Ceramics-Silikáty 39 (1) 1-7 (1995)

DETERMINATION OF DIFFUSION COEFFICIENTS OF GASES IN GLASS MELTS USING THE METHOD OF ABSORBED GAS VOLUME

L. Němec, J. Kloužek

The values of diffusion coefficients of gases in glass melt represent a significant quantity when studying refining process and kinetics of gas dissolving in glass melt. As the determination of gas concentration profiles in glass is very difficult owing to the extremely low solubility of most gases in glass, the method following the rate of absorption of given gas volume in glass melt using the high temperature visual method has been developed. Special measuring vessels from silica glass were applied to this purpose making it possible to follow the movement of phase boundary between measured gas and glass melt. The analysis of gas content of the measuring vessel after the experiment has been ensured. The equations were stated describing the absorption of pure gases as well as gas mixture into melt. Using the method, the temperature dependencies of D_O2 and D_H2O have been obtained for soda-lime-silica glass in the temperature range 1200-1480°C.