Interaction of vitrinites in similar middle-rank coals during coking process

• The interaction of vitrinites in similar middle-rank coals during coking process were evaluated by the characteristics of coke-CO 2 gasification. • An index based on the gasification reactivity is proposed to characterize the interaction degree of vitrinites during coking process. • The interaction of vitrinites during coking process can enhance the graphite characteristics in the coke. • The extension of graphitization characteristics can improve the resistance of CO 2 erosion for the cokes. Interaction of vitrinites in coals during coking process has effect on the properties of the coke. The evaluation of the vitrinites interaction is of great significance of coal blending and coke quality prediction. Vitrinites separated from the similar middle-rank coals in Tangshan (TS) and Ewirgol (EW) are mixed with ratio of 0:1, 1:3, 1:1, 3:1, 1:0 to prepare cokes. The characteristics of coke-CO 2 gasification were studied to evaluate the interaction of vitrinites during coking process. The results show that the maximum reaction rate ( r max ) and the comprehensive gasification index ( G c ) of cokes have negative quadratic linear relationships with the content of TS vitrinite, and the difference between the experimental and theoretical gasification reactivity of cokes indicates the interaction of EW and TS vitrinites in the coking process. An interaction index ( δ ) based on the gasification reactivity of cokes is proposed to characterize the degree of interaction between the two kinds of vitrinites in coking process, and the interaction index based on G c is 6.9%. Also, XRD and Raman spectroscopy analysis results show that the microcrystalline structure parameters ( n and f a ) have a negative linear relationship with G c , and the Raman parameter A D1+D2+D3+D4 /A G has a positive quadratic linear relationship with G c , the Raman parameter A G /A All has a negative quadratic linear relationship with G c . TS vitrinite in coal blending can enhance the graphite characteristics in the coke and increase the order degree of carbon structure in the coke, which improve the resistance of CO 2 erosion for the cokes.