Zhao H.-B.,Central South University |
Zhao H.-B.,Key Laboratory of Bio hydrometallurgy of the Ministry of Education |
Wang J.,Central South University |
Wang J.,Key Laboratory of Bio hydrometallurgy of the Ministry of Education |
And 8 more authors.
International Journal of Minerals, Metallurgy and Materials | Year: 2015
Interactions between chalcopyrite and bornite during bioleaching by moderately thermophilic bacteria were investigated mainly by X-ray diffraction, scanning electron microscopy, and electrochemical measurements performed in conjunction with bioleaching experiments. The results showed that a synergistic effect existed between chalcopyrite and bornite during bioleaching by both Acidithiobacillus caldus and Leptospirillum ferriphilum and that extremely high copper extraction could be achieved when chalcopyrite and bornite coexisted in a bioleaching system. Bornite dissolved preferentially because of its lower corrosion potential, and its dissolution was accelerated by the galvanic current during the initial stage of bioleaching. The galvanic current and optimum redox potential of 390−480 mV vs. Ag/AgCl promoted the reduction of chalcopyrite to chalcocite (Cu2S), thus accelerating its dissolution. © 2015, University of Science and Technology Beijing and Springer-Verlag Berlin Heidelberg.