abstract
This work describes an exploratory study of the devitrification behaviour of a commercial lime-silica based glass frit to which a high alumina residue generated in a previous waste recycling process was added (up to 30 wt-%). Mixtures were melted at temperatures varying from 1100 to 1500 degrees C, and the devitrification behaviour of the resulting glass frits upon heat treatment was studied using X-ray diffraction, differential thermal analysis, Fourier transform infrared spectroscopy and scanning electron microscopy. No significant changes in the frit melting or casting behaviour were observed, and devitrification was interpreted in terms of the phase equilibrium diagram of the alumina-lime-silica system. Gehlenite-anorthite based glass ceramic powders could be obtained from the fritted glasses after heat treatment at 900 degrees C for <2 h, which suggests a high added value application for the waste material in the production of glass ceramic frits for ceramic glazes.
keywords
GRANITE REJECTS; RAW-MATERIALS; CERAMICS; CRYSTALLIZATION; NUCLEATION; GROWTH
subject category
Materials Science
authors
Mello-Castanho, SRH; Ferreira, MC; Acchar, W; Segadaes, AM
our authors
Ana Maria B C Segadães
Retired Professoracknowledgements
The authors acknowledge the financial support received from The State of Sao Paulo Research Foundation (FAPESP/SP) and the National Council for Scientific and Technological Development (CNPq).