Reduction Behavior of In-flight Fine Hematite Ore Particles by CO + H_2 Mixtures in a High-Temperature Drop Tube Furnace

摘要

The ironmaking processes that directly use the raw materials of iron ore fines are expected to significantly reduce energy consumption, carbon dioxide emission and have great advantages in iron ore resource utilization. In this paper, the reduction behavior of the in-flight fine hematite particles in CO and H_2 mixture atmosphere is studied with a modified high-temperature drop tube furnace. The kinetic mechanism of the gas-solid reduction of hematite ore fines is determined in the temperature range of 1450 ~ 1550 K. The particle size is 53 ~ 64μm and the reaction time is less than 2 s. The effect of carbon monoxide concentration in the gas mixture on the reaction rate is examined. Based on the kinetic analysis and the morphology observation, the unreacted shrinking core model is used as the mathematical description for the reduction mechanism. The reaction rate equation is obtained and the calculated results are in good agreement with the experimental ones.