China Nonferrous Metallurgy

The grade of copper-cobalt ore in Zambia is low, the occurrence of copper and cobalt is complex, and the leaching and recovery technology is immature. A smelter uses the “leaching-extraction-purification-cobalt precipitation” process to produce crude cobalt hydroxide from the copper-cobalt ore. In the leaching section, there is excess water in the production process, and before the purification section, the cobalt in the raffinate is difficult to concentrate, resulting in a waste of resources. This article uses acid leaching reduction-Lix984 extraction-HBL110 extraction process to test this copper-cobalt ore and has achieved satisfactory results. Using the reducing agent hydrogen peroxide and sodium sulfite combined method for acid leaching reduction, the leaching rates of cobalt and copper were 98.27% and 98.59% respectively. The copper is extracted and recovered with the extractant Lix984, and the three-stage countercurrent extraction copper extraction rate is 99.13%, and the cobalt extraction rate is 7.12%, achieving the purpose of separating copper and cobalt. The raffinate after copper extraction mainly contains Co and Fe, and the raffinate is pretreated with hydrogen peroxide, and then cobalt is extracted with the extractant HBL110. The extraction rate of cobalt reaches more than 99%, and the iron removal rate is also greatly improved.