Kinetics study on oxidation of iron ore concentrate

Isothermal and uniform temperature-rise experiments were done to study the oxidation kinetics of iron ore concentrate with a TG instrument. The results indicated that the major control unit of the oxidation process changed from out-diffusion to inner-diffusion, and out-diffusion finally during uniform temperature rise. After oxidation, partial hematite decomposed into magnetite and oxygen; as a result, the mass change ratio on the TG curve gradually decreases. The isothermal experiment also proves that the main step is inner-diffusion and the apparent activation energy of oxidation is 26.193 kJ·mol^-1. Oxidation of iron ore concentrate accelerates titanium enrichment and changes the microstructure of oxidized products.