%0 Journal Article %T Removal of Metallic Impurities from Off-Grade Copper Concentrate in Alkaline Solution %A Zhi-xiong Liu %A Lin Sun %A Liang-dong Tang %A Jie Hu %A Yang Xiao %A Yi-guang Chen %A Zhou-lan Yin %J International Journal of Nonferrous Metallurgy %P 9-23 %@ 2168-2062 %D 2018 %I Scientific Research Publishing %R 10.4236/ijnm.2018.72002 %X The removal of metallic impurities from off-grade copper concentrate was investigated in alkaline solution with H₂O₂. The analysis results of XRD and SEM-EDS revealed the oxidative mechanisms of all sulfides. The influence of various parameters of alkaline leaching were investigated including concentrations of sodium hydroxide and hydrogen peroxide, liquid to solid ratio, leaching time and temperature. The results showed that the removal rate of Mo, As and Zn were increased with increasing leaching time and H₂O₂ concentration, and that the removal rate of Mo, As and Zn were firstly increased and then slightly decreased with increasing liquid to solid ratio, temperature and NaOH concentration, respectively. More than 95% Mo, 94% As, and 94 % Zn are removed from the off-grade concentrate under the optimum conditions, while only 1.7% Cu is dissolved. These optimum conditions were sodium hydroxide 1.5 mol/L, hydrogen peroxide 1.0 mol/L, temperature 50°C, liquid to solid ratio 5/1 mL/g and leaching time 5 h. %K Copper Concentrate %K Impurities %K Removal %K Alkaline Leaching %K Hydrogen Peroxide %U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=84120