Leaching Parameters Optimization and Kinetic Studies for Leaching of Copper from Zarara Hill Sulphide Ore in HCl, H2SO4 and HNO3 Solutions

Abstract

This study used HCl, H₂SO₄ and HNO₃ to optimize and study the kinetics of copper dissolution from Zarara Hill sulphide ore. Fe, Zn, Cu, Pb, and S are the main elements found in the ore, according to the ICP-OES technique, while Co, Ni, Mo, and Cd are the minor elements. Response Surface Methodology (RSM) was used to model, optimize and evaluate the effects and interactions of the influential specifications on the recovery of copper using the acid solutions. A regression model significant test and an individual model coefficients with lack of fit test were conducted in order to fit a good model. With a 95% confidence level, the significant components were sorted using the P-value (probability value). The smaller ‘P’ values from the ANOVA generated for both HNO₃, HCl and H₂SO₄ show more significant of the corresponding coefficients. Dissolution kinetics, studies shows that for zinc dissolution, the order of reaction with regard to H⁺ ion concentration using HCl, H₂SO₄ and HNO₃ were 0.67, 0.53 and 0.46 respectively. And the activation energy was calculated from Arrhenius plot and were found to be 19.7, 22.7 and 20.6 kJ/mol for HCl, H₂SO₄ and HNO₃ dissolutions respectively.