Experimental Approach to Matte–Slag Reactions in the Flash Smelting Process

Improving metal–slag separation in pyrometallurgical processes is increasingly important. Due to the harsh conditions, direct observations of the molten phases behavior in the settler of the Outotec Flash Smelting Furnace (FSF) are not possible and the ways to improve metal settling can only be studied by simulation and modeling. This study focuses on kinetics and mechanisms of the chemical reactions between matte droplets and slag, which were investigated in laboratory-scale heat-quench equipment at a typical smelting temperature of 1300°C as a function of time in both air and argon atmosphere. The reaction mechanism in the FSF settler was formulated and results in argon atmosphere also indicate that the oxidation of cuprous sulfide by ferric ions in the slag contributes strongly to the copper losses in the slag.