Bulk and sintered glass-ceramics by recycling municipal incinerator bottom ash

Glass-ceramics were produced using an Italian municipal incinerator bottom ash and glass cullet coming from a community glass recycling program. The capability of three different mixtures to be vitrified and subsequently devitrified by both bulk and sintering process was investigated by means of differential thermal analysis, X-ray diffraction, hot stage microscopy, firing shrinkage, water absorption and bulk density measurements, as well as scanning electron microscopy observations. High ash contents favour the growth of crystallised fraction volume and the formation of crystals of the pyroxene group, and anorthite in addition to wollastonite. Since the nucleation mechanism starts from the surface and sintering occurs before crystallisation, all the compositions humidified with a water solution are easily sinterable in dense materials at the relatively low temperature of about 850°C, in such way as to render the process economically advantageous