Phase transitions, micro-morphology and its oxidation mechanism in oxidation of ilmenite (FeTiO3) powder

Phase transitions, morphology changes, and oxidation mechanism of the ilmenite oxidation process were investigated. FeTiO3 transforms to hematite and rutile when oxidation at 700-800 °C, and pseudobrookite is formed when the oxidation temperature reaches 900 °C. The initial ilmenite powder exhibits paramagnetism; however, after being oxidized at the intermediate temperature (800-850 °C), the oxidation product exhibits weak ferromagnetism. The oxidation mechanism was discussed. The microstructure observations show that a lot of micro-pores emerge on the surfaces of ilmenite particles at the intermediate temperature, which is deemed to be capable of enhancing the mass transfer of oxygen during oxidation.