常温酸性条件下黄铜矿的电化学行为

Electrochemical behavior of chalcopyrite at normal temperature in acidic solution

在温度为25℃及pH=2的条件下,通过循环伏安法和恒电位I—t曲线研究了黄铜矿特殊的电化学分解行为。通过循环伏安曲线发现:电位在400～800mV(vs SHE)范围内,黄铜矿电极表面的阳极氧化反应电流很小;主要是由于生成的中间产物很难被进一步氧化分解,从而产生了钝化;当电位小于-400mV(vs SHE)时,黄铜矿阴极还原反应电流较大,晶格中的Fe3+能较快地溶解出来,产生的中间产物(铜的硫化物)在氧化电位下发生较强的阳极氧化分解反应,但是随后反应进一步被钝化。黄铜矿的阴极还原反应较强烈,且对黄铜矿氧化浸出具有重要意义。此外,恒电位I—t曲线也证实了以上结论。

The elecrochemical reaction behaviors on chalcopyrite were investigated using cycle voltammetry and potentiostatic I-t curve at 20℃ and pH=2. The voltammograms show that the oxidization of chalcopyr/te occurs at slow rate in potential range from 400 to 800 mV（vs SHE）. The reason is that the intermediate products are very difficult to be further dissolved unceasingly if Fe3＋ ion in lattice has not been dissolved. Fe^3＋ ion in lattice can be dissolved effectively for the strong deoxidization when the negative potential is lower than -400 mV（vs SHE）. Meanwhile, the products can be oxidized easily under higher positive potential, but this reactions are also passivated later. The cathodic reduction is stronger and plays an important role for the dissolution of chalcopyrite. The potentialstatic I-t curve also identify the above conclusion.