Selective copper recovery with HCL leaching from copper oxalate material

Chalcopyrite extraction in an aqueous acid medium occurs through solid transformations into distinct intermediaries. As intermediates, mineral phases CuS, Cu2 S and Cu5 FeS4 may generate in the leaching solution before CuFeS2 completely decomposes to Cu2+, Fe2+ and S0. Oxalic acid is a common organic acid, and it dissolves easily in warm water. Due to the chelating feature of oxalic acid, it hinders iron precipitation by composing soluble complex anions in a wide range of pH. In this study, recovery of copper from solid material (obtained by leaching of chalcopyrite with oxalic acid in the presence of hydrogen peroxide) with a copper oxalate structure was carried out selectively using hydrochloric acid (HCl). Selective recovery of copper by degrading the copper oxalate structure with a low-solubility product (Ksp= 4.43 × 10 −10) was performed by conventional leaching in the presence of HCl.