Gaseous reduction of Fe₂O₃ compacts at 600 to 1050° C

Abstract

Dense Fe₂O₃ briquettes were isothermally reduced with hydrogen, carbon monoxide and H₂-CO mixtures at 600 to 1050‡ C. The course of reduction was followed by measuring the oxygen weight loss, as a function of time, using a thermogravimetric technique. Microscopic examination, X-ray and carbon analyses were also used to elucidate the kinetics and mechanisms of reduction of Fe₂O₃ briquettes. In the initial stages of reduction, the highest reduction rate was obtained in hydrogen while the slowest was in carbon monoxide. In CO-H₂ gas mixtures, the rate decreased with increasing amounts of carbon monoxide. In the later stages of reduction, a minimum reduction rate was only observed during the reduction with hydrogen and hydrogen-rich gas mixtures due to the formation of denseγ-iron at 900 to 950‡ C. This was eliminated in carbon monoxide and carbon-monoxide-rich gas mixtures due to the carbon deposition in the samples and secondary reactions.