Method for manufacturing glass product, and glass product

Abstract

To provide a method for manufacturing a glass product, capable of avoiding and / or minimizing the problem of forming bubbles.SOLUTION: The problem is solved by a method of manufacturing a glass product having less than 0.2 of a molar ratio of Fe2+ to Fe3+ and a glass product having a low CO2 solubility and / or a reduced total carbon content. The CO2 solubility is a CO2 bar-1 having molecules of less than 5×1019 per 1 cm3 at 1100°C; and the glass product has less than 0.2 of a ratio of Fe2+ to Fe3+; and further the glass product is excellent in bubbles having a number and / or size reduced in the glass product.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention, Fe 2+ Fe 3+ A method for manufacturing a glass product having a molar ratio value of less than 0.2, and a glass product having low CO2 solubility and / or reduced total carbon content, wherein the CO2 solubility is 1 cm³ at 1100°C. 3 5 x 10 19 CO2 bar of molecules less than -1 Furthermore, the glass product is Fe 2+ Fe 3+ The present invention relates to a glass product having a ratio value of less than 0.2. The glass product is further superior in that it has a reduced number of bubbles and / or reduced size of bubbles within it. [Background technology]

[0002] Glass compositions with a wide range of desired properties for numerous applications in industry and household are widely known and available. Some glass compositions are relatively easy to manufacture to a satisfactory quality depending on the desired use and application, while others require sophisticated equipment and / or extremely well-balanced manufacturing methods.

[0003] For example, glass compositions used to manufacture drinking glass and ordinary window glass belong to the first type because the glass used in these products has a very low melting temperature and is characterized by a steep viscosity-temperature curve. The quality standards for these products are also not very strict; for example, ordinary window glass and drinking glass may contain accidental air bubbles, and slight variations in shape and dimensions are acceptable.

[0004] The quality required for a given product depends on its intended use. For specific applications, high-quality glass must be free of accidental bubbles and meet even stricter standards, for example, with respect to variations in their shape and / or dimensions. High-quality glass is often difficult to manufacture, not only because of the standards mentioned, but also because of the high melting temperatures required to achieve sufficient melt viscosity for homogenization and bubble removal from the molten material during production.

[0005] Therefore, there is still a need to overcome the shortcomings of conventional technologies. [Overview of the project] [Problems that the invention aims to solve]

[0006] Therefore, an object of the present invention is to provide a method for manufacturing glass products that avoids and / or minimizes the problem of bubble formation. A further object of the present invention is to provide a method for manufacturing glass products in which both the number and size of bubbles in the glass product are simultaneously reduced. [Means for solving the problem]

[0007] These issues are resolved by the scope of the claims and by the scope described below.

[0008] Summary of the Invention In a first embodiment, the present invention relates to a method for manufacturing glass products, • The step of melting a batch of glass raw materials in a melting tank to form a molten glass product. • A step of heating the glass raw material and / or the glass molten material using at least one fuel burner. • Steps to remove the molten glass from the melting tank, • The stage of obtaining glass products The fuel burner heats the glass raw material and / or the glass molten material by reacting hydrogen and oxygen, and the glass product is Fe2+ Fe of 3+ The method relates to having a ratio value less than 0.2 or less than 0.05 with respect to

[0009] The inventors have demonstrated that the provided method reduces the number and size of bubbles in glass products. The inventors have also demonstrated that the provided method for manufacturing glass products is technically feasible.

[0010] In a second aspect, the present invention is a glass product comprising a composition, wherein the glass product has a ratio value less than 0.2 or less than 0.05 with respect to Fe 2+ Fe of 3+ and the glass product has less than 80 bubbles in the size range of 0.1 mm to 0.2 mm per 10 kg of glass and / or less than 2 bubbles with a size greater than 0.2 mm per 10 kg of glass. The present invention relates to the glass product.

