Abstract:Rhenium extraction from rhenium rich slag in copper smelting was studied by the process of leaching of rhenium rich slag, pretreatment of leachate, extraction, stripping and crystallization. Effects of H2O2 dosage, sulfuric acid concentration, leaching time and leaching temperature on rhenium leaching rate in leaching process, as well as the effect of CaO dosage on recovery of rhenium and arsenic in pretreatment process. The results show that the leaching rate of rhenium and arsenic is 92.2% and 96.6% respectively under the optimum conditions including rhenium rich slag of 50 g, H2O2 dosage of 150 mL, L/S=2, sulfuric acid concentration of 20 g/L, leaching time of 2 h at room temperature (20—25 ℃). After pretreating of leaching solution with CaO, the total recovery rate of rhenium is more than 98%, and the total recovery rate of arsenic is less than 1.8%, which can effectively separate rhenium and arsenic. The purity of ammonium rhenate obtained in one step crystallization is about 95%, and the rhenium crystallization ratio is 66%.