Mechanochemical leaching of chalcopyrite in low moisture conditions

Copper concentrates represent 80% of the world's copper production. The main processing routes for copper extraction are pyrometallurgical via smelting or hydrometallurgical using moderate to high temperatures and/or high-pressure conditions, which affects the processing costs. An alternative presented in this work is the mechanochemical processing of concentrates, where the combined use of grinding and oxidizing reagents accelerates the leaching kinetics. Several mechanochemical tests were run in a laboratory mill using chalcopyrite in conjunction with various oxidants in low moisture conditions. The oxidants were ferric chloride (FeCl3), ferric sulfate Fe2(SO4)3, and ferric sulfate with silver added as a catalyst. The best results were for ferric chloride with 56% copper recovery after grinding for 15 min and ferric sulfate with added silver with 63% copper recovery after grinding for 25min.