Glaze Coatings Based On Zirconium Glass With Low Boron Content

The Na20-B203-Al203-Si02-Zr02 system was chosen as the starting system to synthesize glazes for facing tiles. The optimum glass compositions contained 10-17.5 mol% B203 and 4-5 mol% Zr02. The resulting glasses had good founding and processing properties. The glass samples were specified with X-ray amorphism and small regions of phase separation. Transparent, opaque and partially opaque glasses were produced. The marjority of transparent glasses preserved no opacity even after long thermal treatment, which indicates a trend towards crsytallization. The glass structure was studied by methods of differential and thermal analysis and by infrared spectroscopy.