Physicochemical principles of hydrogen metallurgy in blast furnace

Based on the stoichiometric method and the free energy minimization method, an ideal model for the reduction of iron oxides by carbon and hydrogen under blast furnace conditions was established, and the reduction efficiency and theoretical energy consumption of the all-carbon blast furnace and the hydrogen-rich blast furnace were compared. The results show that after the reduction reaction is completed at the bottom of the blast furnace, the gas produced by reduction at 1600 degrees C still has a certain excessive reduction capacity, which is due to the hydrogen brought in by the hydrogen-rich blast as well as the excess carbon monoxide generated by the reaction of the coke and the oxygen brought in by the blast. During the process of the gas with excessive reduction capacity rising from the bottom of the blast furnace and gas reduction process, the excessive reduction capacity of the gas gradually decreases with the increase in the dydrogen content in the blast. In the all-carbon blast furnace, the excess gas reduction capacity is the strongest, and the total energy consumption per ton of iron reduction is the lowest. This shows that, for the current operation mode of the blast furnace, adding hydrogen in the blast furnace cannot reduce the consumption of carbon required for reduction per ton of iron, but rather increases the consumption of carbon.