Effects of initial pH, temperature, liquid volume, rotation speed, galvanic interaction （pyrite ratio） and pulp density on bioleaching of complex Cu-polymetallic concentrate were investigated. The results indicated ...Effects of initial pH, temperature, liquid volume, rotation speed, galvanic interaction （pyrite ratio） and pulp density on bioleaching of complex Cu-polymetallic concentrate were investigated. The results indicated that the copper extraction at pH 1.5 was 1.5 and 1.4 times that at pH 1.0 and pH 2.0 respectively. The copper extraction obtained at 45 ℃ was 1236.8%higher than that at 50 ℃. With the increase of rotation speed or the decrease of liquid volume, copper extraction was improved obviously. Copper extraction was improved gradually with the increase of pyrite ratio. However, when the ratio was higher than 20.0%, no further increase in copper extraction was observed. And the statistically significant interactive effects on copper extraction were found between temperature and pH, and temperature and pyrite ratio.展开更多
Cyclic voltammetry and potentiodynamic polarization analyses were utilized to investigate the mechanism and kinetics of glycine leaching reactions for chalcopyrite.The effects of pH(9−12),temperature(30−90℃)and glyci...Cyclic voltammetry and potentiodynamic polarization analyses were utilized to investigate the mechanism and kinetics of glycine leaching reactions for chalcopyrite.The effects of pH(9−12),temperature(30−90℃)and glycine concentration(0−2 mol/L)on corrosion current density,corrosion potential and cyclic voltammograms were investigated using chalcopyrite concentrate−carbon paste electrodes.Results showed that an increase in the glycine concentration from 0 to 2 mol/L led to an increased oxidation peak current density.Under the same conditions,corrosion current density was found to change from approximately 28 to 89μA/cm2,whereas corrosion potential was decreased from−80 to−130 mV.Elevated temperatures enhanced the measured current densities up to 60℃;however,above this level,current density was observed to decrease.A similar current density behavior was determined with pH.A pH change from 9 to 10.5 resulted in an increase in current density and pH higher than 10.5 gave rise to a reduced current density.In addition,the thermodynamic stability of copper and iron oxides was found to increase at higher temperatures.展开更多
Some effective parameters on the copper extraction from Kiire chalcopyrite concentrate were optimized by using response surface methodology （RSM）. Experiments designed by RSM were carried out in the presence of ammo...Some effective parameters on the copper extraction from Kiire chalcopyrite concentrate were optimized by using response surface methodology （RSM）. Experiments designed by RSM were carried out in the presence of ammonium persulfate （APS） and different types of impeller in an autoclave system. Ammonium persulfate concentration and leaching temperature were defined numerically and three types of impellers were defined categorically as independent variables using experimental design software. The optimum condition for copper extraction from the chalcopyrite concentrate is found to be ammonium persulfate concentration of 277.77 kg/m3, leaching temperature of 389.98 K and wheel type of impeller. The proposed model equation using RSM has shown good agreement with the experimental data, with correlation coefficients R2 and RaZaj for the model as 0.89 and 0.84, respectively.展开更多
The treatment of the Gacun complex Cu concentrate with high contents of Pb,Zn,Ag,etc by oxygen pressure acid leaching was studied.It is unusual that tetrahedrite,whose treatment was rarely studied,is the primary coppe...The treatment of the Gacun complex Cu concentrate with high contents of Pb,Zn,Ag,etc by oxygen pressure acid leaching was studied.It is unusual that tetrahedrite,whose treatment was rarely studied,is the primary copper mineral of the concentrates.Most of silver also occurs in the mineral.The optimum operating parameters of oxygen pressure acid leaching were established by conditional tests.Pilot scale test was carried out under the parameters,and the leaching rates of copper and zinc are as high as 97.10% and 89.83% while lead and silver are transformed into sulfate and sulfide respectively and stay in leaching residue.The copper and zinc in lixivium were reclaimed by extraction-electrowinning and purification-electrowinning,respectively,and the lead and silver in the residue were reclaimed separately by chloride leaching and thiourea leaching.The extraction rate of copper achieves 96%,and the leaching rates of lead and silver reach 90% and 95%,respectively.展开更多
The mechanism of the leaching process of chalcopyrite concentrate with sodium nitrate in sulphuric acid solution were studied and discussed. Chemical reactions of leaching and their thermodynamic probabilities are pre...The mechanism of the leaching process of chalcopyrite concentrate with sodium nitrate in sulphuric acid solution were studied and discussed. Chemical reactions of leaching and their thermodynamic probabilities are predicted based on the calculated Gibbs energies and analysis of E-pH diagrams. Experimental data, thermodynamic analysis, chemical, XRD, and SEM/EDX analyses of concentrate and the leach residues, were performed to develop a better understanding of the chemical reactions that took place in the system. Elemental sulphur was formed as the main leaching product, precipitated at the particle surfaces and tended to inhibit the leaching rate.展开更多
基金Project (2012zzts026) supported by the Fundamental Research Funds for the Central Universities,ChinaProject (201205020) supported by Scientific Research Program of Marine Public Welfare Industry of China+2 种基金Project (51074195) supported by the National Natural Science Foundation of ChinaProject (CX2012B123) supported by Research Innovation for Graduate Student of Hunan Province,ChinaProject (12C517) supported by Education Department of Hunan Province,China
文摘Effects of initial pH, temperature, liquid volume, rotation speed, galvanic interaction （pyrite ratio） and pulp density on bioleaching of complex Cu-polymetallic concentrate were investigated. The results indicated that the copper extraction at pH 1.5 was 1.5 and 1.4 times that at pH 1.0 and pH 2.0 respectively. The copper extraction obtained at 45 ℃ was 1236.8%higher than that at 50 ℃. With the increase of rotation speed or the decrease of liquid volume, copper extraction was improved obviously. Copper extraction was improved gradually with the increase of pyrite ratio. However, when the ratio was higher than 20.0%, no further increase in copper extraction was observed. And the statistically significant interactive effects on copper extraction were found between temperature and pH, and temperature and pyrite ratio.
