Electron probe micro-analysis(EPMA)and scanning electron microscopy(SEM)equipped with energy dispersive spectrometry(EDS)have been used to investigate the principal ore minerals and coexisting metallic mineral inclusi...Electron probe micro-analysis(EPMA)and scanning electron microscopy(SEM)equipped with energy dispersive spectrometry(EDS)have been used to investigate the principal ore minerals and coexisting metallic mineral inclusions in polished thin sections from the Tiegelongnan deposit,which consists of a high-sulfidation epithermal system(HSES)and a porphyry system(PS).Molybdenite,chalcopyrite,bornite,tennantite,enargite,digenite,anilite,covellite,and tetrahedrite have been identified by EPMA.Intergrowth,cross-cutting and replacement relationships between the metallic minerals suggest that molybdenite formed first(stage 1),followed by chalcopyrite±bornite±hematite(stage 2),then bornite±Cu-sulfides±Cu-Fe-sulfoarsenides(stage 3),and lastly Cu-Fe-sulfoarsenides±Cu-sulfides(stage 4).Pyrite is developed throughout all the stages.Droplet-like inclusions of Au-Te minerals commonly occur in tennantite but not in the other major sulfides(molybdenite,chalcopyrite and bornite),implying that tennantite is the most important Au telluride carrier.The pervasive binary equilibrium phases of calaverite and altaite constrain fin the range from~-6.5 to~-8 and f<-11.The intergrowth of bornite and chalcopyrite and the conversion from bornite to digenite suggest fluctuated and relatively low precipitation temperature conditions in the HSES relative to the PS.Contrastingly,the dominance of chalcopyrite in the PS,with minor bornite,suggests relatively high temperature conditions.These new results are important for further understanding the mineral formation processes superimposed by HSES and PS systems.展开更多
The purpose of this study was to enhance the content of valuable metals, such as Au, Ag, and Te, in tellurium-bearing minerals via bioleaching. The ore samples composed of invisible Au and Au paragenesis minerals(such...The purpose of this study was to enhance the content of valuable metals, such as Au, Ag, and Te, in tellurium-bearing minerals via bioleaching. The ore samples composed of invisible Au and Au paragenesis minerals(such as pyrite, chalcopyrite, sphalerite and galena) in combination with tellurium-bearing minerals(hessite, sylvanite and Tellurobismuthite) were studied. Indigenous microbes from mine drainage were isolated and identified as Acidithiobacillus ferrooxidans, which were used in bioleaching after adaption to copper. The effect of the microbial adaption on the bioleaching performance was then compared with the results produced by the non-adaptive process. The microbial adaption enhanced the Au–Ag–Te contents in biological leaching of tellurium-bearing ore minerals. This suggests that bioleaching with adapted microbes can be used both as a pretreatment and in the main recovery processes of valuable metals.展开更多
基金supported by Public Science and Technology Research Funds Projects,Ministry of Land Resources of the People's Republic of China(project No.201511017 and 201511022-05)the Basic Research Fund of Chinese Academy of Geological Sciences(Grant No.YYWF201608)+1 种基金the National Natural Science Foundationof China(Grant No.41402178)Geological Survey Project of the China Geological Survey(project 1212011405040)
文摘Electron probe micro-analysis(EPMA)and scanning electron microscopy(SEM)equipped with energy dispersive spectrometry(EDS)have been used to investigate the principal ore minerals and coexisting metallic mineral inclusions in polished thin sections from the Tiegelongnan deposit,which consists of a high-sulfidation epithermal system(HSES)and a porphyry system(PS).Molybdenite,chalcopyrite,bornite,tennantite,enargite,digenite,anilite,covellite,and tetrahedrite have been identified by EPMA.Intergrowth,cross-cutting and replacement relationships between the metallic minerals suggest that molybdenite formed first(stage 1),followed by chalcopyrite±bornite±hematite(stage 2),then bornite±Cu-sulfides±Cu-Fe-sulfoarsenides(stage 3),and lastly Cu-Fe-sulfoarsenides±Cu-sulfides(stage 4).Pyrite is developed throughout all the stages.Droplet-like inclusions of Au-Te minerals commonly occur in tennantite but not in the other major sulfides(molybdenite,chalcopyrite and bornite),implying that tennantite is the most important Au telluride carrier.The pervasive binary equilibrium phases of calaverite and altaite constrain fin the range from~-6.5 to~-8 and f<-11.The intergrowth of bornite and chalcopyrite and the conversion from bornite to digenite suggest fluctuated and relatively low precipitation temperature conditions in the HSES relative to the PS.Contrastingly,the dominance of chalcopyrite in the PS,with minor bornite,suggests relatively high temperature conditions.These new results are important for further understanding the mineral formation processes superimposed by HSES and PS systems.
文摘The purpose of this study was to enhance the content of valuable metals, such as Au, Ag, and Te, in tellurium-bearing minerals via bioleaching. The ore samples composed of invisible Au and Au paragenesis minerals(such as pyrite, chalcopyrite, sphalerite and galena) in combination with tellurium-bearing minerals(hessite, sylvanite and Tellurobismuthite) were studied. Indigenous microbes from mine drainage were isolated and identified as Acidithiobacillus ferrooxidans, which were used in bioleaching after adaption to copper. The effect of the microbial adaption on the bioleaching performance was then compared with the results produced by the non-adaptive process. The microbial adaption enhanced the Au–Ag–Te contents in biological leaching of tellurium-bearing ore minerals. This suggests that bioleaching with adapted microbes can be used both as a pretreatment and in the main recovery processes of valuable metals.
