Phase relations in the Ti-Fe-O ternary system and the equilibrium partial pressures of oxygen have been determined at 1, 173K by using a thermogravimetric technique in CO-CO2 gas mixtures. The results indicate that upgrading ilmenite to rutile is basically possible and its possibility was confirmed experimentally. The standard Gibbs energy of the reactions at 1, 173K were also obtained as follows:
Fe (s) +FeTiO3 (s) +1/2O2 (g) =Fe2TiO4 (s), -197.4kJ·mol-1,
Fe (s) +TiO2 (s) +1/2O2 (g) =FeTiO3 (s), -208.6kJ·mol-1. Both the activities of magnetite and ulvospinel in the Fe3O4-Fe2TiO4 solid solutions coexisting with metallic iron at 1, 173K show negative deviation from Raoult's law.
