Mechanically induced reduction of ilmenite (FeTiO3) and rutile (TiO2) by magnesium

Ilmenite (FeTiO3) and rutile (TiO2) have been ball milled with various ratios of metallic magnesium for 100 h in a laboratory mill. The reduction of both oxides was evident directly after milling: with substantial formation of MgO. Ilmenite also formed a mixed cation titanate (Mg, Fe)TiO3 and elemental iron, no reduced phases were observed far rutile. There was no difference between the products obtained by thermal reaction and milling, although energetic reactions observed in milled powder by DTA were not seen in the milled sample and there was no obvious crystallisation of a reduced titanium phase. Solubilisation of titanium from milled powders was found to increase with magnesium content and was >90% for a starting ratio of 1: greater than or equal to 1 ilmenite: Mg. The unleached material was composed of incompletely reduced phases such as TiO2, MTiO3 and Ti3O5. (C) 1998 Elsevier Science S.A.