Solubility of gases in glass melts

Abstract

A short overview on gas solubility and solubility mechanism in oxide melts in given. Many gases of practical importance in glass melting like oxygen, nitrogen, carbon dioxide and sulfur dioxide and others dissolve in a glass forming melt both chemically by a chemical controlled process and physically by occupying the holes in the network structure. The chemical solubility at conditioning temperatures is orders of magnitude higher than the physical solubility and decreases with increasing temperatures. An exception is water whose chemical solubility increases with increasing temperature, and that is why water cannot be used as a fining agent. The physical solubility on the other hand increases slightly with increasing temperatures. At measuring physical solubilities mistakes can be made because of the omnipresent chemical solubility or because of impurities. Therefore the known relationship between physical inert gas solubilities and the size of the dissolving atoms or molecules was used to calculate the physical solubility of a lot of non-inert gases for soda-lime silica melts, for fused silica and for molten boric oxide.

Development of low‐loss lead‐germanate glass for mid‐infrared fiber optics: I. glass preparation optimization

“…According to Henry's law, the chemical solubility of water in a glassmelt is proportional to the square root of its pressure in the melting atmosphere. 27 This has been verified for tellurite glass through the increase in the OH absorption coefficient with increasing water partial pressure above the melt. 28 As the crucible lid only covers the crucible but does not seal it, enhanced flow of dry gas into the liner determines the water partial pressure above the glassmelt via three effects.…”

“…27 However, the O 2 in the presence of multivalent ions in the glassmelt is chemically dissolved. 27 In lead-germanate glass, 29 Pb acts as a multivalent ion, supporting O 2 solubility via a redox process. When using O 2 bubbling for dehydration of phosphate 30 melts, O 2 is regarded as a nonreactive gas that helps remove OH groups by reaching an equilibrium between the water dissolved in the glass (in form of OH groups) and that in the gas bubble.…”

The Role of Sulfur Compounds in Coloring and Melting Kinetics of Industrial Glass

“…In the first case, gas molecules occupy the free space available in the interstice of the silicon oxide network. The second process arises when the gas molecule chemically reacts with the network components, becoming part of the glass structure (Kramer 2005). The topic of this paragraph is discussed extensively in Backnaes and Deubener (2011, this volume) and only a short, but necessary, description is reported here in order to link sulfur solubility to industrial glass color.…”

Interim glycol flowsheet reduction/oxidation (redox) model for the Defense Waste Processing Facility (DWPF)

“…Argon sparges or degasses excess oxygen from the melt and creates a more reduced melt. [6,7,8] Therefore, the Ar impact was quantified so that the overall REDOX, including the impact of Ar, could continue to be targeted at Fe 2+ /ΣFe=0.2 in the middle of the 0.09> Fe 2+ /ΣFe <0.33 production range.…”