Vitrification of wastes and preparation of chemically stable sintered glass-ceramic products

The present work illustrates the conversion of wastes, such as panel glass from dismantled cathode ray tubes, mining residues from feldspar excavation and lime from fume abatement systems in the glass industry, into two glasses which were subjected to a sinter-crystallization process. The surface mechanism of nucleation, starting from finely ground powders (< 37 mu m), allowed a rapid crystallization at a relatively low temperature (2 h at 880 degrees C). This resulted in with the preparation of glass-ceramics possessing a mechanical properties (bending strength and microhardness exceeding 60 MPa and 6.3 GPa, respectively) comparable to that of commercial glass-ceramics and natural stones for building applications, coupled with a good chemical durability. This feature, together with the type of crystals developed, was correlated to the fluorine content of the parent glasses. (c) 2006 Elsevier B.V. All rights reserved.