中国科学院地球化学研究所机构知识库

The electrochemical behaviors of chalcopyrite in 1.0 M H2SO4 were studied by potentiodynamic polarization. The experimental results revealed that chalcopyrite has four different potential ranges: passive for OCP up to 500 mV; trans-passive dissolution/passive from 500 mV to 780 mV; active from 780 mV to 900 mV; and pseudo-passive above 900 mV. When the electrolyte contained 3.0 g/L Fe3+, the passive phenomenon weakened markedly, the trans-passive dissolution/passive range became narrower, the active potential sharply decreased, and the electrochemical promoting efficiency increased 34.86-fold. Electrochemical impedance spectroscopy (EIS) confirmed the potentiodynamic results, namely, that chalcopyrite is in a passive state at OCP and its charge transfer resistance R-sc and passive film resistance R-p are 816.5 and 18,722 Omega.cm(2), respectively. At a potential of 800 mV, the chalcopyrite Rsc decreased to 42.9 Omega.cm(2), and an equivalent inductance occurred. Passive film did not observed, which was also consistent with the electrode's active characterization. These results have direct implications for chalcopyrite hydrometallurgy.