湿法炼锌除钴锌渣硫酸浸出液中高锰酸钾氧化沉钴热力学分析

Thermodynamic analysis on cobalt removal by potassium permanganate oxidization in leaching solution by sulfuric acid of zinc residue containing cobalt in zinc hydrometallurgy

锌湿法冶金生产中除钴产出的锌渣尚含有大量的锌钴等有色金属资源,这种渣用硫酸浸出后锌钴等有色金属进入浸出液中,可用高锰酸钾等氧化剂将钴氧化沉淀而从含锌溶液中分离出来.用电极电势理论和能斯特方程对此除钴过程进行了热力学分析,结果表明:高锰酸根的氧化对溶液中杂质Fe2+、Mn2+、Co2+的去除是可行的,可以达到工业生产对杂质的浓度要求;对于N i2+只能进行部分氧化.氧化过程中溶液pH对钴的沉淀效果具有决定性影响,pH低于4时沉淀效果将显著降低.

Zinc residue, containing cobalt from cobalt removing in zinc hydrometallurgy, is a byproduct difficult to treat because of containing much nonferrous metals resource including zinc, cobalt, etc. The treatment for resource recycle of the residue is much concerned. After leached in sulfuric acid solution, bivalent cobalt could be oxidized by potassium permanganate to remove from leaching solution. Thermodynamic analysis of cobalt removing process was carried out according to electrode potential theory and Nernst equation and proves that the removal of Fe^2 ＋ , Mn^2 ＋ , Co^2 ＋ impurities in the solution is possible through oxidization by potassium permanganate to reduce the concentration level requested by industrial production, but not applied to Ni^2＋. During oxidizing, solution pH presents an effect on cobalt removing , in which cobalt purifying effect can be decreased drastically at pH lower than 4.