Pressure leaching behaviors of copper-cobalt sulfide concentrate from Congo

Abstract

Pressure leaching is a promising technology to process the copper-cobalt sulfide. In this work, the behaviors of copper-cobalt sulfide flotation concentrates received from Congo during pressure leaching were investigated for varying temperatures, acidity, leaching time, solid to liquid ratio, and oxygen partial pressure. A one factor at a time method was implemented to obtain the optimal operating condition, XRD, EDS, ICP-OES methods were used to examine the chemical composition, state as well as metal content of samples. It is found that the recovery percentage for copper and cobalt can reach 99 % and 98 % under temperature 190 °C, oxygen partial pressure 6 atm, leaching time 2 h, liquid to solid ratio 5:1, initial acidity 0 g/L. The kinetics study shows that the chemical reaction is the control step during pressure leaching of copper and cobalt. The coating of hematite on the mineral surface is the main reason for the incomplete leaching of copper and cobalt.