[0011] In a third aspect, the present invention is a method for manufacturing a glass product, comprising: · Melting a batch of glass raw materials in a melting tank to form a glass melt; · Heating the glass raw materials and / or the glass melt using at least one fuel burner; · Drawing the glass melt out of the melting tank; · Obtaining a glass product wherein the fuel burner heats the glass raw materials and / or the glass melt by reacting hydrogen and oxygen, and the glass product has a CO2 solubility of less than 5×10 3 per 1 cm of glass melt at 1100 °C and / or a total carbon content of less than 310 ppm based on the mass of carbon atoms with respect to the mass of the glass product. The present invention relates to the method. 19 less than molecules of CO2bar -1

[0012] In a fourth aspect, the present invention is a method for manufacturing a glass product, comprising: • The step of melting a batch of glass raw materials in a melting tank to form a molten glass product. • A step of heating the glass raw material and / or the glass molten material using at least one fuel burner. • Steps to remove the molten glass from the melting tank, • The stage of obtaining glass products The method comprises a fuel burner that heats the glass raw material and / or the glass molten material by reacting hydrogen and oxygen at an oxygen-to-fuel equivalent ratio λ > 1.00.

[0013] In a fifth embodiment, the present invention relates to a glass product comprising a composition, wherein the glass product is molten glass at 1100°C and 1 cm³ 3 5 x 10 19 CO2 bar of molecules less than -1 The present invention relates to a glass product having a CO2 solubility and / or a composition exhibiting a total carbon content of less than 310 ppm based on the mass of carbon atoms relative to the mass of the glass product.

[0014] The glass product may also have low CO2 solubility and a reduced total carbon content. The glass product is further superior in that it has a reduced number of bubbles and the size of those bubbles.

[0015] Definitions and Methods "Molten glass" is 10 7.6 This is a batch of glass raw materials with a viscosity of less than dPas.

[0016] A “melting tank” is a container used to melt glass. The container defines a volume that can contain the molten glass. The melting tank may have a substantially rectangular bottom or bottom plate, particularly for continuous melting processes. Alternatively, the melting tank may have a substantially rounded bottom or a substantially polygonal bottom, particularly for discontinuous melting processes. It may have walls for holding the molten material within the tank. Typically, the melting tank is not filled to the rim. The melting tank may have a cover over the surface of the molten glass (“covered melting tank”). The cover may be domed. The “melting tank” may be part of a larger melting facility that may include further parts, such as a clarification tank or clarification area. Some melting facilities have combined tanks having different areas, one for melting and one for clarification, in which case “melting tank” as used in this disclosure refers to the entire combined tank including the clarification area.

[0017] The aforementioned “bottom plate” is a part of the melting tank that forms the bottom of the tank. The bottom plate may be a single piece of material. Alternatively, the bottom plate may consist of multiple parts or sections. The bottom plate may be closed, that is, essentially impermeable to the molten glass. Alternatively, the bottom plate may have an opening that can be opened and closed, through which the molten glass can be drawn out of the melting tank.

[0018] A "bubble" is a gas inclusion in glass or glass molten material having a diameter of at least 10 μm. The "diameter" refers to the maximum diameter of the gas inclusion. Whenever "bubble" is referred to in this description, it may be understood as a bubble in its broadest sense, but it may also be understood as a "CO2 bubble" in a more specific sense.

[0019] The aforementioned "oxygen-fuel equivalent ratio λ" defines the amount of oxygen present to react with the combustible compound ("fuel") and thereby convert the fuel into combustion products. Therefore, while λ = 1.00 in stoichiometric composition, concentrated mixtures have λ < 1.00 with respect to the amount of fuel, and dilute mixtures have λ > 1.00. Thus, dilute mixtures with λ > 1.00 allow for the complete or total conversion of the fuel into combustion products, such as CO2 or H2O, while retaining some excess oxygen.

[0020] The viscosity can be measured, for example, using a rotational viscometer, as described in DIN ISO 7884-2:1998-2. The temperature dependence of the viscosity is described by the VFT equation (Vogel-Fulcher-Tammann).

[0021] When referring to "oxygen," "hydrogen," "CO2," and other gases, this should be understood to include gas mixtures containing that particular gas in a dominant proportion, especially exceeding 50 vol%, 60 vol%, 70 vol%, 80 vol%, 90 vol%, 95 vol%, 99 vol%, 99.5 vol%, or essentially 100.0 vol%. In particular, the aforementioned terms also refer to so-called "industrial" gases with corresponding specifications.

