The effect of temperature on molten zone length was investigated through simulation to optimize the control of molten zone length during the experimental process. The temperature gradient distribution within the molte...The effect of temperature on molten zone length was investigated through simulation to optimize the control of molten zone length during the experimental process. The temperature gradient distribution within the molten zone during zone refining was simulated using COMSOL Multiphysics software and experimentally validated. The simulated molten zone length showed good agreement with the actual measured length. The experimental study of tellurium purification by zone refining was conducted under the following conditions: three passes of zone refining, a hydrogen flow rate of 0.5 L/min, and molten zone movement speeds of 0.5 and 1.0 mm/min. The results demonstrated that the removal efficiencies of impurities such as Ca and Cu exceeded 95%, while the removal efficiency of phosphorus (P) reached over 70%. And the purity of tellurium reached 6N.展开更多
Stability of base-exposed backfill roof in underhand drift-and-fill mining is crucial for the safety of those working beneath.Given the commonly used primary-and-secondary mining sequence,interfaces are formed between...Stability of base-exposed backfill roof in underhand drift-and-fill mining is crucial for the safety of those working beneath.Given the commonly used primary-and-secondary mining sequence,interfaces are formed between adjacent filled drifts,which can weaken the integrity of the backfill roof.These interfaces also lead to two common drift layouts:aligned drifts and staggered drifts.However,less attention has been paid to the interfaces and the two drift layouts were not adequately distinguished in previous studies.In this paper,the interfaces between filled drifts were firstly considered to investigate the stability of backfill roof.Failure modes and strength requirements of backfill roof in aligned and staggered drifts are comprehensively investigated by FLAC3D,with a focus on considerations of varied shear parameters of the interfaces.Results show that failure modes in aligned drifts transition from block sliding to top caving,bottom caving or sloughing as the interface cohesion increases from zero to at least half of the backfill cohesion.Further increases in interface cohesion allow aligned drifts to behave as if there are no interfaces between them.The critical stability conditions of backfill roof in aligned drifts were mostly determined by the interface strength instead of the backfill strength.However,the stability of backfill roof in staggered drifts is barely affected by the interface strength.The outcomes are expected to provide references for mining engineers to optimize drift layouts and perform cost-effective backfill roof strength design at mines using underhand drift-and-fill mining method.展开更多
To achieve the utilization of the abandoned ultrafine ilmenite(-20 μm) produced in the titanium magnetite processing plant in Panzhihua,the superconducting high-gradient magnetic separation(SMS) technology was propos...To achieve the utilization of the abandoned ultrafine ilmenite(-20 μm) produced in the titanium magnetite processing plant in Panzhihua,the superconducting high-gradient magnetic separation(SMS) technology was proposed in this study.After optimizing the conditions of magnetic intensity,feeding and pulsation,an SMS concentrate with TiO_(2) grade of 16.03% and TiO_(2) recovery of 66.39% was obtained through one roughing-one cleaning pre-concentration flowsheet.The specific magnetic force and magnetic force were calculated and analysed to illustrate the pre-concentration mechanism,and the results revealed that the combination of high magnetic field and strong pulsating resulted in the effective preconcentration of the ultrafine ilmenite in the SMS process.In addition,the magnetic force analysis indicated that the high magnetic intensity and high magnetic gradient are the key factors of the SMS technology.Furthermore,the EDS-Mapping detection certified that the ultrafine ilmenite was concentrated from the gangue minerals using SMS technology.展开更多
This article analyzes the current research status and development trend of intelligent technologies for underground metal mines in China, where such technologies are under development for use to develop mineral resour...This article analyzes the current research status and development trend of intelligent technologies for underground metal mines in China, where such technologies are under development for use to develop mineral resources in a safe, efficient, and environmentally friendly manner. We analyze and summarize the research status of underground metal mining technology at home and abroad, including some specific examples of equipment, technology, and applications. We introduce the latest equipment and technolo- gies with independent intellectual property rights for unmanned mining, including intelligent and unmanned control technologies for rock-drilling jumbos, down-the-hole （DTH） drills, underground scrapers, underground mining trucks, and underground charging vehicles. Three basic platforms are used for intelligent and unmanned mining： the positioning and navigation platform, information-acquisition and communication platform, and scheduling and control platform. Unmanned equipment was tested in the Fankou Lead-Zinc Mine in China, and industrial tests on the basic platforms of intelligent and unmanned mining were carried out in the mine. The experiment focused on the intelligent scraper, which can achieve autonomous intelligent driving by relying on a wireless communication system, location and navigation system, and data-acquisition system. These industrial experiments indicate that the technol- ogy is feasible. The results show that unmanned mining can promote mining technology in China to an intelligent level and can enhance the core competitive ability of China＇s mining industry.展开更多
As the mining industry continues to expand and international oil prices increase,more rigorous demands are being placed on the design of mining equipment.Given this,there is an urgent need to develop new power-driven ...As the mining industry continues to expand and international oil prices increase,more rigorous demands are being placed on the design of mining equipment.Given this,there is an urgent need to develop new power-driven mining equipment to solve the problems of high energy consumption and insufficient power coupling of current equipment.This study proposed a design of a hybrid power system for underground Load Haul Dump(LHD).The proposed design integrated Quality Function Deployment(QFD)and Theory of Inventive Problem Solving(TRIZ).It identified 7 user requirements and 10 related technical features,formulated 11 innovative design solutions,and ultimately adopting an electric drive hybrid power scheme.This scheme effectively addressesd power transmission coupling problems and improve the efficiency of loaders.A 6 m³hybrid power loader prototype has been developed,which reduces operational energy consumption and advances the electrification and green,low-carbon evolution of mining equipment.展开更多
This study systematically investigated the effects of experimental conditions,crystal phase,and microstructure on the preparation of V_(2)O_(3)for vanadium flow batteries by reducing ammonium metavanadate extracted fr...This study systematically investigated the effects of experimental conditions,crystal phase,and microstructure on the preparation of V_(2)O_(3)for vanadium flow batteries by reducing ammonium metavanadate extracted from waste catalyst.The optimized experimental conditions were determined as follows:the CO reduction temperature was set at 575℃,the reduction time was 1 hour,the CO flow rate was 50 mL/min,and furnace cooling was performed subsequently.Under these conditions,the samples obtained were predominantly composed of single-phase V_(2)O_(3).Microstructural analysis reveals tightly packed grain configurations exhibiting flake-like or block-like morphologies.Significantly,the as-synthesized V_(2)O_(3)demonstrates sufficient purity for fabricating high-performance electrolytes in all-vanadium flow batteries,showing promising electrochemical applicability.展开更多
