Glycine leaching kinetics of chalcocite in alkaline medium in the presence of hydrogen peroxide

The leaching of copper-containing raw materials with environmentally friendly reagents under near-environmental conditions is an important problem of modern hydrometallurgy. In this regard this article presents kinetic regularities of leaching of sulfide mineral – chalcocite (Cu2S) using the simplest amino acid – glycine (Gly) in alkaline medium at 25 ºС. It is assumed that the leaching is mainly due to complexation of copper (II) glycinates. The influence of different parameters on the amino acid leaching process such as concentrations of glycine, sodium hydroxide, hydrogen peroxide, reagent ratio and duration of the experiment were studied. The results of atomic absorption analysis indicated a significant increasing of copper recovery efficiency from chalcocite when the oxidant hydrogen peroxide was added to the alkaline glycine solution system. After 30 minutes the degree of copper recovery has reached 30.79 % in the system «Cu2S-0.1M Gly-0.1M NaOH-0.1M H2O2» while without hydrogen peroxide about 4 % of copper has been leached. The research results allow to recommend glycine as a promising reagent for hydrometallurgical copper production process.