Investigations on reduction of ilmenite ore with different sources of carbon

Abstract

It is crucial to understand the relative impact of different reductants on ilmenite ore from the same source, since different reductants may have different levels of impact on the reduction of the ore. Such a study will throw light on the nature and mechanism of reduction and help in devising suitable industrial processes for the production of TiO₂ and titanium metal. Reduction of ilmenite with graphite and coke has been investigated in the temperature range 1273–1423 K. Iron was the only phase produced in the ore after reduction at 1173 K, when coke was used as the reducing agent. Significant reduction occurred at 1273 K and above. At 1273 K, Fe₃C and rutile were formed by reduction. At higher temperatures, lower oxides of titanium were also formed by reduction. The process was controlled by diffusion at 1373 K and by reaction at the phase boundary at 1423 K, when coke was used as the reducing agent. The reduction process was controlled by nucleation at 1373 K and by reaction at the phase boundary at 1423 K, when graphite was used as the reducing agent. The rate of reduction decreased at 1423 K compared to that at 1373 K in the case of both reductants. Graphite was less effective as a reducing agent at 1273 K but more effective compared to coke at 1423 K. Whereas reduction of TiO₂ to lower oxides occurred at shorter time intervals when graphite was used as the reductant, this reaction occurred only after longer reduction periods when coke was used for reduction.