Evolution Of Coal Char Structure Of Vitrinite With Different Rank

The studies of the structure evolutions of vitrinite pyrolysis and the influence of the interaction of active and inert on the structure evolutions can deepen the understanding of coal blending and coking mechanism.Four coking coals with different coalification degree（TK gas coal,HZ fat coal,SKLS coking coal,and KT lean coal）were studied,and the vitrinites were enriched.The pyrolysis and coking experiments were carried out for the vitrinites and the blending of vitrinite and standard anthracite with equal proportion.The microstructures of pyrolysis products were studied by XRD,Raman and FT-IR.The structure evolution from coal to char for vitrinite with coalification degree was investigated,and the influence of inert component on the evolution was studied.The results show that the fluidity of metaplast was divided into two stages:the development and solidification of the metaplast,with the increase of pyrolysis temperature L_cand f_aincrease,and L_adecreases;A_D1/A_G,A_D2/A_G,A_D3/A_Gdecrease,and A_G/A_allincreases;CH₂/CH₃and H_al/H_alldecrease gradually;f_arincreases,and f_aldecreases.Moreover,and the change rates for the structural parameters of the metaplast are slower in the development stage and faster in the solidification stage.The structural evolution rate k is related to the coalification degree,and k（L_c）and k(A_D1/A_G)decrease with the increase of coalification degree.For the coking process,f_aand L_aincrease with the increase of coking temperature;L_cand A_G/A_alldecreased at first and then increased,while A_D1/A_G,A_D2/A_Gand A_D3/A_Gincrease at first and then decreased.The turning point is900℃.The evolution rate k（L_c）increases gradually with the increase of the coalification degree.The addition of standard anthracite has great effect on the structure evolution rate of vitrinite.In the ratio of k _VAto k _Vis used to characterize the influence of the active-inert interaction on the structure evolution.For the plastic phase stage,β（L_c）andβ(A_D1/A_G)increases with the increase of the coalification degree.For the coking stage,with the increase of the coalification degree,β（L_c）gradually decreases,and theβ(A_D1/A_G)increases gradually.Figure 88;Table 3;Reference 67...