In a process for manufacturing glass, a mixture of solid glass-forming materials may be melted by application of heat from one or more submerged combustion burners 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 may be melted by application of heat from one or more submerged combustion burners 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 glass refining system, glass refining device, and method are disclosed. The apparatus in accordance with one aspect of the disclosure includes an objective having a laterally outer extremity, where a molten metal stream flows from an opening in the objective and over the objective, and separates from the objective at a molten metal separation location that is inboard of the extremity; and a molten metal receptacle disposed below the objective and configured to receive the molten metal stream, wherein a molten glass stream flows downwardly toward the objective and over the molten metal stream, and wherein the molten glass stream separates from the molten metal stream at a molten glass separation location that is laterally outboard of the molten metal separation location and flows into a molten glass receptacle.

A method of manufacturing a glass article includes flowing molten glass through a first vessel to a downstream second vessel, the molten glass flowing through a conduit connecting the first vessel to the second vessel, the first vessel and the conduit defining a continuous free volume above a free surface of the molten glass extending into at least a portion of the conduit. The method further includes venting a first atmosphere contained in the free volume to a second atmosphere external to the first vessel through a vent tube connected to the conduit proximate a top of the conduit and above the free surface, the vent tube extending downward from the conduit to a distal end of the vent tube along a longitudinal axis at an angle a relative to horizontal and providing fluid communication between the first atmosphere and the second atmosphere.

A method of manufacturing a glass article includes flowing molten glass through a first vessel to a downstream second vessel, the molten glass flowing through a conduit connecting the first vessel to the second vessel, the first vessel and the conduit defining a continuous free volume above a free surface of the molten glass extending into at least a portion of the conduit. The method further includes venting a first atmosphere contained in the free volume to a second atmosphere external to the first vessel through a vent tube connected to the conduit proximate a top of the conduit and above the free surface, the vent tube extending downward from the conduit to a distal end of the vent tube along a longitudinal axis at an angle a relative to horizontal and providing fluid communication between the first atmosphere and the second atmosphere.

An alkali-free glass substrate contains, as represented by mass % based on oxides: 54% to 68% of SiO.sub.2; 10% to 25% of Al.sub.2O.sub.3; 0.1% to 5.5% of B.sub.2O.sub.3; and 8% to 26% of MgO+CaO+SrO+BaO. The alkali-free glass substrate has β-OH of 0.15 mm.sup.−1 to 0.35 mm.sup.−1, and a Cl content of 0.15 to 0.3 mass %. A bubble growth index I of the alkali-free glass substrate given by the following formula is 320 or more: I=590.5×[β-OH]+874.1×[Cl]−5.7×[B.sub.2O.sub.3]−33.3. In the formula, [β-OH] is β-OH of the alkali-free glass substrate in mm.sup.−1, [Cl] is the Cl content of the alkali-free glass substrate in mass %, and [B.sub.2O.sub.3] is a B.sub.2O.sub.3 content of the alkali-free glass substrate in mass %.

The present invention discloses a glass with high refractive index for fiber optic imaging elements with medium-expansion and fabrication method therefor, the glass comprising the following components in percentage by weight: SiO.sub.2 5-9%, Al.sub.2O.sub.3 0-1%, B.sub.2O.sub.3 23-28%, CaO 0-3%, BaO 6-12%, La.sub.2O.sub.3 30-34%, Nb.sub.2O.sub.5 4-8%, Ta.sub.2O.sub.5 0-1%, Y.sub.2O.sub.3 0-1%, ZnO 4-9%, TiO.sub.2 4-8%, ZrO.sub.2 4-6%, SnO.sub.2 0-1%. The present invention further provides a fabrication method for the glass with a high refractive index, comprising: putting raw materials quartz sand, aluminum hydroxide, boric acid or boric anhydride, calcium carbonate, barium carbonate or barium nitrate, lanthanum oxide, niobium oxide, tantalum oxide, yttrium oxide, zinc oxide, titanium dioxide, zirconium oxide and stannic oxide, etc. into a platinum crucible according to the requirement of dosing, melting at a high temperature, cooling and fining, leaking and casting to form a glass rod, and then annealing, cooling and chilling the molded glass rod.

The present invention discloses a glass with high refractive index for fiber optic imaging elements with medium-expansion and fabrication method therefor, the glass comprising the following components in percentage by weight: SiO.sub.2 5-9%, Al.sub.2O.sub.3 0-1%, B.sub.2O.sub.3 23-28%, CaO 0-3%, BaO 6-12%, La.sub.2O.sub.3 30-34%, Nb.sub.2O.sub.5 4-8%, Ta.sub.2O.sub.5 0-1%, Y.sub.2O.sub.3 0-1%, ZnO 4-9%, TiO.sub.2 4-8%, ZrO.sub.2 4-6%, SnO.sub.2 0-1%. The present invention further provides a fabrication method for the glass with a high refractive index, comprising: putting raw materials quartz sand, aluminum hydroxide, boric acid or boric anhydride, calcium carbonate, barium carbonate or barium nitrate, lanthanum oxide, niobium oxide, tantalum oxide, yttrium oxide, zinc oxide, titanium dioxide, zirconium oxide and stannic oxide, etc. into a platinum crucible according to the requirement of dosing, melting at a high temperature, cooling and fining, leaking and casting to form a glass rod, and then annealing, cooling and chilling the molded glass rod.

A vitrifiable feed material for producing flint glass by way of a process that uses submerged combustion melting includes a base glass portion, an oxidizing agent, and a decolorant. The base glass portion includes an SiO.sub.2 contributor, an Na.sub.2O contributor, and a CaO contributor to provide SiO.sub.2, Na.sub.2O, and CaO, respectively, to a glass melt when melted therein. The oxidizing agent may be a sulfate compound in an amount ranging from 0.20 wt % to 0.50 wt % as expressed as SO.sub.3 based on the total weight of the vitrifiable feed material, and the decolorant may be selenium in an amount ranging from 0.008 wt % to 0.016 wt % or manganese oxide in an amount ranging from 0.1 wt % to 0.2 wt % based on the total weight of the vitrifiable feed material.

A vitrifiable feed material for producing flint glass by way of a process that uses submerged combustion melting includes a base glass portion, an oxidizing agent, and a decolorant. The base glass portion includes an SiO.sub.2 contributor, an Na.sub.2O contributor, and a CaO contributor to provide SiO.sub.2, Na.sub.2O, and CaO, respectively, to a glass melt when melted therein. The oxidizing agent may be a sulfate compound in an amount ranging from 0.20 wt % to 0.50 wt % as expressed as SO.sub.3 based on the total weight of the vitrifiable feed material, and the decolorant may be selenium in an amount ranging from 0.008 wt % to 0.016 wt % or manganese oxide in an amount ranging from 0.1 wt % to 0.2 wt % based on the total weight of the vitrifiable feed material.