Low-temperature Containment of Thermally Degradable Hazardous Waste

A patent has been issued for a low-temperature method that produces coated hazardous waste pellets for use as aggregate in a concrete waste form. The process combines hazardous waste with a chemically setting organic polymer to make a mixture for forming pellets. The pellets are first coated with epoxy and then coated with a silicate-based powder. The liquid-concrete/pellet mixture then goes to molds which can be rotated to concentrate the pellets away from the perimeter of the waste form. The double-coated hazardous waste pellets reportedly offer high bonding when used as a coarse aggregate in a concrete mixture. The resulting waste form is self-supporting and needs no external container for transportation, storage, or disposal. Assignee: The United States of America as represented by the Secretary of the Army; patent number: 5595561; issue date: January 21, 1997.