The preparation methods of simultaneous electro deposition for pyrite (FeS 2) thin film are introduced from aqueous solution of FeSO 4 and Na 2S 2O 3. Electrical process is studied in detail in the paper. From the exp...The preparation methods of simultaneous electro deposition for pyrite (FeS 2) thin film are introduced from aqueous solution of FeSO 4 and Na 2S 2O 3. Electrical process is studied in detail in the paper. From the experiment result, the best way of drying the sample is to dry it in vacuum. Electro deposition method for the preparation of pyrite thin film is a safe, simple and low cost method.展开更多
Gold bearing pyrite leaching was conducted in H2SO4-Fe2（SO4）3 system at different reaction temperatures,with different ferric ion concentrations,sulfuric acid concentrations and stirring speeds.The leaching kinetics...Gold bearing pyrite leaching was conducted in H2SO4-Fe2（SO4）3 system at different reaction temperatures,with different ferric ion concentrations,sulfuric acid concentrations and stirring speeds.The leaching kinetics and mechanism were studied.When the temperature ranged between 30-75 °C,the pyrite leaching was mainly controlled by chemical reaction with positive correlation to the ferric ion concentration.The activation energy obtained from Arrhenius empirical formula is 51.39 k J/mol.The EDS and XPS analyses suggest that the oxidation of sulfur within pyrite is through a series of intermediate stages,and eventually is oxidized to sulphate accompanied with the formation of element sulfur.This indicates a thiosulfate oxidation pathway of the gold bearing pyrite oxidation in H2SO4-Fe2（SO4）3 system.展开更多
Fe(Ⅲ)has been proved to be a more eff ective oxidant than dissolved oxygen at ambient temperature,however,the role of Fe(Ⅲ)in pyrite acidic pressure oxidation was rarely discussed so far.In this paper,in-situ electr...Fe(Ⅲ)has been proved to be a more eff ective oxidant than dissolved oxygen at ambient temperature,however,the role of Fe(Ⅲ)in pyrite acidic pressure oxidation was rarely discussed so far.In this paper,in-situ electrochemical investigation was performed using a flow-through autoclave system in acidic pressure oxidation environment.The results illustrated that increasing Fe(Ⅲ)concentrations led to raising in redox potential of the solution,and decreased passivation of pyrite caused by deposition of elemental sulfur.Reduction of Fe(Ⅲ)at pyrite surface was a fast reaction with low activation energy,it was only slightly promoted by rising temperatures.While,the oxidation rate of pyrite at all investigated Fe(Ⅲ)concentrations increased obviously with rising temperatures,the anodic reaction was the rate-limiting step in the overall reaction.Activation energy of pyrite oxidation decreased from 47.74 to 28.79 kJ/mol when Fe(Ⅲ)concentration was increased from 0.05 to 0.50 g/L,showing that the reaction kinetics were limited by the rate of electrochemical reaction at low Fe(Ⅲ)concentrations,while,it gradually turned to be diffusion control with increasing Fe(Ⅲ)concentrations.展开更多
Simulated heap bioleaching of low-grade high pyrite-bearing chalcocite ore was conducted at 40 °C with aeration of CO_2 and N_2.Ore samples were collected at day 43,64,85,106 and subjected to microbial community ...Simulated heap bioleaching of low-grade high pyrite-bearing chalcocite ore was conducted at 40 °C with aeration of CO_2 and N_2.Ore samples were collected at day 43,64,85,106 and subjected to microbial community analysis by 16S rRNA gene clone library.Phylogenetic analyses of 16S rDNA fragments revealed that the retrieved sequences are mainly related to genus Acidithiobacillus,Leptospirillum and Sulfobacillus.Aeration of CO_2 and N_2 significantly impacted the microbial community composition.When CO_2 was aerated,the proportion of genus Acidithiobacillus considerably increased,whereas the proportion of genus Leptospirillum and genus Sulfobacillus declined.However,with the aeration of N_2,the proportion of genus Acidithiobacillus and Leptospirillum increased,but genus Sulfobacillus decreased.When there was no aeration,the microbial community was similar to the inocula with the proportion of genus Leptospirillum mounted.These results indicated that the limitation of oxygen could change the bioleaching microbial community and the aeration of CO_2 and N_2 was favourable for the growth of sulfur-oxidizer(At.caldus) and iron-oxidizer(L.ferriphilum) respectively,which could be used for the regulation of microorganisms' role in mineral bioleaching.展开更多
The role of CaCl2 during the high temperature chloridizing-reduction roasting process was investigated, aiming at acquiring high strength blast furnace burden with high iron grade and low nonferrous metals content. Th...The role of CaCl2 during the high temperature chloridizing-reduction roasting process was investigated, aiming at acquiring high strength blast furnace burden with high iron grade and low nonferrous metals content. The effects of CaCl2 dosage on pelletizing, preheating and reduction were investigated. The results show that CaCl2 can improve the wet drop strength but reduces the thermostability of pyrite cinder green balls. When the dosage of CaCl2 exceeds 1%, the compressive strength of preheated pellets decreases while the growth of iron oxide particles is improved. Furthermore, the compressive strength of pre-reduced pellets increases but the metallization degree of pre-reduced pellets decreases with CaCl2 additive. The removal tests indicate that Zn can be removed completely without CaCl2 additive, Cu is removed only under the condition with CaCl2 additive and part of Pb must be removed by CaCl2 additive.展开更多
文摘The preparation methods of simultaneous electro deposition for pyrite (FeS 2) thin film are introduced from aqueous solution of FeSO 4 and Na 2S 2O 3. Electrical process is studied in detail in the paper. From the experiment result, the best way of drying the sample is to dry it in vacuum. Electro deposition method for the preparation of pyrite thin film is a safe, simple and low cost method.
