Establishment of product morphology during the initial stages of wustite reduction

Abstract

The product morphologies obtained on the reduction of wustite in CO/CO2 gas mixtures between 1073 and 1373 K are reported. Three types of product morphology are identified, namely, type A (porous iron), type B (porous wustite covered with dense iron), and type C (dense wustite covered with dense iron). The reactions which occur during the reduction of wustite in CO/CO2 and H2/H2O systems both before and after iron nucleation are examined. The product morphologies obtained on reduction are explained qualitatively in terms of the relative rates of the chemical reaction with the gas and the mass transport processes both in and on the solid.