Influence of Ferrous Sulfide on Carbothermic Reduction of Panzhihua Ilmenite Concentrate

To elucidate the effects of FeS on the carbothermic reduction of ilmenite, a series of tests were conducted using non-isothermal thermogravimetric analysis at heating rates of 10°C/min, 15°C/min, 20°C/min, and 25°C/min. The Malek method was used to analyze the reduction mechanism and obtain a kinetic model, and the Starink method was used to calculate the apparent activation energy. The morphology of the reduction products was examined by scanning electron microscopy. A complementary series of isothermal carbothermic reductions tests was also performed in a vertical tube furnace to study the effect of FeS on the metallization of Fe and TiO2 grade in the slag phases. The results show that the carbothermic reduction of the ilmenite concentrate in the presence of FeS proceeds in four stages. FeS showed a negative effect to the carbothermic reduction of ilmenite as its addition of 2.5 wt.% increased the apparent activation energy from 486 kJ mol−1 to 565 kJ mol−1 and decreased metallization by 11.1% and TiO2 grade in the slag phases by 7.2%.