The Influence of Ageing on the Performance of Taphole Clay and the Study of Rapid-setting Mechanism

The Influence of Ageing on the Performance of Taphole Clay and the Study of Rapid-setting Mechanism | 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 The Influence of Ageing on the Performance of Taphole Clay and the Study of Rapid-setting Mechanism Xiao Wang, Houyou Zhou, Wenbo Zhao, Qingwen Li, Ya Yin This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6291038/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 08 Jul, 2025 Read the published version in Scientific Reports → Version 1 posted 10 You are reading this latest preprint version Abstract This study investigated the influence of curing time on the mechanical properties of rapid-setting blasting mud materials, analyzed the variation pattern of mechanical strength during the increase of curing time, and employed techniques such as XRD and SEM-EDS to study the impact of curing time on the crystalline phase transformation, microstructure, and element distribution of blasting mud materials. The results revealed that with the increase of curing time, all mechanical strengths of the blasting mud materials increased significantly, with a faster growth rate within the first 6 hours and stabilization around 24 hours. The main hydration products of the blasting mud materials are calcium carbonate and ettringite, whose contents increase with curing time, promoting the hydration process and enhancing mechanical strength. The internal structure of the material becomes denser with increasing curing time, resulting in decreased porosity, specific surface area, and total pore volume, and the formation of a dense spatial structure, which explains the trend of strength change. This study is of great significance for selecting optimal plugging materials and curing times for mines in China to achieve efficient blasting operations. Physical sciences/Engineering/Civil engineering Physical sciences/Materials science/Structural materials/Mechanical properties rapid-setting blasting mud curing time mechanical strength microscopic testing XRD analysis 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 Introduction Currently, metal mines globally are predominantly categorized into two types: open-pit mines and underground mines. Regardless of the type, the predominant method of extraction is blasting mining. This involves drilling boreholes into the ore body, followed by the placement of explosives to harness the energy of the blast to fragment the rock, thereby detaching the ore from the surrounding rock mass [ 1 ] . The utilization of explosive energy directly affects the blasting effect, and then has a profound impact on many factors such as mining cost, mining safety, mining efficiency and so on[ 2 ] . A variety of strategies exist to improve the efficiency of explosive energy utilization, with blast hole stemming being a notably effective and significant method. Good quality of blast hole stemming can prolong the detonation gas in the hole time, and then produce a larger range of fissures, and then expansion, penetration, cutting; can guarantee the full reaction of the explosives in the blast hole, reduce the explosives unit consumption, improve the effect of blasting [ 3 ] . In recent years, scholars have shifted their focus towards the research of rapid and efficient hole-sealing materials, exploring the optimal material ratios. The choice of the main material of high water rapid-setting material is based on sulfur-aluminate cement [ 4 ] , while Guo [ 5 ] chose ferroaluminate cement as the main material. Feng [ 6 ] chose sulphoaluminate cement as the main material by comparing and analyzing the composition and hydration mechanism of several kinds of cement. In the formulation of high water rapid-setting materials, auxiliary materials predominantly consist of gypsum and lime, complemented by the addition of a small amount of suspending agents and early strength agents [ 7 ] . Sometimes small amounts of alkaline materials or fly ash slag are added, etc [ 8 ] . Feng [ 6 ] mentioned that a small amount of retarding agent should be added to the auxiliary material, so that the retarding effect of the main material can be quickly lifted after the mixing of the two materials, and the mixing slurry can quickly complete the initial setting. Peng et al [ 9 ] on the other hand, pointed out that not only modified montmorillonite as a suspending agent, but also sodium tripolyphosphate and sodium lignosulfonate as dispersing agents were added to their excipients.. In addition, scholars have also carried out some investigations on the mechanical strength of rapid-setting materials [ 10 ][ 11 ] . Kang et al [ 12 ] developed a new type of blast hole plugging agent by using polyurethane as raw material in response to the many shortcomings and limitations of traditional taphole mud filling materials, which has the advantages of high safety and reliability performance, reducing the amount of explosives loss, enhancing the utilization rate of blast holes as well as reducing the noise of blasting and other harmful pollutants. Hu et al [ 13 ] plotted the stress-strain curves of high water quick-consolidation materials at four ages (1d, 3d, 7d, 28d), and pointed out that the uniaxial compression damage of high water rapid-setting materials is divided into four stages. Feng et al [ 14 ] conducted uniaxial compressive strength as well as triaxial compression tests at different ages under normal curing for high water materials with 91%~97% water volume. It was pointed out that the strength of high water rapid-setting materials under uniaxial compression accounted for 66%~90% of the final strength at 7d, with obvious early strength characteristics, and the strength at all ages increased by about 25% on average when compressed in three directions. Zhang et al [ 15 ] further found that the peak and residual intensity were increased when the water temperature increased within 25°C to 40°C, and the lower the water-cement ratio, the greater the strength increase. Yu et al [ 16 ] studied that the increase in curing temperature will enhance the early strength of the material, but will reduce the final strength of the material. However, Liu [ 17 ] did not find the phenomenon of strength retrogression in the test for the effect of curing temperature. In summary, the existing research on the effect of age on the strength of rapid-setting materials is relatively small, and the conclusions are different, and there is no uniform conclusion. Based on this, this study explores the influence of age on the mechanical properties of rapid-setting materials, and analyzes the variation of each mechanical strength in the process of age increase. Using XRD, SEM-EDS and other analytical means, this study investigates the effect of age on the crystallization transition, microstructure and elemental distribution of taphole clay materials, revealing the intrinsic connection between strength growth and microstructure evolution. This study is of great significance for choosing better stemming materials and age periods in blasting operations in China's mines, so as to realize the convenient, safe, reliable and efficient blasting operation. Rapid-setting mechanism of rapid-setting taphole clay Rapid-setting taphole clay is a new type of taphole clay material with high solid water content, which is based on the generation mechanism of high water rapid-setting materials and obtained through formula experiments according to the requirements of taphole clay stemming. It is mainly formed by hydration reaction of main material of sulfoaluminate cement and auxiliary material of dihydrate gypsum and quicklime. The main body of the structure is ettringite. Therefore, the whole hydration reaction mechanism is based on the formation mechanism of ettringite to a certain extent. Rapid-setting taphole clay main and auxiliary materials through the hydration reaction to generate solidification is a complex process. In the process of using the main material and auxiliary materials are first prepared into a slurry, and then mix the two when using, after mixing the reaction to generate the solidified body. From the material composition analysis, the main substances involved in the reaction are \({C_4}{A_3}\overline {S}\) , \(\beta - C2S\) , calcium sulfate and calcium oxide, and its hydration process and products determine the main mechanical properties of the solid. When the main and auxiliary materials slurry mixing, the main substances in the liquid phase environment will quickly react to generate ettringite precipitation, when the system is sufficient reactants, the reaction will give priority to all generated ettringite, and analyze the main substances before and after the reaction changes. The reaction equation is as follows. $$\begin{gathered} {\text{C}_4}{\text{A}_3}\overline {\text{S}} {\text{+8}}\left( {{\text{CaS}}{{\text{O}}_{\text{4}}}\cdot 2{\varvec{H}_2}\text{O}} \right){\text{+6CaO+96}}{\text{H}_{\text{2}}}\text{O} \to \hfill \\ {\text{3}}\left( {{\text{3}}\text{C}\text{a}\text{O}\cdot \text{A}{\text{l}_2}{\text{O}_3}\cdot {\text{3CaS}}{{\text{O}}_{\text{4}}}\cdot {\text{32}}{\text{H}_{\text{2}}}\text{O}} \right) \hfill \\ \end{gathered}$$ 1 When there is not enough CaO in the system, the product will not be all ettringite, but will instead form a partial aluminum gel. $$\begin{gathered} {\text{C}_4}{\text{A}_3}\overline {\text{S}} {\text{+2}}\left( {{\text{CaS}}{{\text{O}}_{\text{4}}}\cdot 2{\varvec{H}_2}\text{O}} \right){\text{+34}}{\text{H}_{\text{2}}}\text{O} \to \hfill \\ {\text{3}}\text{C}\text{a}\text{O}\cdot \text{A}{\text{l}_2}{\text{O}_3}\cdot {\text{3CaS}}{{\text{O}}_{\text{4}}}\cdot {\text{32}}{\text{H}_{\text{2}}}\text{O}+2\left( {\text{A}{\text{l}_2}{\text{O}_3}\cdot 3{\text{H}_2}\text{O}} \right) \hfill \\ \end{gathered}$$ 2 When the CaSO 4 content in the system is insufficient, the reaction will no longer produce ettringite but low-sulfur hydrated calcium thioaluminate (AFm) and aluminum gel. The generated ettringite will also decompose to form low-sulfur hydrated calcium thioaluminate. $${\text{C}_4}{\text{A}_3}\overline {\text{S}} {\text{+18}}{\text{H}_{\text{2}}}\text{O} \to {\text{3CaO}}\cdot {\text{A}}{{\text{l}}_{\text{2}}}{{\text{O}}_{\text{3}}}\cdot {\text{CaS}}{{\text{O}}_{\text{4}}}\cdot {\text{12}}{{\text{H}}_{\text{2}}}{\text{O+2}}\left( {\text{A}{\text{l}_2}{\text{O}_3}\cdot 3{\text{H}_2}\text{O}} \right)$$ 3 $$\begin{gathered} {\text{3}}\text{C}\text{a}\text{O}\cdot \text{A}{\text{l}_2}{\text{O}_3}\cdot {\text{3CaS}}{{\text{O}}_{\text{4}}}\cdot {\text{32}}{\text{H}_{\text{2}}}\text{O} \to \hfill \\ {\text{3}}\text{C}\text{a}\text{O}\cdot \text{A}{\text{l}_2}{\text{O}_3}\cdot {\text{CaS}}{{\text{O}}_{\text{4}}}\cdot {\text{12}}{\text{H}_{\text{2}}}\text{O}+2\left( {{\text{CaS}}{{\text{O}}_{\text{4}}}\cdot {\text{2}}{\text{H}_{\text{2}}}\text{O}} \right)+{\text{16}}{\text{H}_{\text{2}}}\text{O} \hfill \\ \end{gathered}$$ 4 When calcium carbonate is added to the formula of rapid-setting taphole clay, it will prevent the transformation of high sulfur type salt to low sulfur type salt in the solution, which may lead to the absence of AFm in the product. So a certain proportion of calcium carbonate can be added to the formula of rapid-setting taphole clay instead of calcium oxide, which prevents the generation of AFm and improves the coagulation time of the taphole clay. In addition to \({C_4}{A_3}\overline {S}\) ,, another major component in sulfoaluminate cement, hydrates to produce calcium silicate gel (C-S-H). The C/S in this gel is related to the concentration of calcium oxide in the liquid phase. When the concentration of calcium oxide is low, type Ⅰ hydrated calcium silicate is generated, with a C/S between 0.5 and 1.5. Therefore, for every 1 mol of \(\beta - C2S\) hydrated to form 1 mol of C-S-H gel, 1 mol of calcium hydroxide is also generated. The precipitated calcium hydroxide will continue to react with aluminum gel and calcium sulfate to form ettringite. The reaction equation is as follows. $$\beta - {\text{C}_{\text{2}}}\text{S}+2{\text{H}_2}\text{O} \to \text{C} - \text{S} - \text{H}+\text{C}\text{a}{\left( {\text{O}\text{H}} \right)_2}$$ 5 $$\begin{gathered} 3\text{C}\text{a}{\left( {\text{O}\text{H}} \right)_2}+3\left( {\text{C}\text{a}\text{S}{\text{O}_4}\cdot 2{\text{H}_2}\text{O}} \right)+\text{A}{\text{l}_2}{\text{O}_3}\cdot 3{\text{H}_2}\text{O} \to \hfill \\ {\text{3}}\text{C}\text{a}\text{O}\cdot \text{A}{\text{l}_2}{\text{O}_3}\cdot {\text{3CaS}}{{\text{O}}_{\text{4}}}\cdot {\text{32}}{\text{H}_{\text{2}}}\text{O} \hfill \\ \end{gathered}$$ 6 Therefore, the formation of C-S-H can be accelerated by promoting the hydration reaction of \(\beta - C2S\) . Thus, the pores between the structural skeleton formed by ettringite are filled with cementing matters, and the structure of the solid body is made denser. In the above, chemical equations are used to describe the changes of substances in the formation process of ettringite from the perspective of reaction mechanism. However, in reality, the change of substances in the formation process of rapid-setting taphole clay is more complicated than the theoretical description. This is because in the actual hydration reaction, on the one hand, with the deepening of hydration reaction, the consistency of slurry will significantly increase, resulting in the migration of ions in the slurry system becoming more and more difficult. On the other hand, due to the generation of ettringite crystals will be adsorbed on the surface of solid particles which have not yet been involved in the reaction, hindering its further participation in the reaction. Therefore, the hydration process of rapid-setting taphole clay will be constrained by the hydration diffusion rate. The hydration process of rapid-setting taphole clay can be roughly divided into the following four