The Maoping lead–zinc mining area is a significant metal mine site in northeastern Yunnan.In this study,both hydraulic fracturing in situ stress testing and ultrasonic imaging logging were first carried out in the mi...The Maoping lead–zinc mining area is a significant metal mine site in northeastern Yunnan.In this study,both hydraulic fracturing in situ stress testing and ultrasonic imaging logging were first carried out in the mining area.Second,930 focal mechanism solutions and 231 sets of stress data near the mining area were collected.Then,the variations in the type of in situ stress field,the magnitude of in situ stress,the direction of horizontal principal stress,and the ratio of lateral pressure were analyzed to characterize the distribution of the in situ stress field.On this basis,a new method using borehole breakouts and drilling-induced fractures was proposed to determine the stress direction.Finally,the evolution of the mechanical properties of dolomite with burial depth was analyzed and the influence of rock mechanical properties on the distributions of the in situ stress field was explored.The results show that the in situ stress in the mining area isσ_(H)>σ_(V)>σ_(h),indicating a strike–slip stress state.The in situ stress is high in magnitude,and its value increases with burial depth.The maximum and minimum horizontal lateral stress coefficients are stabilized at approximately 1.22 and 0.73,respectively.The direction of the maximum horizontal principal stress is NW,mainly ranging from N58.44°W to N59.70°W.The stress field inferred from the focal mechanism solution is in good agreement with the test results.The proportion of structural planes with dip angles between 30°and 75°exceeds 80%,and the dip direction of the structural planes is mainly NW to NWW.The line density of structural planes shows high density in shallow areas and low density in deep areas.More energy tends to be accumulated in rocks with higher elastic modulus and strength,leading to higher in situ stress levels.These findings are of significant reference for mine tunnel layout,support design optimization,and disaster prevention.展开更多
Copper-nickel tailings(CNTs),consisting of more than 80wt%magnesium-bearing silicate minerals,show great potential for CO_(2)mineral sequestration.The dissolution kinetics of CNTs in HCl solution was investigated thro...Copper-nickel tailings(CNTs),consisting of more than 80wt%magnesium-bearing silicate minerals,show great potential for CO_(2)mineral sequestration.The dissolution kinetics of CNTs in HCl solution was investigated through a leaching experiment and kinetic modeling,and the effects of reaction time,HCl concentration,solid-to-liquid ratio,and reaction temperature on the leaching rate of mag-nesium were comprehensively studied.Results show that the suitable leaching conditions for magnesium in CNTs are 2 M HCl,a solid-to-liquid ratio of 50 g·L^(−1),and 90℃,at which the maximum leaching rate of magnesium is as high as 83.88%.A modified shrinking core model can well describe the leaching kinetics of magnesium.The dissolution of magnesium was dominated by a combination of chemical reaction and product layer diffusion,with a calculated apparent activation energy of 77.51 kJ·mol^(−1).This study demonstrates the feasibil-ity of using CNTs as a media for CO_(2)mineral sequestration.展开更多
The size and distribution patterns of bubbles within a laboratory-scale coarse-particle flotation column were examined using a high-speed camera-based dynamic measurement system.The effects of operational parameters s...The size and distribution patterns of bubbles within a laboratory-scale coarse-particle flotation column were examined using a high-speed camera-based dynamic measurement system.The effects of operational parameters such as superficial water velocity,air-flow rate,and frother dosage on bubble-size and distribution characteristics were investigated.This study aims to provide theoretical support for enabling fluidized-bed flotation within coarse-particle flotation columns.The results show that negative pressure for air inspiratory and bubble formation is generated by passing a high-speed jet through a throat,and the greatest number of bubbles are observed under natural inspiratory state at an air-liquid ratio of 1:3-1:2.5.Increasing the air-flow rate transforms the bubble diameter distribution from a peaked distribution to a more uniform distribution.Furthermore,the frother narrows the range of bubble-size distribution.A positive correlation exists between the bubble Sauter diameter and air-flow rate,with the bubble Sauter diameter bearing a negative correlation with the superficial water velocity and frother concentration.展开更多
Multiple active components in steel slags can optimize soil texture and catalyze the thermal desorption of refractory organic pollutants,especially polycyclic aromatic hydrocarbons(PAHs).In this study,a safety and ris...Multiple active components in steel slags can optimize soil texture and catalyze the thermal desorption of refractory organic pollutants,especially polycyclic aromatic hydrocarbons(PAHs).In this study,a safety and risk assessment was conducted on toxic metals present in collected steel slags,and the refining slag with a high content of free-CaO from the XG iron and steel plant(XGRS)was selected and used to regulate the plasticity index(PI)of clay soils.For the clay soil with high liquid limit and high plasticity(CH),the PI reduced from 34.3%to 24.8%with steel slags at an addition ratio of 10%(mass percent),and for the clay soil with low liquid limit(CL),the PI decreased from 22.8%to 16.5%,resulting in silt soil with optimal thermal properties.The thermal removal efficiency of PAHs in CH decreased from 81.9%to 74.0%at 350℃ as the soil water content increased from 0 to 150 g kg^(-1),due to the hydration and swelling of clay minerals and the heat loss associated with dehydroxylation and dehydration.The efficiency further decreased to 68.7%using 2%(mass percent)CaO as an additive due to the delayed dehydr(oxyl)ation of clay minerals and enhanced aromatization of soil organic matter.In contrast,addition of 2%high-content titania-bearing slag(HTBS)enhanced the removal efficiency of high-ring PAHs,with the efficiency increasing for 5-ring from 52.6%to 59.7%and for 6-ring from 76.6%to 81.8%.This is due to the presence of amorphous TiO_(2) and crystalline CaTiO_(3) in HTBS,which can degrade water to produce reactive oxygen species.The 2%XGRS addition facilitated the complete removal of PAHs by air-supplemented lattice oxygen,leading to the oxidation of C–C bonds in CH to C–O,C=O,and O–C=O functional groups.This study provides valuable insights into the use of additives to enhance the thermal remediation of PAH-contaminated clay soils via activating oxygen species and oxidizing C–C bonds in organo-mineral complexes within clay soils.展开更多
The multi-objective optimization of backfill effect based on response surface methodology and desirability function(RSM-DF)was conducted.Firstly,the test results show that the uniaxial compressive strength(UCS)increas...The multi-objective optimization of backfill effect based on response surface methodology and desirability function(RSM-DF)was conducted.Firstly,the test results show that the uniaxial compressive strength(UCS)increases with cement sand ratio(CSR),slurry concentration(SC),and curing age(CA),while flow resistance(FR)increases with SC and backfill flow rate(BFR),and decreases with CSR.Then the regression models of UCS and FR as response values were established through RSM.Multi-factor interaction found that CSR-CA impacted UCS most,while SC-BFR impacted FR most.By introducing the desirability function,the optimal backfill parameters were obtained based on RSM-DF(CSR is 1:6.25,SC is 69%,CA is 11.5 d,and BFR is 90 m^(3)/h),showing close results of Design Expert and high reliability for optimization.For a copper mine in China,RSM-DF optimization will reduce cement consumption by 4758 t per year,increase tailings consumption by about 6700 t,and reduce CO_(2)emission by about 4758 t.Thus,RSM-DF provides a new approach for backfill parameters optimization,which has important theoretical and practical values.展开更多
