黄铁矿的电化学研究

黄铁矿的化学式为FeS_2,Fe~(2+)-S_2~(2-)以离子键为主,也有一定的金属键成份,具有良好的导电性。黄铁矿的结构不算复杂,但它的电极反应很复杂,文献中有不同的看法。如认为阳极反应生成Fe~(3+)和SO_4~(2-),没有Fe~(2+)和S°,也有的认为阳极氧化产物是Fe~(2+)、S°及少量HSO_4~-,HSO_4~-是通过硫的纯化学氧化所得。至于反应机理就更难以取得一致的意见。本文在总结阳极与阴极过程实验事实的基础上,报告黄铁矿第一步阳极反应与阴极反应的动力学参数并探讨电极反应的历程。

ELECTROCHEMICAL STUDIES ON PYRITE

The anodic and cathodic processes of pyrite in acid solution of sulfate and chloride have been studied. The stable products of anodic processes are Fe~(3+), SO_4~(2-), as well as Fe~(2+) and S. The first stage of anodic reaction is: FeS_3= Fe~(2+)+2S+2e~- (1) followed by the oxidation of Fe~(2+) to Fe~(3+) and the production of SO_4~(2-). The relationship of overpotential (η) and the current density (Ⅰ) can be represented by the equation: η=0.26+0.115lgI the exchange current density is 0.005 A·m~(-2), and the standard rate constant is 2.58×10~(-8) ms~(-1).The mechanism for the reaction (1) might be expressed as:...