A parametric study of the mechanically activated carbothermic reduction of ilmenite

The Becher process has been the commercial way to upgrade ilmenite for over twenty years and the basic process has changed surprisingly little. It has recently been shown that ball milling ilmenite and coal together prior to thermal processing leads to a decrease in both temperature and time of reaction compared with powders milled separately then mixed. In this paper, the effect of milling time and annealing conditions on the extent of reduction and leachability of products are examined to give an overview of potential improvements in the process. Reduction of ilmenite to rutile can be attained within an hour of annealing at temperatures below that used industrially. Leaching indicates that it may be possible to produce a higher grade of TiO2 than the current processing technique. However, over-reduction leads to the formation of phases which cause the fraction of titanium leached to increase and the iron solubility to decrease. Copyright (C) 1996 Elsevier Science Ltd