stages according to the state change. (1) Hydration induction period At this stage of hydration induction, the main and auxiliary grout are just mixed and stirred. The ions contained in it quickly dispersed into the mixed slurry and began to react to form part of the ettringite unit cells. This stage lasted for a short time, the hydration heat release was not obvious and the viscosity of the slurry almost did not change. (2) Hydration acceleration period When the mixed slurry enters the stage of accelerated hydration, the rate of hydration reaction starts to increase dramatically. Ettringite unit cells formed earlier start to develop and are constantly accompanied by the formation of new ettringite unit cells. In this process, because the slurry system is not ideally uniformly distributed, there will be a small amount of other products such as gel generation. The continuously formed and developed ettringite unit cells will be connected with each other to form a ettringite skeleton, which will fix the gel and free water in it, so that the viscosity of the slurry will increase rapidly to complete the initial coagulation and begin to harden continuously. The whole process of accelerated hydration will release a large amount of heat of hydration, so that the surface temperature of rapid-setting taphole clay is significantly higher than the ambient temperature. (3) Hydration deceleration period When the rapid-setting taphole clay hydration rate reached the peak, began to enter the stage of hydration deceleration period. At this time, the system in the ettringite unit cell generation is significantly reduced, began to generate a large number of other substances such as gel, hydration exothermic slowed down significantly. The surface temperature of the gradually hardened rapid-setting taphole clay consolidated body began to decrease. (4) Hydration stabilization period In this stage, the hydration reaction rate is further reduced, and the hydration process has basically ended. The surface temperature of the slurry gradually decreases until it is the same as the ambient temperature. Experimental Plan 2.1 Experimental material According to the literature research, the material formation includes two parts: main and auxiliary materials (hereinafter referred to as A and B materials). When the main and auxiliary material slurries are mixed, the substances in them react in a liquid phase environment to form the main structure with ettringite as the backbone. Part of the free water and gel filled with it, so as to complete the transformation from slurry to solid. A material is composed of sulfoaluminate cement and compound retarding dispersant. B material consists of other auxiliary materials such as lime, gypsum and composite rapid-setting agent, A and B microscopic morphology is shown in Fig. 1 . In order to equalize the A, B composition, improve the suspension performance of the B material, the B material is sometimes also added to a certain suspension of dispersant. Retarder is one of the key links in the development of ultra-high water materials. Efficient retarding agents not only simplify the filling process, but importantly, the fired materials in water need to be rapidly put in a stable state by retarding agents to avoid premature hydration with water. The role of rapid-setting agent is to promote their rapid hydration, so as to achieve the purpose of rapid hardening and early strength. And with a lot of water, conventional admixtures can't be as effective as they should be. Finding composite admixtures with good compatibility should be the goal of the test. In the stage of retarding and rapid-setting, suitable suspending and dispersing agents, so that the solid material can be more uniformly and stably suspended in the liquid. The material can be uniformly and stably hydrated to form a homogeneous hydration hardening body. The composition of sulfoaluminate cement clinker used in this experiment is shown in Table 1 . Auxiliary materials are gypsum, lime, calcium carbonate, bentonite and additives. It is determined that the number of cement mesh should be ground and screened to more than 200 mesh during the test, and the auxiliary materials of the preliminary formula are gypsum: lime: calcium carbonate: bentonite = 7:2:3:3. The percentage of additive amount of main and auxiliary materials is calculated according to the total weight of main and auxiliary materials respectively. The gypsum used in the auxiliary materials is calcium sulfate dehydrate, the rest of the additives are analytical pure auxiliary materials such as gypsum, lime, calcium carbonate, bentonite and additives. Table 1 The chemical composition of sulpho-aluminate cement Composition analysis of sulfho-aluminate cement clinker chemical composition LOSS SiO 2 Al 2 O 3 Fe 2 O 3 CaO MgO SO 3 TiO 2 ∑ percentage 0.32 13 27.63 1.67 44.80 2.20 8.40 1.47 99.49 minerals CM N P C 4 A 3 S C 2 S C 4 AF CT percentage 0.951 2.13 3.29 52.86 37.31 5.08 2.50 The role of rapid-setting taphole clay auxiliary additives is to make the main and auxiliary materials of the two slurries can be quickly solidified after mixing. Therefore, in this part of the test, consult the literature to screen out the different categories of rapid-setting agent may be applicable. And through the test to determine the type of rapid-setting agent and the amount of additive, so that the rapid-setting taphole clay main and auxiliary slurry can be mixed in a short period of time to complete the rapid solidification (the initial solidification time of < 3 min, the final solidification time of about 30 min). And then optimize and adjust the proportion of auxiliary materials of rapid-setting taphole clay. Finally, the test was conducted to observe whether the addition of rapid-setting agent would affect the flow state of the auxiliary slurry. 2.2 Preparation process In order to ensure the accuracy of the test data, the following specific test operation steps are set up. The single pulp preparation process consists of weighing and mixing the material using an analytical electronic balance, taking tap water from the measuring cylinder, adding it to the mixing pot and wetting it, and then slowly adding the material to the pot and placing it on the mixing equipment. With low gears stir into container in about 10 minutes, finally clean mixing pot and impeller. Then mix the slurry and add B and A slurry to the mixing container according to the test requirements. Mix by hand for 30 seconds to combine the two thoroughly. Then pour the mixture into the test block box and divide it into three parts, record the start time of standing and observe the state of the test block. 2.3 Test method (1) Uniaxial compression test and splitting test: The instrument used is WDW microcomputer-controlled electro-hydraulic servo testing machine, supplemented by XTDIC three-dimensional whole strain deformation measurement and analysis system. The acquisition speed of the high-speed camera is 5000 frames/s. The loading rate is 0.01 kN/s through the pressure loading control mode, and the test loading and measurement system is shown in Fig. 2 . (2) XRD: The dried specimens were ground into powder form, and the test data were processed and analyzed using XRD analysis software. (3) SEM: The samples of different ages were observed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). (4) Mercury injection test scheme: The pore structure parameters were determined by mercury injection method (MIP) to analyze the pore structure changes of taphole clay at different ages. Mercury injection instrument is used to measure pore structure parameters of materials. Experimental conclusion 3.1 Mechanical strength Figure 3 shows the stress-strain curves of the test blocks at different ages. The key parameters, such as the magnitude of peak stress and the rate of ascent, are different. According to the image, the stress-strain curve can be roughly divided into four stages: pore fracture compaction stage, elastic deformation to microelastic fracture stable development stage, plastic yield to unstable fracture development stage, and strain softening stage after fracture. After the peak compressive strength is reached, the curve is basically flat and slowly decreases within a certain range, and the internal structure of the sample is destroyed. The samples basically keep the whole shape, the cracks expand rapidly, cross and combine with each other to form a fracture surface. The compressive strength measured by the test blocks of different ages is shown in Fig. 3 . The strengths of the four instars are 0.51 MPa, 0.83 MPa, 1.31 MPa and 1.58 MPa, respectively. The compressive strength of 1h to 6h increases rapidly with time. From 6h to 24h, the growth rate decreased to 1.48%. It can be seen from the figure that with the same other conditions, the compressive strength of the test block increases with the increase of age. It can be seen that the age has a great influence on the compressive strength of the taphole clay. The change of the test force along with the displacement during the loading process of the splitting experiment is shown in Fig. 4 . The shape of the failure curve is basically the same for different ages. No visible crack was generated at the center of the specimen before the peak load was reached. When the peak load is reached, a clear crack appears and begins to expand rapidly. Subsequently, cracks permeate the whole specimen and the load drops sharply. As can be seen from the figure, there are obvious differences in the test forces of the test blocks at different ages during failure, and the peak loads at the four ages (0.5h, 1h, 6h and 24h) are 0.25 kN, 0.45 kN, 1.02kN and 1.25 kN respectively. The peak load increases with the age. It can be seen that with the increase of age, the tensile strength of the taphole clay also increases significantly. The measured tensile strength of the test blocks at different ages is shown in Fig. 4 . The tensile strength of the four ages is 0.033 MPa, 0.059 MPa, 0.13 MPa and 0.16 MPa respectively. It can be seen from the figure that the tensile strength before 6 hours increases rapidly with time, and the growth rate from 1h to 6h is 1.48%. 6h to 24h showed a slower growth rate of 0.17%. It can be concluded that the taphole clay is more sensitive to age. In the age period from 1h to 6h, the strength increases most obviously. 3.2 XRD analysis of taphole clay at different ages Figure 5 shows the XRD analysis results of 0.5h and 6h taphole clay samples respectively. The figure shows the characteristic peaks of taphole clay at different ages. After adequate hydration, the main products are calcium carbonate and ettringite, followed by calcium clinosilicate, quartz and hatrurite. Ettringite, as the main hydration product of sulfoaluminate cement, has a significant contribution to the strength of taphole clay. Under the same temperature and water-cement ratio, the contents of calcium carbonate and ettringite increased with the increase of curing age, and the peak diffraction value increased significantly. Therefore, the content of hydration products produced by different taphole clay ages is also different. This shows that the age can affect the hydration of cement, and the longer the age, the more hydration products. At the same time, it also explains that with the increase of age, the strength of taphole clay is better. The diffraction pattern of the sample to be measured is compared with that of the standard sample. According to the intensity and position of the diffraction peak, the content of each phase in the sample to be measured can be calculated. Table 2 and Table 3 detail the composition and content of taphole clay at ages 0.5h and 6h. The contents of calcium carbonate, ettringite, quartz, calcium clinosilicate and hatrurite at 0.5h age are 50.4%, 23.4%, 3.1%, 18.9% and 4.2% respectively. The contents of various substances in the 6h taphole clay are 39.5%, 40.0%, 1.0%, 17.9% and 1.6% respectively. With the age increasing from 0.5h to 6h, the content of ettringite increased by 16.6% and the content of calcium carbonate decreased by 10.9%. The content of quartz, calcium clinosilicate and hatrurite decreased, but not obviously. It can be seen that the age has a great influence on the content of calcium carbonate and ettringite in the hydrated products of the taphole clay, so the age is also an important factor affecting the properties of the taphole clay. Table 2 Material composition and content of 0.5h cannon clay The Object Name Source Weight% Calcite-Ca(CO 3 ) PDF#01-078-4614 50.4 Ettringite -Ca 6 Al 2 (SO 4 ) 3 (OH) 12 (H 2 O) 26 PDF#04-013-3691 23.4 Quartz-SiO 2 PDF#04-016-2085 3.1 Larnite-Ca 2 (SiO 4 ) PDF#01-083-0461 18.9 Hatrurite -Ca 3 (SiO 4 )O PDF#04-014-9801 4.2 XRF(Wt%): Ca = 35.7%, S = 1.8%, Si = 5.0%, A1 = 1.0%, O = 49.2%, C = 6.1%, H = 1.2% Table 3 Composition and content of 6h gun-mud material The Object Name Source Weight% Calcite-Ca(CO 3 ) PDF#01-078-4614 39.5 Ettringite-Ca 6 Al 2 (SO 4 ) 3 (OH) 12 (H 2 O) 26 PDF#04-013-3691 40.0 Quartz-SiO 2 PDF#04-016-2085 1.0 Larnite-Ca 2 (SiO 4 ) PDF#01-083-0461 17.9 Hatrurite-Ca 3 (SiO 4 )O PDF#04-014-9801 1.6 XRF(Wt%): Ca = 32.7%, S = 3.1%, Si = 3.6%, A1 = 1.7%, O = 52.2%, C = 4.7%, H = 2.1% 3.3 Microscopic mechanism analysis of taphole clay at different ages SEM of taphole clay samples at different ages is shown in Fig. 6 . The hydration products of the taphole clay cured to 0.5h are mainly fibrous and honeycomb hydrated calcium silicate and a small amount of needle-like ettringite. Its internal structure is fluffy and rich in holes, which is not conducive to the strength performance of the taphole clay. With the increase of curing age, a large amount of ettringite is interspersed in the gap between the hydrated calcium silicate and the particle. The internal pore network structure of the taphole clay is refined, segmented and filled, and the density of the taphole