Low-temperature oil shale and tar sand extraction process

Fertilizers and kerogen materials are extracted from crushed oil shale utilizing a low temperature dekerosing (kerogen removal) solvent phase followed by a second fertilizer extraction phase using water as solvent. Process control factors are effective in producing delamination of the crushed oil shale resulting in high yield of kerogen and fertilizer values. The dross shale residue is not disintegrated and constitutes an ecologically acceptable soil conditioner and land restoration residuum. Proper blending of the various extracts and residues result in a wide variety of commercial fertilizer products. Bitumens and fertilizer materials may also be extracted from tar sands of both the hard, stony and soft variety and again a non-petroleum solvent, low temperature extraction process is used in a first step to recover the bitumen fraction. The solvent is totally recovered and recycled. Thermal energies are also recycled resulting in high overall efficiency. The sand residium or dross is clean and uncontaminated, constituting a water wettable land restoration medium with plant nutrient value imparting arable character. A second step may be employed to selectively leach fertilizers, notatably phosphates and potash. Leaching is accomplished by the use of water, which is recovered and recycled.