炭材内装ペレットの加熱によって生成した直接還元鉄のH₂ガス,H₂-H₂O混合ガスによる脱硫

抄録

The direct-reduced iron produced from iron-ore/coal composite pellet is generally contaminated with sulfur. In this study, iron-ore/coal composite pellet is partially or completely reduced during heating up to given temperatures, 1173 to 1473K, at a constant rate in nitrogen atmosphere. Subsequently, it is treated with H₂-H₂O, H₂, or CO-CO₂ gas mixtures to complete reduction and to perform desulfurization. It is shown that hydrogen treatment is effective to remove the sulfur and water-vapor addition to hydrogen can further enhance the desulfurization kinetically and thermodynamically. The desulfurization rate is very fast and is mainly controlled by chemical reaction on the pore surface of reduced iron. On the other hand, to treat it with a CO-CO₂ gas mixture is almost invalid to desulfurization.