Study on Low-Temperature Vacuum Carbothermal Reduction of High-arsenic Copper Dust in Copper Fire Refining Furnace for Arsenic Removal

Using the high arsenic copper dust from the copper fire refining furnace as the raw material, the low-temperature vacuum carbothermic reduction method is used to remove As from the dust. Differential thermal analysis of the raw materials was carried out by TGA-DSC, and the phase, chemical composition and morphology of the dust and evaporation residue were analyzed by XRD, ICP, SEM and other analytical methods. On the basis of thermodynamic analysis, the effect of evaporation temperature, residual pressure, reducing dose, evaporation time, etc. on the removal rate of As and other valuable metals. The results show that when the evaporation temperature is 350℃, the residual pressure is 100 Pa, the reducing amount is 25%, and the evaporation time is 50 min, the removal rate of As can reach 81.63% while ensuring that other metals do not evaporate basically, realizing As Selective separation of other valuable metals. The evaporate is As₂O₃ with higher purity, which can be used as primary As₂O₃ product. Valuable metals are enriched in the evaporation residue, which is convenient for the subsequent recovery of the waste acid leaching process.