Fuel, Vol.253, 32-39, 2019
Phase and mineral behavior of coke in cohesive zone
The metallurgical coke sample collected from the lower section of cohesive zone was examined by SEM/EDS. It was observed that the outer layer of coke was covered with slag and iron, and the solid solution of Ti(C,N) and V (C,N) was distributed around the slag-iron interface and iron droplets. The composition of the slag was unevenly distributed, mainly the crystalline phases of gehlenite or anorthite. The macroscopic coke pores near the slag-iron layer were filled with a large number of slag, and the interconnected pores generated by severe coke gasification reaction provide effective channels for the liquid slag to flow into the coke. The Fe-rich phase, the Ca-rich phase, and the alkalis element were also observed in the coke. Meanwhile, the octahedral spinel crystals were found in the coke pores, and the stress generated by the growth of spinel crystals may cause the formation of cracks in cohesive zone coke.