Kinetics of Reduction Roasting of Hematite to Magnetite in Crude Niobium Concentrate under Microwave Irradiation
In this paper, the method of microwave reduction roasting was applied to investigate the heating and weight loss process from hematite to magnetite in crude niobium concentrate under the protection of argon. The kinetics of microwave reduction roasting of hematite in crude niobium concentrate were analyzed and calculated at the temperature range of 500°C ~850°C by way of non-isothermal thermogravimetry and isothermal gravimetric analysis. Results from this investigation demonstrated that the activation energy of microwave reduction roasting calculated by non-isothermal thermogravimetry was 26.5769kJ•mol-1, and the activation energy calculated by isothermal gravimetric analysis was 64.1203kJ•mol-1. Compared with the method of reduction roasting under resistance heating, the activation energy of microwave reduction roasting was small, and the reaction rate was fast.
Daoguo Yang, Tianlong Gu, Huaiying Zhou, Jianmin Zeng and Zhengyi Jiang
J. Li et al., "Kinetics of Reduction Roasting of Hematite to Magnetite in Crude Niobium Concentrate under Microwave Irradiation", Advanced Materials Research, Vols. 201-203, pp. 1714-1720, 2011