Effect of gasification reaction on pore structure, microstructure, and macroscopic properties of blast furnace coke.

[Display omitted] • The effects of CO 2 concentration and reaction time on the microstructure are mainly due to changes in pore structure. • There is a critical value for both the reaction time and the effect of carbon dioxide concentration on the pore structure. • L c is the best index to reflect the highest temperature experienced by coke in blast furnace. • When the surface concentration reaches the critical value (10%), carbon dioxide reacts with the inner coke through pores and cracks, resulting in larger pores inside the coke. • The macroscopic properties of coke (compressive strength and reactivity after reaction) are influenced by both pore structure and microstructural properties. To address the deterioration of coke properties and subsequent fines caused by coke gasification reaction inside blast furnaces, orthogonal gasification tests were conducted on industrial coke simulating a blast furnace environment, and the effects of reaction temperature, carbon dioxide concentration, and reaction time on the pore structure, microstructure, and macroscopic properties of coke were analyzed. An increase in the reaction temperature led to the reaction of carbon dioxide with the internal coke through the pores and cracks, and a critical value was observed for both the reaction time and CO 2 concentration on the pore structure. Temperature had a significant effect on the degree of graphitization and graphitization defects, whereas the effects of CO 2 concentration and reaction time on the microstructure were mainly due to changes in the pore structure. The macroscopic properties of coke (compressive strength and reactivity) were influenced by both its pore structure and microstructure. As the reaction temperature and time increased, the compressive strength of the coke increased initially and then decreased. [ABSTRACT FROM AUTHOR]