PHASE-TRANSFORMATIONS DURING HEATING OF ILMENITE CONCENTRATES

Ilmenite concentrates were heated in argon and oxygen in the temperature range 700-degrees-C to 1000-degrees-C to study the behavior of the pseudorutile phase and other changes which occur. Pseudorutile does not persist in argon or oxygen in the temperature range studied. In argon at 700-degrees-C, pseudorutile decomposes into hematite and rutile, while at 1000-degrees-C, it combines with ilmenite to form ferrous-ferritic pseudobrookite solid solution. A new phase "Fe2O3.2TiO2" was identified as an intermediate product during the heating of ilmenite or pseudorutile in oxygen. This compound decomposes into hematite and rutile below 800-degrees-C and to pseudobrookite and rutile above 800-degrees-C. The sequence of reactions during the heating of ilmenite and pseudorutile in oxygen is proposed.