KINETIC STUDY OF HAEMATITE REDUCTION BY HYDROGEN.

Article abstract of DOI:10.1007/BF01174669

The reduction of powdered haematite ( alpha -Fe//2O//3) with hydrogen was studied in a fixed-bed differential reactor in the temperature range 968 to 1063 K under different hydrogen partial pressures ranging between 0. 1 and 0. 7 atm. The kinetic parameters were calculated from the measurement of the thermal conductivity variation in the gaseous phase produced by the reaction. The reaction was first order with respect to the hydrogen concentration. In the 968 to 1008 K temperature range, the reaction was chemically controlled and the preexponential factor and the activation energy values obtained were 9. 96 multiplied by 10**4 and 40. 2 plus or minus 1. 6 kcal mol** minus **1, respectively. Beyond 1008 K a retarded reduction was observed indicating that a combined process of direct gas-solid reaction and iron-ion diffusion in the solid occurred.