Effect of elemental iron and gas atmosphere on the carbothermic reduction of rutile

The carbothermic reduction of rutile has been investigated in the presence and absence of elemental iron under either argon or nitrogen atmospheres. Several overlapping reduction stages were evident from differential thermogravimetric analysis. The initial reduction was found to occur at a lower temperature under nitrogen than argon and at even lower temperatures when iron was present. The presence of iron resulted in the formation of iron titanium oxide, FeTiO3, whilst the reduction proceeded via Ti4O7 in its absence. The Ti3O5 phase was only evident in the samples heated under argon with direct reduction from FeTiO3/TiO2 to TiN evident in nitrogen. Under argon the final product was TiC.