Abstract: A process for making soda-lime glass includes forming and refining sodium silicate glass in liquid phase. At least one other material is dissolved in the refined liquid phase sodium silicate glass to produce a liquid phase soda-lime glass melt. Formation of sodium silicate glass as an intermediate product before mixing with at least one other glass-forming material has the advantage of promoting release of gaseous reaction products from the sodium silicate glass during the refining step due at least in part to the relatively low viscosity of the sodium silicate glass. One or more steps in the process can be carried out under reduced pressure to promote release of gases and to reduce bubble formation.

Abstract: A process for making soda-lime glass includes calcining calcium carbonate in solid phase and at elevated temperature to form calcium oxide in solid phase and carbon dioxide gas. Sodium silicate glass is formed and refined separately in liquid phase. The solid phase calcium oxide is dissolved in the refined liquid phase sodium silicate glass to form a soda-lime glass melt. Formation of sodium silicate glass as an intermediate product before mixing with calcium oxide has the advantage of promoting release of gaseous reaction products from the sodium silicate glass during the refining step due at least in part to the relatively low viscosity of the sodium silicate glass. One or more steps in the process can be carried out under reduced pressure to promote release of gases and to reduce bubble formation.

Abstract: A process for making silica-based glass includes: (a) forming a glass precursor melt that includes glass network formers and glass network modifiers, the glass precursor melt being at a temperature in the range of 900 C to 1700 C and having a viscosity of not more than 3 Pa·s, and (b) refining the glass precursor melt. Either or both steps (a) and (b) can include stirring and/or be carried out under reduced pressure to enhance refining. The refined glass precursor melt preferably is mixed with additional materials including silica (SiO2) to form a silica-based glass melt.

Abstract: A process for making silica-based glass includes: (a) forming a glass precursor melt that includes glass network formers and glass network modifiers, the glass precursor melt being at a temperature in the range of 900 C to 1700 C and having a viscosity of not more than 3 Pa·s, and (b) refining the glass precursor melt. Either or both steps (a) and (b) can include stirring and/or be carried out under reduced pressure to enhance refining. The refined glass precursor melt preferably is mixed with additional materials including silica (SiO2) to form a silica-based glass melt.

Abstract: A process for making soda-lime glass includes calcinating calcium carbonate in solid phase and at elevated temperature to form calcium oxide and release gases such as carbon dioxide. Sodium silicate glass is formed separately in liquid phase while releasing gaseous reaction products. The calcium oxide and the sodium silicate glass intermediate products are mixed in liquid phase to form a soda-lime glass melt. Formation of sodium silicate glass as an intermediate product before mixing with the calcium oxide has the advantage of promoting release of gaseous reaction products in the sodium silicate due at least in part to the relatively low viscosity of the sodium silicate glass. The calcination step and/or the sodium silicate-forming step and/or the final mixing step can be carried out under reduced pressure further to promote release of gases and reduce bubble formation.