Suppression of CO₂ discharged from iron- and steel- making companies is an example of the biggest issues for the protection of global environment and sustainable growth of steelmaking industry. One of the efforts made to decrease the emission of CO₂ in ironmaking process is blowing of hydrogen gas into blast furnace. Hydrogen gas can reduce iron oxide and form harmless H₂O. Cementite (Fe₃C) may be formed by introduction of hydrogen into blast furnace and play an important role on carburization and smelting behavior of reduced iron.
The conditions that Fe₃C was formed were experimentally determined by changing CO–CO₂–H₂ gas composition in the present work. As the result, it was found that there is a possibility of Fe₃C formation by hydrogen gas introduction into blast furnace. Therefore, the effect of Fe₃C on smelting behavior of reduced iron was also observed, and it was confirmed that the presence of Fe₃C will have positive effect on enhancing carburization and smelting of reduced iron.