Abstract:The process of copper flash smelting with high-oxygen enrichment has high productivity and high concentration of SO2 in the gas, but it is difficult to control matte grade and copper content in slag. The smelting temperature should be higher than liquidus temperature of slag to ensure its fluidity for efficient separation of matte and slag, and smooth tapping of slag. However, excessive temperature accelerates erosion of refractory and reduces furnace life. To obtain the optimized production parameters, microstructures and phase compositions of quenched slag and matte from a copper flash smelting furnace were determined by electron probe X-ray microanalysis (EPMA). FactSage 8.1 software was used to calculate correlations among matte grade, sulfur partial pressure and oxygen partial pressure. Effects of slag composition (Fe/SiO2, Al2O3, CaO, MgO, ZnO concentrations) and sulfur partial pressure on liquidus temperature of slag were also discussed.