[0022] When "ppm" is mentioned in relation to solids or liquids, it should be understood as "mass / mass" (w / w). When "ppm" is mentioned in relation to gases, it should be understood as "volume / volume" (vol / vol).

[0023] When referring to individual chemical species, for example, the amount of carbonate less than 15% by mass in a batch of glass raw materials, this can be calculated by multiplying the number of moles of that chemical species by its molar mass and dividing by the total mass of the batch of glass raw materials, e.g., CO3 2- It should be understood that its mass is less than 15% by mass.

[0024] Glass raw materials should be understood as any glass component suitable for forming a glass molten material in combination with other similar components, and optionally for forming a glass product after a reaction occurs in the glass molten material. Examples of glass raw materials used in relation to the present invention include, but are not limited to, oxides of metals and metalloids, nitrates of metals and metalloids, and carbonates of metals and metalloids.

[0025] Where this description relates to a glass composition that is essentially free of a certain component, does not contain a particular component, or includes a hypothetical case where that component is present at 0% by mass, it should be understood that the component may be present at most as an impurity. This means that it is not added in significant amounts and is not added intentionally. The term “component” refers to the elemental species itself, as well as any molecule containing that element. An essential amount should be understood as less than 100 ppm, preferably less than 50 ppm, and most preferably less than 10 ppm, based on the mass percent of all intentionally added components.

[0026] "Residence time" is the time a given portion of molten glass spends in a molten tank before being withdrawn from it. Residence time can be measured using so-called tracers, which are components that can be added to the molten glass and detected in the product, allowing conclusions to be drawn about the time spent in the molten tank. Examples of tracer compounds are Ca, Sr, and Y. "Minimum residence time" is the time required for a portion of the molten glass to pass through the molten tank via the fastest path, i.e., the time from when a certain amount of tracer compound is added to the molten tank until the tracer first appears in the product. "Hydrodynamic residence time" is calculated as "volume of the molten tank [m³] 3 ] and "Throughput of the melting tank [m 3 h -1"Mean residence time" is defined as the ratio between "term" and "term". "Mean residence time" is defined as the expected value of the residence time distribution obtained and identified in the tracer experiment. If the "throughput of the melting tank" is constant throughout the melting tank, then "hydrodynamic residence time" and "mean residence time" are the same. Where in doubt, references to "residence time" in this disclosure refer to hydrodynamic residence time. [Brief explanation of the drawing]

[0027] [Figure 1] Figure 1 shows dry measurements of flue gas compositions derived from domestic gas combustion and hydrogen combustion using oxygen from air fractionation (e.g., 95.5 vol% O2, 2 vol% N2, 2.5 vol% Ar). [Modes for carrying out the invention]

[0028] Detailed explanation In one embodiment, the present invention relates to a method for manufacturing glass products, • The step of melting a batch of glass raw materials in a melting tank to form a molten glass product. • A step of heating the glass raw material and / or the glass molten material using at least one fuel burner. • Steps to remove the molten glass from the melting tank, • The stage of obtaining glass products The fuel burner heats the glass raw material and / or glass molten material by reacting hydrogen and oxygen, and the glass product is Fe 2+ Fe 3+ The method relates to having a ratio value of less than 0.2 or less than 0.05.

[0029] The method of this invention makes it possible to establish and / or adjust the partial pressure of oxygen in a molten glass, and provides suitable clarification conditions in the molten glass and a low number of bubbles in the resulting glass product. The method allows for a very wide range of oxygen-to-fuel equivalent ratios λ because it uses hydrogen and oxygen for heating. In contrast, conventional methods that rely on heating with fuels such as natural gas cannot be applied at high oxygen-to-fuel equivalent ratios λ because of the excessive concentration of nitrous oxide (NOx). x This is because NO forms in the flue gas. x It is toxic, and its emissions are restricted by law in many jurisdictions. The method of this disclosure uses hydrogen and oxygen for heating, resulting in the formation of water as the combustion product. Furthermore, the method allows for oxygen partial pressures that avoid the formation of CO and C. CO and C degrade platinum components by forming alloys. The method of this disclosure avoids the need for the significantly excess oxygen required to avoid the undesirable formation of CO and carbon between methods known in the art.

