Reduction of Hematite Ore and Iron Oxide with Methane

Abstract

To develop a one-step direct reduction process in which CH₄-reforming and iron ore reduction occur simultaneously, experiments on reduction of a hematite ore and three kinds of simulated iron oxides (pure αFe₂O₃, Al₂O₃ (5%) -αFe₂O₃, and SiO₂ (5%) -αFe₂O₃) prepared by the precipitation method were carried out with CH₄ (10080%) -CO₂ (05%) -N₂ mixture, mainly at 950°C. The rate and behavior of reduction from Fe₂O₃ to Fe were investigated with data obtained from simultaneous measurements of weight changes by a thermobalance and outlet gas composition by a high-speed gas chromatograph.
Both the Al₂O₃ contained in ore/iron oxide and the CO₂ (0.4 5%) mixed with CH₄ showed remarkable effect in enhancing the rate of carbon deposit from CH₄-cracking and CH₄-CO₂ reaction accompanying the formation of Fe through the reduction step from wilstite (FeO_1-y, ) to Fe. However, the promising possibility that fractional reduction above 95% for iron are containing Al₂O₃ could be obtained by suppressing the carbon deposit was confirmed by reforming CH₄ with coexisting CO₂ (CH₄+CO₂→2CO+2H₂) and allowing a longer contact time.