硫酸盐体系非均匀电场提镉工艺研究

Technical Study on Cadmium Extraction from Sulfate System by Non-uniform Electric Field

以铜镉渣浸出液为原料,首先考察均匀电场和非均匀电场对提取金属镉的影响,再对非均匀电场的提镉工艺进行研究。单因素法获得非均匀电场提镉最佳工艺条件是:电流密度200 A m^(2)、温度40℃、脉冲占空比30%、溶液pH=3.0、电源频率200 Hz、反应时间2.5 h。最后,在不同温度和不同溶液pH下,对镉锌硫酸盐溶液进行循环伏安扫描,探究锌置换提取镉的阳极反应机理。结果表明,升高温度能促进镉的还原析出,减小pH不利于锌对镉的置换反应。铜镉渣浸出液中镉的提取回收对实现镉的源头减排与污染控制有重大意义。

Using leaching solution of copper cadmium slag as raw material,the effects of uniform and non-uniform electric fields on extraction of metal cadmium were first investigated,and then the cadmium extraction process using non-uniform electric fields was studied.The optimal process conditions for obtaining non-uniform electric field cadmium extraction using single factor method are:current density of 200 A m^(2),temperature of 40℃,pulse duty factor of 30%,pH value of solution of 3.0,power frequency of 200 Hz,and reaction time of 2.5 hours.Finally,under different temperatures and different pH value of solution,cyclic voltammetry scanning was carried out on the cadmium and zinc sulfate solution to explore the anodic reaction mechanism of zinc displacement extraction of cadmium,the results indicate that the increase of temperature can promote the reduction and precipitation of cadmium,and the drops of pH is not conducive to the single displacement reaction of zinc to cadmium.The extraction and recovery of cadmium from leaching solution of copper cadmium slag is of great significance for achieving source emission reduction and pollution control of cadmium at source.