1 Introduction The large clusters of Zn-Pb deposits in northeastern Yunnan,located in the southwestern margin of the Yangtze Block,are an important part of the Sichuan-YunnanGuizhou Pb-Zn Poly-metallic Metallogenic Tr...1 Introduction The large clusters of Zn-Pb deposits in northeastern Yunnan,located in the southwestern margin of the Yangtze Block,are an important part of the Sichuan-YunnanGuizhou Pb-Zn Poly-metallic Metallogenic Triangle Area展开更多
Driven by the rapid advancement of wind,solar,and electric vehicle technologies,the global copper demand has increased significantly,prompting greater attention to complex and refractory copper-bearing minerals.As a r...Driven by the rapid advancement of wind,solar,and electric vehicle technologies,the global copper demand has increased significantly,prompting greater attention to complex and refractory copper-bearing minerals.As a representative example,valleriite is widely distributed in Cu-Ni sulfide ores and regarded as the second-most important copper-bearing phase after chalcopyrite.Structurally,valleriite features a layered crystal lattice composed of alternating hydrophobic sulfide and hydrophilic hydroxide layers,imparting it characteristics intermediate between sulfide and oxide ores.This unique structure,combined with its fine grain size,poor crystallinity,and complex intergrowths,greatly limits the efficiency of conventional beneficiation methods,such as flotation and magnetic separation.This review systematically summarizes the global distribution and physicochemical properties of valleriite and critically assesses beneficiation studies reported over the past seven decades.Furthermore,key factors contributing to poor recovery are identified,and potential strategies for improving the processing of valleriite-bearing ores are proposed.展开更多
Rare metal ore reserves are an important strategic resource, and their metallogenic mechanism and mineralization studies have also been received widespread international attention.
Spinel exsolution is widespread in titanomagnetite from the Fe-Ti oxide gabbro of the Panzhihua intrusion, Emeishan Large Igneous Province, SW China. However, little research has been conducted into the implications o...Spinel exsolution is widespread in titanomagnetite from the Fe-Ti oxide gabbro of the Panzhihua intrusion, Emeishan Large Igneous Province, SW China. However, little research has been conducted into the implications of patterns in the mineralogical characteristics of the spinel for spatial variation in the controls on the exsolution mechanism and, hence, the formation process of the ore deposit. This study selected the Lanjiahuoshan Ore Block in the Panzhihua V-Ti magnetite deposit to explore this issue, systematically studying exsolution textures in the titanomagnetite through petrographic observation and the integrated use of in-situ microanalysis. The results show that the exsolved spinel gradually becomes finer-grained and less abundant from the center to edge and the bottom to top of the ore bodies. Compositionally, there is an inverse correlation between the size of exsolved spinel grains and their Mg# value. In addition, there is compositional zonation in the spinel interiors, with a gradual increase in the Mg content and decrease in Fe content from the core to the rim. The analysis suggests that fractional crystallization of ferrotitanium magma with a high oxygen fugacity in a shallow magma chamber caused compositional differences in the primary magnetite solid solution in different parts of the Panzhihua intrusion. Additionally, the thermal evolution of the magnetite solid solution differed in different parts of orebody, bringing about variations in spinel development. Together, these effects resulted in spatial variation in the abundance, grain size, and morphology of spinel in different parts of the orebody and intrusion that follows an identifiable distribution law. Furthermore, the compositional zonation of exsolved spinels reflects the rapid growth of exsolution features in a high-temperature environment. Thus, the size, morphology, abundance, and composition of spinel exsolution features in titanomagnetite provide a valuable petrogenetic tool for estimating the maturity and formational environment of the deposit.展开更多
The effects of various general and heavy metal ions in acidic cadmium-containing wastewater on SBR desulfurization and cadmium removal under different concentrations were studied.CrO_(4)^(2-) and S^(2-) inhibited SRB ...The effects of various general and heavy metal ions in acidic cadmium-containing wastewater on SBR desulfurization and cadmium removal under different concentrations were studied.CrO_(4)^(2-) and S^(2-) inhibited SRB mineralization,and Mg^(2+),Ca^(2+),Fe^(2+),and Fe^(3+) promoted SRB mineralization at low concentration(<50 mg/L).The inhibitory concentrations of Cu^(2+),Mn^(2+),Co^(2+),Zn^(2+),Pb^(2+),Hg^(2+),Cr^(3+),and Ni^(2+) were 10,30,2,20,25,5,30 mg/L,respectively.The inhibition order was Co^(2+)>Hg^(2+)>Cu^(2+)>Ni^(2+)>Zn^(2+)>Pb^(2+)>Mn^(2+)>Cr^(3+).Furthermore,the inverted microscopy and scanning electron microscopy(SEM)were used to observe the sediment crystallization process from macroscopic and microscopic viewpoints in the optimized ion environment.The experimental results show that under the mineralization of SRB,cadmium sediment crystallization is mainly divided into the rapid growth of bacteria,crystal nucleus production,block formation,and crystallization occuration.At the same time,X-ray diffraction(XRD)and energy-dispersive spectra(EDS)have also confirmed the sediment and crystallization.展开更多
