Copper Smelting Slag Cleaning in an Electric Furnace by Using Waste Cooking Oil

In view of the non-renewable reductant resources and carbon neutralization in the process of copper slag cleaning in an electric furnace, this study proposed to use waste cooking oil as reductant to replace fossil energy. Combined with the phase equilibrium theory and experimental results, the harm of excessive magnetite in the copper smelting slag to the cleaning process was clarified. The reduction thermodynamics of magnetite by using WCO is analyzed. A series of copper slag cleaning experiments with different WCO dosages along with various temperatures and settling durations was systematically carried out in a laboratory-scale electric furnace. The distribution of matte particles in each slag layer after cleaning was investigated in detail, which indicates that the copper content in the upper slag layer can be reduced to 0.56 wt pct via WCO reduction, realizing the green cleaning of copper slag.