Comprehensive utilization technology of arsenic sulphide slag

The treatment processes of arsenic sulphide slag produced in copper smelting are reviewed and a new developed technique of acidic oxidization pressure leaching is further introduced in this paper. After the pressure leaching, the extraction of copper, arsenic and rhenium can be all achieved as more than 95% from the sulphide slag, of which sulphidic sulfur is oxidized into elemental sulfur and kept in the leaching residue. The leaching solution can be treated by sulfur dioxide reduction and further cooling to produce high-quality As₂O₃. Ammonium perrhenate can be produced through solvent extraction from the arsenic-removed solution and afterwards copper sulfate can be produced by evaporation crystallization from the raffinate. Thus, the valuables of copper, rhenium, sulfur as well as arsenic are all recovered comprehensively.