A technique is described by which organic matter can be separated and concentrated from carbonaceous rocks by physical means. Ball-mill grinding to colloidal sizes is carried out in a mixture of water and kerosene. Separation of such fine-sized particles is possible because two colloidal systems are formed, an organosol of organic material in kerosene and a hydrosol of mineral matter in water. The colloidal systems are isolated, the suspending media removed, and organic and mineral concentrates collected.

Analytical data for ash, carbon, and hydrogen are given for the separates from the fractionation of three carbonaceous shales, a carbonaceous sandstone, and an argillite. Shales and sandstone with carbon contents ranging from 12 per cent to 20 per cent yielded fractions with 3- to 4-fold concentrations of organic matter. An argillite containing 1.46 per cent carbon yielded an organic concentrate containing 38.94 per cent carbon.