Comparison of bioleaching and dissolution process of p-type and n-type chalcopyrite. (1st August 2017)

• Record Type: Journal Article
• Authors: Zhao, Hongbo; Huang, Xiaotao; Wang, Jun; Li, Yini; Liao, Rui; Wang, Xingxing; Qiu, Xiao; Xiong, Yuming; Qin, Wenqing; Qiu, Guanzhou
• Is Part Of: Minerals engineering. Volume 109(2017)
• Page Start: 153
• Page End: 161
• Publication Date: 2017-08-01
• Subjects: Chalcopyrite -- Bioleaching -- Semiconductor -- Electrochemistry; Mines and mineral resources -- Periodicals; Ressources minérales -- Périodiques; Mines and mineral resources; Periodicals; Electronic journals; 622
• DOI: 10.1016/j.mineng.2017.03.013
• Languages: English
• ISSNs: 0892-6875

Abstract

Graphical abstract: Highlights: Bioleaching of p-type and n-type chalcopyrite was studied. Dissolution process of p-type and n-type chalcopyrite in bioleaching was studied. Semiconducting properties caused the different bioleaching behaviors. Abstract: In this work, bioleaching and dissolution processes of chalcopyrite from three different regions were investigated and compared mainly by leaching experiments, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and electrochemical analysis. Hall effect experiments showed that one (chalcopyrite A) belonged to p-type chalcopyrite whose carrier concentrations were high, while the other two (chalcopyrite B and C) were both n-type chalcopyrite whose carrier concentrations were low. A remarkably higher copper extraction of p-type chalcopyrite could be achieved during bioleaching by L. ferriphilum compared with n-type chalcopyrite. Redox potential in bioleaching of p-type chalcopyrite can be maintained at the appropriate range (about 380–480 mV vs. Ag/AgCl) for a longer period of time. Acid consumption in bioleaching of p-type chalcopyrite was significantly lower than that of n-type chalcopyrite. SEM analysis indicated that p-type chalcopyrite was more easily corroded by microorganism than n-type chalcopyrite. XPS analysis revealed that monosulfide (S 2− ), disulfide (S2 2− ), polysulfide (Sn 2− ) and sulfate (SO4 2− ) were the main intermediate species during bioleaching of both p-type and n-type chalcopyrite. Electrochemical analysis showed that the electrochemical dissolution processes of p-type and n-type chalcopyrite were similar, while the conductivity and oxidation-reduction rate of p-type chalcopyrite was significantly higher than those of n-type chalcopyrite, thus resulting in significant higher electrochemical dissolution kinetics and copper extraction. This work is potentially useful in explaining the inconsistences in chalcopyrite hydrometallurgy.