Relationship of Coke Reactivity and Critical Coke Properties

The gasification reactions of five metallurgical cokes were studied using a thermogravimetric analyzer at 1273 K and 1673 K in CO₂-CO-N₂ gas mixture. The results show that these cokes showed different reactivities in the gasification reactions. Properties that potentially influence coke reactivity including ash content, catalytic index, surface area, and crystallite size were measured and correlated with reactivity. The results indicate that reactivity had a good correlation with ash content, catalytic index, and crystallite size. The effect of surface area on coke reactivity was marginal. Coke reactivity was positively affected by catalytic index but inversely affected by ash content. Although crystallite size inversely affected reactivity, the reaction rate at the initial stage was more predominantly influenced by the mineral matter. Therefore, the influence of surface area and crystallite size was overshadowed by the impact of ash content and catalytic index at the initial stage of reaction.