Laboratory Scale Separation of Coal Macerals

Abstract

A laboratory scale procedure for separation of the maceral constituents of coal has been developed. This procedure is a modification and scale-up of our earlier density gradient centrifugation method. The technique enables us to separate larger quantities and to obtain higher density resolutions of individual coal macerals than was previously possible. The procedure involves an initial sink-float separation on finely ground chemically demineralized coal using a high speed centrifuge to obtain large quantities of single maceral groups (i.e., exinite, vitrinite, or inertinite). The maceral concentrate, 15–20 g in quantity, rather than the entire coal serves as the feed for the DGC separation. Efforts to apply continuous centrifugation techniques as an alternative to the sink-float separation to concentrate maceral groups were only partially successful.