[0030] In one embodiment of this disclosure, the glass molten material and / or the glass product is Fe 2+ Fe 3+ Ratio values ​​less than 0.2, less than 0.15, less than 0.10, less than 0.05, and / or Fe 2+ Fe 3+ The ratio to has a value of at least 0.005, or at least 0.01. In a related embodiment, the glass molten material and / or the glass product is Fe 2+ Fe 3+ Fe has a ratio value of 0.005 to 0.2, or 0.01 to 0.05. 2+ Fe 3+ The ratio value for Fe in the molten and / or product is 2+ and Fe 3+ This is the ratio of the molar amounts of Fe. 2+ Fe 3+ The ratio value can serve as a fingerprint of the partial oxygen concentration during manufacturing.

[0031] The method of this invention is suitable for producing glass products having a very small number of bubbles. Optionally, the glass composition contains only a limited amount of carbonate in the batch of glass raw materials. The glass composition is such that the glass molten material and / or the glass product are formed at 1100°C. 3 5 x 10 19 CO2 bar of molecules less than -1 , 1 cm of molten glass at 1100℃ 3 4 x 10 19 CO2 bar of molecules less than -1 , 1 cm of molten glass at 1100℃ 3 3 x 10 19 CO2 bar of molecules less than -1 , or 1 cm of molten glass at 1100°C 3 2 x 10 19 CO2 bar of molecules less than -1 The composition of the glass product may have a CO2 solubility of 1 cm³. 3 At least 1 × 10 15 CO2 bar of molecules -1 , 1 cm of molten glass at 1100℃ 3 At least 1 × 10 16 CO2 bar of molecules -1 , or 1 cm of molten glass at 1100°C 3 At least 1 × 10 17 CO2 bar of molecules -1 The composition of the glass product may have a CO2 solubility of 1 cm³. 3 1 x 10 15 ~5×10 19 CO2 bar of molecules -1 , 1 cm of molten glass at 1100℃ 3 1 x 10 16 ~4×10 19 CO2 bar of molecules -1 , or 1 cm of molten glass at 1100°C 3 1 x 10 17~3×10 19 CO2 bar of molecules -1 It can have a CO2 solubility of such a degree.

[0032] When "glass composition" is referred to, it should be understood as the composition of glass oxides after a batch of glass raw materials has been melted and the molten material has been solidified to obtain glass products. This means that any volatile components are in a gaseous state, and that metals and metalloids exist in the glass composition as oxides and / or fluorides. In other words, "glass composition" is the combination of oxides and / or fluorides that can be obtained by melting glass products and / or glass articles.

[0033] The glass composition according to the present invention may contain large amounts of SiO2 and B2O3. This makes it possible to obtain glass products of very high quality. In particular, glass products manufactured by the above method and / or glass products described herein may have a particularly small number of bubbles, specifically a particularly small number of CO2 bubbles.

[0034] The glass composition may be borosilicate glass, aluminoborosilicate glass, aluminosilicate glass, or lithium aluminosilicate (LAS) glass. The glass composition may contain alkali metal oxides, such as Li2O, Na2O, and K2O, in amounts of less than 20% by mass, less than 15% by mass, less than 12% by mass, less than 10% by mass, or less than 5% by mass. Optionally, the glass composition may be alkali metal oxide-free. In an alternative embodiment, the amount of alkali metal oxide in the glass composition may be at least 1% by mass. Advantageously, a small amount of alkali metal oxide contributes to the low CO2 solubility in the glass molten material.

[0035] The glass composition may contain alkaline earth metal oxides, such as MgO, CaO, SrO, or BaO, in amounts of less than 20% by mass, less than 15% by mass, less than 12% by mass, less than 10% by mass, or less than 5% by mass. Optionally, the glass composition may not contain alkaline earth metal oxides. In an alternative embodiment, the amount of alkaline earth metal oxide in the glass composition may be at least 1% by mass.

