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
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.