As a pyrometallurgical process,circulating fluidized bed(CFB) roasting has good potential for application in desulfurization of high-sulfur bauxite.The gas-solid distribution and reaction during CFB roasting of high-s...As a pyrometallurgical process,circulating fluidized bed(CFB) roasting has good potential for application in desulfurization of high-sulfur bauxite.The gas-solid distribution and reaction during CFB roasting of high-sulfur bauxite were simulated using the computational particle fluid dynamics(CPFD) method.The effect of primary air flow velocity on particle velocity,particle volume distribution,furnace temperature distribution and pressure distribution were investigated.Under the condition of the same total flow of natural gas,the impact of the number of inlets on the desulfurization efficiency,atmosphere mass fraction distribution and temperature distribution in the furnace was further investigated.展开更多
In the underhand cut-and-fill mining method,a sill mat(i.e.an artificial horizontal pillar)constructed by cemented backfill is essential to prevent mine workers from being directly exposed under problematic rock roofs...In the underhand cut-and-fill mining method,a sill mat(i.e.an artificial horizontal pillar)constructed by cemented backfill is essential to prevent mine workers from being directly exposed under problematic rock roofs.A critical issue is to determine the minimum required strength of the sill mat to ensure a safe and cost-effective design.Until now,Mitchell’s analytical solution is the only available option,considering two stiff and immobile rock walls.Unavoidable rock wall closure associated with stope excavation below the sill mat was neglected.This,along with other undefined parameters,explains why Mitchell’s solution is rarely used in sill mat design.A new analytical solution for determining the minimum required strength of the sill mat accounting for wall closure is necessary.In this study,a closed-form analytical solution for estimating rock wall closure generated by stope excavation below a sill mat is developed by using Salamon’s and Flamant’s models.The proposed analytical solution does not contain any coefficients of correction or calibration.Despite several assumptions(or somewhat of oversimplifications)necessary to render a simple analytical solution possible,good agreements are obtained between the rock wall closures predicted by applying the proposed analytical solution and those obtained numerically with FLAC3D for many cases with arbitrarily chosen geometrical and material parameters.The proposed analytical solution is therefore validated and can be used to evaluate the rock wall closure generated by stope excavation below a sill mat.展开更多
The increasing risk of ground pressure disasters resulting from deep well mining highlights the urgent need for advanced monitoring and early warning systems.Ground pressure monitoring,supported by microseismic techno...The increasing risk of ground pressure disasters resulting from deep well mining highlights the urgent need for advanced monitoring and early warning systems.Ground pressure monitoring,supported by microseismic technology,plays a pivotal role in ensuring mine safety by enabling real-time identifi cation and accurate classification of vibration signals such as microseismic signals,blasting signals,and noise.These classifications are critical for improving the efficacy of ground pressure monitoring systems,conducting stability analyses of deep rock masses,and implementing timely and precise roadway support measures.Such eff orts are essential for mitigating ground pressure disasters and ensuring safe mining operations.This study proposes an artificial intelligence-based automatic classification network model for mine vibration signals.Based on conventional convolutional neural networks,the proposed model further incorporates long short-term memory(LSTM)networks and attention mechanisms.The LSTM component eff ectively captures temporal correlations in time-series mining vibration data,while the attention mechanism enhances the models’ability to focus on critical features within the data.To validate the eff ectiveness of our proposed model,a dataset comprising 480,526 waveform records collected in 2022 by the microseismic monitoring system at Guangxi Shanhu Tungsten Mine was used for training,validation,and testing purposes.Results demonstrate that the proposed artifi cial intelligence-based classifi cation method achieves a higher recognition accuracy of 92.21%,significantly outperforming traditional manual classification methods.The proposed model represents a signifi cant advancement in ground pressure monitoring and disaster mitigation.展开更多
Underhand cut-and-fill mining has been widely used in underground mining operations,especially when the rock mass or orebody is of poor quality or prone to rockburst due to high stress.In such cases,mining workers sho...Underhand cut-and-fill mining has been widely used in underground mining operations,especially when the rock mass or orebody is of poor quality or prone to rockburst due to high stress.In such cases,mining workers should carry out all production activities under the cemented backfill roof or sill mat instead of a highly fractured and unstable rock roof or a strong rock roof with a high potential of rockburst.Therefore,the stability and required strength of the sill mat are critical issues for mining engineers.In 1991,Mitchell considered that sill mat could fail by caving,sliding,rotation,and flexure.Mitchell also proposed an analytical solution to determine the minimum required strength of the sill mat for each type of failure based on two stiff or immobile rock walls.However,recent publications using numerical modeling and field measurements indicate that the compressive stresses in the sill mat induced by rock wall closure due to a stope excavation beneath the sill mat can be significant.It is thus highly necessary to investigate the required strength of the sill mat by considering rock wall closure.In this study,the crushing failure of sill mat due to rock wall closure generated by underground excavation and a new failure mode called"crushing and caving”is revealed by numerical modeling.An analytical solution corresponding to each failure mode is then developed to estimate the minimum required cohesion(cmin)of the sill mat.A criterion is also proposed to determine if the sill mat fails by crushing or crushing-and-caving failure.The proposed analytical solution does not involve any correction coefficients.The validity of the proposed analytical solution is demonstrated by numerical modeling.The proposed analytical solution can thus be employed to predict the cmin of sill mat subjected to wall closure generated by underlying stope excavation.展开更多
