Acid Leaching of Chalcopyrite Concentrate with Hematite Powder as an Effective Promoter.

Leaching of chalcopyrite concentrate having specific surface area of about 3 m2/g in 0.5 mol/dm3 HCl solution was conducted at 333 K using hematite (Fe2O3) and ferric chloride (FeCl3) powders, respectively. The leaching of the concentrate with Fe2O3 powder permits to achieve about 75 % copperextraction within 24 hours, while about 65 % copper is extracted by the leaching with FeCl3 powder. Theyield of copper in the leaching with Fe2O3 powder is twice or more higher than that without the promoters. High copper extraction can be achieved when much of the elemental sulfur is formed on thesolid residue after the leaching. Especially, the presence of Fe2O3 powder gives us the elemental sulfurprecipitates more than that of FeCl3 powder. Therefore, Fe2O3 can be an effective promoter inthe leaching of chalcopyrite concentrate using HCl solution.