Influence of hydrogen concentration on Fe₂O₃ particle reduction in fluidized beds under constant drag force

The fixed-gas drag force from a model calculation method that stabilizes the agitation capabilities of different gas ratios was used to explore the influence of temperature and hydrogen concentration on fluidizing duration, metallization ratio, utilization rate of reduction gas, and sticking behavior. Different hydrogen concentrations from 5vol% to 100vol% at 1073 and 1273 K were used while the drag force with the flow of N₂ and H₂ (N₂:2 L·min^-1; H₂:2 L·min^-1) at 1073 K was chosen as the standard drag force. The metallization ratio, mean reduction rate, and utilization rate of reduction gas were observed to generally increase with increasing hydrogen concentration. Faster reduction rates and higher metallization ratios were obtained when the reduction temperature decreased from 1273 to 1073 K. A numerical relation among particle diameter, particle drag force, and fluidization state was plotted in a diagram by this model.