Abstract
The dissolution routes of chalcopyrite in acidic sulfate aqueous solution have been discussed by thermodynamic calculation under different aqueous species concentrations, such as Cu2+, Fe2+ and H2S. The results show that for both oxidative dissolution and non-oxidative dissolution of chalcopyrite, the dissolution process undergoes several intermediate steps before completely decomposing to Cu2+, Fe2+ and elemental sulfur, in which bornite and covellite are the most likely intermediates. The dissolution routes of the secondary intermediates have also been discussed and covellite is the most likely final intermediate. Based on these results, some frequently reported phenomena, such as the existence of an optima redox potential range, the promotive action of the addition of Cu2+ and Fe2+ , as well as the preferential release of Fe2+ in the chalcopyrite leaching process, have been explained and elucidated.
Highlights
Chalcopyrite (CuFeS2 ) is one of the most abundant and wide-spread copper-bearing minerals, accounting for approximately 70% of the earth’s copper [1]
The oxidative dissolution of chalcopyrite in acidic ferric or cupric solutions can be described by the normal mixed-potential electrochemical model proposed by Nicol et al [7], and it was adopted by Jones and Peters [8], Miller et al [9] and others, where the following anodic reaction
If the direct complete oxidizing dissolution rate is lower than those reaction routes with Cu5 FeS4 and CuS intermediates, it will be in accordance with the fact that the addition of Cu2+ can promote the leaching rate of chalcopyrite
Summary
Chalcopyrite (CuFeS2 ) is one of the most abundant and wide-spread copper-bearing minerals, accounting for approximately 70% of the earth’s copper [1]. Reductive/oxidative dissolution can partly lead to the formation of the above surface species, such as elemental sulfur and covellite, and it can explain the existence of an optimum redox potential and iron being preferentially dissolved, but this model seems to contradict the thermodynamics principal. It should be apparent from this brief review of the mechanisms of the dissolution of chalcopyrite in sulfate media that there is little agreement on the nature of the rate-determining step and the mechanisms involved in this important process. The possible reaction routes of chalcopyrite leaching in sulfuric acid media under ambient conditions are analyzed based on thermodynamic principals, which aims to further the understanding of the above phenomena
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
