Effect of unconsumed mixed small coke on permeability in lower part of blast furnace

Abstract

Utilization of small coke in the blast furnace was carried out to improve the permeability in the lower part of the blast furnace. However, at high small coke rates, it was thought that some small coke continues to exist in the lower part of the blast furnace because the small coke charging rate is larger than the gasification reaction rate of the small coke. Therefore, the effect of the small coke rate on permeability in the lower part of the blast furnace was investigated. At high small coke rates, residual small coke with a reduced particle size counted to exist in the lower part of the blast furnace after the coke gasification reaction, and the average particle diameter of the coke and the void fraction of the coke packed bed in the lower part of the blast furnace decreased. It was estimated that the increase in the pressure drop of the coke packed bed in the lower part of the blast furnace was larger than the decrease in pressure drop in the cohesive zone, and as a result, the pressure drop in the lower part of the blast furnace increased.