A Comparison of Bioleaching Behavior of Two Pure Chalcopyrite Minerals through Investigating Chalcopyrite Crystallographic Properties

Chemical element analysis and X-ray diffraction (XRD) analysis showed that the two chalcopyrite minerals were of high purity. A mixed culture of moderately thermophiles was used for chalcopyrite bioleaching at 45°C and the copper recovery of chalcopyrite (a) and chalcopyrite (b) was 66.1% and 21.4%, respectively, after 19 days of leaching. Bioleaching behavior of the two different chalcopyrite samples was studied through comparing the lattice parameter and grain size of chalcopyrite. It was shown that lattice parameter and grain size are not the key factors affecting the leaching of chalcopyrite. The corrosion current density of chalcopyrite (a) calculated through Tafel curves was 1.149 μA/cm 2 , while that of chalcopyrite (b) was only 0.5696 μA/cm 2 . The higher corrosion current density suggested that chalcopyrite (a) can be more easily dissolved than chalcopyrite (b).