Abstract: The oxidation kinetics of magnetite at 750~900 ℃ in air are studied by using thermogravimetric analysis.The results show that the oxidation rate of magnetite concentrate is much greater than that of pellets, and its oxidation reaction can be basically completed within 2 min.The larger specific surface area is, and the higher temperature is, the faster the oxidation reaction rate of magnetite concentrate will be.The oxidation of magnetite is controlled by chemical reaction at the initial stage and by combination of chemical reaction and gas inner diffusion at later stage.According to the oxidation rate of concentrate and its FeO content, the suitable time required for the different pellet during preheating can be determined.

Key words: Magnetite concentrate, Thermogravimetric analysis(TGA), High temperature oxidation kinetics, Pelletizing