Abstract:Based on the relationship between bosh gas index and permeability resistance index, some influences of bosh gas index on improvement of burden permeability and preservation of gas-liquid equilibrium in blast furnace lower zone were investigated. Some actual production data were used to analyze bounds of these influences, and then some new flooding diagrams were described based on bosh gas index. The results show that the bosh gas index is a proper indicator in evaluating operation intensity, keeping gas-liquid equilibrium in lower zone, increasing the gas utilization efficiency and facilitating stabilization and smooth of ironmaking blast furnace operation.