An investigation into the process of centrifugal sink/float separations of micronized coals. 1. Some inferences for coal maceral separations

The process of maceral separation using sink/float centrifugal methods was investigated for several bituminous coals with particle sizes <10 μm. Density gradient methods were used to monitor the separations. It was found that swinging bucket rotors were the best for most work. Higher centrifugal speeds also provided more pure phase, not only became of the higher centrifugal force but also due to better packing of the pellets. Several of the media commonly used for maceral separation were also used. The best media were aqueous CsCl and Ca(NO 3 ) 2 with the nonionic surfactant, Brij-35