黄铜矿在含铁酸性介质中氧化过程的电化学研究

以天然黄铜矿为研究对象,运用开路电位,循环伏安曲线,Tafel极化曲线和交流阻抗(EIS)等电化学手段,对在硫酸介质中三价铁离子对黄铜矿的氧化过程的电化学行为进行了研究.结果表明,黄铜矿在酸性介质中的氧化可能通过两步反应完成,第一步中电极表面形成了一层主要成分是含硫中间产物的钝化膜,第二步则是黄铜矿主体的氧化.Fe3+离子有助于黄铁矿的直接氧化,在黄铜矿的溶解过程中起到了重要作用.极化曲线测量的结果显示随着溶液中Fe3+离子浓度的增加,黄铜矿的极化电流也在增加,黄铜矿也更容易进入钝化阶段.同时,交流阻抗对Fe3+离子浓度改变的响应也很敏感.

An electrochemical study of the oxidation of chalcopyrite in acidic mediums with ferric iron (Fe3+)

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.