铜阳极泥氯化浸金液连续萃铜试验

针对铜阳极泥氯化浸金液含铜高造成稀贵金属置换困难且损失量大的问题,采用Lix984萃取分离铜,进行萃取槽连续试验,考察铜萃取率变化,分析存在的问题并探讨解决方案。试验发现采用Lix984从含铜10～20g/L和Cl-～200g/L的氯化浸金液中分离和回收铜,技术上可行。在萃取混合时间3min、萃取相比(O/A)2/1、反萃水相为180～260g/L硫酸条件下,经过4级萃取、2级洗涤和2级反萃,铜直收率可达99%以上。金、银、钯、铅、镍等不被萃取,仅有少量夹带,可洗涤回收。萃取过程发生界面污物累积和乳化,主要与料液含固量高、金属离子水解、相比和搅拌速度不当、萃取剂降解等因素有关,可通过精滤、过渡槽调pH值、实时监控流量和转速、定期补充萃取剂和清除第三相等措施,实现萃取稳定运行。

Continuous solvent extraction of copper from the chloride leaching solution of copper anode slime

In order to solve the problem that high copper content in chloride leaching solution of copper anode slime made it difficult to replace rare and precious metals and caused large losses, Lix984 was used to extract and separate copper. Continuous solvent extraction tests were carried out in mixer-settler to investigate the extraction of copper and the existing problems were assessed and corresponding solutions were suggested. It was found that it was technically feasible to separate and recover copper from chloride leaching solution containing 10~20g/L of copper and ~200g/L of Cl-. Under the conditions of mixing time of 3 min, extraction phase ratio (O/A) of 2:1 and stripping aqueous phase of 180-260 g/L sulfuric acid, the recovery of copper could reach over 99% after four-stage extraction, two-stage washing and two-stage stripping. Gold, silver, palladium, lead and nickel were not extracted and only a small amount was entrained, which could be washed and recovered. The accumulation of interfacial contaminants and emulsification are mainly related to the factors such as high solid content of feed solution, hydrolysis of metal ions, improper phase ratio and stirring speed, degradation of extractant, etc. The stable operation of solvent extraction can be achieved by means of fine filtration, adjusting pH in transition tank, real-time monitoring of flow rate and stirring speed, periodic supplementation of extractant and removal of third phase.