Zinc dross generated during the melting of zinc cathodes contains appreciable amounts of metallic zinc contaminated with high levels of chlorides, which prevents its direct use in solution purification at hydrometallurgical electrowinning zinc plants. An investigation has been made to separate the available metallic zinc by dechlorination and leaching. Laboratory-scale experiments with available dechlorination processes, use of the metallic zinc thus produced in the solution purification and zinc recovery from the leach solution are reported here, with results of plant-scale trials. The method reported provides an almost chloride-free zinc sulphate solution and a high grade of metallic zinc which performs the same function as that of fresh atomised zinc dust for the removal of cadmium and copper in the relevant purification stages in zinc and cadmium circuits, at a much lower cost. © 1989.
Gupta, M. K., Gupta, B. L., & Raghavan, R. (1989). Investigation of use of zinc dross as a substitute for zinc dust in solution purification in zinc electrowinning hydrometallurgical plant. Hydrometallurgy, 22(3), 379–391. https://doi.org/10.1016/0304-386X(89)90032-7