[0036] The glass composition may contain iron, calculated as Fe2O3, in amounts less than 0.05% by mass, less than 0.01% by mass, or less than 0.005% by mass. In one embodiment, the glass composition may contain Fe2O3 in amounts of at least 0.0005% by mass, at least 0.001% by mass, or at least 0.002% by mass. In related embodiments, the glass composition may contain Fe2O3 in amounts of 0.0005% to 0.05% by mass, 0.001% to 0.01% by mass, or 0.002% to 0.005% by mass. The amounts of Fe2O3 shown above relate to the total mass of iron in the glass composition, assuming it exists in the form of Fe2O3 oxide. This does not mean that all iron exists in this form. For example, any iron in the form of FeO may be included.

[0037] In further embodiments, the glass composition may contain Fe2O3 in amounts of less than 1000 ppm by mass, less than 500 ppm by mass, or less than 200 ppm by mass. Optionally, the glass composition may contain Fe2O3 in amounts of at least 1 ppm by mass, at least 10 ppm by mass, or at least 50 ppm by mass. In related embodiments, the glass composition may contain Fe2O3 in amounts of 1 to 1000 ppm, 10 to 500 ppm, or 50 to 200 ppm.

[0038] The glass composition may contain SiO2 in an amount of at least 48% by mass, at least 55% by mass, at least 65% by mass, at least 70% by mass, or at least 75% by mass. Optionally, the amount of SiO2 may be in the range of up to 90% by mass, up to 87.5% by mass, up to 85% by mass, up to 82.5% by mass, or up to 80% by mass.

[0039] Optionally, the glass composition may be a glass ceramic glass composition, that is, a glass composition that can be further processed into a glass ceramic by appropriate heat treatment. If the glass composition is a glass ceramic glass composition, it may contain a nucleating agent, such as TiO2 and / or ZrO2. Optionally, the total amount of TiO2 and / or ZrO2 may be at least 2.0% by mass, for example, at least 2.5% by mass. Optionally, the total amount of TiO2 and / or ZrO2 may be less than 7.0% by mass, or less than 5.0% by mass. For example, the glass composition may be a lithium aluminosilicate glass composition containing, for example, at least 2.0% by mass of Li2O.

[0040] Optionally, the glass composition contains Al2O3 in an amount of at least 1.5 ppm by mass, or at least 5.0 ppm by mass, or even at least 10.0 ppm by mass. The amount of Al2O3 may be in the range of up to 25.0% by mass, up to 23.0% by mass, up to 20.0% by mass, or up to 18.0% by mass. In a particular embodiment, the amount of Al2O3 may be in the range of 1.5% to 23.0% by mass, 5.0% to 20.0% by mass, or 10.0% to 18.0% by mass.

[0041] Additionally or alternatively, the glass composition may contain B2O3 in an amount of at least 0.5% by mass, at least 8.0% by mass, or at least 10.0% by mass. The amount of B2O3 may be up to 25.0% by mass, up to 23.0% by mass, up to 20.0% by mass, up to 18.0% by mass, up to 16.0% by mass, or up to 14.0% by mass. In certain embodiments, the amount of B2O3 may be in the range of 0.5% to 20.0% by mass, 8.0% to 16.0% by mass, or 10.0% to 14.0% by mass.

[0042] Many highly viscous glass compositions contain significant amounts of SiO2, Al2O3, and B2O3. Optionally, the glass compositions used in this invention have a total content of at least 75.0% by mass, at least 78.0% by mass, at least 80.0% by mass, at least 82.0% by mass, or at least 85.0% by mass of SiO2, Al2O3, and B2O3. The total amount of SiO2, Al2O3, and B2O3 may be limited to 97.0% by mass or less, up to 93.5% by mass, or up to 90.0% by mass. Optionally, the amounts of SiO2, Al2O3, and B2O3 may be in the range of 75.0% by mass to 95.0% by mass, 78.0% by mass to 92.5% by mass, or 85.0% by mass to 90.0% by mass.

[0043] In one embodiment, the glass composition may be a lithium aluminosilicate glass comprising 3.0 to 4.2 mass% Li2O, 19 to 23 mass% Al2O3, 60 to 69 mass% SiO2, and optionally TiO2 and / or ZrO2, preferably 2.0 to 4.0 mass% TiO2 and / or ZrO2.

[0044] In certain embodiments, the glass composition may be characterized by the compositional range shown in the following table, either alternatively or additionally to the characteristics of the compositions described above.

