On the Unreacted-core Shrinking Model for Reduction of a Single Hematite Pellet with Hydrogen

A n equation for the rate of reduction of a hematite pellet has been derived on the basis of the unreacted-core shrinking model by introducing the resistance due to the rate of gas flow.T he estimating jJrocedu res of the viscosi(y and the dijJusion coefficients or the equilibrium constallt are then discussed standing on the fact that the equation ga ve a close agreement with the experimental values.I n consideration of the above-mentioned equation and the experimmtai data obtained by T akahashi, et ai.0 1' by Feinman, et al. , the calculation has been made after the method proposed by Yagi and Ono.Quite reasonable values were obtained for the chemical reaction rate constants and the e.!Jective dijJusion codficients through the porous shell of a reduced pellet .On the other hand, the calculation based on a reduction rate equation without considering the resistance due to the rate of gas flow did not give satisfactory results .The results obtained clearly indicate that the introduction of this resistance is rather important.Vl ' " 01 F ig.I .Concen tration distribu tion profi le of the u nreac tedcore shri n ki ng model for a sin gle hema tite p elle t reducti o n • Origina ll y pu blished in Tetsu-to-Hagane, 59 ( 1973), 1888, in J ap a nese.