clay is improved. At the age of 6h, a large amount of ettringite is attached to the surface of calcium silicate hydrate in the taphole clay, which strengthens the connection between calcium silicate hydrate and promotes the formation of dense spatial structure. Combined with XRD results, the hydrated calcium silicate produced by taphole clay hydration reaction is mostly high-density C-S-H gel. With the increase of age, SEM shows more ettringite, forming denser microscopic results and better strength properties. In order to further study the mechanism of increasing compressive strength, flexural strength and splitting tensile strength of taphole clay with age. SEM-EDS analysis was performed on sample microblocks of 0.5h and 6h ages, as shown in Fig. 7 and Fig. 8 . It can be seen from the figure that elements can be evenly distributed in each area of the scan in the element distribution diagram, and no significant difference was found in the scanning results of the two ages. The highest chemical elements are O and Ca elements, followed by Al, S and C, and Si elements are the least. Therefore, according to XRD, the main components of the mud are calcium silicate (Ca(CO 3 )) and ettringite (Ca 6 Al 2 (SO 4 ) 3 (OH) 12 (H 2 O) 26 ), so the O and Ca elements are highest. At 0.5h age, the contents of O and Ca elements are 51.30% and 27.72% respectively. At 6h age, the contents of O and Ca elements are 47.27% and 28.75% respectively. It can be seen that with the growth of age, the content of O elements decreases and the content of Ca elements increases, which is mutually confirmed with the results of XRD. 3.4 Mercury injection analysis of taphole clay Mercury injection test was carried out on taphole clay samples of different ages (0.5, 1, 6, 24h), and the experimental data were analyzed and processed to obtain the structural characteristics of taphole clay. (1) Porosity Porosity is defined as the percentage of the total apparent volume of the void of the material, calculated as follows. $$P=\frac{{{V_{\text{a}}}}}{{{V_{\text{b}}}}} \times {\text{100\% }}$$ 7 In the formula: Va is the actual volume of mercury injected into the sample, which can also be called the void volume, ml; V b is the total volume of the sample, ml. The porosity of the taphole clay samples under four ages are shown in Fig. 9 . It can be seen from the figure that the porosity of the taphole clay decreases with the increase of age. The porosity of the taphole clay at 0.5h is 27.39%. When the age is 1h, the porosity decreases by 8.18–25.15%. When the age reaches 6h and 24h, the porosity relative to the age of 0.5h decreases by 16.79% and 20.74% respectively, to 22.79% and 21.71%. The strength of the taphole clay increases gradually with the increase of age, mainly because the chemical composition of the raw material and the binder gradually react to form a more stable structure, so that the internal organization of the taphole clay is more compact. At the same time, the particle size composition and particle grading of the raw material enable the fine particles to fill the void between the coarse particles, further reducing the porosity. In addition, the evaporation of water in the raw material also promotes the compact structure of the taphole clay and reduces the porosity. In the initial hardening period of the taphole clay, especially in the first 6 hours, the rapid reaction of the binder to the feedstock, the rapid evaporation of water, and the tight arrangement and filling of particles together lead to a significant reduction in porosity during this stage. (2) Specific surface area and total pore volume The variation of cumulative pore area with pore diameter per unit mass of taphole clay measured by intrusive mercury test is shown in Fig. 10 . It can be seen from the figure that the cumulative pore area changes with the pore size at different ages in a basically consistent trend, showing that the large pore area is small. With the increasing of mercury inlet pressure, mercury gradually invades smaller diameter pores. The pore area mainly depends on the pore diameter of 5 ~ 500 nm. The peak point of the curve represents the specific surface area of the porous material, which is defined as the internal surface area of the pores in the porous material per unit mass (volume). The specific surface area of the taphole clay at age 0.5h is the largest, and that of 24h age taphole clay is the smallest. The total pore volume is defined as the total volume of pores per unit mass of the material, that is, the total amount of mercury injected. The total pore volume and specific surface area in the old and new mortar calculated by mercury injection are shown in Fig. 11 . The results show that the total pore volume in the taphole clay increases with the increase of age. Since the mercury injection method assumes that the pores in the material are all connected cylindrical holes, the pores in the actual material are irregular in shape and there are closed holes, resulting in irregular variation of the specific surface area. The total pore volume and specific surface area of the 0.5h taphole clay are 1.827 ml/g and 29.08 m 2 /g. The total pore volume and specific surface area of 1h are 1.7579 ml/g and 24.568 m 2 /g respectively, and the total pore volume and specific surface area are reduced by 3.78% and 15.52% respectively. The total pore volume and specific surface area at age 6h are 1.5586 ml/g and 25.37 m 2 /g. At 24h age, the total pore volume and specific surface area are 1.4372 ml/g and 26.03 m 2 /g. The total pore volume continues to decrease, while the specific surface area increases slightly. With the hydration reaction of cement, more cement gel fills the pores. This process not only increases the gel-space ratio, but also results in the decrease of the total pore volume of the material. With the increase of age and the deepening of cement hydration, the compactness of the taphole clay increases gradually. The increase in compactness means that the internal pores of the material are reduced, that is, the total pore volume is reduced. (3) Pore size distribution The pore size distribution of quick-setting taphole clay at different ages is shown in Table 4 . Table 4 Pore size distribution of old and new mortar Age/h Pore size distribution(%) 1000 nm 0.5 13.11 51.33 25.69 9.88 1 13.28 51.73 25.53 9.46 6 13.48 52.61 24.09 9.82 24 13.95 54.23 23.69 8.13 The cumulative pore size distribution curve of the quick-setting taphole clay at different ages is shown in Fig. 12 . In the range of pore size from 1000 nm to 50000 nm, the curve rose slowly, and the accumulated mercury content in the taphole clay increased with the increase of age. The variation trend of accumulated mercury content in taphole clay at different ages is similar. In the range of pore size from 5 nm to 1000nm, the slope of the curve increases rapidly, and it can be seen that the pore size of the taphole clay is concentrated in the range of 5 nm to 1000nm. The cumulative mercury content of taphole clay at 0.5h and 1h increased significantly, while the cumulative mercury content of taphole clay at 6h and 24h increased relatively little.The pore size of taphole clay is mainly concentrated between 5 nm and 1000 nm. With the increase of age, the number of gel pores ( 1000 nm) increased, and the change amplitude was more obvious when the age increased from 1h to 6h. This is consistent with the growth of the strength of the quick-setting taphole clay from 1h to 6h, which can be mutually confirmed. In the cumulative pore diameter distribution curve, the pore diameter corresponding to the slope mutation point is defined as the critical pore diameter, that is, the maximum pore diameter corresponding to the significant increase in the volume of mercury injected. The cement-based material contains pores of different sizes, and the larger pores are connected by smaller pores. The critical aperture is the maximum aperture of each hole connecting the larger pores, which reflects the connectivity of the pores and the curvature of the permeability path [ 16 ] . The critical pore sizes of 0.5, 1, 6 and 24h taphole clay are 2916.21 nm, 2466.93 nm, 1597.29 nm and 1311.12 nm, respectively, which increase with the age. In other words, the increase of age reduces the connectivity of the pore structure of taphole clay. With the increase of age, the hydration reaction of cement inside the quick-setting taphole clay continues, resulting in the change of pore structure. Larger pores may gradually decrease or close due to the filling of hydration products, while smaller pores may become more complex and tortuous due to the growth of hydration products. Therefore, although the total volume of the pores may be reduced, the connectivity between the pores may also be reduced due to the reduction of the pore size and the zigzag of the path. In summary, the critical pore diameter of quick-setting taphole clay decreases with the increase of age, which reflects the decrease of pore structure connectivity and the increase of permeability path curvature. This is caused by the continuous hydration reaction of cement and the gradual change of pore structure. With dV/dlgr as the vertical axis and aperture as the horizontal axis, the differential aperture distribution curves of taphole clay under different curing time were obtained, as shown in Fig. 13 . The curve reflects the pore distribution in different pore sizes, and the area surrounded by the curve is the total pore volume of the sample. In the differential aperture distribution curve, the aperture corresponding to the peak value in different aperture ranges is defined as the most feasible aperture in the corresponding aperture range. Its physical meaning is the largest aperture within a certain aperture distribution, namely hole has the highest probability aperture. It can be seen from the analysis of the figure that the maximum availability and pore size of the taphole clay at the age of 0.5, 1, 6 and 24h are 1053.93 nm, 1053.93 nm, 830.37 nm and 830.37 nm, respectively, distributed in the range of 500 nm to 1500 nm. The most available apertures of 0.5 and 1h, 6 and 24h are consistent, respectively. It shows that the number of pores in the taphole clay is more because the age is shorter. Conclusion (1) With the increase of age, the mechanical strength of taphole clay showed a significant increase trend.The age has a great influence on the mechanical properties of taphole clay. The mechanical strength before 6 hours increases rapidly with time. The maximum growth rate was observed between 1h and 6h, while the growth rate was slower between 6h and 24h. About 24h, the strength is basically stable. (2) The main hydration products of taphole clay are calcium carbonate and ettringite, and their contents increase with the increase of age. This indicates that the age promotes the hydration process of the taphole clay, which in turn improves its mechanical strength. With the increase of age, the content of ettringite increased significantly, and the content of calcium carbonate decreased. (3) The material at 0.5h age has fluffy internal structure and abundant holes, which is not conducive to the strength performance of the taphole clay. With the increase of curing age, the density of taphole clay is improved. A large amount of ettringite is attached to the surface of hydrated calcium silicate, which promotes the formation of dense spatial structures. With the increase of age, the content of O element decreases and the content of Ca element increases, which is consistent with the results of XRD. (4) The porosity of the taphole clay decreases with increasing age, mainly because the chemical composition of the feedstock and the binder gradually react to form a more stable structure. In the initial hardening period, the porosity decreased significantly. The specific surface area decreased with age, while the total pore volume showed a complicated trend. However, it eventually decreased due to the increase of material density caused by cement hydration reaction, which explained the change trend of strength. The critical pore size increases with age, which decreases the connectivity of pore structure. Most of the pore sizes can be in the range of 500nm ~ 1500nm, and the number of short pores in the age is more. Declarations CRediT authorship contribution statement Xiao Wang: Formal analysis, Investigation, Methodology, Validation, Visualization, Data Curation, Writing original draft, Review & editing. Houyou Zhou: Conceptualization, Supervision, Methodology, Funding acquisition, Project administration. Wenbo Zhao: Investigation, Supervision Qingwen Li: Conceptualization, Investigation, Methodology, Validation, Review &editing. Ya Yin: Investigation, Supervision. Author Contribution Xiao Wang: Formal analysis, Investigation, Methodology, Validation, Visualization, Data Curation, Writing original draft, Review & editing. Houyou Zhou: Conceptualization, Supervision, Methodology, Funding acquisition, Project administration. Wenbo Zhao: Investigation, SupervisionQingwen Li: Conceptualization, Investigation, Methodology, Validation, Review &editing.Ya Yin: Investigation, Supervision. Acknowledgments This work was supported by the National Natural Science Foundation of China (52274107) and Interdisciplinary Research Project for Young Teachers of USTB (FRF-IDRY-GD21-001). Data Availability Some or all data that support the findings of this study are available from the corresponding author upon reasonable request. References Li, X. Rock drilling and blasting engineering[M] (Central South University, 2011). Leng, Z. et al. Research progress in theory and technology of energy regulation for rock drilling and blasting[J]. Metal Mine , (05): 64–76. (2023). Wang, C. & Han, L. Optimization study on charge structure for blasting in small cross-section hard rock roadways of metal mines[J]. Gold 45 (10), 40–46 (2024). Zou, C., Guan, Y. & Kang, Y. Application of high water quick setting material in filling mining in Ningdong mining area[J]. Copp. Eng. , (03): 28–31. (2022). Guo, J., Zhang, Q. & Zheng, S. Research on development and application of low cost and high water rapid coagulation materials for mining[J]. Nonferrous Metals(Mining Section) , (01): 13–14. (2003). Feng, G. Research on the superhigh-water packing material and filling mining technology and their application[D] (China University of Mining and Technology, 2009). Yi, Q. Study on deformation characteristics of surrounding rock in loess cemented fill mining under slope terrain[D] (Hunan University of Science and Technology, 2023). Qiu, J. et al. Research progress on dealkalization and activation of red mud and its application in cementitious materials[J]. Appl. Chem. Ind. 53 (06), 1421–1426 (2024). Peng, M. et al. Effect of composition on the performance and microstructures of mining high-water solidified materials[J]. Mineral. Eng. Res. 26 (03), 56–59 (2011). Shi, S. et al. Study on physical and mechanical properties of modified high water filling material with fly ash and calcium carbide slag[J]. Mater. Rep. 35 (07), 7027–7032 (2021). Tu, B. et al. Differential analysis of properties of cement based and mining alkali activated cementitious materials[J]. Metal Mine , (10): 48–56. (2022). Kang, Y. et al. Application experimental on the single component polyurethane blasting hole filler[J]. Eng. Blasting . 