Coupled Dissolution with Reprecipitation (CDR) Reactions and Their Impact on Copper Sulphide Mineral Surface Area and Dissolution Rates

Abstract

Copper is a critical metal required for green energy technologies such as wind turbines and solar cells. However, copper supply is limited by copper recovery from primary copper sulphides (e.g., chalcopyrite-CuFeS2) due to passivating reaction products. Therefore, this study examined surface ‘passivation’ of primary copper sulphide minerals undergoing coupled dissolution with reprecipitation (CDR) reactions and the associated mineral surface changes in acidic and chloride-rich lixiviants (FeCl3-only, AlCl3-rich, NaCl-rich, and CaCl2-rich lixiviants). Acidic FeCl3-only, NaCl-rich, and CaCl2-rich lixiviants resulted in only bornite dissolution and the formation of a residual Cu-S phase and Fe-..