SUPERCRITICAL EXTRACTION OF COAL USING WA TER - MICROSCOPIC STUDIES ON SOLID RESIDUES

Residues obtained by supercritical water extraction of coals of variou s coalification degrees and lithotypes of low rank coal were examined under the microscope. The optical texture of residues is closely conne cted with the rank of the original coals and their petrographic compos ition. Supercritical conditions of coal extraction with water appear t o have a favourable influence on the formation of porous structures an d the development of optical anisotropy in residues. The optical textu re of the examined residues is similar to the texture of metallurgical cokes.