Research development of lead anode slime treatment technology

Lead anode slime is a by product and an important secondary resource produced from the process of electrolytic refining of crude lead, whichcontainsvarious valuable metal elements. Hence its comprehensive recovery has been attracting more and more attention. In this paper, the research development in the pyrometallurgical, hydrometallurgical and pyrometallurgical-hydrometallurgical treatment processes of lead anode slime has been introduced in detail. In addition, vacuum treatment technology and direct preparation technology of pure material from lead anode slime were reported. According to the characteristics of bismuth-rich and arsenic-rich lead anode slime collected from a metallurgy enterprise in Yunnan province, a research programme of "pressure oxidation alkaline leaching-crude bismuth alloy casting-bismuth electrolysis" was presented by authors' research group. Based on the research programme, separation of arsenic, antimony and leadcan be realized, and meanwhile clean extraction of bismuth and the enrichment of gold and silver can be achieved. The research results show that the recovery rate of bismuth is over 98 %, antimony and lead over 96 %, gold and silver over 99 % and 97 % respectively. Finally, the gold content of 22 g/t and silver content of 3 595 g/t in lead anode slime are enriched to 201 g/t and 31 270 g/t in bismuth electrolysis anode slime.