2009 Volume 125 Issue 3 Pages 121-128
In the copper smelting industries, it is important to increase the capacity of existing smelters in order to meet the increase in worldwide demand and to achieve cost cutting. With regard to flash smelting furnaces, an increase in the concentrate smelting capacity is required to achieve capacity expansion. It is necessary to examine the performance of the existing concentrate burners when the feed rate is increased. The authors have developed a mathematical model to describe the combustion phenomena observed in a flash smelting furnace. The fluid flow, heat and mass transfer, and chemical reactions of the copper concentrate were incorporated in this model. The copper concentrate was considered to mainly comprise chalcopyrite (CuFeS2) . The reaction of CuFeS2 was assumed to consist of two steps, namely, the decomposition of CuFeS2 and the oxidation of the resulting sulfur (S) and pyrrhotite (FeS) . The combustion phenomena observed in the furnace when the feed rate was increased and when accretion was formed on the burner tip were predicted using this model. It was found that the existing burner was capable of enhancing the smelting capacity. This has been attributed to the wide dispersion of the concentrate particles and its long residence time in the reaction shaft. However, the reaction in the reaction shaft became nonuniform with the increase in the feed rate. In order to improve the uniformity of the reaction, an increase in industrial oxygen supplied through the oxy-fuel burner and an increase in the diameter of the dispersing cone proved useful.