25 (02), 14–18 (2019). Hu, H. & Cui, M. Characteristics of high water content hardening body and analysis on the mechanical mechanism of fill body[J]. Min. Res. Dev. , (05): 23–25. (2001). Feng, G. Research on the superhigh-water packing material and filling mining technology and their application[D] (China University of Mining and Technology, 2009). Zhang, Z. et al. Experimental study on the effect of water temperature on the mechanical properties of high-water materials[J]. J. Sichuan Univ. Sci. Engineering(Natural Sci. Edition) . 32 (06), 60–66 (2019). Yu, Q. et al. Investigation on the hydration and hardening mechanism and properties of a newly developed rapid setting and solidifying material with high water content[J]. Cem. Technol. , (05): 3–6. (1995). Liu, D. Study on hydrating and hardening mechanisms of high-water rapid-setting material[D] (China University of Mining and Technology, 2015). Additional Declarations No competing interests reported. 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2","display":"","copyAsset":false,"role":"figure","size":660884,"visible":true,"origin":"","legend":"\u003cp\u003eTest Loading and DIC Monitoring System\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-6291038/v1/f80f2273b11a86aa6d65021a.png"},{"id":81018187,"identity":"af4321ec-e1ff-471d-862a-ea64da0c8dcc","added_by":"auto","created_at":"2025-04-21 09:16:14","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":93436,"visible":true,"origin":"","legend":"\u003cp\u003eDisplacement-test force curves and Compressive strength of stemming clay\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-6291038/v1/d28389b29d591f3ae522c466.png"},{"id":81017047,"identity":"d4d29bcb-3f87-4050-8b79-f77b4481f428","added_by":"auto","created_at":"2025-04-21 09:08:14","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":99617,"visible":true,"origin":"","legend":"\u003cp\u003eDisplacement-test force curves and splitting tensile strength of stemming clay\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-6291038/v1/b91c471373ba144d304a2b05.png"},{"id":81017024,"identity":"0c9dd22e-24ed-45f1-b8ff-8ecdb544275d","added_by":"auto","created_at":"2025-04-21 09:08:14","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":20875,"visible":true,"origin":"","legend":"\u003cp\u003eXRD analysis of shot mud at ages 0.5h and 6h\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-6291038/v1/118c2c835dc00e56b6237732.png"},{"id":81017034,"identity":"21f9226c-1c33-42b9-85dd-d746b8547e1d","added_by":"auto","created_at":"2025-04-21 09:08:14","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":754592,"visible":true,"origin":"","legend":"\u003cp\u003eSEM images of clay samples at different ages\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-6291038/v1/ff844ce0e04471db26817201.png"},{"id":81017003,"identity":"52579380-bfe6-4c0b-8445-967f698e787a","added_by":"auto","created_at":"2025-04-21 09:08:13","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":713917,"visible":true,"origin":"","legend":"\u003cp\u003eEnergy spectrum analysis of shotclay samples at age 0.5h\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-6291038/v1/bcc5dc014764d8c314a526c2.png"},{"id":81017027,"identity":"dfcd3cad-c779-4346-99e9-a4d1fac4da34","added_by":"auto","created_at":"2025-04-21 09:08:14","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":583615,"visible":true,"origin":"","legend":"\u003cp\u003eEnergy spectrum analysis of shotclay samples at 6h age\u003c/p\u003e","description":"","filename":"8.png","url":"https://assets-eu.researchsquare.com/files/rs-6291038/v1/ddbdd34d5ccc554d8106c168.png"},{"id":81018192,"identity":"957bde2f-18c2-47bb-9cc4-6d59c9561c97","added_by":"auto","created_at":"2025-04-21 09:16:14","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":12447,"visible":true,"origin":"","legend":"\u003cp\u003ePorosity of gun-mud at different ages\u003c/p\u003e","description":"","filename":"9.png","url":"https://assets-eu.researchsquare.com/files/rs-6291038/v1/7440354ba07b4636fe319e24.png"},{"id":81018190,"identity":"b414ded7-252e-4ee1-86c2-c9db36c79e9a","added_by":"auto","created_at":"2025-04-21 09:16:14","extension":"png","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":21795,"visible":true,"origin":"","legend":"\u003cp\u003eCumulative hole area curve with aperture\u003c/p\u003e","description":"","filename":"10.png","url":"https://assets-eu.researchsquare.com/files/rs-6291038/v1/fd809ab78141ddc7a121595b.png"},{"id":81018195,"identity":"fc558926-2cbc-406e-a743-d534a8db4fa1","added_by":"auto","created_at":"2025-04-21 09:16:15","extension":"png","order_by":11,"title":"Figure 11","display":"","copyAsset":false,"role":"figure","size":34332,"visible":true,"origin":"","legend":"\u003cp\u003eTotal pore volume and specific surface area of old and new mortar\u003c/p\u003e","description":"","filename":"11.png","url":"https://assets-eu.researchsquare.com/files/rs-6291038/v1/5ae760f5ad32728950e3194d.png"},{"id":81017039,"identity":"141b93b1-7ed8-4f4a-b086-64fb85c5df03","added_by":"auto","created_at":"2025-04-21 09:08:14","extension":"png","order_by":12,"title":"Figure 12","display":"","copyAsset":false,"role":"figure","size":24660,"visible":true,"origin":"","legend":"\u003cp\u003eCumulative aperture distribution curve\u003c/p\u003e","description":"","filename":"12.png","url":"https://assets-eu.researchsquare.com/files/rs-6291038/v1/a089618a0fd3fe7d7a440304.png"},{"id":81017017,"identity":"ba509185-0d7e-4c37-bbc1-14e81620c5ad","added_by":"auto","created_at":"2025-04-21 09:08:14","extension":"png","order_by":13,"title":"Figure 13","display":"","copyAsset":false,"role":"figure","size":23933,"visible":true,"origin":"","legend":"\u003cp\u003eDifferential aperture distribution curve\u003c/p\u003e","description":"","filename":"13.png","url":"https://assets-eu.researchsquare.com/files/rs-6291038/v1/0ca79854192bd251f6b14e00.png"},{"id":86699714,"identity":"a43020ba-063c-4896-b237-d6e081fa6013","added_by":"auto","created_at":"2025-07-14 16:11:12","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":4782989,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6291038/v1/a86f4572-6009-4c22-b500-97c3ab0a9a77.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"The Influence of Ageing on the Performance of Taphole Clay and the Study of Rapid-setting Mechanism","fulltext":[{"header":"Introduction","content":"\u003cp\u003eCurrently, metal mines globally are predominantly categorized into two types: open-pit mines and underground mines. Regardless of the type, the predominant method of extraction is blasting mining. This involves drilling boreholes into the ore body, followed by the placement of explosives to harness the energy of the blast to fragment the rock, thereby detaching the ore from the surrounding rock mass\u003csup\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]\u003c/sup\u003e. The utilization of explosive energy directly affects the blasting effect, and then has a profound impact on many factors such as mining cost, mining safety, mining efficiency and so on[\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]\u003c/sup\u003e. A variety of strategies exist to improve the efficiency of explosive energy utilization, with blast hole stemming being a notably effective and significant method. Good quality of blast hole stemming can prolong the detonation gas in the hole time, and then produce a larger range of fissures, and then expansion, penetration, cutting; can guarantee the full reaction of the explosives in the blast hole, reduce the explosives unit consumption, improve the effect of blasting\u003csup\u003e[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eIn recent years, scholars have shifted their focus towards the research of rapid and efficient hole-sealing materials, exploring the optimal material ratios. The choice of the main material of high water rapid-setting material is based on sulfur-aluminate cement\u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/sup\u003e, while Guo\u003csup\u003e[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]\u003c/sup\u003e chose ferroaluminate cement as the main material. Feng\u003csup\u003e[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]\u003c/sup\u003e chose sulphoaluminate cement as the main material by comparing and analyzing the composition and hydration mechanism of several kinds of cement. In the formulation of high water rapid-setting materials, auxiliary materials predominantly consist of gypsum and lime, complemented by the addition of a small amount of suspending agents and early strength agents\u003csup\u003e[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]\u003c/sup\u003e. Sometimes small amounts of alkaline materials or fly ash slag are added, etc\u003csup\u003e[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/sup\u003e. Feng\u003csup\u003e[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]\u003c/sup\u003e mentioned that a small amount of retarding agent should be added to the auxiliary material, so that the retarding effect of the main material can be quickly lifted after the mixing of the two materials, and the mixing slurry can quickly complete the initial setting. Peng et al\u003csup\u003e[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/sup\u003e on the other hand, pointed out that not only modified montmorillonite as a suspending agent, but also sodium tripolyphosphate and sodium lignosulfonate as dispersing agents were added to their excipients..\u003c/p\u003e \u003cp\u003eIn addition, scholars have also carried out some investigations on the mechanical strength of rapid-setting materials\u003csup\u003e[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e][\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]\u003c/sup\u003e. Kang et al\u003csup\u003e[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/sup\u003e developed a new type of blast hole plugging agent by using polyurethane as raw material in response to the many shortcomings and limitations of traditional taphole mud filling materials, which has the advantages of high safety and reliability performance, reducing the amount of explosives loss, enhancing the utilization rate of blast holes as well as reducing the noise of blasting and other harmful pollutants. Hu et al\u003csup\u003e[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]\u003c/sup\u003e plotted the stress-strain curves of high water quick-consolidation materials at four ages (1d, 3d, 7d, 28d), and pointed out that the uniaxial compression damage of high water rapid-setting materials is divided into four stages. Feng et al\u003csup\u003e[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]\u003c/sup\u003e conducted uniaxial compressive strength as well as triaxial compression tests at different ages under normal curing for high water materials with 91%~97% water volume. It was pointed out that the strength of high water rapid-setting materials under uniaxial compression accounted for 66%~90% of the final strength at 7d, with obvious early strength characteristics, and the strength at all ages increased by about 25% on average when compressed in three directions. Zhang et al\u003csup\u003e[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]\u003c/sup\u003e further found that the peak and residual intensity were increased when the water temperature increased within 25\u0026deg;C to 40\u0026deg;C, and the lower the water-cement ratio, the greater the strength increase. Yu et al\u003csup\u003e[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]\u003c/sup\u003e studied that the increase in curing temperature will enhance the early strength of the material, but will reduce the final strength of the material. However, Liu\u003csup\u003e[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]\u003c/sup\u003e did not find the phenomenon of strength retrogression in the test for the effect of curing temperature. In summary, the existing research on the effect of age on the strength of rapid-setting materials is relatively small, and the conclusions are different, and there is no uniform conclusion.\u003c/p\u003e \u003cp\u003eBased on this, this study explores the influence of age on the mechanical properties of rapid-setting materials, and analyzes the variation of each mechanical strength in the process of age increase. Using XRD, SEM-EDS and other analytical means, this study investigates the effect of age on the crystallization transition, microstructure and elemental distribution of taphole clay materials, revealing the intrinsic connection between strength growth and microstructure evolution. This study is of great significance for choosing better stemming materials and age periods in blasting operations in China's mines, so as to realize the convenient, safe, reliable and efficient blasting operation.