Phase transitions, micro-morphology and its oxidation mechanism in oxidation of ilmenite (FeTiO3) powder
(Shanghai Key Laboratory of Modern Metallurgy and Materials Processing, Shanghai University,
Shanghai 200072, China)
Shanghai 200072, China)
Abstract: 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.
Key words: ilmenite; phase transitions; micro-morphology; oxidation mechanism