[0045] In one embodiment, the glass composition may be a borosilicate glass containing the following components in mass%: [Table 1]

[0046] In one embodiment, the glass composition may be a borosilicate glass containing the following components in mass%: [Table 2]

[0047] In a particular embodiment, the glass composition may be a borosilicate glass containing the following components in mass%: [Table 3]

[0048] In other embodiments, the glass composition may be an alkali borosilicate glass containing the following components in mass%: [Table 4]

[0049] In an alternative embodiment, the glass composition may be an alkali borosilicate glass containing the following components in mass%: [Table 5]

[0050] In further embodiments, the glass composition may contain the following components in mass%: [Table 6]

[0051] and optionally colorants, such as oxides of Co, Ni, Fe, Nd, Mo, and other suitable colorants. Optionally, the glass may contain clarifying agents, such as SnO2, Cl, As2O5, and / or Sb2O5. The total amount of clarifying agents may be 0.1 to 1.5% by mass. The amount of SnO2 may be 0.1 to 1.5% by mass, and / or the amount of As2O5 may be 0.1 to 1.5% by mass, and / or the amount of Sb2O5 may be 0.1 to 1.5% by mass.

[0052] In one embodiment, the glass composition may contain the following components in mass%: [Table 7]

[0053] Here, the total amount of MgO, CaO, and BaO is between 8.0 and 18.0 mass%.

[0054] In further embodiments, the glass composition may contain the following components in mass%: [Table 8]

[0055] The present invention includes melting a batch of glass raw materials in a melting tank to form a glass molten material, and heating the glass raw materials and / or the glass molten material using at least one fuel burner. These two process steps require a significant amount of energy. A sufficiently high temperature is required for bubbles, such as CO2 bubbles, to escape from the molten material.

[0056] The method further includes a step in which a fuel burner heats the glass raw material and / or glass molten material by reacting hydrogen and oxygen. Both hydrogen and oxygen can be obtained from renewable resources. In one embodiment, the hydrogen and oxygen are obtained at least partially from electrolysis, i.e., from the electrochemical conversion of water into hydrogen and oxygen, and in a further embodiment, the hydrogen and oxygen are obtained essentially entirely from electrolysis. When the electrolysis of water is carried out using renewable resources, the production of hydrogen and oxygen is essentially emission-free.

[0057] It is advantageous for a fuel burner to heat the glass raw materials and / or glass molten material by reacting hydrogen and oxygen, because it reduces and / or minimizes CO2 generation in the manufacturing of glass products. This is particularly advantageous if gas exchange is possible between the glass molten material and the flue gas originating from the heating and melting stages.

[0058] In one embodiment of this disclosure, a glass molten and / or glass product is characterized by the temperature dependence of the CO2 solubility of the composition within a certain temperature range. The temperature range includes the temperature at which the composition is in the form of a glass molten. This does not necessarily mean that the method involves heating the molten material to each and all temperatures within that range; rather, it describes the properties of the composition within that range. The temperature dependence of CO2 solubility is measured within a temperature range of 1000–1600°C at 1 cm³. 3 2 x 10 14 Molecular CO2 bar -1 K -1 This can be exceeded. In a further embodiment, the temperature dependence of CO2 solubility is 1 cm within the temperature range of 1000 to 1600°C. 3 5 x 10 14 Molecular CO2 bar -1 K -1 It can exceed that, or 1 cm within the temperature range of 1000-1600°C. 3 1 x 10 15 Molecular CO2 bar -1 K -1can be exceeded. In related embodiments, the temperature dependence of CO2 solubility is 1 cm per cm within the temperature range of 1000 to 1600 °C 3 per 1×10 18 less than molecules of CO2 bar -1 K -1 per 1 cm within the temperature range of 1000 to 1600 °C 3 per 1×10 17 less than molecules of CO2 bar -1 K -1 or per 1 cm within the temperature range of 1000 to 1600 °C 3 per 5×10 16 less than molecules of CO2 bar -1 K -1 in the related embodiments of the method, the temperature dependence of CO2 solubility is 2×10 per 1 cm within the temperature range of 1000 to 1600 °C 3 of molecules of CO2 bar 14 K -1 K -1 ~1 cm per 1 cm 3 per 1×10 18 of molecules of CO2 bar -1 K -1 per 1 cm within the temperature range of 1000 to 1600 °C 3 per 5×10 14 of molecules of CO2 bar -1 K -1 ~1 cm per 1 cm 3 per 1×10 17 of molecules of CO2 bar -1 K -1 or per 1 cm within the temperature range of 1000 to 1600 °C 3 per 1×10 15 of molecules of CO2 bar -1 K -1 ~1 cm per 1 cm 3 per 5×10 16 of molecules of CO2 bar -1 K -1This may be the case. This temperature dependence of CO2 solubility is advantageous because it provides optimal degassing of the glass molten material within the temperature range of 1300 to 1650°C. In this regard, those skilled in the art know and acknowledge that CO2 solubility decreases with increasing temperature. Depending on the viscosity and temperature behavior of the glass molten material, the temperature dependence of CO2 solubility is such that within the temperature range of 1000 to 1600°C, it decreases by 1 cm. 3 2 x 10 14 CO2 bar of molecules -1 K -1 It is also advantageous to exceed this. The composition of the glass molten material can be designed to produce a reduced viscosity within the temperature range of 1300-1650°C, which in turn leads to more efficient and faster degassing of the glass molten material within this temperature range.

