Alternative Reduction of Copper Matte in Reduction Process of Copper Slag

Abstract

In order to make full use of copper slag and solve the problem of its storage, the direct reduction of copper slag to antibacterial stainless steel was proposed. However, mixture of copper matte in the product reduces the value of the alloy. In this article, we studied the changes of Cu₂S and FeS in chemical reactions. The Fact-Sage software was used to calculate the ΔG of the reaction, the phase diagram of FeS–CaO–C system, Cu₂S–CaO–C system and FeS–Cu₂S–CaO–C system. Three reduction experiments have been done to verify the calculation results. Cu₂S and FeS in alloy can be alternatively reduced to elemental metal. In reduction of matte, the recovery of metal is 73.96%, and the removal rate of sulfur is 99.11%. In reduction of copper slag, the recovery of metal is 88.50%. In reduction of matte in metal, the removal rate of sulfur is 99.64%. The sulfur is with the presence of CaS in slag eventually.