电化学
(1. 北京有色金属研究总院， 北京 100088；
2. 中南大学 矿物工程系， 长沙 410083)
摘 要: 制备了T.ｆ菌修饰碳粉粉末微电极， 应用细菌修饰粉末微电极系统研究了Fe2+在T.f菌存在时氧化的电化学反应机理， 并测定了相应的电极过程动力学参数。循环伏安研究表明， Fe2+在T.f菌修饰粉末微电极上的氧化反应是一可逆反应，且Fe2+浓度在0.22mol/L以下变动时， Fe2+氧化反应的可逆程度不变。 对于快速扫描过程， 通过T.ｆ菌修饰粉末微电极上的电流为微盘电流与薄层电流之和。电化学动力学研究认为Fe2+在T.f菌修饰粉末微电极上的氧化反应受扩散过程影响，稳态极化法测定的极限扩散电流密度为JL=18.5mA/m2，以此计算的电荷扩散系数为6.25×10-6cm2·s-1。
关键字: 细菌浸矿; T.f菌修饰粉末微电极;
电化学机理
（1. General Research Institute for Nonferrous Metal,
Beijing 100088, China;
2. Department of Mineral Engineering,
Central South University, Changsha 410083, China）
Abstract: The thiobacillus ferrooxidants modified carbon powder microelectrode is prepared, and using it the electrochemical mechanisms of the Fe2+oxidation are studied and the relatively dynamic parameters are measured. Cyclic voltammetry studies show that the oxidation on of Fe2+ the T.ferrooxidans modified carbon powder microelectrode is a reversibility reaction, and at c(Fe2+)＜ 0.16mol/L, the concentration variation of ferrous concentration can not change the reversibility of oxidation reaction. Under quick scan speed, the current through the T.ferrooxidans modified powder microelectrode include the micro-disc and thin layer current. The electrochemical dynamic studies show that the oxidation reaction of Fe2+ is controlled by diffusion process. By steady potentialdynamic measurement, the unti-diffusion current is 18.5mA/m2 and the charge diffusion coefficient is 6.25×10-6cm2·s-1.
Key words: bio-leaching; T.f modified powder electrode; electrochemical mechanism
