GLASS-CERAMICS FROM FILTER DUSTS FROM WASTE INCINERATORS

Glass-ceramics have been produced from filter dusts of domiciliary waste incinerators without the addition of nucleating additives. A two-step heat treatment of melted filter dusts (1 h at 880 degrees C, 10 h at 950 degrees C) was used to obtain a fine crystalline microstructure, the principal constituents being crystals of the pyroxene group. The glass-ceramic materials have better mechanical and thermomechanical properties than those of the parent glass, being potential candidates for industrial applications. A fracture-mirror analysis was carried out to evaluate the measured fracture strength and fracture toughness of the glass and glass-ceramics produced. The data are in agreement with previous studies showing that the parameter A/K-Ic, where A is the fracture-mirror constant, is a dimensionless, material-independent constant.