China Nonferrous Metallurgy

The purification slag produced in the purification process of silver electrolyte has a high copper content. There are the features of long copper removal period, low gold and silver direct yield in the traditional pyrotechnic process and the generated soot containing gold and silver needs secondary treatment, which increases the treatment cost for the treatment of purification slag. In this paper, sulfuric acid method was used to treat the purification residue produced in the purification process of silver electrolyte. The results showed that the leaching rate of copper could reach more than 99% and the silver content in the solution could be reduced to 0.5mg/L by sulfuric acid wet process with sulfuric acid concentration of 6%, reaction temperature of 75℃, reaction time of 2h, liquid-solid ratio of 5∶1, and salt dosage of 11g. The separation of silver and copper was realized and the silver content in the leaching residue could be stabilized at more than 70% and the copper content was less than 0.4% by the production process application. Compared with the traditional treatment process, this process has the advantages of simple operation and good economic and environmental benefits.