\u003c/p\u003e"},{"header":"Rapid-setting mechanism of rapid-setting taphole clay","content":"\u003cp\u003eRapid-setting taphole clay is a new type of taphole clay material with high solid water content, which is based on the generation mechanism of high water rapid-setting materials and obtained through formula experiments according to the requirements of taphole clay stemming. It is mainly formed by hydration reaction of main material of sulfoaluminate cement and auxiliary material of dihydrate gypsum and quicklime. The main body of the structure is ettringite. Therefore, the whole hydration reaction mechanism is based on the formation mechanism of ettringite to a certain extent.\u003c/p\u003e\n\u003cp\u003eRapid-setting taphole clay main and auxiliary materials through the hydration reaction to generate solidification is a complex process. In the process of using the main material and auxiliary materials are first prepared into a slurry, and then mix the two when using, after mixing the reaction to generate the solidified body. From the material composition analysis, the main substances involved in the reaction are \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({C_4}{A_3}\\overline {S}\\)\u003c/span\u003e\u003c/span\u003e, \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\beta - C2S\\)\u003c/span\u003e\u003c/span\u003e, calcium sulfate and calcium oxide, and its hydration process and products determine the main mechanical properties of the solid. When the main and auxiliary materials slurry mixing, the main substances in the liquid phase environment will quickly react to generate ettringite precipitation, when the system is sufficient reactants, the reaction will give priority to all generated ettringite, and analyze the main substances before and after the reaction changes. The reaction equation is as follows.\u003c/p\u003e\n\u003cdiv id=\"Equ1\" class=\"Equation\"\u003e\n\u003cdiv id=\"FileID_Equ1\" class=\"mathdisplay\"\u003e$$\\begin{gathered} {\\text{C}_4}{\\text{A}_3}\\overline {\\text{S}} {\\text{+8}}\\left( {{\\text{CaS}}{{\\text{O}}_{\\text{4}}}\\cdot 2{\\varvec{H}_2}\\text{O}} \\right){\\text{+6CaO+96}}{\\text{H}_{\\text{2}}}\\text{O} \\to \\hfill \\\\ {\\text{3}}\\left( {{\\text{3}}\\text{C}\\text{a}\\text{O}\\cdot \\text{A}{\\text{l}_2}{\\text{O}_3}\\cdot {\\text{3CaS}}{{\\text{O}}_{\\text{4}}}\\cdot {\\text{32}}{\\text{H}_{\\text{2}}}\\text{O}} \\right) \\hfill \\\\ \\end{gathered}$$\u003c/div\u003e\n\u003cdiv class=\"EquationNumber\"\u003e1\u003c/div\u003e\n\u003c/div\u003e\n\u003cp\u003eWhen there is not enough CaO in the system, the product will not be all ettringite, but will instead form a partial aluminum gel.\u003c/p\u003e\n\u003cdiv id=\"Equ2\" class=\"Equation\"\u003e\n\u003cdiv id=\"FileID_Equ2\" class=\"mathdisplay\"\u003e$$\\begin{gathered} {\\text{C}_4}{\\text{A}_3}\\overline {\\text{S}} {\\text{+2}}\\left( {{\\text{CaS}}{{\\text{O}}_{\\text{4}}}\\cdot 2{\\varvec{H}_2}\\text{O}} \\right){\\text{+34}}{\\text{H}_{\\text{2}}}\\text{O} \\to \\hfill \\\\ {\\text{3}}\\text{C}\\text{a}\\text{O}\\cdot \\text{A}{\\text{l}_2}{\\text{O}_3}\\cdot {\\text{3CaS}}{{\\text{O}}_{\\text{4}}}\\cdot {\\text{32}}{\\text{H}_{\\text{2}}}\\text{O}+2\\left( {\\text{A}{\\text{l}_2}{\\text{O}_3}\\cdot 3{\\text{H}_2}\\text{O}} \\right) \\hfill \\\\ \\end{gathered}$$\u003c/div\u003e\n\u003cdiv class=\"EquationNumber\"\u003e2\u003c/div\u003e\n\u003c/div\u003e\n\u003cp\u003eWhen the CaSO\u003csub\u003e4\u003c/sub\u003e content in the system is insufficient, the reaction will no longer produce ettringite but low-sulfur hydrated calcium thioaluminate (AFm) and aluminum gel. The generated ettringite will also decompose to form low-sulfur hydrated calcium thioaluminate.\u003c/p\u003e\n\u003cdiv id=\"Equ3\" class=\"Equation\"\u003e\n\u003cdiv id=\"FileID_Equ3\" class=\"mathdisplay\"\u003e$${\\text{C}_4}{\\text{A}_3}\\overline {\\text{S}} {\\text{+18}}{\\text{H}_{\\text{2}}}\\text{O} \\to {\\text{3CaO}}\\cdot {\\text{A}}{{\\text{l}}_{\\text{2}}}{{\\text{O}}_{\\text{3}}}\\cdot {\\text{CaS}}{{\\text{O}}_{\\text{4}}}\\cdot {\\text{12}}{{\\text{H}}_{\\text{2}}}{\\text{O+2}}\\left( {\\text{A}{\\text{l}_2}{\\text{O}_3}\\cdot 3{\\text{H}_2}\\text{O}} \\right)$$\u003c/div\u003e\n\u003cdiv class=\"EquationNumber\"\u003e3\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Equ4\" class=\"Equation\"\u003e\n\u003cdiv id=\"FileID_Equ4\" class=\"mathdisplay\"\u003e$$\\begin{gathered} {\\text{3}}\\text{C}\\text{a}\\text{O}\\cdot \\text{A}{\\text{l}_2}{\\text{O}_3}\\cdot {\\text{3CaS}}{{\\text{O}}_{\\text{4}}}\\cdot {\\text{32}}{\\text{H}_{\\text{2}}}\\text{O} \\to \\hfill \\\\ {\\text{3}}\\text{C}\\text{a}\\text{O}\\cdot \\text{A}{\\text{l}_2}{\\text{O}_3}\\cdot {\\text{CaS}}{{\\text{O}}_{\\text{4}}}\\cdot {\\text{12}}{\\text{H}_{\\text{2}}}\\text{O}+2\\left( {{\\text{CaS}}{{\\text{O}}_{\\text{4}}}\\cdot {\\text{2}}{\\text{H}_{\\text{2}}}\\text{O}} \\right)+{\\text{16}}{\\text{H}_{\\text{2}}}\\text{O} \\hfill \\\\ \\end{gathered}$$\u003c/div\u003e\n\u003cdiv class=\"EquationNumber\"\u003e4\u003c/div\u003e\n\u003c/div\u003e\n\u003cp\u003eWhen calcium carbonate is added to the formula of rapid-setting taphole clay, it will prevent the transformation of high sulfur type salt to low sulfur type salt in the solution, which may lead to the absence of AFm in the product. So a certain proportion of calcium carbonate can be added to the formula of rapid-setting taphole clay instead of calcium oxide, which prevents the generation of AFm and improves the coagulation time of the taphole clay.\u003c/p\u003e\n\u003cp\u003eIn addition to \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({C_4}{A_3}\\overline {S}\\)\u003c/span\u003e\u003c/span\u003e,, another major component in sulfoaluminate cement, hydrates to produce calcium silicate gel (C-S-H). The C/S in this gel is related to the concentration of calcium oxide in the liquid phase. When the concentration of calcium oxide is low, type Ⅰ hydrated calcium silicate is generated, with a C/S between 0.5 and 1.5. Therefore, for every 1 mol of \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\beta - C2S\\)\u003c/span\u003e\u003c/span\u003e hydrated to form 1 mol of C-S-H gel, 1 mol of calcium hydroxide is also generated. The precipitated calcium hydroxide will continue to react with aluminum gel and calcium sulfate to form ettringite. The reaction equation is as follows.\u003c/p\u003e\n\u003cdiv id=\"Equ5\" class=\"Equation\"\u003e\n\u003cdiv id=\"FileID_Equ5\" class=\"mathdisplay\"\u003e$$\\beta - {\\text{C}_{\\text{2}}}\\text{S}+2{\\text{H}_2}\\text{O} \\to \\text{C} - \\text{S} - \\text{H}+\\text{C}\\text{a}{\\left( {\\text{O}\\text{H}} \\right)_2}$$\u003c/div\u003e\n\u003cdiv class=\"EquationNumber\"\u003e5\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Equ6\" class=\"Equation\"\u003e\n\u003cdiv id=\"FileID_Equ6\" class=\"mathdisplay\"\u003e$$\\begin{gathered} 3\\text{C}\\text{a}{\\left( {\\text{O}\\text{H}} \\right)_2}+3\\left( {\\text{C}\\text{a}\\text{S}{\\text{O}_4}\\cdot 2{\\text{H}_2}\\text{O}} \\right)+\\text{A}{\\text{l}_2}{\\text{O}_3}\\cdot 3{\\text{H}_2}\\text{O} \\to \\hfill \\\\ {\\text{3}}\\text{C}\\text{a}\\text{O}\\cdot \\text{A}{\\text{l}_2}{\\text{O}_3}\\cdot {\\text{3CaS}}{{\\text{O}}_{\\text{4}}}\\cdot {\\text{32}}{\\text{H}_{\\text{2}}}\\text{O} \\hfill \\\\ \\end{gathered}$$\u003c/div\u003e\n\u003cdiv class=\"EquationNumber\"\u003e6\u003c/div\u003e\n\u003c/div\u003e\n\u003cp\u003eTherefore, the formation of C-S-H can be accelerated by promoting the hydration reaction of \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\beta - C2S\\)\u003c/span\u003e\u003c/span\u003e. Thus, the pores between the structural skeleton formed by ettringite are filled with cementing matters, and the structure of the solid body is made denser.\u003c/p\u003e\n\u003cp\u003eIn the above, chemical equations are used to describe the changes of substances in the formation process of ettringite from the perspective of reaction mechanism. However, in reality, the change of substances in the formation process of rapid-setting taphole clay is more complicated than the theoretical description. This is because in the actual hydration reaction, on the one hand, with the deepening of hydration reaction, the consistency of slurry will significantly increase, resulting in the migration of ions in the slurry system becoming more and more difficult. On the other hand, due to the generation of ettringite crystals will be adsorbed on the surface of solid particles which have not yet been involved in the reaction, hindering its further participation in the reaction. Therefore, the hydration process of rapid-setting taphole clay will be constrained by the hydration diffusion rate. The hydration process of rapid-setting taphole clay can be roughly divided into the following four stages according to the state change.\u003c/p\u003e\n\u003cp\u003e(1) Hydration induction period\u003c/p\u003e\n\u003cp\u003eAt this stage of hydration induction, the main and auxiliary grout are just mixed and stirred. The ions contained in it quickly dispersed into the mixed slurry and began to react to form part of the ettringite unit cells. This stage lasted for a short time, the hydration heat release was not obvious and the viscosity of the slurry almost did not change.\u003c/p\u003e\n\u003cp\u003e(2) Hydration acceleration period\u003c/p\u003e\n\u003cp\u003eWhen the mixed slurry enters the stage of accelerated hydration, the rate of hydration reaction starts to increase dramatically. Ettringite unit cells formed earlier start to develop and are constantly accompanied by the formation of new ettringite unit cells. In this process, because the slurry system is not ideally uniformly distributed, there will be a small amount of other products such as gel generation. The continuously formed and developed ettringite unit cells will be connected with each other to form a ettringite skeleton, which will fix the gel and free water in it, so that the viscosity of the slurry will increase rapidly to complete the initial coagulation and begin to harden continuously. The whole process of accelerated hydration will release a large amount of heat of hydration, so that the surface temperature of rapid-setting taphole clay is significantly higher than the ambient temperature.\u003c/p\u003e\n\u003cp\u003e(3) Hydration deceleration period\u003c/p\u003e\n\u003cp\u003eWhen the rapid-setting taphole clay hydration rate reached the peak, began to enter the stage of hydration deceleration period. At this time, the system in the ettringite unit cell generation is significantly reduced, began to generate a large number of other substances such as gel, hydration exothermic slowed down significantly. The surface temperature of the gradually hardened rapid-setting taphole clay consolidated body began to decrease.\u003c/p\u003e\n\u003cp\u003e(4) Hydration stabilization period\u003c/p\u003e\n\u003cp\u003eIn this stage, the hydration reaction rate is further reduced, and the hydration process has basically ended. The surface temperature of the slurry gradually decreases until it is the same as the ambient temperature.\u003c/p\u003e"},{"header":"Experimental Plan","content":"\u003ch2\u003e2.1 Experimental material\u003c/h2\u003e\u003cp\u003eAccording to the literature research, the material formation includes two parts: main and auxiliary materials (hereinafter referred to as A and B materials). When the main and auxiliary material slurries are mixed, the substances in them react in a liquid phase environment to form the main structure with ettringite as the backbone. Part of the free water and gel filled with it, so as to complete the transformation from slurry to solid. A material is composed of sulfoaluminate cement and compound retarding dispersant. B material consists of other auxiliary materials such as lime, gypsum and composite rapid-setting agent, A and B microscopic morphology is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. In order to equalize the A, B composition, improve the suspension performance of the B material, the B material is sometimes also added to a certain suspension of dispersant. Retarder is one of the key links in the development of ultra-high water materials. Efficient retarding agents not only simplify the filling process, but importantly, the fired materials in water need to be rapidly put in a stable state by retarding agents to avoid premature hydration with water. The role of rapid-setting agent is to promote their rapid hydration, so as to achieve the purpose of rapid hardening and early strength. And with a lot of water, conventional admixtures can't be as effective as they should be. Finding composite admixtures with good compatibility should be the goal of the test. In the stage of retarding and rapid-setting, suitable suspending and dispersing agents, so that the solid material can be more uniformly and stably suspended in the liquid. The material can be uniformly and stably hydrated to form a homogeneous hydration hardening body.\u003c/p\u003e\u003cp\u003e \u003c/p\u003e\u003cp\u003eThe composition of sulfoaluminate cement clinker used in this experiment is shown in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. Auxiliary materials are gypsum, lime, calcium carbonate, bentonite and additives. It is determined that the number of cement mesh should be ground and screened to more than 200 mesh during the test, and the auxiliary materials of the preliminary formula are gypsum: lime: calcium carbonate: bentonite = 7:2:3:3. The percentage of additive amount of main and auxiliary materials is calculated according to the total weight of main and auxiliary materials respectively. The gypsum used in the auxiliary materials is calcium sulfate dehydrate, the rest of the additives are analytical pure auxiliary materials such as gypsum, lime, calcium carbonate, bentonite and additives.