The underhand cut-and-fill mining method is widely employed in underground mines,especially when the quality of surrounding rock mass or ore body is inferior or subjected to high stresses.Such a method typically requi...The underhand cut-and-fill mining method is widely employed in underground mines,especially when the quality of surrounding rock mass or ore body is inferior or subjected to high stresses.Such a method typically requires the construction of sill mats with cemented backfill to provide operators with safe artificial roofs.Accurate estimation of the minimum required strength of the sill mat is crucial to minimize binder consumption and ensure its stability upon base exposure.Over the years,only a few publications were devoted to determining the minimum required cohesion(cmin)of sill mats.None of them considered rock wall closure to be associated with the creep of surrounding rock mass.Moreover,the effect of rock wall closure associated with rock creep on the cminof the sill mat remains unknown.Thus,a series of numerical simulations was performed to fill this gap.The influence of rock creep on the cminof base-exposed sill mat was investigated for the first time.The numerical results indicate that Mitchell’s models could be suitable for sill mats subjected to negligible wall closure.However,this scenario is rare,especially when mine depth is large.In general,the cminof sill mats increases as mine depth increases.Neglecting rock creep would significantly underestimate the cminof sill mats.When mine depth is large and the rock mass exhibits severe creep,cemented backfill with ductile behavior(i.e.,with low stiffness but enough strength)should be considered to reduce binder consumption and prevent crushing failure.In all cases,promptly filling the mined-out stope below the sill mat can improve its stability and reduce its cminvalue.展开更多
To meet the growing demand for high-energy-density lithium-ion batteries(LIBs),silicon(Si)anodes have gained attention as a promising material for next-generation anodes owing to their ultrahigh gravimetric capacity.N...To meet the growing demand for high-energy-density lithium-ion batteries(LIBs),silicon(Si)anodes have gained attention as a promising material for next-generation anodes owing to their ultrahigh gravimetric capacity.Nevertheless,the Si anode faces significant challenges,particularly severe volume expansion during cycling,which leads to rapid capacity degradation and greatly hinders its commercialization potential.Although extensive research has focused on mitigating volume changes and constructing stable solid-electrolyte interphases on Si-based anodes,a crucial factor for practical application,namely the volumetric capacity,has been often overlooked.For Si-based anodes to replace conventional graphite anodes,their volumetric capacity must be thoroughly evaluated.Key factors determining the volumetric capacity include gravimetric capacity,active material mass ratio,initial Coulombic efficiency,electrode swelling ratio,and the negative-to-positive capacity ratio.This paper systematically analyzes,discusses,and summarizes each of these factors in detail.Common issues with existing strategies are identified,and future research directions concerning the commercialization of Si-based anodes are outlined.This study provides a systematic and novel perspective on effectively modifying and designing Si-based anodes,aiming to promote the volumetric capacity toward the large-scale industrialization of next-generation LIBs.展开更多
Carboxymethyl cellulose(CMC)was introduced as a depressant in reverse flotation separation of quartz from magnesite.The flotation behavior and surface properties of magnesite and quartz exposed to CMC were studied by ...Carboxymethyl cellulose(CMC)was introduced as a depressant in reverse flotation separation of quartz from magnesite.The flotation behavior and surface properties of magnesite and quartz exposed to CMC were studied by zeta potential tests,atomic force microscopy imaging and contact angle measurements.The addition of CMC as the depressant in reverse flotation using dodecylamine(DDA)as the collector exhibited a selectively depressive performance towards magnesite and achieved an improved recovery of magnesite.The study of surface properties demonstrated that CMC and DDA exhibited different adsorption strengths on the surface of magnesite and quartz.It was found that the adsorption of CMC on magnesite surface was stronger than that of DDA,which hindered the subsequent adsorption of DDA on magnesite surface.On the contrary,the quartz surface was strongly adsorbed by DDA instead of CMC,which proved that the addition of CMC did not influence the flotation of quartz.展开更多
A direct alkaline leaching process was proposed to extract molybdenum and lead from low-grade wulfenite ore containing 2.87%Mo and 9.39%Pb.The results show that increasing temperature and alkali concentration enhances...A direct alkaline leaching process was proposed to extract molybdenum and lead from low-grade wulfenite ore containing 2.87%Mo and 9.39%Pb.The results show that increasing temperature and alkali concentration enhances the extraction of Mo and Pb,and more than 99.7%of Mo and 64.6%of Pb are extracted under conditions of 75℃,L/S of 2:1,leaching time of 1.0 h,initial NaOH concentration of 80 g/L and stirring speed of 100 r/min.The alkaline leaching of molybdenum follows a chemical reaction control mechanism with activation energy of 46.3 kJ/mol.Lead in the residue is recovered by hydrochloric acid leaching.99.8%of lead is leached under the conditions of 80℃,[MnO2]/[Pb]molar ratio of 1.3:1,sodium chloride concentration of 40 g/L,and hydrochloric acid concentration of 3 mol/L,and a product of crystallized PbCl2 with purity higher than 99.5%is obtained after cooling.展开更多
The separation of andalusite and quartz was investigated in the sodium oleate flotation system, and its mechanism was studied by solution chemical calculation, zeta-potential tests, Fourier transform infrared spectros...The separation of andalusite and quartz was investigated in the sodium oleate flotation system, and its mechanism was studied by solution chemical calculation, zeta-potential tests, Fourier transform infrared spectroscopic(FTIR), and X-ray photoelectron spectroscopic(XPS). The flotation tests results show that FeCl3·6H2O has a strong activation effect on andalusite and quartz and citric acid has a strong inhibitory effect on activated quartz, thus increasing the floatability difference between quartz and andalusite when the pulp p H is approximately 8. The FTIR, Zeta potential, and XPS analyses combined with the chemical calculation of flotation reagent solutions demonstrate that Fe forms hydroxide precipitates on the surface of andalusite and quartz and that oleate anions and metal ions adsorb onto the surface of the minerals. The elements Al and Fe can be chemically reacted. The anions in citric acid have different degrees of dissolution of Fe on the andalusite and quartz surfaces, thereby selectively eliminating the activation of the elemental Fe on andalusite and quartz and increasing the floatability of andalusite, leading to a better separation effect between andalusite and quartz.展开更多
基金financial support from the National Key Research and Development Program of China(No.2023YFC2907904)the National Natural Science Foundation of China(Nos.52374364,52104355,52074363)+1 种基金National Sustainable Development Agenda Innovation Demonstration Zones:Provincial Special“Open Competition”Project in Chenzhou,China(No.2022sfq57)Postdoctoral Innovation Talent Support Program,China(No.BX20230438)。
文摘The effect of temperature on molten zone length was investigated through simulation to optimize the control of molten zone length during the experimental process. The temperature gradient distribution within the molten zone during zone refining was simulated using COMSOL Multiphysics software and experimentally validated. The simulated molten zone length showed good agreement with the actual measured length. The experimental study of tellurium purification by zone refining was conducted under the following conditions: three passes of zone refining, a hydrogen flow rate of 0.5 L/min, and molten zone movement speeds of 0.5 and 1.0 mm/min. The results demonstrated that the removal efficiencies of impurities such as Ca and Cu exceeded 95%, while the removal efficiency of phosphorus (P) reached over 70%. And the purity of tellurium reached 6N.
