Coal liquefaction process employing extraneous minerals

Claim 1

A coal liquefaction process comprising passing mineral-containing feed coal, hydrogen, recycle dissolved liquid solvent, recycle normally solid dissolved coal, recycle mineral residue derived from said feed coal and a recycle extraneous catalytic mineral to a coal liquefaction zone which does not contain a fixed bed of added catalyst to dissolve hydrocarbonaceous material from mineral residue and to hydrocrack said hydrocarbonaceous material to produce a mixture comprising hydrocarbon gases, dissolved liquid, normally solid dissolved coal, suspended mineral residue and suspended extraneous catalytic mineral; passing a liquefaction zone effluent stream through vapor-liquid separator means to remove overhead hydrogen, hydrocarbon gases and naphtha from a residue slurry comprising liquid coal and normally solid dissolved coal, suspended mineral residue and suspended particles of extraneous catalytic mineral; recycling a first portion of said residue slurry to said liquefaction zone; passing a second portion of said residue slurry to a product separation means; passing a third portion of said residue slurry through hydroclone means; recovering from said hydroclone means an overflow slurry comprising liquid coal and normally solid dissolved coal with suspended mineral residue and a higher than aliquot weight proportion of suspended particles of extraneous catalytic mineral; recycling said overflow slurry to said liquefaction zone to reduce the median diameter of particles recycled to said liquefaction zone and to selectively increase the proportion of said extraneous catalytic mineral in said liquefaction zone; recovering from said hydroclone means a concentrated solids underflow slurry comprising liquid coal and normally solid dissolved coal with suspended mineral residue; and passing said underflow slurry to said product separation means.