湿法炼锌净化渣有价金属综合回收生产实践及改进

Production Practice and Improvement on Comprehensive Recovery of Valuable Metals from Purification Residues of Zinc Hydro-metallurgy

某湿法炼锌厂以一段、二段净化渣为原料,采用浸出、置换等湿法工艺回收渣中的Cu、Cd、Co、Zn等有价金属。该工艺在生产实践中存在除铁矿浆压滤困难、一次置换产出海绵镉质量差、二次置换锌粉加入量高、除钴过程除钴剂用量大及除钴效果不稳定的问题。通过改变石灰石浆和双氧水的添加顺序,可以改善除铁过程除铁渣的过滤性能;通过调整搅拌转速、溶液pH、停止压缩风的通入可以提高一次置换产出海绵镉的质量;通过改变取样操作和降低反应温度,可以降低二次置换的锌粉加入量;通过调整溶液pH和除钴剂的加入方式,可以降低除钴过程除钴剂用量和稳定除钴效果。

In one zinc hydro-metallurgy plant,purification slag of one-section,two-section is taken as the raw material,the valuable metals in recovery residues,such as Cu,Cd,Co,Zn and so on were recovered by wet processes like leaching,replacement and so on.The process has the following problems in the production practice,such as it is hard to filter press iron removal pulp,sponge cadmium with poor quality generated by first replacement,in the second replacement,the addition amount of zinc powder is large,the consumption of cobalt removal agent is large in cobalt removal process,and the cobalt removal effect is not stable.The filtration performance of iron slag removal in iron removal process can be improved through changing the addition sequence of limestone pulp and hydrogen peroxide;the quality of sponge cadmium generated by first replacement can be improved through adjustment of stirring speed,pH value of solution,stop feeding of compression wind;the addition amount of zinc powder in the second replacement can be decreased through changing the sampling operation and decreasing the reaction temperature;the dosage of cobalt removal agent can be decreased and the cobalt removal effect can be stabilized through adjustment pH value of solution and addition way of cobalt removal agent.