中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 36 No. 1 January 2026 |
（a School of Minerals Processing & Bioengineering, Central South University, Changsha 410083, China;
b Key Laboratory of Biohydrometallurgy, Ministry of Education, Central South University, Changsha 410083, China）
Abstract:A series of leaching and electrochemical experiments were conducted to elucidate the critical role of hydrogen sulfide (H2S) in copper-driven reduction of chalcopyrite. Results demonstrate that in the absence of H2S, metallic copper converts chalcopyrite into bornite (Cu5FeS4). However, the introduction of H2S promotes the formation of chalcocite (Cu2S) by altering the oxidation pathway of copper. Electrochemical analysis demonstrates that the presence of H？S significantly reduces the corrosion potential of copper from 0.251 to -0.223 V (vs SHE), reaching the threshold necessary for the formation of Cu2S. Nevertheless, excessive H2S triggers sulfate reduction via the reaction of 8Cu+H2SO4+3H2S=4Cu2S+4H2O (ΔG=-519.429 kJ/mol at 50 °C), leading to inefficient copper utilization.
Key words: chalcopyrite reduction; copper; hydrogen sulfide; chalcocite
