1. A fundamental DFT study of chalcopyrite surface evolution due to impurity divalent ions during leaching process
- Author
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Shaoxian Song, Zhenlun Wei, Huimin Gao, Qing Xiao, Yubiao Li, Li, Yubiao, Wei, Zhenlun, Xiao, Qing, Gao, Huimin, and Song, Shaoxian
- Subjects
Materials science ,divalent ions ,Passivation ,Inorganic chemistry ,02 engineering and technology ,020501 mining & metallurgy ,Divalent ,Adsorption ,Impurity ,Atom ,surface ,passivation layer ,density functional theory ,chemistry.chemical_classification ,Chalcopyrite ,Mechanical Engineering ,General Chemistry ,Geotechnical Engineering and Engineering Geology ,chalcopyrite ,0205 materials engineering ,chemistry ,Control and Systems Engineering ,visual_art ,visual_art.visual_art_medium ,Density functional theory ,Leaching (metallurgy) - Abstract
Chalcopyrite leaching process is hindered predominantly due to the passivation layers formed on its surface. The impurity salts normally present in the leaching systems may influence chalcopyrite leaching process. In this work, density functional theory (DFT) was carried out to investigate the influence of Mg 2+ and Ca 2+ on chalcopyrite (0 0 1)-S surface using Materials Studio. The results indicated that the presence of CaSO 4 contributed to the breakage of S–S bonds on chalcopyrite (0 0 1)-S surface. Although Ca 2+ was not found to bond with any of the S atoms derived from broken S 2 2− bond, a stable structure of Ca–SO 4 –Fe was formed. Similarly, the adsorption of MgSO 4 on chalcopyrite (0 0 1)-S surface contributed to the breakage of S 2 2− bond, forming a complex and stable structure of S–Mg–SO 4 –Fe as new passivation layers due to the bonding effects between Mg 2+ and a S atom from the broken S 2 2− bond. The formation of these new structures covered on chalcopyrite (0 0 1)-S surface, further reducing chalcopyrite leaching rates. This study, therefore for the first time, reveals the influencing mechanisms of Mg 2+ and Ca 2+ sulfates on chalcopyrite leaching at an atomic level.
- Published
- 2018