Chemical kinetics of gaseous reduction of hematite

Abstract

Abstract The chemical kinetics of the gaseous reduction of natural hematite and artificial iron oxide were studied with a new technique using ceramic coated one-dimensional specimens. The rates of reaction at various solid-solid interfaces were obtained directly. The difficulties in interpreting the experimental results are discussed. Based on single-reaction interface theory, the results of wustite reduction are analyzed. The chemical reaction rate constants are evaluated and it is found that the average values for the effective diffusivities of reducing gases through the porous iron layer are located within a narrow region of known limits. Resume La cinetique chimique de reduction directe de l'hemalite naturelle et d'oxydes de fer synthetiques a ete etudiee a l'aide d'une technique nouvelle ou l'on se sert d'echantillons revetus d'une gaine impermeable de ceramique dans toutes les directions, sauf une. Les taux de reaction aux divers interfaces solide-solide ont ete obtenus directement. Les difficultes ...