Metal recovery process and method

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. Complete combustion of the organic material is allowed to take place, and the metal and metal oxides resulting from the combustion process are recovered by known methods. The heat generated by combustion may be used to pyrolyze additional amounts of shale by known methods. In the most advanced modes of this invention, pressures on the oder of several hundred bar and particle temperatures on the order of 4500.degree. C. can be used in a combined combustion-pyrolysis-synthesis to recover vapor phase minerals and oil from the pyrolysis of shale, with the additional capability of cracking the oil into lighter hydrocarbons and/or the production of useful synthesis products. This method reduces total energy consumption, produces a range of useful finished products, provides for greater recovery from the shale and renders all ash and effluents ecologically safe.