Stepwise dissolution of chalcopyrite bioleaching by thermophile A.manzaensis and mesophile L. ferriphilum

• Published in: Journal of Central South University Vol. 22; no. 10; pp. 3751 - 3759
• Main Authors: Gu, Guo-hua, Xiong, Xian-xue, Hu, Ke-ting, Li, Shuang-ke, Wang, Chong-qing
• Format: Journal Article
• Language: English
• Published: Changsha Central South University 01.10.2015
• Subjects: Engineering; Metallic Materials; electrochemistry; chalcopyrite; bioleaching
• ISSN: 2095-2899; 2227-5223
• DOI: 10.1007/s11771-015-2919-6

Chalcopyrite dissolution was evaluated by bioleaching and electrochemical experiments with thermophile A. manzaensis ( Acidianus manzaensis ) and mesophile L. ferriphilum ( Leptospirillum ferriphium ) cultures at 65 °C and 40 °C, respectively. It was investigated that the bioleaching of chalcopyrite was stepwise. It was reduced to Cu 2 S at a lower redox potential locating in the whole bioleaching process by A. manzaensis at high temperature while only at initial days of bioleaching by L. ferriphilum at a relative low temperature. No reduced product was detected when the redox potential was beyond a high level (e.g., 550 mV (vs SCE)) bioleached by L. ferriphilum . Chalcopyrite bioleaching efficiency was substantially improved bioleached by A. manaensis compared to that by L. ferriphilum , which was mainly attributed to the reduction reaction occurring during bioleaching. The reductive intermediate Cu 2 S was more amenable to oxidation than chalcopyrite, causing enhanced copper extraction.