Microtextures and struetures of 9 hydrothermal chimneys sampled on the small spreading ridge Of the Mari ana Trough during SONNE Cruise 57 (SO57) and 69 (SO69) in 1988 and 1990 were studied by means of scanning elec...Microtextures and struetures of 9 hydrothermal chimneys sampled on the small spreading ridge Of the Mari ana Trough during SONNE Cruise 57 (SO57) and 69 (SO69) in 1988 and 1990 were studied by means of scanning electron microscope. The results reveal that the two types of chimneys from the Mariana Trough. the 'silicic chimneys' containing Fe sulfide and the pure 'silica chimneys' without sulfide, vary distinctly not only in mineral and chemical compositions, but also in microtextures and structures. The silicic chimneys generally show three major types of microtextures.The inside of the chimneys is dominated by holocrystalline or semicrystalline idiomorphic and hypidiomorphic granular textures and the outwall by amorphous colloidal texture. In some of the silicic chimneys relict texture is observed. However,the pure silica chimneys show chiefly amorphous colloidal texture from the inside to the outwall. Microstructurally. theinside of the silicic chimneys is dominated by a 'silica-covering' structure and a 'voidfilling' structure, and the outwall by a chain-like or three-dimentional chain-network structure built up by individual opal globules, whereas the pure silica chimneys are mainly three-dimentional chain-network and the dense silica bands in structure. These variations suggest that not only mineralizing conditions but also processes differ distinctly during the formation of the two types of chimneys, and that hydrothermal mineralization in the Mariana Trough shows a multistage or multieplsodical nature.展开更多
1 Introduction Studies of marine sedimentary phosphate rock have lasted decades,scholars proposed some standpoints about mineralization,however,the genesis of mineral deposits remains to be a controversial question(Sh...1 Introduction Studies of marine sedimentary phosphate rock have lasted decades,scholars proposed some standpoints about mineralization,however,the genesis of mineral deposits remains to be a controversial question(She et al.,2013).There are many viewpoints of mineralization about the Doushantuo phosphorites,Central Guizhou,including biological mineralization(Mi et al.,2010;Shi et al.,2005),展开更多
Coupled dissolution-precipitation is one of the critical processes influencing the mineralogical and geochemical evolution of pegmatites.This mechanism involves the simultaneous dissolution of primary mineral phases a...Coupled dissolution-precipitation is one of the critical processes influencing the mineralogical and geochemical evolution of pegmatites.This mechanism involves the simultaneous dissolution of primary mineral phases and the precipitation of secondary phases,driven by changes in the chemical environment,often mediated by hydrothermal fluids.The Bailongshan Li deposit,located in the West Kunlun region of northwest China,is a significant geological formation known for its rich lithium content and associated rare metals such as tantalum,niobium,and tin.This study investigates the coupled dissolution-precipitation processes that have played a crucial role in the mineralization of this deposit,focusing on key minerals,including cassiterite(Cst),columbite-group minerals(CGM),and elbaite(Elb).Using a combination of petrographic analysis,back-scattered electron(BSE)imaging,cathodoluminescence(CL)imaging,and micro X-ray fluorescence(XRF)mapping,we examined the textural and chemical characteristics of these minerals.Our findings reveal intricate patchy zoning patterns and element distributions(indicated by the Nb,Ta,W,Mn,Fe,Hf,Ti for CGM;Hf,Ti Rb,W,Nb,Ta for Cst;Ti,Zn,Fe,W,Hf,Mn,K for Elb)that indicate multiple stages of mineral alteration driven by fluid-mediated processes.The coupled dissolution-precipitation mechanisms observed in the Bailongshan deposit have resulted in significant redistribution and enrichment of economically valuable elements.The study highlights the importance of hydrothermal fluids in altering primary mineral phases and precipitating secondary phases with distinct compositions.These processes not only modified the mineralogical makeup of the pegmatite but also enhanced its economic potential by concentrating rare metals.Signatures of coupled dissolutionprecipitation processes can serve as an essential tool for mineral exploration,guiding the search for high-grade zones within similar pegmatitic formations.展开更多
Spatially superimposed multiple processes such as multiplicative cascade processes often generate multifractal measures possessing so-called self-similarity or self-affinity that can be described by power- law type of...Spatially superimposed multiple processes such as multiplicative cascade processes often generate multifractal measures possessing so-called self-similarity or self-affinity that can be described by power- law type of functions within certain scale ranges The multifractalities can be estimated by applying multifractal modeling to the measures reflecting the characteristics of the physical processes such as the element concentration values analyzed in rock and soil samples and caused by the underlying mineralization processes and the other geological processes. The local and regional geological processes may result in geochemical patterns with distinct multifractalities as wall as variable scaling ranges. Separation of these multifractal measures on the basis of both the distinct multifractalities and the scaling ranges will be significant for both theoretical studies of multifractal modeling and its applications. Multifractal scaling breaks have been observed from various multifractal patterns. This paper introduces a technique for separating multifractal measures on the basis of scaling breaks. It has been demonstrated that the method is effective for decomposing geochemical and geophysical anomalies required for mineral exploration. A dataset containing the element concentration values of potassium and phosphorus in soil samples was employed for demonstrating the application of the method for studying the fertilizer and yield optimization in agriculture展开更多
Ionic liquids as green solvents have shown important application in the extraction and separation of nonferrous metals.The new application perspective,the important fundamental and the applied studies of the extractio...Ionic liquids as green solvents have shown important application in the extraction and separation of nonferrous metals.The new application perspective,the important fundamental and the applied studies of the extraction and separation of nonferrous metals in ionic liquids,including the dissolution and corrosion of metal and metal oxide,hydrometallurgy of chalcopyrite and metallic oxidized ore,and extraction and separation of metal ions,are introduced.展开更多