基金supported by Deep Earth Probe and Mineral Resources Exploration-National Science and Technology Major Project(Grant No.2024ZD1003705)the Beijing Nova Program(Grant No.20220484057)support from China Scholarship Council under Grant CSC No.202110300001.
文摘Stability of base-exposed backfill roof in underhand drift-and-fill mining is crucial for the safety of those working beneath.Given the commonly used primary-and-secondary mining sequence,interfaces are formed between adjacent filled drifts,which can weaken the integrity of the backfill roof.These interfaces also lead to two common drift layouts:aligned drifts and staggered drifts.However,less attention has been paid to the interfaces and the two drift layouts were not adequately distinguished in previous studies.In this paper,the interfaces between filled drifts were firstly considered to investigate the stability of backfill roof.Failure modes and strength requirements of backfill roof in aligned and staggered drifts are comprehensively investigated by FLAC3D,with a focus on considerations of varied shear parameters of the interfaces.Results show that failure modes in aligned drifts transition from block sliding to top caving,bottom caving or sloughing as the interface cohesion increases from zero to at least half of the backfill cohesion.Further increases in interface cohesion allow aligned drifts to behave as if there are no interfaces between them.The critical stability conditions of backfill roof in aligned drifts were mostly determined by the interface strength instead of the backfill strength.However,the stability of backfill roof in staggered drifts is barely affected by the interface strength.The outcomes are expected to provide references for mining engineers to optimize drift layouts and perform cost-effective backfill roof strength design at mines using underhand drift-and-fill mining method.
基金financial support from the Joint Fund (Key program U2067201) for Nuclear Technology Innovation Sponsored by the National Natural Science Foundation of China and the China National Nuclear CorporationNational key research and development program (2019YFC1907702) Sponsored by MOSTthe Fundamental Research Funds for the Central Universities (N2001013) for supporting this research。
文摘To achieve the utilization of the abandoned ultrafine ilmenite(-20 μm) produced in the titanium magnetite processing plant in Panzhihua,the superconducting high-gradient magnetic separation(SMS) technology was proposed in this study.After optimizing the conditions of magnetic intensity,feeding and pulsation,an SMS concentrate with TiO_(2) grade of 16.03% and TiO_(2) recovery of 66.39% was obtained through one roughing-one cleaning pre-concentration flowsheet.The specific magnetic force and magnetic force were calculated and analysed to illustrate the pre-concentration mechanism,and the results revealed that the combination of high magnetic field and strong pulsating resulted in the effective preconcentration of the ultrafine ilmenite in the SMS process.In addition,the magnetic force analysis indicated that the high magnetic intensity and high magnetic gradient are the key factors of the SMS technology.Furthermore,the EDS-Mapping detection certified that the ultrafine ilmenite was concentrated from the gangue minerals using SMS technology.
文摘This article analyzes the current research status and development trend of intelligent technologies for underground metal mines in China, where such technologies are under development for use to develop mineral resources in a safe, efficient, and environmentally friendly manner. We analyze and summarize the research status of underground metal mining technology at home and abroad, including some specific examples of equipment, technology, and applications. We introduce the latest equipment and technolo- gies with independent intellectual property rights for unmanned mining, including intelligent and unmanned control technologies for rock-drilling jumbos, down-the-hole （DTH） drills, underground scrapers, underground mining trucks, and underground charging vehicles. Three basic platforms are used for intelligent and unmanned mining： the positioning and navigation platform, information-acquisition and communication platform, and scheduling and control platform. Unmanned equipment was tested in the Fankou Lead-Zinc Mine in China, and industrial tests on the basic platforms of intelligent and unmanned mining were carried out in the mine. The experiment focused on the intelligent scraper, which can achieve autonomous intelligent driving by relying on a wireless communication system, location and navigation system, and data-acquisition system. These industrial experiments indicate that the technol- ogy is feasible. The results show that unmanned mining can promote mining technology in China to an intelligent level and can enhance the core competitive ability of China＇s mining industry.
文摘As the mining industry continues to expand and international oil prices increase,more rigorous demands are being placed on the design of mining equipment.Given this,there is an urgent need to develop new power-driven mining equipment to solve the problems of high energy consumption and insufficient power coupling of current equipment.This study proposed a design of a hybrid power system for underground Load Haul Dump(LHD).The proposed design integrated Quality Function Deployment(QFD)and Theory of Inventive Problem Solving(TRIZ).It identified 7 user requirements and 10 related technical features,formulated 11 innovative design solutions,and ultimately adopting an electric drive hybrid power scheme.This scheme effectively addressesd power transmission coupling problems and improve the efficiency of loaders.A 6 m³hybrid power loader prototype has been developed,which reduces operational energy consumption and advances the electrification and green,low-carbon evolution of mining equipment.
文摘This study systematically investigated the effects of experimental conditions,crystal phase,and microstructure on the preparation of V_(2)O_(3)for vanadium flow batteries by reducing ammonium metavanadate extracted from waste catalyst.The optimized experimental conditions were determined as follows:the CO reduction temperature was set at 575℃,the reduction time was 1 hour,the CO flow rate was 50 mL/min,and furnace cooling was performed subsequently.Under these conditions,the samples obtained were predominantly composed of single-phase V_(2)O_(3).Microstructural analysis reveals tightly packed grain configurations exhibiting flake-like or block-like morphologies.Significantly,the as-synthesized V_(2)O_(3)demonstrates sufficient purity for fabricating high-performance electrolytes in all-vanadium flow batteries,showing promising electrochemical applicability.
