H<sub>2</sub>-CO混合ガスによる酸化鉄の還元反応の速度解析

Abstract

A lot of steel engineers researched various means to decrease reducing agents at a blast furnace in order to reduce CO2 emissions. For example, injection of H2, waste plastics and carbon neutral materials such as biomass into a blast furnace is better alternative. When iron oxide is reduced by H2 gas, CO2 don' t form. We have studied optimal reduction conditions of iron oxide. In this work, we focused on H2-CO gas mixtures reduction of iron oxide. In order to prepare samples, reagent Fe2O3 was mixed with SiO2 and CaO in the mass ratio of Fe2O3：SiO2：CaO = 80：7.14：12.86. Then the mixture was pelletized by handrolling and sintered at 1220℃ (Sinter-A, a porous sample) or 1250℃ (Sinter-B, a relatively porous sample). The formed pellets were reduced from Fe2O3 to FeO at 800℃ and from FeO to Fe 1100℃. From weight loss curves of samples, chemical reaction rate content (kc) and effective diffusion coefficient (De) in a product layer were calculated by using an unreacted core model. The values of kc and De in H2 reduction were much higher than those values in CO reduction. The particle size of the reduced Fe in H2 reduction was smaller than that one in CO reduction.