An electrochemical study of the oxidation of chalcopyrite in acidic mediums with ferric iron (Fe3+)
黄铜矿在含铁酸性介质中氧化过程的电化学研究

The electrochemical behavior of the effect of ferric iron (Fe3+) on the solution of chalcopyrite was investigated using electrochemical techniques including measurements of open circuit potential, cyclic voltammetry, Tafel polarization curves and electrochemical impedance spectroscopy (EIS).The results show that the chalcopyrite oxidation process in acidic mediums takes place via a two-step reaction.A passivation film composed of intermediate product mixed with sulfur is formed during the first step, and the bulk of chalcopyrite is oxidized in the second step.Ferric iron plays an important role in the dissolution of chalcopyrite by enhancing the direct oxidation.The Tafel polarization curves indicate that the polarization current of the chalcopyrite electrode increases with an increase of Fe3+ concentration.It has also been shown that the higher concentration of Fe3+ is, the more easily the chalcopyrite can be transformed into the passivation region.In addition, the EIS response is found to be sensitive to changes in Fe3+ concentration.