基金National Key Research and Development Program of China,Grant/Award Number:2022YFC2904100National Natural Science Foundation of China,Grant/Award Number:5220409Beijing Noval Program,Grant/Award Number:20230484242。
文摘The Maoping lead–zinc mining area is a significant metal mine site in northeastern Yunnan.In this study,both hydraulic fracturing in situ stress testing and ultrasonic imaging logging were first carried out in the mining area.Second,930 focal mechanism solutions and 231 sets of stress data near the mining area were collected.Then,the variations in the type of in situ stress field,the magnitude of in situ stress,the direction of horizontal principal stress,and the ratio of lateral pressure were analyzed to characterize the distribution of the in situ stress field.On this basis,a new method using borehole breakouts and drilling-induced fractures was proposed to determine the stress direction.Finally,the evolution of the mechanical properties of dolomite with burial depth was analyzed and the influence of rock mechanical properties on the distributions of the in situ stress field was explored.The results show that the in situ stress in the mining area isσ_(H)>σ_(V)>σ_(h),indicating a strike–slip stress state.The in situ stress is high in magnitude,and its value increases with burial depth.The maximum and minimum horizontal lateral stress coefficients are stabilized at approximately 1.22 and 0.73,respectively.The direction of the maximum horizontal principal stress is NW,mainly ranging from N58.44°W to N59.70°W.The stress field inferred from the focal mechanism solution is in good agreement with the test results.The proportion of structural planes with dip angles between 30°and 75°exceeds 80%,and the dip direction of the structural planes is mainly NW to NWW.The line density of structural planes shows high density in shallow areas and low density in deep areas.More energy tends to be accumulated in rocks with higher elastic modulus and strength,leading to higher in situ stress levels.These findings are of significant reference for mine tunnel layout,support design optimization,and disaster prevention.
基金finacially supported by the National Key Research and Development Program of China(No.2022YFE0135100)the National Natural Science Found-ation of China(Nos.52378255,52278270,and 52008151).
文摘Copper-nickel tailings(CNTs),consisting of more than 80wt%magnesium-bearing silicate minerals,show great potential for CO_(2)mineral sequestration.The dissolution kinetics of CNTs in HCl solution was investigated through a leaching experiment and kinetic modeling,and the effects of reaction time,HCl concentration,solid-to-liquid ratio,and reaction temperature on the leaching rate of mag-nesium were comprehensively studied.Results show that the suitable leaching conditions for magnesium in CNTs are 2 M HCl,a solid-to-liquid ratio of 50 g·L^(−1),and 90℃,at which the maximum leaching rate of magnesium is as high as 83.88%.A modified shrinking core model can well describe the leaching kinetics of magnesium.The dissolution of magnesium was dominated by a combination of chemical reaction and product layer diffusion,with a calculated apparent activation energy of 77.51 kJ·mol^(−1).This study demonstrates the feasibil-ity of using CNTs as a media for CO_(2)mineral sequestration.
基金supported by the National Key R&D Program of China(Nos.2023YFC3904202,2022YFC2904500)Major Science and Technology Program of Yunnan Province,China(No.202202AB080012).
文摘The size and distribution patterns of bubbles within a laboratory-scale coarse-particle flotation column were examined using a high-speed camera-based dynamic measurement system.The effects of operational parameters such as superficial water velocity,air-flow rate,and frother dosage on bubble-size and distribution characteristics were investigated.This study aims to provide theoretical support for enabling fluidized-bed flotation within coarse-particle flotation columns.The results show that negative pressure for air inspiratory and bubble formation is generated by passing a high-speed jet through a throat,and the greatest number of bubbles are observed under natural inspiratory state at an air-liquid ratio of 1:3-1:2.5.Increasing the air-flow rate transforms the bubble diameter distribution from a peaked distribution to a more uniform distribution.Furthermore,the frother narrows the range of bubble-size distribution.A positive correlation exists between the bubble Sauter diameter and air-flow rate,with the bubble Sauter diameter bearing a negative correlation with the superficial water velocity and frother concentration.
基金sponsored by the National Key R&D Program of China(No.2018YFC1802101)the National Natural Science Foundation of China(No.52170149)。
文摘Multiple active components in steel slags can optimize soil texture and catalyze the thermal desorption of refractory organic pollutants,especially polycyclic aromatic hydrocarbons(PAHs).In this study,a safety and risk assessment was conducted on toxic metals present in collected steel slags,and the refining slag with a high content of free-CaO from the XG iron and steel plant(XGRS)was selected and used to regulate the plasticity index(PI)of clay soils.For the clay soil with high liquid limit and high plasticity(CH),the PI reduced from 34.3%to 24.8%with steel slags at an addition ratio of 10%(mass percent),and for the clay soil with low liquid limit(CL),the PI decreased from 22.8%to 16.5%,resulting in silt soil with optimal thermal properties.The thermal removal efficiency of PAHs in CH decreased from 81.9%to 74.0%at 350℃ as the soil water content increased from 0 to 150 g kg^(-1),due to the hydration and swelling of clay minerals and the heat loss associated with dehydroxylation and dehydration.The efficiency further decreased to 68.7%using 2%(mass percent)CaO as an additive due to the delayed dehydr(oxyl)ation of clay minerals and enhanced aromatization of soil organic matter.In contrast,addition of 2%high-content titania-bearing slag(HTBS)enhanced the removal efficiency of high-ring PAHs,with the efficiency increasing for 5-ring from 52.6%to 59.7%and for 6-ring from 76.6%to 81.8%.This is due to the presence of amorphous TiO_(2) and crystalline CaTiO_(3) in HTBS,which can degrade water to produce reactive oxygen species.The 2%XGRS addition facilitated the complete removal of PAHs by air-supplemented lattice oxygen,leading to the oxidation of C–C bonds in CH to C–O,C=O,and O–C=O functional groups.This study provides valuable insights into the use of additives to enhance the thermal remediation of PAH-contaminated clay soils via activating oxygen species and oxidizing C–C bonds in organo-mineral complexes within clay soils.