基金Project(51474075)supported by the National Natural Science Foundation of China
文摘Gold bearing pyrite leaching was conducted in H2SO4-Fe2（SO4）3 system at different reaction temperatures,with different ferric ion concentrations,sulfuric acid concentrations and stirring speeds.The leaching kinetics and mechanism were studied.When the temperature ranged between 30-75 °C,the pyrite leaching was mainly controlled by chemical reaction with positive correlation to the ferric ion concentration.The activation energy obtained from Arrhenius empirical formula is 51.39 k J/mol.The EDS and XPS analyses suggest that the oxidation of sulfur within pyrite is through a series of intermediate stages,and eventually is oxidized to sulphate accompanied with the formation of element sulfur.This indicates a thiosulfate oxidation pathway of the gold bearing pyrite oxidation in H2SO4-Fe2（SO4）3 system.
基金supported by the Science and Technology Foundation of Guizhou Province,China(No.[2020]1Y163)the National Natural Science Foundation of China(No.41827802).
文摘Fe(Ⅲ)has been proved to be a more eff ective oxidant than dissolved oxygen at ambient temperature,however,the role of Fe(Ⅲ)in pyrite acidic pressure oxidation was rarely discussed so far.In this paper,in-situ electrochemical investigation was performed using a flow-through autoclave system in acidic pressure oxidation environment.The results illustrated that increasing Fe(Ⅲ)concentrations led to raising in redox potential of the solution,and decreased passivation of pyrite caused by deposition of elemental sulfur.Reduction of Fe(Ⅲ)at pyrite surface was a fast reaction with low activation energy,it was only slightly promoted by rising temperatures.While,the oxidation rate of pyrite at all investigated Fe(Ⅲ)concentrations increased obviously with rising temperatures,the anodic reaction was the rate-limiting step in the overall reaction.Activation energy of pyrite oxidation decreased from 47.74 to 28.79 kJ/mol when Fe(Ⅲ)concentration was increased from 0.05 to 0.50 g/L,showing that the reaction kinetics were limited by the rate of electrochemical reaction at low Fe(Ⅲ)concentrations,while,it gradually turned to be diffusion control with increasing Fe(Ⅲ)concentrations.
基金Project(51404033)supported by the National Natural Science Foundation of ChinaProject(2010CB630905)supported by the National Basic Research Program of China
文摘Simulated heap bioleaching of low-grade high pyrite-bearing chalcocite ore was conducted at 40 °C with aeration of CO_2 and N_2.Ore samples were collected at day 43,64,85,106 and subjected to microbial community analysis by 16S rRNA gene clone library.Phylogenetic analyses of 16S rDNA fragments revealed that the retrieved sequences are mainly related to genus Acidithiobacillus,Leptospirillum and Sulfobacillus.Aeration of CO_2 and N_2 significantly impacted the microbial community composition.When CO_2 was aerated,the proportion of genus Acidithiobacillus considerably increased,whereas the proportion of genus Leptospirillum and genus Sulfobacillus declined.However,with the aeration of N_2,the proportion of genus Acidithiobacillus and Leptospirillum increased,but genus Sulfobacillus decreased.When there was no aeration,the microbial community was similar to the inocula with the proportion of genus Leptospirillum mounted.These results indicated that the limitation of oxygen could change the bioleaching microbial community and the aeration of CO_2 and N_2 was favourable for the growth of sulfur-oxidizer(At.caldus) and iron-oxidizer(L.ferriphilum) respectively,which could be used for the regulation of microorganisms' role in mineral bioleaching.
基金Project(51504155)supported by the National Natural Science Foundation of ChinaProject(BK20140337)supported by the Basic Research Program of Jiangsu Province+2 种基金ChinaProject(SDY2013A13)supported by the Young Teacher Natural Science Fund of Soochow UniversityChina
文摘The role of CaCl2 during the high temperature chloridizing-reduction roasting process was investigated, aiming at acquiring high strength blast furnace burden with high iron grade and low nonferrous metals content. The effects of CaCl2 dosage on pelletizing, preheating and reduction were investigated. The results show that CaCl2 can improve the wet drop strength but reduces the thermostability of pyrite cinder green balls. When the dosage of CaCl2 exceeds 1%, the compressive strength of preheated pellets decreases while the growth of iron oxide particles is improved. Furthermore, the compressive strength of pre-reduced pellets increases but the metallization degree of pre-reduced pellets decreases with CaCl2 additive. The removal tests indicate that Zn can be removed completely without CaCl2 additive, Cu is removed only under the condition with CaCl2 additive and part of Pb must be removed by CaCl2 additive.