\u003c/p\u003e\u003cp\u003e \u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" 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=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\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\u003eThe chemical composition of sulpho-aluminate cement\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"10\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colspan=\"10\" nameend=\"c10\" namest=\"c1\"\u003e \u003cp\u003eComposition analysis of sulfho-aluminate cement clinker\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003echemical composition\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLOSS\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSiO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eAl\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eFe\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eCaO\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eMgO\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eSO\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eTiO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e∑\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epercentage\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.32\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e27.63\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.67\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e44.80\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e2.20\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e8.40\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e1.47\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e99.49\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eminerals\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCM\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eP\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eC\u003csub\u003e4\u003c/sub\u003eA\u003csub\u003e3\u003c/sub\u003eS\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eC\u003csub\u003e2\u003c/sub\u003eS\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eC\u003csub\u003e4\u003c/sub\u003eAF\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eCT\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epercentage\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.951\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.13\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.29\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e52.86\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e37.31\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e5.08\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e2.50\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eThe role of rapid-setting taphole clay auxiliary additives is to make the main and auxiliary materials of the two slurries can be quickly solidified after mixing. Therefore, in this part of the test, consult the literature to screen out the different categories of rapid-setting agent may be applicable. And through the test to determine the type of rapid-setting agent and the amount of additive, so that the rapid-setting taphole clay main and auxiliary slurry can be mixed in a short period of time to complete the rapid solidification (the initial solidification time of \u0026lt; 3 min, the final solidification time of about 30 min). And then optimize and adjust the proportion of auxiliary materials of rapid-setting taphole clay. Finally, the test was conducted to observe whether the addition of rapid-setting agent would affect the flow state of the auxiliary slurry.\u003c/p\u003e\u003ch3\u003e2.2 Preparation process\u003c/h3\u003e\u003cp\u003eIn order to ensure the accuracy of the test data, the following specific test operation steps are set up. The single pulp preparation process consists of weighing and mixing the material using an analytical electronic balance, taking tap water from the measuring cylinder, adding it to the mixing pot and wetting it, and then slowly adding the material to the pot and placing it on the mixing equipment. With low gears stir into container in about 10 minutes, finally clean mixing pot and impeller. Then mix the slurry and add B and A slurry to the mixing container according to the test requirements. Mix by hand for 30 seconds to combine the two thoroughly. Then pour the mixture into the test block box and divide it into three parts, record the start time of standing and observe the state of the test block.\u003c/p\u003e\u003ch3\u003e2.3 Test method\u003c/h3\u003e\u003cp\u003e(1) Uniaxial compression test and splitting test: The instrument used is WDW microcomputer-controlled electro-hydraulic servo testing machine, supplemented by XTDIC three-dimensional whole strain deformation measurement and analysis system. The acquisition speed of the high-speed camera is 5000 frames/s. The loading rate is 0.01 kN/s through the pressure loading control mode, and the test loading and measurement system is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e \u003c/p\u003e\u003cp\u003e(2) XRD: The dried specimens were ground into powder form, and the test data were processed and analyzed using XRD analysis software.\u003c/p\u003e\u003cp\u003e(3) SEM: The samples of different ages were observed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS).\u003c/p\u003e\u003cp\u003e(4) Mercury injection test scheme: The pore structure parameters were determined by mercury injection method (MIP) to analyze the pore structure changes of taphole clay at different ages. Mercury injection instrument is used to measure pore structure parameters of materials.\u003c/p\u003e"},{"header":"Experimental conclusion","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\n \u003ch2\u003e3.1 Mechanical strength\u003c/h2\u003e\n \u003cp\u003eFigure\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e shows the stress-strain curves of the test blocks at different ages. The key parameters, such as the magnitude of peak stress and the rate of ascent, are different. According to the image, the stress-strain curve can be roughly divided into four stages: pore fracture compaction stage, elastic deformation to microelastic fracture stable development stage, plastic yield to unstable fracture development stage, and strain softening stage after fracture. After the peak compressive strength is reached, the curve is basically flat and slowly decreases within a certain range, and the internal structure of the sample is destroyed. The samples basically keep the whole shape, the cracks expand rapidly, cross and combine with each other to form a fracture surface. The compressive strength measured by the test blocks of different ages is shown in Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e. The strengths of the four instars are 0.51 MPa, 0.83 MPa, 1.31 MPa and 1.58 MPa, respectively. The compressive strength of 1h to 6h increases rapidly with time. From 6h to 24h, the growth rate decreased to 1.48%. It can be seen from the figure that with the same other conditions, the compressive strength of the test block increases with the increase of age. It can be seen that the age has a great influence on the compressive strength of the taphole clay.\u003c/p\u003e\n \u003cp\u003eThe change of the test force along with the displacement during the loading process of the splitting experiment is shown in Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e. The shape of the failure curve is basically the same for different ages. No visible crack was generated at the center of the specimen before the peak load was reached. When the peak load is reached, a clear crack appears and begins to expand rapidly. Subsequently, cracks permeate the whole specimen and the load drops sharply. As can be seen from the figure, there are obvious differences in the test forces of the test blocks at different ages during failure, and the peak loads at the four ages (0.5h, 1h, 6h and 24h) are 0.25 kN, 0.45 kN, 1.02kN and 1.25 kN respectively. The peak load increases with the age. It can be seen that with the increase of age, the tensile strength of the taphole clay also increases significantly. The measured tensile strength of the test blocks at different ages is shown in Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e. The tensile strength of the four ages is 0.033 MPa, 0.059 MPa, 0.13 MPa and 0.16 MPa respectively. It can be seen from the figure that the tensile strength before 6 hours increases rapidly with time, and the growth rate from 1h to 6h is 1.48%. 6h to 24h showed a slower growth rate of 0.17%. It can be concluded that the taphole clay is more sensitive to age. In the age period from 1h to 6h, the strength increases most obviously.\u003c/p\u003e\n\u003c/div\u003e\n\u003ch3\u003e3.2 XRD analysis of taphole clay at different ages\u003c/h3\u003e\n\u003cp\u003eFigure\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e shows the XRD analysis results of 0.5h and 6h taphole clay samples respectively. The figure shows the characteristic peaks of taphole clay at different ages. After adequate hydration, the main products are calcium carbonate and ettringite, followed by calcium clinosilicate, quartz and hatrurite. Ettringite, as the main hydration product of sulfoaluminate cement, has a significant contribution to the strength of taphole clay. Under the same temperature and water-cement ratio, the contents of calcium carbonate and ettringite increased with the increase of curing age, and the peak diffraction value increased significantly. Therefore, the content of hydration products produced by different taphole clay ages is also different. This shows that the age can affect the hydration of cement, and the longer the age, the more hydration products. At the same time, it also explains that with the increase of age, the strength of taphole clay is better.\u003c/p\u003e\n\u003cp\u003eThe diffraction pattern of the sample to be measured is compared with that of the standard sample. According to the intensity and position of the diffraction peak, the content of each phase in the sample to be measured can be calculated. Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e and Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e detail the composition and content of taphole clay at ages 0.5h and 6h. The contents of calcium carbonate, ettringite, quartz, calcium clinosilicate and hatrurite at 0.5h age are 50.4%, 23.4%, 3.1%, 18.9% and 4.2% respectively. The contents of various substances in the 6h taphole clay are 39.5%, 40.0%, 1.0%, 17.9% and 1.6% respectively. With the age increasing from 0.5h to 6h, the content of ettringite increased by 16.6% and the content of calcium carbonate decreased by 10.9%. The content of quartz, calcium clinosilicate and hatrurite decreased, but not obviously. It can be seen that the age has a great influence on the content of calcium carbonate and ettringite in the hydrated products of the taphole clay, so the age is also an important factor affecting the properties of the taphole clay.\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n \u003ctable id=\"Tab2\" border=\"1\"\u003e\n \u003ccaption\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eMaterial composition and content of 0.5h cannon clay\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eThe Object Name\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSource\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eWeight%\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\u003eCalcite-Ca(CO\u003csub\u003e3\u003c/sub\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePDF#01-078-4614\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e50.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eEttringite -Ca\u003csub\u003e6\u003c/sub\u003eAl\u003csub\u003e2\u003c/sub\u003e(SO\u003csub\u003e4\u003c/sub\u003e)\u003csub\u003e3\u003c/sub\u003e(OH)\u003csub\u003e12\u003c/sub\u003e(H\u003csub\u003e2\u003c/sub\u003eO)\u003csub\u003e26\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePDF#04-013-3691\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e23.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eQuartz-SiO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePDF#04-016-2085\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLarnite-Ca\u003csub\u003e2\u003c/sub\u003e(SiO\u003csub\u003e4\u003c/sub\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePDF#01-083-0461\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e18.9\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eHatrurite -Ca\u003csub\u003e3\u003c/sub\u003e(SiO\u003csub\u003e4\u003c/sub\u003e)O\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePDF#04-014-9801\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"3\" align=\"left\"\u003e\n \u003cp\u003eXRF(Wt%): Ca\u0026thinsp;=\u0026thinsp;35.7%, S\u0026thinsp;=\u0026thinsp;1.8%, Si\u0026thinsp;=\u0026thinsp;5.0%, A1\u0026thinsp;=\u0026thinsp;1.0%, O\u0026thinsp;=\u0026thinsp;49.2%, C\u0026thinsp;=\u0026thinsp;6.1%, H\u0026thinsp;=\u0026thinsp;1.2%\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\n \u003cdiv class=\"colspec\" align=\"left\"\u003e\u0026nbsp;\u003c/div\u003e\n \u003ctable id=\"Tab3\" border=\"1\"\u003e\n \u003ccaption\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eComposition and content of 6h gun-mud material\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eThe Object Name\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSource\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eWeight%\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\u003eCalcite-Ca(CO\u003csub\u003e3\u003c/sub\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePDF#01-078-4614\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e39.