Effect of organic and inorganic compounds on dissolution kinetics of chalcopyrite in hydrogen peroxide– Hydrochloric acid system

Abstract

The addition of 2-Propanol as an organic substance and NaCl as an inorganic compound in hydrochloric acid with hydrogen peroxide as a strong leaching agent of chalcopyrite was investigated. The effects of the leaching parameters on copper extraction, such as stirring speed, H2O2 concentration, temperature, HCl concentration and solid/liquid ratio were studied. The maximum final copper extraction of 54.55% was obtained with 600 rpm stirring speed, 1.5 M H2O2, 0.5 M HCl, 600 rpm, 50 °C, 240 min of the reaction and particle size of −106 +75 µm. Further experiments were performed when the solid-to-liquid ratio (S/L), stirring speed, temperature, HCl, H2O2 and leaching time were kept constant to examine the influence of NaCl and 2-Propanol concentrations in the range of 0–0.5 M and 0–3 M, respectively. The results showed that the copper extraction was increased up to 58.11% with addition of NaCl. While copper extraction yield reached 94.25% in case of addition of 2-propanol with the optimum parameters(0.5 M HCl,50 °C, 1.5 M H2O2, 600 rpm, particle size −106 +75 μm, solid liquid ratio 2g/L, 3 M 2-propanol). The chalcopyrite leaching in hydrogen peroxide– hydrochloric acid system was found to be described by the interface transfer and diffusion across the product layer with activation energy of 77.14 kJ/mol. Addition of 2-propanol suggested that the reaction was under product layer diffusion control and decreased the activation energy of chalcopyrite leaching to 67.98 kJ/mol.