| The kinetics of reduction of hematite pellets with gas mixture H2- H2O was investigated in the range 600℃ to 1000℃. From the analysis of data obtained, it was observed that the diffusion of gas through the reduced iron layer became the controlling factor. A simplified Langmuir-Hinshelwood rate equation of the form, k=k_s·P_(H2)/(1＋b_(H20)·P_(H2O), was found to represent satisfactorily the measured rate data ; where k(g atom 0/min.) is the rate constant derived from diffusion controlled model, k_5 is the rate constant(g atom 0/min·atm) averaged over the pellet, b_(H2O)(atm^(-1)) is the adsorption equilibrium constant for gas mixture. The value of b_(H2O), which is a measure of the `poisoning effect` of the H₂O decreases from 30.31atm^(-1) at 600℃ to 0.75atm^(-1) at 1000℃ for acid pellets and decreases from 9.90atm^(-1) at 600℃ to 2.60atm^(-1) at 1000℃ for basic pellets. |
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