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

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 CO2 concentration on the pore structure. Temperature had a significant effect on the degree of graphitization and graphitization defects, whereas the effects of CO2 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.