ABSTRACT

When batch material is heated up, a huge amount of gases are released by the decomposition of raw materials. These released gases interact with the gases in the furnace atmosphere and in the glass melt, and dissolve into the melt. The solubility of gases in glass melts, as that in normal liquids, is defined as the equilibrium concentration of dissolved gases in those liquids or melts at a given gas pressure and given temperature. The solubility of gases in glass melts depends on temperature, glass composition and on gas fugacities (function of gas partial pressures). These factors, as well as the transport of dissolved gases by diffusion, are of great importance to gas release and gas absorption mechanisms in melting, refining and conditioning. The formation, change of content, growth, shrinkage and general behavior of gas bubbles in glass can essentially be understood by understanding solubility and diffusivity of gases in melts.