Diffusion of H2-H2O through porous iron formed by the reduction of iron oxides

Abstract

Measurements were made of the rate of equimolar counterdiffusion of hydrogen and water vapor through porous iron formed by the reduction of dense hematite, magnetite, and commercial iron ore pellets with hydrogen. The experiments were conducted at temperatures between 400° and 1000°C and at pressures between 0.1 and 40 atm. It is demonstrated that the structure of the porous iron is primarily a function of reduction temperature and that the diffusion process at the higher reduction temperatures is normal. The effect of gaseous diffusion on the rate of reduction of dense hematite with hydrogen is discussed. It is shown that gaseous diffusion limits the rate at the higher temperatures and pressures.