Study on the Rate of Reduction of Single Iron Oxide Pellet with Hydrogen
1973 Volume 59 Issue 14 Pages 1888-1901
Details
1973 Volume 59 Issue 14 Pages 1888-1901
An equation for the rate of reduction of a hematite pellet is derived based on an unreacted-core shrinking model, considering the resistance due to the mass b alance of reactions. Then, a modified diffusion coefficient, D′H2-H2O, of H2 gas in ternary gas system, H2-H2O-N2, is derived considering the influence of stagnant N2 gas. The estimation methods for the viscosity and diffusion coefficients or equiliblium constants are also described in view of the best agreement with experimental values.
Using these results, the above mentioned equation and experiment al data of TAKAHASHI, et al. and FEINMAN, et al., calculation is carried out by the method offered by YAGI and ONO, then the reasonable values of effective diffusion coefficient through the porous shell of reduced pellet and chemical reaction constants are obtained. On the other hand reduction rate equation without the resistance due to the mass balance gives unsatisfactory results. Consequently, it becomes clear that consideration of this resistance is rather reasonable and necessary.