Locating the mineral processing plant near a mine is the most important parameter that affects the whole process.Many factors,and their preferences,should be considered in this stage.The factors include economical,geo...Locating the mineral processing plant near a mine is the most important parameter that affects the whole process.Many factors,and their preferences,should be considered in this stage.The factors include economical,geological,technical,environmental and tectonic parameters.A multi-criteria decision making method is necessary to rank the alternatives.In this paper we describe how plant location is selected by using the Analytic Hierarchy Process(AHP).This method,with eight criteria,was used to select a location for the mineral processing plant at the Sangan iron ore mine(phase 1).Three alternatives for the processing plant were evaluated.The main criteria were distance from the mine,access to heavy machinery transport,the amount of excavation required for grading,bed mixture capacity,belt conveyor length,distance from the tailing dam,distance from the waste dumps and surface water diversion requirements.Finally,the alternatives were ranked and the best location was proposed.展开更多
More than 40 kinds of selected minerals and compounds were individually irradiated by microwaves under an inert atmosphere,and the temperatures of samples were measured with a metal-sheathed thermocouple inserted into...More than 40 kinds of selected minerals and compounds were individually irradiated by microwaves under an inert atmosphere,and the temperatures of samples were measured with a metal-sheathed thermocouple inserted into the samples directiy.The results indicated that most sulphide and some oxide minerals and compounds could be heated to high temperatures in a short timet whereas the common gangue minerals,some oxide and oxy-salt minerals or compounds could not.The sulphide minerals had faster heating rate than the oxide minerals containing the same cations.The impurities of minerals had significant effect on the heating rate.The selective heating characteristics of microwaves on different minerals and compounds could be attributed to the differences between their conductivities or dielectric loss factors and bonding properties.展开更多
A better understanding of solid-liquid separation would assist in improving the thickening performance and perhaps water recovery as well. The present work aimed to develop an empirical model to study the effects of o...A better understanding of solid-liquid separation would assist in improving the thickening performance and perhaps water recovery as well. The present work aimed to develop an empirical model to study the effects of ore properties on the thickening process based on pilot tests using a column. A hydro-cyclone was used to prepare the required samples for the experiments. The model significantly predicted the experimental underflow solid content using a regression equation at a given solid flux and bed level for different samples, indicating that ore properties are the effective parameters in the thickening process. This work confirned that the water recovery would be increased about 5% by separating the feed into two parts, overflow and underflow, and introducing two different thickeners into them separately. This is duo to the fact that thickeners are limited by permeability and compressibility in operating conditions.展开更多
The relationship of time to minerals composition in sinters is investigated by mineragraphy are claritied observation and component analysis,and the effects of temperature and atmosphere on mineralization process.Resu...The relationship of time to minerals composition in sinters is investigated by mineragraphy are claritied observation and component analysis,and the effects of temperature and atmosphere on mineralization process.Results are obtained as follows.The initial melt forms below the eutectic temperature of CaO·Fe2O3 and CaO·2Fe2O3,which is complex substance containing Ca,Fe,Si and Al,rather than the binary calcium ferrite melt.Minerals composition of binding phase is related to local content of silica in melt,which is influenced by temperature.Appearance of the melt promotes the transition from hematite to magnetite,which then alters the mechanism of calcium ferrite formation.Before the formation of magnetite,the contents of Fe and Ca within the multiple calcium ferrite decrease with temperature,but in the case of magnetite presence,the content of Fe increases solely with increase of temperature and decrease of oxygen potential.Temperature and atmosphere determine minerals composition together,and bring influence on sintering process in different ways.It can be deduced that temperature affects kinetics of the mineralization process,but atmosphere just plays a role in thermodynamics.展开更多
A feasible method to improve the reliability and processing efficiency of large vibrating screen via the application of an elastic screen surface with multiple attached substructures （ESSMAS） was proposed. In the ES...A feasible method to improve the reliability and processing efficiency of large vibrating screen via the application of an elastic screen surface with multiple attached substructures （ESSMAS） was proposed. In the ESSMAS, every screen rod, with ends embedded into elastomer, is coupled to the main screen structure in a relatively flexible manner. The theoretical analysis was conducted, which consists of establishing dynamic model promoted from the fuzzy structure theory as well as calculating for the equivalent stiffness of each attached structure. According to the numerical simulation using the NEWMARK-fl integration method, this assembling pattern significantly leads to the screen surface/rod having larger vibration intensity than that of the corresponding position on screen structure, which specifically, with an averaged acceleration amplitude increasing ratio of 11.37% in theoretical analysis and 20.27% in experimental test. The experimental results, within a tolerant error, also confirm the established model and demonstrate the feasibility of ESSMAS.展开更多
