Alkali reductive roasting of ilmenite ore

Reductive roasting of ilmenite ore by carbon in the presence of sodium carbonate was carried out at 1000-1200 degrees C for periods of up to 180 min. Additions of sodium carbonate of up to 30 wt% of the ore enhanced the reduction efficiency. The maximum metallization obtained at 1200 degrees C was about 85%, and the rest of the iron exists in the form of sodium-iron-titanates. The type of sodium compound formed in the final product depends on the roasting temperature. The reduction rate data under isothermal conditions were represented by a phase-boundary reaction model for conversions of up to 70 wt%. The apparent activation energy obtained is about 67 kJ/mol. Magnetic separation of roasted products gave different magnetic fractions having different Fe/TiO2 ratios (ranging from 2-3) as well as a non-magnetic fraction that was low in iron and suitable for titanium dioxide production.