| In order to investigate the effect of particle size on gaseous reduction rate of iron ore, two kinds of iron oxide pellets of different diameters were reduced with CO-CO₂ gas mixture. Results were analyzed using two models, the intermediate model and the unreacted-core model. From the analysis of the former model, the effective diffusivity through product layer, D_s, the effective diffusivity through reactant layer, D_(so), and volume-based chemical reaction rate constant k_v, were not changed with particle diameter while Thiele`s modulus φ and effectiveness factor, E₁ were changed. From that of the latter model, the effective diffusivity through product layer, D_s was not varied with particle diameter, while the interface chemical reaction rate constant, k_c was varied. Investigation revealed that particle size affected a gas-solid reaction modules and that this affected gaseous reduction rate. |
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