Direct Reduction Behaviors of Titanomagnetite Ore by Carbon Monoxide in Fluidized Bed

Abstract

On the background of the two stages short process of direct reduction - electric arc furnace melting separation, the gas-solid direct reduction behaviors of South Africa titanomagnetite ore particles by carbon monoxide in fluidized bed have been investigated. The results showed that, due to the lower apparent diffusion activation energy without the gas mass transfer among particles, the CO gas reduction of titanomagnetite in fluidized bed present much higher efficiency than the pellet reduction. Continuous solid solution formed by MgO and MnO in FeO can impede reduction through the barrier effect and increase the required CO reduction potential of FeO, 2FeO·TiO₂ and FeO·TiO₂ in titanomagnetite. The generated FeO would combine with FeO·TiO₂ to form 2FeO·TiO₂ in the reduction process and lower the metallization degree after the first reduction step of iron oxides in titanomagnetite. Finally, the relationship between the metallization degree and the equilibrium CO–CO₂ gas reduction potential has been analyzed and established, with the impurities effect and the phase transformation taken into consideration.