Thermoplastic Properties of Coal and Coal Extract

The aim of this study is to find a simple, effective, and non-destructive way to estimate the fluidity of coal. Three kinds of metallurgical coals were blended in a specific ratio for fluidity measurement by a Gieseler plastometer and coke strength by the Roga test. One of the metallurgical coals was extracted with four kinds of solvents. The solvent-extracted extracts further underwent heat treatment at different temperatures and were then added to the blended coal to examine the change of fluidity and coke strength. Both the heat-treated and untreated coal extracts were further investigated by elemental analysis, thermogravimetric analysis, solid-state ¹³C nuclear magnetic resonance, and X-ray diffractometry, and it was found that the heat treatment will increase the degree of graphitization. The aromatic carbon content was found to correlate significantly with the fluidity of coal, and the relationship among the ratio of aromatic carbon/aliphatic carbon, aromaticity, and fluidity was studied in this work. Finally, X-ray diffractometry is suggested to be a non-destructive method to estimate the fluidity of coal.