基金Funded by the Deep Underground National Science&Technology Major Project gram of China(No.2024ZD1003704)the National Natural Science Foundation of China(Nos.51834001 and 52374111)。
文摘The multi-objective optimization of backfill effect based on response surface methodology and desirability function(RSM-DF)was conducted.Firstly,the test results show that the uniaxial compressive strength(UCS)increases with cement sand ratio(CSR),slurry concentration(SC),and curing age(CA),while flow resistance(FR)increases with SC and backfill flow rate(BFR),and decreases with CSR.Then the regression models of UCS and FR as response values were established through RSM.Multi-factor interaction found that CSR-CA impacted UCS most,while SC-BFR impacted FR most.By introducing the desirability function,the optimal backfill parameters were obtained based on RSM-DF(CSR is 1:6.25,SC is 69%,CA is 11.5 d,and BFR is 90 m^(3)/h),showing close results of Design Expert and high reliability for optimization.For a copper mine in China,RSM-DF optimization will reduce cement consumption by 4758 t per year,increase tailings consumption by about 6700 t,and reduce CO_(2)emission by about 4758 t.Thus,RSM-DF provides a new approach for backfill parameters optimization,which has important theoretical and practical values.
基金supported by the National Key Research and Development Program of China(2022YFC2904400)Guangxi Science and Technology Major Project(Gui Ke AA23023033)。
文摘As a pyrometallurgical process,circulating fluidized bed(CFB) roasting has good potential for application in desulfurization of high-sulfur bauxite.The gas-solid distribution and reaction during CFB roasting of high-sulfur bauxite were simulated using the computational particle fluid dynamics(CPFD) method.The effect of primary air flow velocity on particle velocity,particle volume distribution,furnace temperature distribution and pressure distribution were investigated.Under the condition of the same total flow of natural gas,the impact of the number of inlets on the desulfurization efficiency,atmosphere mass fraction distribution and temperature distribution in the furnace was further investigated.
基金financial support from the Young Scientist Project of the National Key Research and Development Program of China(Grant No.2021YFC2900600)the Beijing Nova Program(Grant No.20220484057)+1 种基金The authors acknowledge the financial support from the Natural Sciences and Engineering Research Council of Canada(Grant No.RGPIN-2018-06902)industrial partners of the Research Institute on Mines and the Environment(RIME UQAT-Polytechnique:https://irme.ca/en/).
文摘In the underhand cut-and-fill mining method,a sill mat(i.e.an artificial horizontal pillar)constructed by cemented backfill is essential to prevent mine workers from being directly exposed under problematic rock roofs.A critical issue is to determine the minimum required strength of the sill mat to ensure a safe and cost-effective design.Until now,Mitchell’s analytical solution is the only available option,considering two stiff and immobile rock walls.Unavoidable rock wall closure associated with stope excavation below the sill mat was neglected.This,along with other undefined parameters,explains why Mitchell’s solution is rarely used in sill mat design.A new analytical solution for determining the minimum required strength of the sill mat accounting for wall closure is necessary.In this study,a closed-form analytical solution for estimating rock wall closure generated by stope excavation below a sill mat is developed by using Salamon’s and Flamant’s models.The proposed analytical solution does not contain any coefficients of correction or calibration.Despite several assumptions(or somewhat of oversimplifications)necessary to render a simple analytical solution possible,good agreements are obtained between the rock wall closures predicted by applying the proposed analytical solution and those obtained numerically with FLAC3D for many cases with arbitrarily chosen geometrical and material parameters.The proposed analytical solution is therefore validated and can be used to evaluate the rock wall closure generated by stope excavation below a sill mat.
基金supported in part by the National Science Fund for Distinguished Young Scholars under Grant (42025403)the National Key Research and Development Plan of China (2021YFA0716800)the National Key Research and Development Plan of China (2022YFC2903804)。
文摘The increasing risk of ground pressure disasters resulting from deep well mining highlights the urgent need for advanced monitoring and early warning systems.Ground pressure monitoring,supported by microseismic technology,plays a pivotal role in ensuring mine safety by enabling real-time identifi cation and accurate classification of vibration signals such as microseismic signals,blasting signals,and noise.These classifications are critical for improving the efficacy of ground pressure monitoring systems,conducting stability analyses of deep rock masses,and implementing timely and precise roadway support measures.Such eff orts are essential for mitigating ground pressure disasters and ensuring safe mining operations.This study proposes an artificial intelligence-based automatic classification network model for mine vibration signals.Based on conventional convolutional neural networks,the proposed model further incorporates long short-term memory(LSTM)networks and attention mechanisms.The LSTM component eff ectively captures temporal correlations in time-series mining vibration data,while the attention mechanism enhances the models’ability to focus on critical features within the data.To validate the eff ectiveness of our proposed model,a dataset comprising 480,526 waveform records collected in 2022 by the microseismic monitoring system at Guangxi Shanhu Tungsten Mine was used for training,validation,and testing purposes.Results demonstrate that the proposed artifi cial intelligence-based classifi cation method achieves a higher recognition accuracy of 92.21%,significantly outperforming traditional manual classification methods.The proposed model represents a signifi cant advancement in ground pressure monitoring and disaster mitigation.
基金financial support from the Young Scientist Project of the National Key Research and Development Program of China(Grant No.2021YFC2900600)Beijing Nova Program(Grant No.20220484057)+1 种基金The authors acknowledge the financial support from the Natural Sciences and Engineering Research Council of Canada(Grant No.RGPIN-2018-06902)industrial partners of the Research Institute on Mines and the Environment(RIME UQAT-Polytechnique:https://irme.ca/en/).
文摘Underhand cut-and-fill mining has been widely used in underground mining operations,especially when the rock mass or orebody is of poor quality or prone to rockburst due to high stress.In such cases,mining workers should carry out all production activities under the cemented backfill roof or sill mat instead of a highly fractured and unstable rock roof or a strong rock roof with a high potential of rockburst.Therefore,the stability and required strength of the sill mat are critical issues for mining engineers.In 1991,Mitchell considered that sill mat could fail by caving,sliding,rotation,and flexure.Mitchell also proposed an analytical solution to determine the minimum required strength of the sill mat for each type of failure based on two stiff or immobile rock walls.However,recent publications using numerical modeling and field measurements indicate that the compressive stresses in the sill mat induced by rock wall closure due to a stope excavation beneath the sill mat can be significant.It is thus highly necessary to investigate the required strength of the sill mat by considering rock wall closure.In this study,the crushing failure of sill mat due to rock wall closure generated by underground excavation and a new failure mode called"crushing and caving”is revealed by numerical modeling.An analytical solution corresponding to each failure mode is then developed to estimate the minimum required cohesion(cmin)of the sill mat.A criterion is also proposed to determine if the sill mat fails by crushing or crushing-and-caving failure.The proposed analytical solution does not involve any correction coefficients.The validity of the proposed analytical solution is demonstrated by numerical modeling.The proposed analytical solution can thus be employed to predict the cmin of sill mat subjected to wall closure generated by underlying stope excavation.
