Reduction behavior and reaction kinetics of iron ore-biomass composite pellets

The reduction reaction rate, reduction degree, surface microstructure and weight loss of composite pellets with different components under biomass syngas atmosphere were investigated to illustrate the effects of biomass addition in pellets on the reduction behavior and reaction kinetics. The porosity of pellets with the addition of biomass is higher than that without the addition of biomass, which is favorable to heat and mass transfer of the reduction process, increases the reduction degree of products and decreases the apparent activation energy of reaction. The reduction of pellets was carried out in the manner of a shrinking core model. In the range of 1123 to 1323 K, the rate-controlling mechanism of reduction for these two kinds of pellets is inteffacial chemical reaction. The addition of biomass in pellets can improve the inteffacial chemical reaction, and thus the apparent activation energy of reaction decreases from 95.448 kJ. mol^-1 to 68.131 kJ. mol^-1.