Producing glass using outgassed frit

Disclosed is a process of producing glass materials wherein outgassing materials are mixed, melted, outgassed and formed into frits, and the frits are then mixed with essentially non-outgassing materials and melted to form the glass. Because the frits are already outgassed, lass gas is generated in the final glass melting step, thus foaming and scum forming are reduced. As a result, heat transfer efficiency in the glass furnace is improved and lower melting temperature is achieved. The process can be carried out in any type of glass furnaces and is particularly suitable for high silica glass compositions.