Effect of hydrogen addition on reduction behavior of iron oxides in gas-injection blast furnace

Based on the technology of gas-injection in blast furnace (BF), the thermodynamics and kinetics of ore reduction with H2 assistance were investigated. The results show that the gas utilization decreases with H2 addition below 847 °C, and the situation is opposite above 847 °C. In addition, it also exhibits a greater promotion on the gas utilization when the H2 adds from 0% to 10% against 20% to 30%. The reduction rate increase with H2 addition, however, the gas utilization will decrease when H2 content surpasses 15% at 1000 °C. In terms of the energy distribution, it is not necessary that iron oxides are completely reduced at lumpish section in BF smelting. Giving a synthetically consideration for the effect of H2 addition on the reduction rate, gas utilization and reasonable distribution of the energy in gas-injection BF, the H2 content should be controlled in the range of 5%-10%.