Modelling in-furnace phenomena in a hydrogen-rich low-carbon reduction smelting furnace: Influence of blast parameters of hydrogen-rich gas

Abstract

CFD study of the reduction smelting furnace (RSF) of a full-oxygen hydrogen-rich low-carbon reduction smelting ironmaking process is presented in this work. The influences of hydrogen-rich gas blast parameters on the in-furnace phenomena are studied. The results indicate that the hydrogen-rich gas predominantly develops at the edge of the reactor, while CO gas tends to dominate the central gas flow. When the temperature of the hydrogen-rich gas is 1223 K and the ratio φ(H₂):φ(CO) is 7:3, the molar fraction of Fe at the bottom of the reduction section is 0.882. As the injection temperature of the hydrogen-rich gas increases, the reduction effect inside the furnace gradually improves, leading to an increase in Fe content. However, when the temperature exceeds 1273 K, the rate of increase in metallic iron content slows down. As the ratio of hydrogen-rich gas φ(H₂):φ(CO) increases from 6:4 to 9:1, the area of high-temperature zones inside the furnace gradually decreases. The endothermic phenomenon of H₂ intensifies, the matching of physical and chemical energy weakens, and the metallization rate gradually decreases. Considering that a higher carbon emission occurs with a φ(H₂):φ(CO) of 6:4, a ratio of 7:3 for hydrogen-rich gases is more appropriate from an academic perspective. This study provides a theoretical basis for optimizing the operation of the full-oxygen, hydrogen-rich carbon cycle reduction melting furnace process.