Refining of fossil resin flotation concentrate from Western coal. Fourth quarterly final report, October 1, 1993--December 31, 1993

Abstract

Four resinite types, namely yellow, amber, light-brown, and dark-brown in color, occurring in the Wasatch Plateau coal field, are mainly composed of aliphatic components. In contrast coal consists primarily of aromatic ring structures, various oxygen functional groups ({minus}OH, >C=O, {minus}C{minus}O) and few aliphatic chains. The color difference observed among the four hand-sorted resin types is explained by the presence of chromophores (O, S, and N atoms and C=C double bonds) and also by the presence of finely dispersed coal particle inclusions in the resin matrix. The extraction rate for these resin types follows the order yellow > amber > light-brown > dark-brown. Hexane purified resin from all resin types closely resembles the properties of the physically separated yellow resin. Resinites are distinct from other coal macerals, which show a high heat value and high volatile matter content. The four resin types also show distinct differences among certain physical and chemical properties such as density, and softening point. All these properties were noted to change gradually from yellow to dark-brown resin.