文摘Cyclic voltammetry and potentiodynamic polarization analyses were utilized to investigate the mechanism and kinetics of glycine leaching reactions for chalcopyrite.The effects of pH(9−12),temperature(30−90℃)and glycine concentration(0−2 mol/L)on corrosion current density,corrosion potential and cyclic voltammograms were investigated using chalcopyrite concentrate−carbon paste electrodes.Results showed that an increase in the glycine concentration from 0 to 2 mol/L led to an increased oxidation peak current density.Under the same conditions,corrosion current density was found to change from approximately 28 to 89μA/cm2,whereas corrosion potential was decreased from−80 to−130 mV.Elevated temperatures enhanced the measured current densities up to 60℃;however,above this level,current density was observed to decrease.A similar current density behavior was determined with pH.A pH change from 9 to 10.5 resulted in an increase in current density and pH higher than 10.5 gave rise to a reduced current density.In addition,the thermodynamic stability of copper and iron oxides was found to increase at higher temperatures.
基金supported by the TUBITAK(Scientific and Technological Research Council of Turkey) under the Project No:106M177
文摘Some effective parameters on the copper extraction from Kiire chalcopyrite concentrate were optimized by using response surface methodology （RSM）. Experiments designed by RSM were carried out in the presence of ammonium persulfate （APS） and different types of impeller in an autoclave system. Ammonium persulfate concentration and leaching temperature were defined numerically and three types of impellers were defined categorically as independent variables using experimental design software. The optimum condition for copper extraction from the chalcopyrite concentrate is found to be ammonium persulfate concentration of 277.77 kg/m3, leaching temperature of 389.98 K and wheel type of impeller. The proposed model equation using RSM has shown good agreement with the experimental data, with correlation coefficients R2 and RaZaj for the model as 0.89 and 0.84, respectively.
基金Project(2007BAB22B01) supported by the National Science and Technology Pillar Program during the 11th Five-year Plan Period of China
文摘The treatment of the Gacun complex Cu concentrate with high contents of Pb,Zn,Ag,etc by oxygen pressure acid leaching was studied.It is unusual that tetrahedrite,whose treatment was rarely studied,is the primary copper mineral of the concentrates.Most of silver also occurs in the mineral.The optimum operating parameters of oxygen pressure acid leaching were established by conditional tests.Pilot scale test was carried out under the parameters,and the leaching rates of copper and zinc are as high as 97.10% and 89.83% while lead and silver are transformed into sulfate and sulfide respectively and stay in leaching residue.The copper and zinc in lixivium were reclaimed by extraction-electrowinning and purification-electrowinning,respectively,and the lead and silver in the residue were reclaimed separately by chloride leaching and thiourea leaching.The extraction rate of copper achieves 96%,and the leaching rates of lead and silver reach 90% and 95%,respectively.
文摘The mechanism of the leaching process of chalcopyrite concentrate with sodium nitrate in sulphuric acid solution were studied and discussed. Chemical reactions of leaching and their thermodynamic probabilities are predicted based on the calculated Gibbs energies and analysis of E-pH diagrams. Experimental data, thermodynamic analysis, chemical, XRD, and SEM/EDX analyses of concentrate and the leach residues, were performed to develop a better understanding of the chemical reactions that took place in the system. Elemental sulphur was formed as the main leaching product, precipitated at the particle surfaces and tended to inhibit the leaching rate.
