith the current firing recipe of KPO furnace (with a power output of 0.8 MW), increasing the iron addition to 760 kg per melt should, according to the model, increase the raw lead production to 857 kg with a Pb yield of 55.4%. The low Pb yield in raw lead is mainly due to the evaporation of metallic lead and PbS into a large amount of gas phase containing a high amount of N\u003csub\u003e2\u003c/sub\u003e.\u003c/p\u003e\n\u003cp\u003eWith the new natural gas and oxygen burner (with a power of 1.2 MW), the amount of gases will decrease significantly due to the elimination of N2 introduced with air, resulting in a significant reduction in the evaporation of metallic lead and PbS and an increase in the recovery of Pb in raw lead. For the new KPO furnace firing recipe, the amount of lead produced will increase to 1084 kg per melt with a Pb recovery of 70.7%.\u003c/p\u003e\n\u003cp\u003eThe non-recoverable losses of Pb in matte and slag with the new furnace firing recipe will be 6.7%, which means that with a dust return for remelting (10% addition to the base mix), the total recovery of Pb in raw lead will be approximately 93%.\u003c/p\u003e"},{"header":"CONCLUSIONS","content":"\u003cp\u003eThermodynamic equilibrium calculations carried out by minimising the free enthalpy of the system concluded that the use of a 1.2MW burner (instead of the 0.8MW burner currently used) would allow the Pb- to raw lead yield to be increased from 55.4\u0026ndash;70.7%. Calculations have shown that the total Pb recovery rate will drop from 93.7% (for the 0.8MW burner) to 93.3%. However, the distribution of lead in the products will change completely (lead will mainly go to the metallic phase) which is desirable.\u003c/p\u003e \u003cp\u003eThe use of a gas-oxygen burner will reduce the total volume of process gases generated (elimination of N\u003csub\u003e2\u003c/sub\u003e), which will contribute to reducing the lead content in process dust and obtaining a lower mass of dust (reduced evaporation of metallic lead and PbS) which, from the point of view of the need to return them to the furnace, will improve material circulation in the process.\u003c/p\u003e \u003cp\u003eThe results of these calculations allowed further work to be undertaken on the project involving the installation of a new burner and the implementation of shaft slurry-based lead-bearing material remelting tests using a short rotary kiln (KPO ) with a capacity of 5 Mg.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eP.M. obtained funding for the research, wrote the article, carried out the analysis of the results obtained, prepared the results, managed the research workR. P. performed the calculations\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eThe research was funded by the National Centre for Research and Development under grant no. POIR.01.01.01-00-1300/20-01.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe datasets generated and/or analysed during the current study are not publicly available as these data belong to the Lukasiewicz Research Network - Institute of Non-ferrous Metals, but are available from the author responding to a reasonable request after obtaining permission from the management of the Lukasiewicz Research Network - Institute of Non-ferrous Metals. Requests for data sharing should be addressed to Mr. Grzegorz Krawiec at: [email protected].\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003ehttps://www.pgi.gov.pl/psg-1/psg-2/informacja-i-szkolenia/wiadomosci-surowcowe/9795-miedz-i-srebro.html\u003c/li\u003e\n\u003cli\u003eJ. Czernecki, Z. Śmieszek, S. Gizicki, J. Dobrzański, i M. Warmuz, \u0026bdquo;Problems with elimination of the main impurities in the KGHM Polsa Miedż S.A. copper concentrates from copper productio cycle\u0026rdquo;, Polska Metalurgia w latach 2006-2010, Cracow: Scientific Publishers \u0026bdquo;AKAPIT\u0026rdquo;, 2010, pp. 315\u0026ndash;343.\u003c/li\u003e\n\u003cli\u003eMonografia KGHM Polska Miedź S.A. Lubin, 2007\u003c/li\u003e\n\u003cli\u003ehttps://kghm.com/pl/o-nas/historia\u003c/li\u003e\n\u003cli\u003eZ. Śmieszek, T. Sak, i P. Madej; Metalurgia Metali Nieżelaznych w Polsce; Ores And Non-Ferrous Metals; vol. 1; no. 6; pp. 7\u0026ndash;16, 2017; doi: 10.15199/67.2017.6.1.\u003c/li\u003e\n\u003cli\u003eP. Madej, et al; Report nr 8115/21 Environmentally friendly technology for vitrification of lead-bearing slag by intensifying the work of a short rotary furnace with the dust and process gas conditioning system Phase 1; Łukasiewicz Research Network \u0026ndash; Institute of Non-Ferrous Metals; Gliwice; 2021.