基金financially supported by the Project of National Key Research and Development Program of China(No.2022YFE0129200)the Beijing Nova Program(No.20220484057)+3 种基金the China Scholarship Council(No.202010300001)the National Natural Science Foundation of China(No.52304101)financial support from the Natural Sciences and Engineering Research Council of Canada(No.RGPIN-201806902)industrial partners of the Research Institute on Mines and the Environment(No.RIME UQAT-Polytechnique)。
文摘The underhand cut-and-fill mining method is widely employed in underground mines,especially when the quality of surrounding rock mass or ore body is inferior or subjected to high stresses.Such a method typically requires the construction of sill mats with cemented backfill to provide operators with safe artificial roofs.Accurate estimation of the minimum required strength of the sill mat is crucial to minimize binder consumption and ensure its stability upon base exposure.Over the years,only a few publications were devoted to determining the minimum required cohesion(cmin)of sill mats.None of them considered rock wall closure to be associated with the creep of surrounding rock mass.Moreover,the effect of rock wall closure associated with rock creep on the cminof the sill mat remains unknown.Thus,a series of numerical simulations was performed to fill this gap.The influence of rock creep on the cminof base-exposed sill mat was investigated for the first time.The numerical results indicate that Mitchell’s models could be suitable for sill mats subjected to negligible wall closure.However,this scenario is rare,especially when mine depth is large.In general,the cminof sill mats increases as mine depth increases.Neglecting rock creep would significantly underestimate the cminof sill mats.When mine depth is large and the rock mass exhibits severe creep,cemented backfill with ductile behavior(i.e.,with low stiffness but enough strength)should be considered to reduce binder consumption and prevent crushing failure.In all cases,promptly filling the mined-out stope below the sill mat can improve its stability and reduce its cminvalue.
基金National Natural Science Foundation of China(Grant Nos.52302249 and 12304003)Shenzhen Science and Technology Innovation Program(Grant No.KCXFZ20201221173010027).
文摘To meet the growing demand for high-energy-density lithium-ion batteries(LIBs),silicon(Si)anodes have gained attention as a promising material for next-generation anodes owing to their ultrahigh gravimetric capacity.Nevertheless,the Si anode faces significant challenges,particularly severe volume expansion during cycling,which leads to rapid capacity degradation and greatly hinders its commercialization potential.Although extensive research has focused on mitigating volume changes and constructing stable solid-electrolyte interphases on Si-based anodes,a crucial factor for practical application,namely the volumetric capacity,has been often overlooked.For Si-based anodes to replace conventional graphite anodes,their volumetric capacity must be thoroughly evaluated.Key factors determining the volumetric capacity include gravimetric capacity,active material mass ratio,initial Coulombic efficiency,electrode swelling ratio,and the negative-to-positive capacity ratio.This paper systematically analyzes,discusses,and summarizes each of these factors in detail.Common issues with existing strategies are identified,and future research directions concerning the commercialization of Si-based anodes are outlined.This study provides a systematic and novel perspective on effectively modifying and designing Si-based anodes,aiming to promote the volumetric capacity toward the large-scale industrialization of next-generation LIBs.
基金the financial support from the National Natural Science Foundation of China(No.51774041)。
文摘Carboxymethyl cellulose(CMC)was introduced as a depressant in reverse flotation separation of quartz from magnesite.The flotation behavior and surface properties of magnesite and quartz exposed to CMC were studied by zeta potential tests,atomic force microscopy imaging and contact angle measurements.The addition of CMC as the depressant in reverse flotation using dodecylamine(DDA)as the collector exhibited a selectively depressive performance towards magnesite and achieved an improved recovery of magnesite.The study of surface properties demonstrated that CMC and DDA exhibited different adsorption strengths on the surface of magnesite and quartz.It was found that the adsorption of CMC on magnesite surface was stronger than that of DDA,which hindered the subsequent adsorption of DDA on magnesite surface.On the contrary,the quartz surface was strongly adsorbed by DDA instead of CMC,which proved that the addition of CMC did not influence the flotation of quartz.
基金Project(2012BAB10B06) supported by the National Science and Technology Pillar Program of ChinaProject(51434001) supported by the National Natural Science Foundation of China
文摘A direct alkaline leaching process was proposed to extract molybdenum and lead from low-grade wulfenite ore containing 2.87%Mo and 9.39%Pb.The results show that increasing temperature and alkali concentration enhances the extraction of Mo and Pb,and more than 99.7%of Mo and 64.6%of Pb are extracted under conditions of 75℃,L/S of 2:1,leaching time of 1.0 h,initial NaOH concentration of 80 g/L and stirring speed of 100 r/min.The alkaline leaching of molybdenum follows a chemical reaction control mechanism with activation energy of 46.3 kJ/mol.Lead in the residue is recovered by hydrochloric acid leaching.99.8%of lead is leached under the conditions of 80℃,[MnO2]/[Pb]molar ratio of 1.3:1,sodium chloride concentration of 40 g/L,and hydrochloric acid concentration of 3 mol/L,and a product of crystallized PbCl2 with purity higher than 99.5%is obtained after cooling.
基金financially supported by the State Key Laboratory of Mineral Processing of BGRIMM Technology Group, China (No.BGRIMM-KJSKL-2017-11)
文摘The separation of andalusite and quartz was investigated in the sodium oleate flotation system, and its mechanism was studied by solution chemical calculation, zeta-potential tests, Fourier transform infrared spectroscopic(FTIR), and X-ray photoelectron spectroscopic(XPS). The flotation tests results show that FeCl3·6H2O has a strong activation effect on andalusite and quartz and citric acid has a strong inhibitory effect on activated quartz, thus increasing the floatability difference between quartz and andalusite when the pulp p H is approximately 8. The FTIR, Zeta potential, and XPS analyses combined with the chemical calculation of flotation reagent solutions demonstrate that Fe forms hydroxide precipitates on the surface of andalusite and quartz and that oleate anions and metal ions adsorb onto the surface of the minerals. The elements Al and Fe can be chemically reacted. The anions in citric acid have different degrees of dissolution of Fe on the andalusite and quartz surfaces, thereby selectively eliminating the activation of the elemental Fe on andalusite and quartz and increasing the floatability of andalusite, leading to a better separation effect between andalusite and quartz.