The latest progress in mineral processing in China is described. It is also pointed out that the existing technology can not meet the needs of economic development. The combined challenges of poor resources, economica...The latest progress in mineral processing in China is described. It is also pointed out that the existing technology can not meet the needs of economic development. The combined challenges of poor resources, economical benefits and environmental pollution issues require further research to upgrade the separation efficiency economically. The methods of mineral processing should play a more important part in waste treatment such as wastewater treatment, the remediation of contaminated soil and the recycling of wastes. Biomineral technology will be utilised in the near future.展开更多
Carbon dioxide mineral sequestration with steelmaking slag is a promising method for reducing carbon dioxide in a large- scale setting. Existing calcium oxide or calcium hydroxide in steelmaking slag can be easily lea...Carbon dioxide mineral sequestration with steelmaking slag is a promising method for reducing carbon dioxide in a large- scale setting. Existing calcium oxide or calcium hydroxide in steelmaking slag can be easily leached by water, and the formed calcium carbonate can be easily wrapped on the surface of unreacted steelmaking slag particles. Thus, further increase in the carbonation reaction rate can be prevented. Enhanced carbon dioxide mineral sequestration with steel- making slag in dilute alkali solution was analysed in this study through experiments and process evaluation. Operating conditions, namely alkali concentration, reaction temperature and time, and liquid-to-solid ratio, were initially investigated. Then, the material and energy balance of the entire process was calculated, and the net carbon dioxide sequestration efficiency at different reaction times was evaluated. Results showed that dilute alkali solution participated in slowing down the leaching of active calcium in the steelmaking slag and in significantly improving carbonation conversion rate. The highest carbonation conversion rate of approximately 50% can be obtained at the optimal conditions of 20 g/L alkali concentration, 2 mL/L liquid-to-solid ratio, and 70 ℃ reaction temperature. Carbonation reaction time significantly influences the net carbon dioxide sequestration efficiency. According to calculation, carbon dioxide emission of 52.6 kg/t- slag was avoided at a relatively long time of 120 min.展开更多
The Cr：Fe ratio （chromium-to-iron mass ratio） of chromite affects the production of chrome-based ferroalloys. Although the lit- erature contains numerous reports related to the magnetic separation of different mine...The Cr：Fe ratio （chromium-to-iron mass ratio） of chromite affects the production of chrome-based ferroalloys. Although the lit- erature contains numerous reports related to the magnetic separation of different minerals, limited work concerning the application of mag- netic separation to fine chromite from the Sukinda region of India to enhance its Cr：Fe ratio has been reported. In the present investigation, magnetic separation and mineralogical characterization studies of chromite fines were conducted to enhance the Cr：Fe ratio. Characterization studies included particle size and chemical analyses, X-ray diffraction analysis, automated mineral analysis, sink-and-float studies, and mag- netic susceptibility measurements, whereas magnetic separation was investigated using a rare earth drum magnetic separator, a rare earth roll magnetic separator, an induced roll magnetic separator, and a wet high-intensity magnetic separator. The fine chromite was observed to be upgraded to a Cr：Fe ratio of 2.2 with a yield of 55.7% through the use of an induced roll magnetic separator and a feed material with a Cr：Fe ratio of 1.6.展开更多
Alunite is the most important non bauxite resource for alumina. Various methods have been proposed and patented for processing alunite, but none has been performed at industrial scale and no technical,operational and ...Alunite is the most important non bauxite resource for alumina. Various methods have been proposed and patented for processing alunite, but none has been performed at industrial scale and no technical,operational and economic data is available to evaluate methods. In addition, selecting the right approach for alunite beneficiation, requires introducing a wide range of criteria and careful analysis of alternatives.In this research, after studying the existing processes, 13 methods were considered and evaluated by 14 technical, economic and environmental analyzing criteria. Due to multiplicity of processing methods and attributes, in this paper, Multi Attribute Decision Making methods were employed to examine the appropriateness of choices. The Delphi Analytical Hierarchy Process(DAHP) was used for weighting selection criteria and Fuzzy TOPSIS approach was used to determine the most profitable candidates. Among 13 studied methods, Spanish, Svoronos and Hazan methods were respectively recognized to be the best choices.展开更多
基金supported by the Funds for the program of the National Natural Science Foundation (Noes. 41572060, U1133602)Projects of YM Lab (2011)Innovation Team of Yunnan province and KMUST (2008,2012)
文摘1 Introduction The large clusters of Zn-Pb deposits in northeastern Yunnan,located in the southwestern margin of the Yangtze Block,are an important part of the Sichuan-YunnanGuizhou Pb-Zn Poly-metallic Metallogenic Triangle Area
基金supported by the Key Research and Development Special Project of Xinjiang Uygur Autonomous Region of China(No.2024B040029)the National Natural Science Foundation of China(No.52204301)the Hunan Province Graduate Student Independent Exploration Project,China(No.1053320220682).
