Effect of coke reactivity on reduction behaviours and non-isothermal kinetics of sinter at 1173–1373 K

Abstract

Utilizing high-reactivity coke is a critical approach for low-carbon iron-making. In this study, we investigated the effect of coke reactivity on reduction behavior and non-isothermal kinetics of sinter. The results show that the mass-loss rate of the burden gradually increased with increasing coke reactivity. At 1173-1373 K, the reduction process complied with the mechanism model F₂ of second-order chemical reaction control. The integral form of F₂ is G(α)=(1–α)^-1–1, and the α is the extent of the conversion. The coke reactivity did not affect the reduction mechanism of the sinter. The apparent activation energy E of the reduction process without coke was 93.39 kJ/mol. As the coke CRI was 24.75%, 30.80%, 41.25%, and 45.11%, the E was 89.13 kJ/mol, 88.63 kJ/mol, 85.60 kJ/mol, and 77.27 kJ/mol, respectively. The gasification reaction of coke with high reactivity can enhance the gas-phase reduction ability of the reduction process.