KINETICS AND MECHANISM OF REDUCTION OF FERRIC OXIDE BY HYDROGEN.

Abstract

Kinetic investigations of the reduction of alpha -Fe//2O//3 with hydrogen were carried out at 300 to 500 C by direct loss measurements and differential thermography. The results show that the reduction proceeds by a two-step mechanism via Fe//3O//4, with the overall rate governed by the topochemical reduction of Fe//3O//4 to Fe, i. e. , the formation and nucleation of metallic iron, rather than by any of the mass transport processes. The phase composition of the solid mass was established by x-ray diffraction, Mossbauer spectroscopy, and DTA.