文摘Driven by the rapid advancement of wind,solar,and electric vehicle technologies,the global copper demand has increased significantly,prompting greater attention to complex and refractory copper-bearing minerals.As a representative example,valleriite is widely distributed in Cu-Ni sulfide ores and regarded as the second-most important copper-bearing phase after chalcopyrite.Structurally,valleriite features a layered crystal lattice composed of alternating hydrophobic sulfide and hydrophilic hydroxide layers,imparting it characteristics intermediate between sulfide and oxide ores.This unique structure,combined with its fine grain size,poor crystallinity,and complex intergrowths,greatly limits the efficiency of conventional beneficiation methods,such as flotation and magnetic separation.This review systematically summarizes the global distribution and physicochemical properties of valleriite and critically assesses beneficiation studies reported over the past seven decades.Furthermore,key factors contributing to poor recovery are identified,and potential strategies for improving the processing of valleriite-bearing ores are proposed.
基金financially supported by the National Natural Science Foundation of China(grant No.41302061)
文摘Rare metal ore reserves are an important strategic resource, and their metallogenic mechanism and mineralization studies have also been received widespread international attention.
基金funded by the National Natural Science Foundation of China(Grant No.41172047)the Open Fund of the Key Laboratory of Ore Deposit Geochemistry(Institute of Geochemistry,Chinese Academy of Sciences,Guiyang),(Grant No.201308)the Open Fund of the Key Laboratory Metallogeny and Mineral Resource Assessment,Ministry of Land and Resources(Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing)(Grant No.ZS1407)
文摘Spinel exsolution is widespread in titanomagnetite from the Fe-Ti oxide gabbro of the Panzhihua intrusion, Emeishan Large Igneous Province, SW China. However, little research has been conducted into the implications of patterns in the mineralogical characteristics of the spinel for spatial variation in the controls on the exsolution mechanism and, hence, the formation process of the ore deposit. This study selected the Lanjiahuoshan Ore Block in the Panzhihua V-Ti magnetite deposit to explore this issue, systematically studying exsolution textures in the titanomagnetite through petrographic observation and the integrated use of in-situ microanalysis. The results show that the exsolved spinel gradually becomes finer-grained and less abundant from the center to edge and the bottom to top of the ore bodies. Compositionally, there is an inverse correlation between the size of exsolved spinel grains and their Mg# value. In addition, there is compositional zonation in the spinel interiors, with a gradual increase in the Mg content and decrease in Fe content from the core to the rim. The analysis suggests that fractional crystallization of ferrotitanium magma with a high oxygen fugacity in a shallow magma chamber caused compositional differences in the primary magnetite solid solution in different parts of the Panzhihua intrusion. Additionally, the thermal evolution of the magnetite solid solution differed in different parts of orebody, bringing about variations in spinel development. Together, these effects resulted in spatial variation in the abundance, grain size, and morphology of spinel in different parts of the orebody and intrusion that follows an identifiable distribution law. Furthermore, the compositional zonation of exsolved spinels reflects the rapid growth of exsolution features in a high-temperature environment. Thus, the size, morphology, abundance, and composition of spinel exsolution features in titanomagnetite provide a valuable petrogenetic tool for estimating the maturity and formational environment of the deposit.
