Effect of Iron Ore Size on Kinetics of Gaseous Reduction
In order to investigate the size effect on the kinetics of the gaseous reduction of iron ore, two kinds of iron oxide pellets of different diameters were reduced with CO-CO<sub>2</sub> gas mixture. Results were analysed using two models, Ishida-Wen's model and the unreacted-core model. From the analysis of the former model, the intraparticle diffusivity through the product layer <I>D</I><sub>s</sub>, the intraparticle diffusivity in the reactant zone <I>D</I><sub>so</sub> and the chemical reaction rate constant based on volume <I>k</I><sub>v</sub> were not changed with the particle diameter while Thiele's modulus φ and the effectiveness factor <I>E</I><sub>f</sub> were changed. From that of the latter model, the intraparticle diffusivity through the product layer <I>D</I><sub>e</sub> was not varied with the particle diameter, while the interface chemical reaction rate constant <I>k</I><sub>c</sub> was varied. Further investigation revealed that <I>k</I><sub>c</sub> was affected by the diffusion resistance through the product layer, that is, <I>D</I><sub>s</sub> and the particle size as well as the intraparticle diffusivity in the reactant zone and the reactivity.
- ISIJ international
ISIJ international 38(2), 109-115, 1998-02-15
The Iron and Steel Institute of Japan