[0059] In one embodiment of the above method, the carbonate in the batch of glass raw materials, i.e., CO3 2- The amounts are less than 8% by mass, less than 5% by mass, less than 3% by mass, less than 1.0% by mass, less than 0.3% by mass, and less than 0.1% by mass. In a further embodiment of the method, the amount of carbonate in the batch of glass raw materials is at least 0.001% by mass, at least 0.003% by mass, at least 0.01% by mass, at least 0.03% by mass, or at least 0.05% by mass. In a related embodiment of the method, the amount of carbonate in the batch of glass raw materials is 0.001 to 8% by mass, 0.001 to 5% by mass, 0.003 to 3% by mass, 0.01 to 1.0% by mass, 0.03 to 0.3% by mass, or 0.05 to 0.1% by mass. Carbonates may be present in the batch of glass raw materials intentionally or as impurities. Due to the high temperature in the glass molten material, carbonates tend to decompose, generating CO2 (bubbles) in the glass molten material. Reducing the amount of carbonate in a batch of glass raw materials is advantageous because it generates and releases less CO2 (bubbles) into the glass molten material. A larger amount of CO2 (bubbles) generated and released into the glass molten material results in a longer residence time for the glass molten material in the molten tank between the heating and / or melting stage using at least one fuel burner and the stage of withdrawing the glass molten material from the molten tank.

[0060] To produce crystallizable LAS glass and substrates for further crystallization, it is common to use compounds such as carbonates and nitrates on the one hand, and aluminosilicate minerals, such as spodumene, feldspar, or feldspar, on the other hand, as raw materials. Strictly monitored raw material selection offers room / possibility for reducing gas emissions, such as CO2. The proportion and type of raw materials in the raw material mixture are the criteria for this CO2 emission. Analysis and calculations clearly show that, with the correct selection and control of raw materials, CO2 emissions in, for example, the raw material mixture of colored glass ceramics can be reduced to 20% of the original CO2 emissions, or even to <5%. For LAS glass ceramics, CO2 emission reduction can be achieved by replacing, for example, barium carbonate, sodium carbonate, strontium carbonate, potassium carbonate, and lithium carbonate with suitable nitrates or aluminosilicates.

[0061] In particular, it is advantageous to include a further step that allows for a certain residence time of the molten glass in the molten tank before withdrawing the molten glass from the molten tank. The residence time is 1 × 10⁻¹⁶ per liter of molten glass. -13 CO2 exceeding mg, 5 x 10 per liter of molten glass -13 CO2 exceeding mg, or 1 × 10⁶ per liter of molten glass. -12 The duration may be long enough so that more than mg of CO2 leaves the molten material. Optionally, 2 × 10 per liter of molten glass. -7 Less than mg of CO2, 2 x 10⁻¹⁶ per liter of molten glass -8 Less than mg of CO2, or 2 × 10⁻¹⁶ per liter of molten glass. -9 Less than mg of CO2 leaves the molten material.

