基于正交试验的电置换提镉工艺优化及电化学研究  

Process optimization and electrochemistry study of electrical replacement for cadmium extraction based on orthogonal experiments

作　　者：何静[1] 戚春萍 段良洪 叶龙刚[1] 张家玮[1] 王夏阳[1] 

机构地区：[1]中南大学冶金与环境学院,长沙410083

出　　处：《中国有色金属学报》2015年第4期1063-1071,共9页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(51174240);湖南省科技重大专项(2012FJ1010)

摘　　要：提出一种基于微电流作用下的提镉新工艺,采取正交试验考察各工艺参数对海绵镉提取过程的影响,并对Zn SO4+Cd SO4混合溶液中Zn2+、Cd2+的阴极行为进行电化学研究。结果表明:各因素对提镉率的影响由大到小的顺序依次为温度、p H、极距、电流密度、阴阳极面积比;最佳工艺条件为p H=1、极距3 cm、电流密度400 A/m2、温度90℃、阴阳极面积比1:2,在此条件下电置换1 h提镉率达到79.31%;镉先于锌在阴极析出,当锌开始析出时,溶液中镉离子浓度已降到很低,最低可降至0.528 mg/L。混合溶液阴极沉积的表观活化能为6.379 k J/mol,在60~90℃时属于扩散步骤控制。A new process of cadmium extraction under micro-current was proposed. In order to determine the optimum process parameters, five main effect factors were investigated by an orthogonal experiment. Electrochemical experiments of the cathodic behavior of Zn2+, Cd2+ in mixed solution of CdSO4+ZnSO4 were conducted. The results show that the influence factors on extraction rate decrease in such an order:temperature, pH, polar plate distance, current density, plate area ratio. The optimal conditions are obtained at pH of 1, polar plate distance of 3 cm, current density of 400 A/m2, temperature of 90℃and plate area ratio of 1:2. The maximum extraction rate is 79.31%. Cadmium is prior to precipitate than zinc. The concentration of Cd2+in solution decreases to the minimum of 0.528 mg/L while zinc begins to deposit. The apparent activation energy of deposition is 6.379 kJ/mol. The diffusion-controlled is the dominant process at temperature ranging in 60?90℃.

关 键 词：镉 微电流 锌板置换 电化学 

分 类 号：TF819.2[冶金工程—有色金属冶金]