Effect of SiO2 and/or Al2O3 addition on reduction of dense wustite by hydrogen.

Abstract

The dense wustite plates containing SiO2 and/or Al2O3 have been reduced isothermally in a stream of hydrogen at temperatures between 670 and 930°C. The specimens used in this work consist of FeO phase with a dissolved part of added oxides, fayalite and hercynite.Reduction of FeO is accelerated by the presence of SiO2 in a small amount at temperatures above 800°C, but it is retarded at temperatures below 730°C. On the other hand, reduction of FeO is depressed by the presence of Al2O3 dissolved in the FeO phase, over the temperature range studied in this work. Unlike the single oxide dissolution, simultaneous dissolution of SiO2 and Al2O3 in the FeO phase accelerates reduction over the entire range of temperature studied.The acceleration effect of reduction due to the existence of oxides can be observed if the reduction rate is relatively slow.