8th International Congress on Science and Technology of Ironmaking - ICSTI 2018

Coke degradation by the reaction with carbon dioxide is known to cause the fine particle generation, deteriorating gas and liquid permeability in a blast furnace. Coke degradation must be suppressed or controlled in order to achieve stable operation of blast furnace. In this study, the mechanism of the coke degradation by the reaction with carbon dioxide, i.e. solution loss reaction, was investigated using our developed NMR gas Imaging technique in terms of changes in reactivity of cokes and fine particle generation after mechanical impact by I-drum revolutions when coke qualities were changed. In conclusions, (1) In case that the reaction ratio of coke with CO2 is changed up to the reactivity of cokes, the reactivity of the cokes strongly affects the fine coke particle generation from reacted cokes. (2) In case that the reaction ratio is adjusted to predetermined value (20mass% in this study) as observed in actual blast-furnace operation, the increase in fine coke particle generation due to the reaction appeared unchanged, regardless of the reactivity of cokes. Instead, the coke abrasive strength appears to significantly affect the fine coke particle generation from reacted cokes.