Abstract:
Vitrinite and inertinite separated from Shenmu coal using sink-float method combined with hand-picking were systematically investigated by ultimate analysis, FT-IR,13CNMR and TG/DTG. The results showed that the optimum density for separation of vitrinite and inertinite from Shenmu coal was 1.320 g/cm3~1.324 g/cm3 and 1.378 g/cm3~1.382 g/cm3 respectively. The purity of vitrinite and inertinite was 97.55% and 96.90% at this separation condition. Vitrinite had higher hydrogen content, lower aromaticity of 0.51 and a large amount of hydrogen bonds, while inertinite had higher carbon content and aromaticity of 0.76, and those of parent coal was in the middle of them with aromaticity of 0.68. The result of FTIR showed that at the same temperature vitrinite had more hydrogen bonds, higher aliphatic hydrogen content and lower Har/Hal ratio. With increasing temperature, the content of aromatic hydrogen and Har/Hal ratio all increased and the aliphatic hydrogen decreased. The result of TG/DTG showed that vitrinite had higher thermal stability than inertinite and the remaining volatile matter in vitrinite was lower than that in inertinite at the same Har/Hal ratio, which was consistent with the fact that inertinite had higher aromaticity and lower aliphatic hydrogen content and suggested that the chemical property of maceral affected its reactivity.