Abstract: A foam glass pellet comprising a core of cellular glass and a coating of fine ash particles substantially enclosing said cellular glass core and bonded thereto is disclosed. The foam glass pellet is derived from a glass having a softening point less than 1250.degree. C. The pellets have a median size of about 0.5 to about 20 millimeters and a bulk density of about 8 lbs/ft..sup.3 to about 50 lbs./ft..sup.3 pounds per cubic feet or higher if desired. The ash coating is substantially a mono particle thick layer of ash bonded to the foam glass core. Fly ash is a particularly effective ash for this purpose. Also disclosed are foam glass pellets wherein the core of cellular glass comprises a glass foam body having ash particles dispersed therein. The foam glass pellets of this invention have superior strength and are particularly useful as a light-weight aggregate in matrices such as concrete, thermosetting and thermoplastic organic polymer bodies, metals and gypsum and plaster materials.

Abstract: A method for forming small, smooth surfaced foamed glass pellets with a coated surface of ash is disclosed. The method involves the recovery of waste glass, typically soda/lime/silica glass, crushing and sizing same to obtain particles of less than 200 mesh. The small particles may be pelletized in a pelletizing disk, drum, rotary kiln or other compressive or extrusion devices by the addition of water until the small particles begin to agglomerate. The pellets are then coated with a high-melting point release agent, especially ash, and then heated to a temperature above the softening point of the glass to cellulate the glass agglomerates to form substantially spherical pellets having a bulk density of as low as eight pounds per cubic foot and possessing a very fine, substantially uniform pore structure.