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eEttringite-Ca\u003csub\u003e6\u003c/sub\u003eAl\u003csub\u003e2\u003c/sub\u003e(SO\u003csub\u003e4\u003c/sub\u003e)\u003csub\u003e3\u003c/sub\u003e(OH)\u003csub\u003e12\u003c/sub\u003e(H\u003csub\u003e2\u003c/sub\u003eO)\u003csub\u003e26\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePDF#04-013-3691\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e40.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eQuartz-SiO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePDF#04-016-2085\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLarnite-Ca\u003csub\u003e2\u003c/sub\u003e(SiO\u003csub\u003e4\u003c/sub\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePDF#01-083-0461\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e17.9\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eHatrurite-Ca\u003csub\u003e3\u003c/sub\u003e(SiO\u003csub\u003e4\u003c/sub\u003e)O\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePDF#04-014-9801\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"3\" align=\"left\"\u003e\n \u003cp\u003eXRF(Wt%): Ca\u0026thinsp;=\u0026thinsp;32.7%, S\u0026thinsp;=\u0026thinsp;3.1%, Si\u0026thinsp;=\u0026thinsp;3.6%, A1\u0026thinsp;=\u0026thinsp;1.7%, O\u0026thinsp;=\u0026thinsp;52.2%, C\u0026thinsp;=\u0026thinsp;4.7%, H\u0026thinsp;=\u0026thinsp;2.1%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003ch3\u003e3.3 Microscopic mechanism analysis of taphole clay at different ages\u003c/h3\u003e\n\u003cp\u003eSEM of taphole clay samples at different ages is shown in Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e6\u003c/span\u003e. The hydration products of the taphole clay cured to 0.5h are mainly fibrous and honeycomb hydrated calcium silicate and a small amount of needle-like ettringite. Its internal structure is fluffy and rich in holes, which is not conducive to the strength performance of the taphole clay. With the increase of curing age, a large amount of ettringite is interspersed in the gap between the hydrated calcium silicate and the particle. The internal pore network structure of the taphole clay is refined, segmented and filled, and the density of the taphole clay is improved. At the age of 6h, a large amount of ettringite is attached to the surface of calcium silicate hydrate in the taphole clay, which strengthens the connection between calcium silicate hydrate and promotes the formation of dense spatial structure. Combined with XRD results, the hydrated calcium silicate produced by taphole clay hydration reaction is mostly high-density C-S-H gel. With the increase of age, SEM shows more ettringite, forming denser microscopic results and better strength properties.\u003c/p\u003e\n\u003cp\u003eIn order to further study the mechanism of increasing compressive strength, flexural strength and splitting tensile strength of taphole clay with age. SEM-EDS analysis was performed on sample microblocks of 0.5h and 6h ages, as shown in Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e7\u003c/span\u003e and Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e8\u003c/span\u003e. It can be seen from the figure that elements can be evenly distributed in each area of the scan in the element distribution diagram, and no significant difference was found in the scanning results of the two ages. The highest chemical elements are O and Ca elements, followed by Al, S and C, and Si elements are the least. Therefore, according to XRD, the main components of the mud are calcium silicate (Ca(CO\u003csub\u003e3\u003c/sub\u003e)) and ettringite (Ca\u003csub\u003e6\u003c/sub\u003eAl\u003csub\u003e2\u003c/sub\u003e(SO\u003csub\u003e4\u003c/sub\u003e)\u003csub\u003e3\u003c/sub\u003e(OH)\u003csub\u003e12\u003c/sub\u003e(H\u003csub\u003e2\u003c/sub\u003eO)\u003csub\u003e26\u003c/sub\u003e), so the O and Ca elements are highest. At 0.5h age, the contents of O and Ca elements are 51.30% and 27.72% respectively. At 6h age, the contents of O and Ca elements are 47.27% and 28.75% respectively. It can be seen that with the growth of age, the content of O elements decreases and the content of Ca elements increases, which is mutually confirmed with the results of XRD.\u003c/p\u003e\n\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\n \u003ch2\u003e3.4 Mercury injection analysis of taphole clay\u003c/h2\u003e\n \u003cp\u003eMercury injection test was carried out on taphole clay samples of different ages (0.5, 1, 6, 24h), and the experimental data were analyzed and processed to obtain the structural characteristics of taphole clay.\u003c/p\u003e\n \u003cp\u003e(1) Porosity\u003c/p\u003e\n \u003cp\u003ePorosity is defined as the percentage of the total apparent volume of the void of the material, calculated as follows.\u003c/p\u003e\n \u003cdiv id=\"Equ7\" class=\"Equation\"\u003e\n \u003cdiv id=\"FileID_Equ7\" class=\"mathdisplay\"\u003e$$P=\\frac{{{V_{\\text{a}}}}}{{{V_{\\text{b}}}}} \\times {\\text{100\\% }}$$\u003c/div\u003e\n \u003cdiv class=\"EquationNumber\"\u003e7\u003c/div\u003e\n \u003c/div\u003e\n \u003cp\u003eIn the formula: Va is the actual volume of mercury injected into the sample, which can also be called the void volume, ml; V\u003csub\u003eb\u003c/sub\u003e is the total volume of the sample, ml.\u003c/p\u003e\n \u003cp\u003eThe porosity of the taphole clay samples under four ages are shown in Fig. \u003cspan class=\"InternalRef\"\u003e9\u003c/span\u003e. It can be seen from the figure that the porosity of the taphole clay decreases with the increase of age. The porosity of the taphole clay at 0.5h is 27.39%. When the age is 1h, the porosity decreases by 8.18\u0026ndash;25.15%. When the age reaches 6h and 24h, the porosity relative to the age of 0.5h decreases by 16.79% and 20.74% respectively, to 22.79% and 21.71%. The strength of the taphole clay increases gradually with the increase of age, mainly because the chemical composition of the raw material and the binder gradually react to form a more stable structure, so that the internal organization of the taphole clay is more compact. At the same time, the particle size composition and particle grading of the raw material enable the fine particles to fill the void between the coarse particles, further reducing the porosity. In addition, the evaporation of water in the raw material also promotes the compact structure of the taphole clay and reduces the porosity. In the initial hardening period of the taphole clay, especially in the first 6 hours, the rapid reaction of the binder to the feedstock, the rapid evaporation of water, and the tight arrangement and filling of particles together lead to a significant reduction in porosity during this stage.\u003c/p\u003e\n \u003cp\u003e(2) Specific surface area and total pore volume\u003c/p\u003e\n \u003cp\u003eThe variation of cumulative pore area with pore diameter per unit mass of taphole clay measured by intrusive mercury test is shown in Fig. \u003cspan class=\"InternalRef\"\u003e10\u003c/span\u003e. It can be seen from the figure that the cumulative pore area changes with the pore size at different ages in a basically consistent trend, showing that the large pore area is small. With the increasing of mercury inlet pressure, mercury gradually invades smaller diameter pores. The pore area mainly depends on the pore diameter of 5\u0026thinsp;~\u0026thinsp;500 nm. The peak point of the curve represents the specific surface area of the porous material, which is defined as the internal surface area of the pores in the porous material per unit mass (volume). The specific surface area of the taphole clay at age 0.5h is the largest, and that of 24h age taphole clay is the smallest.\u003c/p\u003e\n \u003cp\u003eThe total pore volume is defined as the total volume of pores per unit mass of the material, that is, the total amount of mercury injected. The total pore volume and specific surface area in the old and new mortar calculated by mercury injection are shown in Fig. \u003cspan class=\"InternalRef\"\u003e11\u003c/span\u003e. The results show that the total pore volume in the taphole clay increases with the increase of age. Since the mercury injection method assumes that the pores in the material are all connected cylindrical holes, the pores in the actual material are irregular in shape and there are closed holes, resulting in irregular variation of the specific surface area. The total pore volume and specific surface area of the 0.5h taphole clay are 1.827 ml/g and 29.08 m\u003csup\u003e2\u003c/sup\u003e/g. The total pore volume and specific surface area of 1h are 1.7579 ml/g and 24.568 m\u003csup\u003e2\u003c/sup\u003e/g respectively, and the total pore volume and specific surface area are reduced by 3.78% and 15.52% respectively. The total pore volume and specific surface area at age 6h are 1.5586 ml/g and 25.37 m\u003csup\u003e2\u003c/sup\u003e/g. At 24h age, the total pore volume and specific surface area are 1.4372 ml/g and 26.03 m\u003csup\u003e2\u003c/sup\u003e/g. The total pore volume continues to decrease, while the specific surface area increases slightly. With the hydration reaction of cement, more cement gel fills the pores. This process not only increases the gel-space ratio, but also results in the decrease of the total pore volume of the material. With the increase of age and the deepening of cement hydration, the compactness of the taphole clay increases gradually. The increase in compactness means that the internal pores of the material are reduced, that is, the total pore volume is reduced.\u003c/p\u003e\n \u003cp\u003e(3) Pore size distribution\u003c/p\u003e\n \u003cp\u003eThe pore size distribution of quick-setting taphole clay at different ages is shown in Table \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e.\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\n \u003cdiv class=\"colspec\" align=\"left\"\u003e\u003cbr\u003e\u003c/div\u003e\n \u003ctable id=\"Tab4\" border=\"1\"\u003e\n \u003ccaption\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003ePore size distribution of old and new mortar\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth rowspan=\"2\" align=\"left\"\u003e\n \u003cp\u003eAge/h\u003c/p\u003e\n \u003c/th\u003e\n \u003cth colspan=\"4\" align=\"left\"\u003e\n \u003cp\u003ePore size distribution(%)\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;10 nm\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e10\u0026ndash;100 nm\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e100\u0026ndash;1000 nm\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u0026gt;\u0026thinsp;1000 nm\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\u003e0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e13.11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e51.33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e25.69\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e9.88\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e13.28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e51.73\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e25.53\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e9.46\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e13.48\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e52.61\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e24.09\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e9.82\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e13.95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e54.23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e23.69\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8.13\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003cp\u003eThe cumulative pore size distribution curve of the quick-setting taphole clay at different ages is shown in Fig. \u003cspan class=\"InternalRef\"\u003e12\u003c/span\u003e. In the range of pore size from 1000 nm to 50000 nm, the curve rose slowly, and the accumulated mercury content in the taphole clay increased with the increase of age. The variation trend of accumulated mercury content in taphole clay at different ages is similar. In the range of pore size from 5 nm to 1000nm, the slope of the curve increases rapidly, and it can be seen that the pore size of the taphole clay is concentrated in the range of 5 nm to 1000nm. The cumulative mercury content of taphole clay at 0.5h and 1h increased significantly, while the cumulative mercury content of taphole clay at 6h and 24h increased relatively little.The pore size of taphole clay is mainly concentrated between 5 nm and 1000 nm. With the increase of age, the number of gel pores (\u0026lt;\u0026thinsp;10 nm) and transition pores (10\u0026ndash;100 nm) decreased, while the number of capillary pores (100\u0026ndash;1000 nm) and large pores (\u0026gt;\u0026thinsp;1000 nm) increased, and the change amplitude was more obvious when the age increased from 1h to 6h. This is consistent with the growth of the strength of the quick-setting taphole clay from 1h to 6h, which can be mutually confirmed.