\u003c/li\u003e\n\u003cli\u003eFinal report on the implementation of the project no. 6 ZR7 2005 C/06597 Intensyfikacja produkcji ołowiu surowego z p\u0026oacute;łprodukt\u0026oacute;w hutnictwa miedzi w piecach obrotowych z zastosowaniem palnika gazowo-tlenowego wraz z ekologiczną utylizacją powstających p\u0026oacute;łprodukt\u0026oacute;w \u0026ndash; żużla, pył\u0026oacute;w Pb-Zn i gaz\u0026oacute;w procesowych; Institute of Non-Ferrous Metals Gliwice; 2005.\u003c/li\u003e\n\u003cli\u003eP. Madej, et al.; Report nr 8115/III/2023 Environmentally friendly technology for vitrification of lead-bearing slag by intensifying the work of a short rotary furnace with the dust and process gas conditioning system Phase 3\u0026rdquo;, Łukasiewicz Research Network \u0026ndash; Institute of Non-Ferrous Metals; Gliwice; 2021.\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":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"lead, shaft sludge, short rotary kiln, recycling, modelling","lastPublishedDoi":"10.21203/rs.3.rs-6509950/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6509950/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eShaft sludge is a lead-bearing material produced by the wet dedusting of shaft furnace process gases generated during copper smelting from concentrates. It is a material with a high concentration of lead and hydrocarbon compounds, the melting of which in short rotary furnaces causes many problems.\u003c/p\u003e \u003cp\u003eThis paper presents the results of thermodynamic modelling of the melting process of shaft sludge and other lead-bearing materials. Computations were carried out using HSC 8 software by calculating thermodynamic equilibrium by minimising the free enthalpy of the system.\u003c/p\u003e \u003cp\u003eCalculations showed that, as a result of the change in technology and the introduction of technical improvements, it is possible to increase the Pb recovery to raw lead from 55.4\u0026ndash;70.7%, while maintaining a total Pb recovery of approximately 93%.\u003c/p\u003e \u003cp\u003eThe calculations presented in the article are realised within the framework of project No. POIR.01.01.01-00-1300/20\u0026thinsp;\u0026minus;\u0026thinsp;01 funded by the National Centre for Research and Development, entitled \u0026bdquo;Environmentally friendly technology for vitrification of lead-bearing slag by intensifying the work of a short rotary furnace with the dust and process gas conditioning system\u0026rdquo;.\u003c/p\u003e","manuscriptTitle":"Modelling the melting of „shaft sludge” from shaft furnace dust removal in a short rotary kiln","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-16 11:12:20","doi":"10.21203/rs.3.rs-6509950/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-06-02T04:32:11+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-05-30T02:42:26+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-05-16T10:38:50+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"244419899040692930361712294410009143394","date":"2025-05-16T09:17:30+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"166929731037634337897140155256054591310","date":"2025-05-14T06:48:21+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-05-14T05:07:46+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-05-14T03:09:30+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-05-06T12:06:40+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-05-05T07:50:13+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2025-04-23T07:11:34+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"f16b29a1-8224-44af-8dc1-65193f79be80","owner":[],"postedDate":"May 16th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":48509223,"name":"Physical sciences/Chemistry/Environmental chemistry/Pollution remediation"},{"id":48509224,"name":"Physical sciences/Engineering/Chemical engineering"},{"id":48509225,"name":"Physical sciences/Mathematics and computing/Computational science"}],"tags":[],"updatedAt":"2025-08-04T16:46:51+00:00","versionOfRecord":{"articleIdentity":"rs-6509950","link":"https://doi.org/10.1038/s41598-025-12808-8","journal":{"identity":"scientific-reports","isVorOnly":false,"title":"Scientific Reports"},"publishedOn":"2025-08-01 16:29:09","publishedOnDateReadable":"August 1st, 2025"},"versionCreatedAt":"2025-05-16 11:12:20","video":"","vorDoi":"10.1038/s41598-025-12808-8","vorDoiUrl":"https://doi.org/10.1038/s41598-025-12808-8","workflowStages":[]},"version":"v1","identity":"rs-6509950","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6509950","identity":"rs-6509950","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}