Effect of temperature and reaction path interaction on fluidization reduction kinetics of iron ore powder

Due to the instability of FeO at temperatures below 843 K, the fluidization reduction pathway of iron ore powder changes with the reduction temperature. Thus, the effect of temperature and reaction pathway interaction on the kinetics of fluidization reduction of iron ore powder under low-temperature conditions ranging from 783 to 903 K was investigated to describe the fluidization reduction rate of iron ore powder from three aspects: microstructure change, reaction limiting link, and apparent activation energy of the reaction, exploring their internal correlation. The experimental results revealed that in a temperature range of 783-813 K, the formation of a dense iron layer hindered the internal diffusion of reducing gas, resulting in relatively high gas diffusion resistance. In addition, due to the differences in limiting links and reaction pathways in the intermediate stage of reduction, the apparent activation energy of the reaction varied. The apparent activation energy of the reaction ranged from 23.36 to 89.13 kJ/mol at temperature ranging from 783 to 813 K, while it ranged from 14.30 to 68.34 kJ/mol at temperature ranging from 873 to 903 K.