Patent ID: 8910497

Claim:
A process for making a glass product melt composition, which includes the steps of: (a) providing a first mixture of raw materials that includes a glass network former and gas releasing glass network modifiers; (b) providing a second mixture of raw materials that includes an additional amount of said glass network former and non-gas releasing glass network modifiers; (c) melting and reacting said first mixture of raw materials to form a glass precursor melt having a temperature in the range of 900 C to 1700 C and having a viscosity of not more than 3 Pa·s; (d) refining said glass precursor melt, wherein said viscosity of said glass precursor melt promotes release of gaseous reactions products from said precursor melt that evolved upon decomposition of said gas releasing glass network modifiers in said step (c); and then (e) dissolving said second mixture of raw materials in said refined glass precursor melt to form a final glass melt that has a greater percentage of said glass network former than said glass precursor melt.