Abstract: A method of treating a composite material such as oil shale or low grade coal to recover metals, metal compounds and additional heat. The method comprises reducing the particle size of said composite material, separating the composite organic portion from the gangue portion which forms a part of the material to form a composite metal-containing organic concentrate. The concentrate is then treated with available oxygen-bearing materials in wet solution in an amount sufficient to supply all or a portion of the stoichiometric amount of oxygen required for combustion of the concentrate. Then or thereafter, the treated concentrate is treated with additional gas phase oxygen in an amount sufficient to make up the remainder if any of the stoichiometric amount of oxygen, thereby producing a treated composite organic material with or without other forms of oxygen. This treated composite organic material is further heated until the material ignites.