基金Funded by the National Natural Science Foundation of China(No.46120511)。
文摘The effects of various general and heavy metal ions in acidic cadmium-containing wastewater on SBR desulfurization and cadmium removal under different concentrations were studied.CrO_(4)^(2-) and S^(2-) inhibited SRB mineralization,and Mg^(2+),Ca^(2+),Fe^(2+),and Fe^(3+) promoted SRB mineralization at low concentration(<50 mg/L).The inhibitory concentrations of Cu^(2+),Mn^(2+),Co^(2+),Zn^(2+),Pb^(2+),Hg^(2+),Cr^(3+),and Ni^(2+) were 10,30,2,20,25,5,30 mg/L,respectively.The inhibition order was Co^(2+)>Hg^(2+)>Cu^(2+)>Ni^(2+)>Zn^(2+)>Pb^(2+)>Mn^(2+)>Cr^(3+).Furthermore,the inverted microscopy and scanning electron microscopy(SEM)were used to observe the sediment crystallization process from macroscopic and microscopic viewpoints in the optimized ion environment.The experimental results show that under the mineralization of SRB,cadmium sediment crystallization is mainly divided into the rapid growth of bacteria,crystal nucleus production,block formation,and crystallization occuration.At the same time,X-ray diffraction(XRD)and energy-dispersive spectra(EDS)have also confirmed the sediment and crystallization.
文摘Microtextures and struetures of 9 hydrothermal chimneys sampled on the small spreading ridge Of the Mari ana Trough during SONNE Cruise 57 (SO57) and 69 (SO69) in 1988 and 1990 were studied by means of scanning electron microscope. The results reveal that the two types of chimneys from the Mariana Trough. the 'silicic chimneys' containing Fe sulfide and the pure 'silica chimneys' without sulfide, vary distinctly not only in mineral and chemical compositions, but also in microtextures and structures. The silicic chimneys generally show three major types of microtextures.The inside of the chimneys is dominated by holocrystalline or semicrystalline idiomorphic and hypidiomorphic granular textures and the outwall by amorphous colloidal texture. In some of the silicic chimneys relict texture is observed. However,the pure silica chimneys show chiefly amorphous colloidal texture from the inside to the outwall. Microstructurally. theinside of the silicic chimneys is dominated by a 'silica-covering' structure and a 'voidfilling' structure, and the outwall by a chain-like or three-dimentional chain-network structure built up by individual opal globules, whereas the pure silica chimneys are mainly three-dimentional chain-network and the dense silica bands in structure. These variations suggest that not only mineralizing conditions but also processes differ distinctly during the formation of the two types of chimneys, and that hydrothermal mineralization in the Mariana Trough shows a multistage or multieplsodical nature.
文摘1 Introduction Studies of marine sedimentary phosphate rock have lasted decades,scholars proposed some standpoints about mineralization,however,the genesis of mineral deposits remains to be a controversial question(She et al.,2013).There are many viewpoints of mineralization about the Doushantuo phosphorites,Central Guizhou,including biological mineralization(Mi et al.,2010;Shi et al.,2005),
基金jointly supported by the National Natural Science Foundation of China(Nos.42250202,92162323,42272075)the Fundamental Research Funds for the Central Universities,Sun Yat-sen University(No.24lgqb001)+1 种基金the Natural Science Foundation Project of Guangdong Province(No.2022A1515010003)the Guangdong Province Introduced Innovative R&D Team of Big Data—Mathematical Earth Sciences and Extreme Geological Events Team(No.2021ZT09H399)。
文摘Coupled dissolution-precipitation is one of the critical processes influencing the mineralogical and geochemical evolution of pegmatites.This mechanism involves the simultaneous dissolution of primary mineral phases and the precipitation of secondary phases,driven by changes in the chemical environment,often mediated by hydrothermal fluids.The Bailongshan Li deposit,located in the West Kunlun region of northwest China,is a significant geological formation known for its rich lithium content and associated rare metals such as tantalum,niobium,and tin.This study investigates the coupled dissolution-precipitation processes that have played a crucial role in the mineralization of this deposit,focusing on key minerals,including cassiterite(Cst),columbite-group minerals(CGM),and elbaite(Elb).Using a combination of petrographic analysis,back-scattered electron(BSE)imaging,cathodoluminescence(CL)imaging,and micro X-ray fluorescence(XRF)mapping,we examined the textural and chemical characteristics of these minerals.Our findings reveal intricate patchy zoning patterns and element distributions(indicated by the Nb,Ta,W,Mn,Fe,Hf,Ti for CGM;Hf,Ti Rb,W,Nb,Ta for Cst;Ti,Zn,Fe,W,Hf,Mn,K for Elb)that indicate multiple stages of mineral alteration driven by fluid-mediated processes.The coupled dissolution-precipitation mechanisms observed in the Bailongshan deposit have resulted in significant redistribution and enrichment of economically valuable elements.The study highlights the importance of hydrothermal fluids in altering primary mineral phases and precipitating secondary phases with distinct compositions.These processes not only modified the mineralogical makeup of the pegmatite but also enhanced its economic potential by concentrating rare metals.Signatures of coupled dissolutionprecipitation processes can serve as an essential tool for mineral exploration,guiding the search for high-grade zones within similar pegmatitic formations.
