Application of an Industrial Waste Glass in Glass-Ceramic Stoneware

Vitrified inorganic wastes are often converted into glass-ceramics; although these products exhibit interesting properties, the processing is quite complex and expensive. This paper reports an alternative approach, based on substituting traditional feldspar fluxes in stoneware with a CaO-Al2O3-SiO2 glass, from industrial plasma vitrification of municipal solid waste incinerator fly ashes. The new materials feature low sintering temperatures, <1000 degrees C, associated to a substantial crystallization. For an optimized balance between crystallization and densification (by introducing soda-lime glass as a sintering promoter), the products exhibit remarkable mechanical properties (e. g., bending strength exceeding 100 MPa), even superior to those of traditional porcelain stoneware.