从湿法炼锌浸出液中选择性萃取分离回收铜

Selective Separation and Recovery of Copper from Zinc Hydrometallurgy Leaching Solution by Solvent Extraction

针对传统湿法炼锌过程铜回收工艺长、铜回收率低的难题,采用M5640直接从湿法炼锌还原浸出液中萃取分离回收铜,缩短铜回收流程,提高铜回收率。研究了混合时间、溶液pH值、萃取剂浓度、萃取级数等因素对铜萃取率的影响,以及反萃时间、相比等因素对载铜有机相中铜反萃率的影响。结果表明,M5640对硫酸锌溶液中的铜离子具有很好的选择性萃取性能,在M5640浓度为15%、溶液pH值为2.0、相比(O/A)为1∶2、萃取时间为5 min的条件下,经过4级逆流萃取,铜萃取率为95.2%,锌萃取率仅为0.5%,铜锌分离系数为4080。有机相经洗涤后,锌、铁等杂质离子被脱除,载铜有机相采用模拟铜电积废液反萃,经过2级逆流反萃,铜反萃率为97.1%。采用萃取-洗涤-反萃技术从湿法炼锌浸出液中回收铜,铜的总回收率为92.4%。

In order to solve the problems of the complex recovery processes and low recovery rate of copper in the traditional zinc hydrometallurgical process,M5640 was used to directly extract and recover copper from zinc hydrometallurgy leaching solution,aims to shorten the copper recovery process and increase the copper recovery rate.The effects of reaction time,pH values,extractant concentration on the Cu extraction rate,as well as effects of stripping time,O/A phase ration on the Cu stripping ratio from the copper-loaded organic phase were studied systematacially.The experimental results show that M5640 has ideal selective extraction ability for copper ions in zinc sulfate solution.The extraction ratio of copper and zinc are 95.2%and 0.5%,respectively,with M5640 concentration of 15%,the solution pH of 2.0,the ratio(O/A)of 1∶2,and the extraction time is 5 minutes,by 4-stages counter current extraction.Separation ratio of Cu/Zn is 4080.After washing the organic phase,impurity ions such as zinc and iron were removed,and the copper-loaded organic phase was stripped by simulated copper electrowinning spent liquid.After second-stage countercurrent stripping,the copper stripping ratio was 98%.The total recovery ratio of copper up to 93.3%by the extraction-washing-stripping process to recover copper from the leaching solution of zinc hydrometallurgy.