2019 Volume 59 Issue 4 Pages 672-678
Carbothermic reduction of FeS in the presence of CaO was experimentally studied by employing a multi-mode microwave generator at 1050 W and 2.45 GHz as an external heat source to mitigate CO2 and SO2 emissions. According to XRD analysis, an ion exchange reaction between FeS and CaO was initiated at temperatures lower than 645°C and progressed by a further heating to 850°C without any evidence for the onset of a reduction reaction. Detection of Fe phase in the XRD pattern of sample heated to 920°C and existence of CO/CO2 in the off-gas during microwave treatment demonstrated that the reduction reaction initiates at ca. 850°C. It was found that the onset of reduction reaction promotes the ion exchange reaction by FeO consumption via reduction to Fe. Moreover, optical microscope and SEM-EDX observations showed that carbon can be absorbed by metallic iron to make molten iron particles at 1290°C.