Phase Evolution during Carbothermal Reduction of Langkawi Ilmenite Ore at Different Reaction Times

Abstract

In this research, the carbothermal reduction of Langkawi ilmenite ore, FeTiO3 had been conducted by using coke as carbon reductant. All samples were grinded into size of ≤ 63 µm and pelletized using 2.5 g mixture of ilmenite ore with coke based on C/O molar ratio of 1:3 (carbon to reducible oxygen). The carbothermal reduction was conducted in a horizontal tube furnace using 0.1 L/min of argon gas flow at temperature of 1200°C. The ultimate and proximate analysis of carbon reductant was investigated using carbon, hydrogen, oxygen, nitrogen and sulfur (CHONS) analyzer. The phase evolutions and chemical composition analysis was conducted using X-ray diffraction (XRD) and X-ray fluorescence (XRF) for raw ilmenite and reduced ilmenite with coke, respectively. The reduction time was set with 2, 3 and 4 hours to understand the phase evolutions. It was found that Langkawi ilmenite ore contained mainly higher TiO2 and hematite, Fe2O3 where the phases of FeTiO3 and titanomagnetite, (Fe2TiO4-Fe3O4) were detected using XRD. The phase of FeTiO3 evolved into the production of Fe, FeO, TiC, TiO2 and Fe3C when increased the reduction time from 2 to 4 hours. The amount of Fe2O3 production was decreased from 59.16 to 47.02 wt%, while higher value of TiO2 was obtained, increasing from 25.2 to 29.1 wt% due to the reduction of TiO2 to Ti3O5 as the reduction time increased. TiC content is also detected when the reduction time increased by reducing TiCxOy into TiC.