Solvent extraction of oil shale or tar sands

摘要

Oil shale or tar sands is extracted under non-thermally destructive conditions with a solvent liquid containing a compound having the general formula: <IMAGE> where M is a carbon, sulfur, or phosphorus atom, R2 and R3 are each a hydrogen atom or a lower alkyl group, R and R1 are each a lower alkyl group, another <IMAGE> a monocyclic aromatic group, or R1 can be another <IMAGE> or R1 and R2 together can represent the atoms necessary to close a heterocyclic ring, and n=1 where M=phosphorus and is otherwise 0, to substantially remove the non-fixed carbon content of the oil shale or tar sands, leaving a solid residue of fixed carbon, ash minerals, and non-extractable matter.