\u003c/p\u003e\n \u003cp\u003eIn the cumulative pore diameter distribution curve, the pore diameter corresponding to the slope mutation point is defined as the critical pore diameter, that is, the maximum pore diameter corresponding to the significant increase in the volume of mercury injected. The cement-based material contains pores of different sizes, and the larger pores are connected by smaller pores. The critical aperture is the maximum aperture of each hole connecting the larger pores, which reflects the connectivity of the pores and the curvature of the permeability path\u003csup\u003e[\u003cspan class=\"CitationRef\"\u003e16\u003c/span\u003e]\u003c/sup\u003e. The critical pore sizes of 0.5, 1, 6 and 24h taphole clay are 2916.21 nm, 2466.93 nm, 1597.29 nm and 1311.12 nm, respectively, which increase with the age. In other words, the increase of age reduces the connectivity of the pore structure of taphole clay. With the increase of age, the hydration reaction of cement inside the quick-setting taphole clay continues, resulting in the change of pore structure. Larger pores may gradually decrease or close due to the filling of hydration products, while smaller pores may become more complex and tortuous due to the growth of hydration products. Therefore, although the total volume of the pores may be reduced, the connectivity between the pores may also be reduced due to the reduction of the pore size and the zigzag of the path. In summary, the critical pore diameter of quick-setting taphole clay decreases with the increase of age, which reflects the decrease of pore structure connectivity and the increase of permeability path curvature. This is caused by the continuous hydration reaction of cement and the gradual change of pore structure.\u003c/p\u003e\n \u003cp\u003eWith dV/dlgr as the vertical axis and aperture as the horizontal axis, the differential aperture distribution curves of taphole clay under different curing time were obtained, as shown in Fig. \u003cspan class=\"InternalRef\"\u003e13\u003c/span\u003e. The curve reflects the pore distribution in different pore sizes, and the area surrounded by the curve is the total pore volume of the sample. In the differential aperture distribution curve, the aperture corresponding to the peak value in different aperture ranges is defined as the most feasible aperture in the corresponding aperture range. Its physical meaning is the largest aperture within a certain aperture distribution, namely hole has the highest probability aperture. It can be seen from the analysis of the figure that the maximum availability and pore size of the taphole clay at the age of 0.5, 1, 6 and 24h are 1053.93 nm, 1053.93 nm, 830.37 nm and 830.37 nm, respectively, distributed in the range of 500 nm to 1500 nm. The most available apertures of 0.5 and 1h, 6 and 24h are consistent, respectively. It shows that the number of pores in the taphole clay is more because the age is shorter.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"Conclusion","content":"\u003cp\u003e(1) With the increase of age, the mechanical strength of taphole clay showed a significant increase trend.The age has a great influence on the mechanical properties of taphole clay. The mechanical strength before 6 hours increases rapidly with time. The maximum growth rate was observed between 1h and 6h, while the growth rate was slower between 6h and 24h. About 24h, the strength is basically stable.\u003c/p\u003e\n\u003cp\u003e(2) The main hydration products of taphole clay are calcium carbonate and ettringite, and their contents increase with the increase of age. This indicates that the age promotes the hydration process of the taphole clay, which in turn improves its mechanical strength. With the increase of age, the content of ettringite increased significantly, and the content of calcium carbonate decreased.\u003c/p\u003e\n\u003cp\u003e(3) The material at 0.5h age has fluffy internal structure and abundant holes, which is not conducive to the strength performance of the taphole clay. With the increase of curing age, the density of taphole clay is improved. A large amount of ettringite is attached to the surface of hydrated calcium silicate, which promotes the formation of dense spatial structures. With the increase of age, the content of O element decreases and the content of Ca element increases, which is consistent with the results of XRD.\u003c/p\u003e\n\u003cp\u003e(4) The porosity of the taphole clay decreases with increasing age, mainly because the chemical composition of the feedstock and the binder gradually react to form a more stable structure. In the initial hardening period, the porosity decreased significantly. The specific surface area decreased with age, while the total pore volume showed a complicated trend. However, it eventually decreased due to the increase of material density caused by cement hydration reaction, which explained the change trend of strength. The critical pore size increases with age, which decreases the connectivity of pore structure. Most of the pore sizes can be in the range of 500nm\u0026thinsp;~\u0026thinsp;1500nm, and the number of short pores in the age is more.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003ch2\u003eCRediT authorship contribution statement\u003c/h2\u003e \u003cp\u003eXiao Wang: Formal analysis, Investigation, Methodology, Validation, Visualization, Data Curation, Writing original draft, Review \u0026amp; editing.\u003c/p\u003e \u003cp\u003eHouyou Zhou: Conceptualization, Supervision, Methodology, Funding acquisition, Project administration.\u003c/p\u003e \u003cp\u003eWenbo Zhao: Investigation, Supervision\u003c/p\u003e \u003cp\u003eQingwen Li: Conceptualization, Investigation, Methodology, Validation, Review \u0026amp;editing.\u003c/p\u003e \u003cp\u003eYa Yin: Investigation, Supervision.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eXiao Wang: Formal analysis, Investigation, Methodology, Validation, Visualization, Data Curation, Writing original draft, Review \u0026amp; editing. Houyou Zhou: Conceptualization, Supervision, Methodology, Funding acquisition, Project administration. Wenbo Zhao: Investigation, SupervisionQingwen Li: Conceptualization, Investigation, Methodology, Validation, Review \u0026amp;editing.Ya Yin: Investigation, Supervision.\u003c/p\u003e\u003ch2\u003eAcknowledgments\u003c/h2\u003e \u003cp\u003eThis work was supported by the National Natural Science Foundation of China (52274107) and Interdisciplinary Research Project for Young Teachers of USTB (FRF-IDRY-GD21-001).\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eSome or all data that support the findings of this study are available from the corresponding author upon reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eLi, X. \u003cem\u003eRock drilling and blasting engineering[M]\u003c/em\u003e (Central South University, 2011).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLeng, Z. et al. Research progress in theory and technology of energy regulation for rock drilling and blasting[J]. \u003cem\u003eMetal Mine\u003c/em\u003e, (05): 64\u0026ndash;76. (2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang, C. \u0026amp; Han, L. Optimization study on charge structure for blasting in small cross-section hard rock roadways of metal mines[J]. \u003cem\u003eGold\u003c/em\u003e \u003cb\u003e45\u003c/b\u003e (10), 40\u0026ndash;46 (2024).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZou, C., Guan, Y. \u0026amp; Kang, Y. Application of high water quick setting material in filling mining in Ningdong mining area[J]. \u003cem\u003eCopp. Eng.\u003c/em\u003e, (03): 28\u0026ndash;31. (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGuo, J., Zhang, Q. \u0026amp; Zheng, S. Research on development and application of low cost and high water rapid coagulation materials for mining[J]. \u003cem\u003eNonferrous Metals(Mining Section)\u003c/em\u003e, (01): 13\u0026ndash;14. (2003).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFeng, G. \u003cem\u003eResearch on the superhigh-water packing material and filling mining technology and their application[D]\u003c/em\u003e (China University of Mining and Technology, 2009).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYi, Q. \u003cem\u003eStudy on deformation characteristics of surrounding rock in loess cemented fill mining under slope terrain[D]\u003c/em\u003e (Hunan University of Science and Technology, 2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eQiu, J. et al. Research progress on dealkalization and activation of red mud and its application in cementitious materials[J]. \u003cem\u003eAppl. Chem. Ind.\u003c/em\u003e \u003cb\u003e53\u003c/b\u003e (06), 1421\u0026ndash;1426 (2024).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePeng, M. et al. Effect of composition on the performance and microstructures of mining high-water solidified materials[J]. \u003cem\u003eMineral. Eng. Res.\u003c/em\u003e \u003cb\u003e26\u003c/b\u003e (03), 56\u0026ndash;59 (2011).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShi, S. et al. Study on physical and mechanical properties of modified high water filling material with fly ash and calcium carbide slag[J]. \u003cem\u003eMater. Rep.\u003c/em\u003e \u003cb\u003e35\u003c/b\u003e (07), 7027\u0026ndash;7032 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTu, B. et al. Differential analysis of properties of cement based and mining alkali activated cementitious materials[J]. \u003cem\u003eMetal Mine\u003c/em\u003e, (10): 48\u0026ndash;56. (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKang, Y. et al. Application experimental on the single component polyurethane blasting hole filler[J]. \u003cem\u003eEng. Blasting\u003c/em\u003e. \u003cb\u003e25\u003c/b\u003e (02), 14\u0026ndash;18 (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHu, H. \u0026amp; Cui, M. Characteristics of high water content hardening body and analysis on the mechanical mechanism of fill body[J]. \u003cem\u003eMin. Res. Dev.\u003c/em\u003e, (05): 23\u0026ndash;25. (2001).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFeng, G. \u003cem\u003eResearch on the superhigh-water packing material and filling mining technology and their application[D]\u003c/em\u003e (China University of Mining and Technology, 2009).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang, Z. et al. Experimental study on the effect of water temperature on the mechanical properties of high-water materials[J]. \u003cem\u003eJ. Sichuan Univ. Sci. Engineering(Natural Sci. Edition)\u003c/em\u003e. \u003cb\u003e32\u003c/b\u003e (06), 60\u0026ndash;66 (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYu, Q. et al. Investigation on the hydration and hardening mechanism and properties of a newly developed rapid setting and solidifying material with high water content[J]. \u003cem\u003eCem. Technol.\u003c/em\u003e, (05): 3\u0026ndash;6. (1995).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu, D. \u003cem\u003eStudy on hydrating and hardening mechanisms of high-water rapid-setting material[D]\u003c/em\u003e (China University of Mining and Technology, 2015).\u003c/span\u003e\u003c/li\u003e\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":"rapid-setting blasting mud, curing time, mechanical strength, microscopic testing, XRD analysis","lastPublishedDoi":"10.21203/rs.3.rs-6291038/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6291038/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis study investigated the influence of curing time on the mechanical properties of rapid-setting blasting mud materials, analyzed the variation pattern of mechanical strength during the increase of curing time, and employed techniques such as XRD and SEM-EDS to study the impact of curing time on the crystalline phase transformation, microstructure, and element distribution of blasting mud materials. The results revealed that with the increase of curing time, all mechanical strengths of the blasting mud materials increased significantly, with a faster growth rate within the first 6 hours and stabilization around 24 hours. The main hydration products of the blasting mud materials are calcium carbonate and ettringite, whose contents increase with curing time, promoting the hydration process and enhancing mechanical strength. The internal structure of the material becomes denser with increasing curing time, resulting in decreased porosity, specific surface area, and total pore volume, and the formation of a dense spatial structure, which explains the trend of strength change. This study is of great significance for selecting optimal plugging materials and curing times for mines in China to achieve efficient blasting operations.\u003c/p\u003e","manuscriptTitle":"The Influence of Ageing on the Performance of Taphole Clay and the Study of Rapid-setting Mechanism","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-04-21 09:08:06","doi":"10.21203/rs.3.rs-6291038/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-04-10T12:26:33+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-04-09T05:08:08+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-04-02T06:13:30+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"117357182752773274181439220104942379841","date":"2025-03-31T15:53:23+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"131451556558998532806720436855671317394","date":"2025-03-31T11:19:40+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-03-31T11:09:39+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-03-31T11:03:52+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-03-31T10:58:59+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-03-29T02:23:26+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2025-03-24T02:42:47+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":"7a24111e-1c94-43b0-b6b7-ef252edbf4d1","owner":[],"postedDate":"April 21st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":46974147,"name":"Physical sciences/Engineering/Civil engineering"},{"id":46974148,"name":"Physical sciences/Materials science/Structural materials/Mechanical properties"}],"tags":[],"updatedAt":"2025-07-14T16:07:52+00:00","versionOfRecord":{"articleIdentity":"rs-6291038","link":"https://doi.org/10.1038/s41598-025-10663-1","journal":{"identity":"scientific-reports","isVorOnly":false,"title":"Scientific Reports"},"publishedOn":"2025-07-08 15:57:14","publishedOnDateReadable":"July 8th, 2025"},"versionCreatedAt":"2025-04-21 09:08:06","video":"","vorDoi":"10.1038/s41598-025-10663-1","vorDoiUrl":"https://doi.org/10.1038/s41598-025-10663-1","workflowStages":[]},"version":"v1","identity":"rs-6291038","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6291038","identity":"rs-6291038","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}