文摘Spatially superimposed multiple processes such as multiplicative cascade processes often generate multifractal measures possessing so-called self-similarity or self-affinity that can be described by power- law type of functions within certain scale ranges The multifractalities can be estimated by applying multifractal modeling to the measures reflecting the characteristics of the physical processes such as the element concentration values analyzed in rock and soil samples and caused by the underlying mineralization processes and the other geological processes. The local and regional geological processes may result in geochemical patterns with distinct multifractalities as wall as variable scaling ranges. Separation of these multifractal measures on the basis of both the distinct multifractalities and the scaling ranges will be significant for both theoretical studies of multifractal modeling and its applications. Multifractal scaling breaks have been observed from various multifractal patterns. This paper introduces a technique for separating multifractal measures on the basis of scaling breaks. It has been demonstrated that the method is effective for decomposing geochemical and geophysical anomalies required for mineral exploration. A dataset containing the element concentration values of potassium and phosphorus in soil samples was employed for demonstrating the application of the method for studying the fertilizer and yield optimization in agriculture
基金Project(50904031) supported by the National Natural Science Foundation of ChinaProject(2008E0049M) supported by the Natural Science Foundation of Yunnan Province,China+1 种基金Project(07Z40082) supported by the Science Foundation of the Education Department of Yunnan Province,ChinaProject(2007-16) supported by the Science Foundation of Kunming University of Science and Technology,China
文摘Ionic liquids as green solvents have shown important application in the extraction and separation of nonferrous metals.The new application perspective,the important fundamental and the applied studies of the extraction and separation of nonferrous metals in ionic liquids,including the dissolution and corrosion of metal and metal oxide,hydrometallurgy of chalcopyrite and metallic oxidized ore,and extraction and separation of metal ions,are introduced.
文摘Locating the mineral processing plant near a mine is the most important parameter that affects the whole process.Many factors,and their preferences,should be considered in this stage.The factors include economical,geological,technical,environmental and tectonic parameters.A multi-criteria decision making method is necessary to rank the alternatives.In this paper we describe how plant location is selected by using the Analytic Hierarchy Process(AHP).This method,with eight criteria,was used to select a location for the mineral processing plant at the Sangan iron ore mine(phase 1).Three alternatives for the processing plant were evaluated.The main criteria were distance from the mine,access to heavy machinery transport,the amount of excavation required for grading,bed mixture capacity,belt conveyor length,distance from the tailing dam,distance from the waste dumps and surface water diversion requirements.Finally,the alternatives were ranked and the best location was proposed.
基金Supported by the National Natural Science Foundation and National Nonferrous Metals Industry Corporation of China。
文摘More than 40 kinds of selected minerals and compounds were individually irradiated by microwaves under an inert atmosphere,and the temperatures of samples were measured with a metal-sheathed thermocouple inserted into the samples directiy.The results indicated that most sulphide and some oxide minerals and compounds could be heated to high temperatures in a short timet whereas the common gangue minerals,some oxide and oxy-salt minerals or compounds could not.The sulphide minerals had faster heating rate than the oxide minerals containing the same cations.The impurities of minerals had significant effect on the heating rate.The selective heating characteristics of microwaves on different minerals and compounds could be attributed to the differences between their conductivities or dielectric loss factors and bonding properties.
文摘A better understanding of solid-liquid separation would assist in improving the thickening performance and perhaps water recovery as well. The present work aimed to develop an empirical model to study the effects of ore properties on the thickening process based on pilot tests using a column. A hydro-cyclone was used to prepare the required samples for the experiments. The model significantly predicted the experimental underflow solid content using a regression equation at a given solid flux and bed level for different samples, indicating that ore properties are the effective parameters in the thickening process. This work confirned that the water recovery would be increased about 5% by separating the feed into two parts, overflow and underflow, and introducing two different thickeners into them separately. This is duo to the fact that thickeners are limited by permeability and compressibility in operating conditions.
基金Item Sponsored by National Natural Science Foundation of China(50974012)National High Technology Research and Development Program of China(2006AA06Z125)
文摘The relationship of time to minerals composition in sinters is investigated by mineragraphy are claritied observation and component analysis,and the effects of temperature and atmosphere on mineralization process.Results are obtained as follows.The initial melt forms below the eutectic temperature of CaO·Fe2O3 and CaO·2Fe2O3,which is complex substance containing Ca,Fe,Si and Al,rather than the binary calcium ferrite melt.Minerals composition of binding phase is related to local content of silica in melt,which is influenced by temperature.Appearance of the melt promotes the transition from hematite to magnetite,which then alters the mechanism of calcium ferrite formation.Before the formation of magnetite,the contents of Fe and Ca within the multiple calcium ferrite decrease with temperature,but in the case of magnetite presence,the content of Fe increases solely with increase of temperature and decrease of oxygen potential.Temperature and atmosphere determine minerals composition together,and bring influence on sintering process in different ways.It can be deduced that temperature affects kinetics of the mineralization process,but atmosphere just plays a role in thermodynamics.
