The invention relates to methods of vitrifying waste and for lowering the
melting point of
glass forming systems by including lithia formers in the
glass forming composition in significant amounts, typically from about 0.16 wt % to about 11 wt %, based on the total
glass forming oxides. The lithia is typically included as a replacement for alkali
oxide glass formers that would normally be present in a particular glass forming
system. Replacement can occur on a mole percent or weight percent basis, and typically results in a composition wherein lithia forms about 10 wt % to about 100 wt % of the alkali
oxide glass formers present in the composition. The present invention also relates to the high lithia glass compositions formed by these methods. The invention is useful for stabilization of numerous types of waste materials, including aqueous waste streams,
sludge solids, mixtures of aqueous supernate and
sludge solids, combinations of spent filter aids from waste
water treatment and waste sludges, supernate alone, incinerator ash, incinerator offgas blowdown, or combinations thereof, geological mine
tailings and sludges,
asbestos, inorganic
filter media,
cement waste forms in need of remediation, spent or partially spent
ion exchange resins or zeolites,
contaminated soils, lead paint, etc. The decrease in
melting point achieved by the present invention desirably prevents volatilization of hazardous or radioactive species during
vitrification.