Reduction Behavior of Packed Bed of Sinter Reduced by CO–CO₂–H₂–H₂O–N₂ Gas

Abstract

To mitigate CO₂ emission from a blast furnace, the use of H₂ as a reducing agent is considered to be a prominent method. Reduction of iron ore was reported to be improved by H₂ addition. In the present research, reduction in a sinter-packed bed by CO and H₂ was carried out under various oxygen partial pressures, and the influence of reduction atmosphere on the reaction behavior was investigated. It was confirmed that the reduction rates were higher when using H₂/H₂O and CO/CO₂/H₂/H₂O mixtures than when using a CO/CO₂ gas mixture. The reaction rate constant for iron ore reduction was determined from the experimental result using a numerical model. The influence of the water-gas shift reaction on the reduction rate was analyzed by comparing the results obtained using the numerical model and those in the experiments. Moreover, the longitudinal distribution of the reaction rate in the packed bed was analyzed to examine the influence of the water-gas shift reaction.