GAS-SOLID REACTION MODEL FOR NONSPHERICAL IRON-OXIDE

Iron oxide pellets of various shapes are reduced from hematite to magn etite with CO-CO2 gas mixture to investigate the shape effect on the g aseous reduction rate of an iron oxide pellet. Based on the observatio n result of the section of partly converted pellets, a model of the mi xed-control kinetics for a non-spherical iron oxide is proposed. A det ermination method of the rate parameters included in this model is pre sented. Applicability of this model is reviewed comparing to one of ex isting models for non-spherical particle. For derivation of the mixed- control rate equation for a non-spherical iron oxide, the concept of n on-spherical radius is introduced.