The present invention relates to a process for producing a boron containing glass, comprising melting raw materials including boron compounds in a submerged combustion melter (11), withdrawing flue gases from said melter and recovering heat from said flue gases in appropriate heat recovery equipment prior to release into the environment.

In a process for manufacturing glass, a mixture of solid glass-forming materials (18) may be melted by application of heat from one or more submerged combustion burners (34) to produce a volume of unrefined molten glass comprising, by volume, 20% to 40% gas bubbles. A refining agent may be introduced into the unrefined molten glass to promote gas bubble removal from the molten glass. The unrefined molten glass including the refining agent may be heated at a temperature in the range of 1200° C. to 1500° C. to produce a volume of refined molten glass. The refined molten glass may comprise, by volume, fewer gas bubbles than the unrefined molten glass. A colorant material may be introduced into the refined molten glass to produce a volume of molten glass having a final desired color.

In a process for manufacturing glass, a mixture of solid glass-forming materials (18) may be melted by application of heat from one or more submerged combustion burners (34) to produce a volume of unrefined molten glass comprising, by volume, 20% to 40% gas bubbles. A refining agent may be introduced into the unrefined molten glass to promote gas bubble removal from the molten glass. The unrefined molten glass including the refining agent may be heated at a temperature in the range of 1200° C. to 1500° C. to produce a volume of refined molten glass. The refined molten glass may comprise, by volume, fewer gas bubbles than the unrefined molten glass. A colorant material may be introduced into the refined molten glass to produce a volume of molten glass having a final desired color.

A method for producing a glass ceramic includes: providing a batch of raw materials; heating the batch of raw materials until a melt is obtained, the batch of raw materials being heated at least in a plurality of sections to a temperature above T3 which corresponds to a viscosity of a molten glass of 10.sup.3 dPa*s; refining the melt, the melt being heated at least in a plurality of sections to a temperature above T2.5 which corresponds to a viscosity of the molten glass of 10.sup.2.5 dPa*s; obtaining a refined glass which is configured for being ceramized to form a glass ceramic material; and ceramizing a glass which is configured for being ceramized to form the glass ceramic material, at least one of the step of heating until the melt is obtained and the step of refining being performed with heating by way of H.sub.2 and O.sub.2 combustion.

A method for producing a glass ceramic includes: providing a batch of raw materials; heating the batch of raw materials until a melt is obtained, the batch of raw materials being heated at least in a plurality of sections to a temperature above T3 which corresponds to a viscosity of a molten glass of 10.sup.3 dPa*s; refining the melt, the melt being heated at least in a plurality of sections to a temperature above T2.5 which corresponds to a viscosity of the molten glass of 10.sup.2.5 dPa*s; obtaining a refined glass which is configured for being ceramized to form a glass ceramic material; and ceramizing a glass which is configured for being ceramized to form the glass ceramic material, at least one of the step of heating until the melt is obtained and the step of refining being performed with heating by way of H.sub.2 and O.sub.2 combustion.

A method for melting and/or refining glass, glass ceramic or glass which can be ceramized to form glass ceramic includes: providing a batch of raw materials; heating the batch until a melt of molten glass is obtained, the batch being heated at least in sections to a temperature above T3 which corresponds to a viscosity of the molten glass of 10.sup.3 dPa*s; refining the melt, the melt being heated at least in sections to a temperature above T2.5 which corresponds to a viscosity of the molten glass of 10.sup.2.5 dPa*s, refining of the melt includes adjusting an oxygen partial pressure p(O.sub.2) which is reduced by at least 60% relative to an O.sub.2 saturation in the melt at temperature T3; and obtaining a re-fined glass, a refined glass ceramic or a refined glass which can be ceramized to form glass ceramic.

A method for melting and/or refining glass, glass ceramic or glass which can be ceramized to form glass ceramic includes: providing a batch of raw materials; heating the batch until a melt of molten glass is obtained, the batch being heated at least in sections to a temperature above T3 which corresponds to a viscosity of the molten glass of 10.sup.3 dPa*s; refining the melt, the melt being heated at least in sections to a temperature above T2.5 which corresponds to a viscosity of the molten glass of 10.sup.2.5 dPa*s, refining of the melt includes adjusting an oxygen partial pressure p(O.sub.2) which is reduced by at least 60% relative to an O.sub.2 saturation in the melt at temperature T3; and obtaining a re-fined glass, a refined glass ceramic or a refined glass which can be ceramized to form glass ceramic.

Provided is an alkali-free glass substrate having a high strain point and excellent bubble count, and a method for manufacturing the alkali-free glass substrate. The method includes: a batch preparing process of preparing a raw material batch so as to obtain alkali-free glass containing, in mass %, 50 to 80% of SiO.sub.2, 15 to 30% of Al.sub.2O.sub.3, 0 to 4.5% of B.sub.2O.sub.3, 0 to 10% of MgO, 0 to 15% of CaO, 0 to 10% of SrO, 0 to 15% of BaO, 0 to 5% of ZnO, 0 to 5% of ZrO.sub.2, 0 to 5% of TiO.sub.2, 0 to 15% of P.sub.2O.sub.5 and 0 to 0.5% of SnO.sub.2 as a glass composition; a melting process of melting the prepared raw material batch; a fining process of fining the molten glass; and a forming process of forming the fined glass into a sheet shape. The raw material batch is melted such that a bubble enlarging temperature of the obtained glass is lower than a maximum temperature of the fining process.

Provided is an alkali-free glass substrate having a high strain point and excellent bubble count, and a method for manufacturing the alkali-free glass substrate. The method includes: a batch preparing process of preparing a raw material batch so as to obtain alkali-free glass containing, in mass %, 50 to 80% of SiO.sub.2, 15 to 30% of Al.sub.2O.sub.3, 0 to 4.5% of B.sub.2O.sub.3, 0 to 10% of MgO, 0 to 15% of CaO, 0 to 10% of SrO, 0 to 15% of BaO, 0 to 5% of ZnO, 0 to 5% of ZrO.sub.2, 0 to 5% of TiO.sub.2, 0 to 15% of P.sub.2O.sub.5 and 0 to 0.5% of SnO.sub.2 as a glass composition; a melting process of melting the prepared raw material batch; a fining process of fining the molten glass; and a forming process of forming the fined glass into a sheet shape. The raw material batch is melted such that a bubble enlarging temperature of the obtained glass is lower than a maximum temperature of the fining process.

A glass comprising at least one oxide of Si and a di- or higher-valent metal element, the glass containing no bubbles with diameters of more than 0.1 mm, wherein an occupied area fraction of bubbles with diameters of 0.1 mm or less is 0.05% or less. A. semiconductor production apparatus and a liquid crystal production apparatus comprising a glass member comprising this glass. A method for producing a glass, comprising the steps of (1) placing raw material powders for at least one oxide of Si and a di- or higher-valent metal element in a container, mixing the raw material powders together and then melting the mixture by heating under reduced pressure to obtain a melt; (2-1) pressurizing the melt in a He gas atmosphere, or (2-2) heating the melt in an inert gas atmosphere other than a He gas atmosphere and then pressurizing the melt in the inert gas atmosphere; and (3) cooling the melt.