Abstract: Organic materials are mixed with metal oxide, such as hydrated metal oxides, prior to or during heat treatments in aerated or oxygenated environments to stabilize thermal decomposition or incineration of the organic materials and to suppress the emission of volatile, hazardous organic compounds. The organic materials may be ion exchange resins and polymeric sorbents, for example, and include contaminated materials such as hazardous wastes. The hydrated metal oxides may be hydrated ferric oxide, hydrated aluminum oxide or hydrated titania oxide, for examples. Ferrihydrite is preferred. The heat treatment may be a preparation for a waste disposal process, such as immobilization in ferric oxide, cement, concrete, a polymer, bitumen or glass, for example. Immobilization processes in ferric oxide are also discussed, including the use of additives such as magnesium oxide, ammonium dihydrogen phosphate and phosphoric acid, enabling consolidation at room temperature and pressures less than 15,000 psi.

Abstract: Processes for immobilizing solid contaminated materials, such as radioactive species, hazardous species, or combinations of both radioactive and hazardous species, comprise mixing the contaminated materials with hydrated ferric oxides, and then pressing the mixture at a temperature of at least about 150.degree. C. and gradually removing a large part of the water while under pressure to produce a solid composition. The water content of the mixture is adjusted if necessary. Contaminated materials dissolved or suspended in an aqueous solution can be immobilized by precipitating hydrated ferric oxide in the solution, and adjusting the water content and pressing, as above. In another process in accordance with the present invention, hydrated ferric oxides are deposited on metal surfaces. The deposited ferric oxide is pressed to produce a solid coating adhered to the surface, to retard corrosion. A ceramic body of ferric oxide composition may also be made in accordance with the present invention.