Effect of Reducing Agent on Structure and Thermal Properties of Autogenous Copper Sulfide Concentrate Smelting Slags

In view of deterioration of the raw material base it is necessary to optimize autogenous smelting of copper sulphide raw materials, to intensify the heating regime, and to increase Vanyukov furnace (VF) productivity, which is possible when additional fuel is supplied to the process also acting as a reducing agent. Physicochemical investigation of the properties of slags obtained during copper sulfide concentrate smelting from the Balkhash Copper Smelting Plant (BMZ) are conducted with and without intr oduction of a reducing agent. It is found that presence of a reducing agent (activated charcoal) within a melt promotes formation of fayalite in the slag whose content reaches 73–77%. Without supplying a reducing agent the amount is 40–50%. In the presence of a reducing agent the slag copper content is at the level of 0.55%, and in its absence it is 0.84%. Thermal studies determine the temperature for complete melting of slag samples. Introduction of a reducing agent into a molten copper sulphide charge makes it possible to obtain slags with melting points not above 1120.4°C, while in its absence a slag sample melting temperature reaches 1220.4°C. Creation of a reducing condition during copper sulfide concentrate smelting makes it possible to reduce the slag melting point by 100–150°C due to a reduction of trivalent into bivalent iron and formation of an additional amount of fayalite.