Liquefaction of density separated coal fractions

Density separations of a single coal, Point of Ayr, UK, have been carried out. The uncrushed coal sample was roll crushed to provide two samples at different roll separations. These samples were further screened into size fractions and selected size fractions were separated using a float-sink procedure in a heavy liquid medium. The fractions produced were analysed for maceral content, proximate analysis and liquefaction potential. The liquefactions were carried out using a tubing-bomb with a non-hydrogen-donating solvent, phenanthrene, and with a hydrogen-donating solvent, hydrogenated anthracene oil. The results show that there are significant potential benefits in carrying out coal beneficiation prior to liquefaction. The beneficiation process used does not have to be severe and density separation on particle sizes in the range 0.5-1.0 mm can be effective.