China Nonferrous Metallurgy

The studies targeted at the separation and recovery of antimony and bismuth were carried out for the Cu anode slime with high-Au & Ag content produced from the electrolysis process of copper smelting enterprises to achieve the purpose of recovering antimony and bismuth from anode slime by adopting chlorination leaching-neutralization & precipitation method, with no precious metals dispersion during this process. Single-factor test was carried out on the factors affecting the leaching efficiency of antimony and bismuth. The test results showed that the leaching rates of antimony and bismuth reached 86% and 98% respectively after cooling and filtration of the solution resulted from 3h reaction under such conditions as the liquid-solid mass ratio of the reaction controlled at 4∶1, the reaction temperature at 80℃, the sulfuric acid concentration of the solution adjusted to 120g/L by using sulfuric acid, and the chloride ion concentration at 140g/L by adding sodium chloride; the unleached copper and arsenic in the copper-removal process were basically leached completely, the leaching rate of lead reached about 10%, and the precious metals gold and silver were further concentrated without being leached. In the test, the antimony and bismuth leachate was subjected to step-by-step neutralization for pH adjustment with relatively high-Sb residue and high-Bi residue obtained under different pH conditions to create conditions for further recovery of antimony and bismuth.