China Nonferrous Metallurgy

Copper anode slime is an important raw material for extracting rare and precious metals, and the separation of impurities arsenic, antimony and bismuth has always been a research hotspot. In this paper, different combined leaching systems of hydrochloric acid, sulfuric acid and sodium chloride were used to carry out leaching tests on copper anode slime. The results showed that Au, Ag, Se, Pb, As, Sb and Bi could not be separated effectively when single hydrochloric acid, sulfuric acid and sodium chloride were used As leaching agents. When the leach agent is a combination of hydrochloric acid, sulfuric acid and sodium chloride, the directional removal of arsenic-antimony bismuth is better when hydrochloric-sulfuric acid is the leach agent, but the acid content is too high, which will easily cause equipment corrosion and increase the cost of subsequent treatment. When the leaching agent is hydrochloric acid, sulfuric acid and sodium chloride, As, Sb and Bi enter the acid leaching solution, and Au, Ag, Pb and Se enter the acid leaching residue, realizing the goal of directional removal of arsenic, antimony and bismuth from copper anode slime, and reducing the acidity of the leaching solution. By XRD and SEM-EDS, the changes of the solid phase before and after the copper anode slime leaching with hydrochloric acid, sulfuric acid and sodium chloride were analyzed. The results showed that Ag and Se existed in the form of Ag₂Se and AgCl before and after the leaching, and part of Se was converted into selenate. Pb mainly exists in the form of PbSO₄.