Phase Evolution During the Carbothermic Reduction Process of Ilmenite Concentrate

The phase evolution during the carbothermic reduction process of Panzhihua ilmenite concentrate was investigated under argon atmosphere. The Panzhihua ilmenite concentrate briquette with graphite powder was reduced at 1473 K, 1573 K, 1673 K, and 1773 K (1200 degrees C, 1300 degrees C, 1400 degrees C, and 1500 degrees C) respectively, with the molar ratios of C to FeTiO3 being 4: 1 and 5: 1. The phase transformation of the briquette reduced at different temperatures was investigated by X-ray diffraction and scanning electron microscope. During the carbothermic reduction process from 1473 K to 1773 K (1200 degrees C to 1500 degrees C), it was found that main phases were Fe, Ti3O5, Ti2O3 and TiCxOy. The lowest temperature for the generation of TiCxOy was 1573 K (1300 degrees C) for both kinds of briquettes with different C contents. The rate controlling step for the carbothermic reduction above 1573 K (1300 degrees C) obeyed the diffusion model. The reduction degree of the ilmenite was increased by increasing the temperature. With the increase of reaction temperature and reaction time, TiCxOy phase would be reduced to TiC phase.