基金Projects(50574091,50774084) supported by the National Natural Science Foundation of China
文摘A feasible method to improve the reliability and processing efficiency of large vibrating screen via the application of an elastic screen surface with multiple attached substructures （ESSMAS） was proposed. In the ESSMAS, every screen rod, with ends embedded into elastomer, is coupled to the main screen structure in a relatively flexible manner. The theoretical analysis was conducted, which consists of establishing dynamic model promoted from the fuzzy structure theory as well as calculating for the equivalent stiffness of each attached structure. According to the numerical simulation using the NEWMARK-fl integration method, this assembling pattern significantly leads to the screen surface/rod having larger vibration intensity than that of the corresponding position on screen structure, which specifically, with an averaged acceleration amplitude increasing ratio of 11.37% in theoretical analysis and 20.27% in experimental test. The experimental results, within a tolerant error, also confirm the established model and demonstrate the feasibility of ESSMAS.
文摘The latest progress in mineral processing in China is described. It is also pointed out that the existing technology can not meet the needs of economic development. The combined challenges of poor resources, economical benefits and environmental pollution issues require further research to upgrade the separation efficiency economically. The methods of mineral processing should play a more important part in waste treatment such as wastewater treatment, the remediation of contaminated soil and the recycling of wastes. Biomineral technology will be utilised in the near future.
基金financially supported by the National Natural Science Foundation of China (No. 21300212)
文摘Carbon dioxide mineral sequestration with steelmaking slag is a promising method for reducing carbon dioxide in a large- scale setting. Existing calcium oxide or calcium hydroxide in steelmaking slag can be easily leached by water, and the formed calcium carbonate can be easily wrapped on the surface of unreacted steelmaking slag particles. Thus, further increase in the carbonation reaction rate can be prevented. Enhanced carbon dioxide mineral sequestration with steel- making slag in dilute alkali solution was analysed in this study through experiments and process evaluation. Operating conditions, namely alkali concentration, reaction temperature and time, and liquid-to-solid ratio, were initially investigated. Then, the material and energy balance of the entire process was calculated, and the net carbon dioxide sequestration efficiency at different reaction times was evaluated. Results showed that dilute alkali solution participated in slowing down the leaching of active calcium in the steelmaking slag and in significantly improving carbonation conversion rate. The highest carbonation conversion rate of approximately 50% can be obtained at the optimal conditions of 20 g/L alkali concentration, 2 mL/L liquid-to-solid ratio, and 70 ℃ reaction temperature. Carbonation reaction time significantly influences the net carbon dioxide sequestration efficiency. According to calculation, carbon dioxide emission of 52.6 kg/t- slag was avoided at a relatively long time of 120 min.
文摘The Cr：Fe ratio （chromium-to-iron mass ratio） of chromite affects the production of chrome-based ferroalloys. Although the lit- erature contains numerous reports related to the magnetic separation of different minerals, limited work concerning the application of mag- netic separation to fine chromite from the Sukinda region of India to enhance its Cr：Fe ratio has been reported. In the present investigation, magnetic separation and mineralogical characterization studies of chromite fines were conducted to enhance the Cr：Fe ratio. Characterization studies included particle size and chemical analyses, X-ray diffraction analysis, automated mineral analysis, sink-and-float studies, and mag- netic susceptibility measurements, whereas magnetic separation was investigated using a rare earth drum magnetic separator, a rare earth roll magnetic separator, an induced roll magnetic separator, and a wet high-intensity magnetic separator. The fine chromite was observed to be upgraded to a Cr：Fe ratio of 2.2 with a yield of 55.7% through the use of an induced roll magnetic separator and a feed material with a Cr：Fe ratio of 1.6.
文摘Alunite is the most important non bauxite resource for alumina. Various methods have been proposed and patented for processing alunite, but none has been performed at industrial scale and no technical,operational and economic data is available to evaluate methods. In addition, selecting the right approach for alunite beneficiation, requires introducing a wide range of criteria and careful analysis of alternatives.In this research, after studying the existing processes, 13 methods were considered and evaluated by 14 technical, economic and environmental analyzing criteria. Due to multiplicity of processing methods and attributes, in this paper, Multi Attribute Decision Making methods were employed to examine the appropriateness of choices. The Delphi Analytical Hierarchy Process(DAHP) was used for weighting selection criteria and Fuzzy TOPSIS approach was used to determine the most profitable candidates. Among 13 studied methods, Spanish, Svoronos and Hazan methods were respectively recognized to be the best choices.
