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

Abstract

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.