[0062] In one embodiment of the method described above, the minimum residence time in the molten tank can be set to at least 10 hours, at least 12 hours, or at least 14 hours. Sufficient residence time is useful for producing high-quality glass products. Optionally, the minimum residence time may be up to 70 hours, up to 65 hours, or up to 60 hours. Additionally or alternatively, the hydrodynamic residence time may be 48 hours ± 12 hours. Considering that long residence times increase the carbon dioxide footprint of glass products, excessively long residence times are undesirable.

[0063] In one embodiment of the above method, the fuel burner operates at least temporarily with an oxygen-to-fuel equivalent ratio λ > 1.00, for example, above 1.01, and optionally below 1.35. In a further embodiment of the above method, the fuel burner operates at least temporarily with an oxygen-to-fuel equivalent ratio λ above 1.03, above 1.05, or above 1.1. In a further embodiment of the above method, the fuel burner operates at least temporarily with an oxygen-to-fuel equivalent ratio λ below 1.35, below 1.30, below 1.25, or below 1.20. It is advantageous to adjust the oxygen-to-fuel equivalent ratio λ to allow for an oxidizing state of the molten material. Depending on the type of fuel or fuel mixture used, it is further possible and advantageous, at least temporarily, for the fuel burner to operate at an oxygen-to-fuel equivalent ratio λ between 1.01 and 1.35, 1.03 and 1.30, 1.05 and 1.25, or 1.05 and 1.20. Those skilled in the art know and acknowledge that the partial or exclusive use of hydrogen as a fuel does not require a significantly excess of oxygen, as opposed to the sole use of fossil fuels, for example, and this is reflected in a suitable oxygen-fuel equivalent ratio λ.

[0064] The steps of melting a batch of glass raw materials in a melting tank to form a glass melt, and / or heating the glass raw materials and / or glass melt using at least one fuel burner, are optionally carried out by direct heating without contact with the flame, or alternatively by direct heating with the flame near the glass raw materials or glass melt. It may be advantageous to provide stoichiometric excess combustion, i.e., an oxygen-to-fuel equivalent ratio λ > 1.00, e.g., greater than 1.01, or to introduce an excess amount of oxygen into the flue gas.

[0065] In one embodiment, the method includes the step of electrolyzing H2O to obtain hydrogen and oxygen, where at least some of the hydrogen and some of the oxygen are sent to a fuel burner. In this case, it may be necessary or desirable to supply additional oxygen from another source to ensure an oxygen-to-fuel equivalent ratio λ > 1.00, for example, greater than 1.01. The additional oxygen may come from, for example, an on-site air decomposer, a separate electrolysis, or an external (e.g., cryogenic) source.

[0066] It is even more advantageous, at least temporarily, for the fuel burner to operate at an oxygen-to-fuel equivalent ratio λ > 1.00, for example, greater than 1.01, because this avoids and / or eliminates the need for (additional) oxidizers, i.e., nitrates, in the glass molten material. Less nitrates or complete removal of nitrates results in less NO during the process. x It brings about generation.

[0067] In one embodiment of the method, the total amount of nitrous oxide in the flue gas generated from the melting and heating stages is less than 500 ppm(v / v), less than 300 ppm(v / v), less than 100 ppm(v / v), or less than 50 ppm(v / v) relative to the total volume of flue gas. In one embodiment of the method, the total amount of nitrous oxide in the flue gas generated from the melting and heating stages is at least 1 ppm(v / v), at least 10 ppm(v / v), at least 20 ppm(v / v), or at least 30 ppm(v / v). In related embodiments of the method, the total amount of nitrous oxide in the flue gas generated from the melting and heating stages is 1 to 500 ppm(v / v), 10 to 300 ppm(v / v), 20 to 100 ppm(v / v), or 30 to 50 ppm(v / v). The nitrous oxide produced during the process is due to the (thermal) combustion of N2 and NO, which originate from any nitrates used that are present in the glass raw materials. x This is a result of both the release of and the release of .

[0068] Nevertheless, nitrates present in the glass raw materials also cause at least partial oxygen release in the molten glass due to the following relationship (M = metal): M x (NO3) y →M x O+yNO+0.5yO2

[0069] The release of oxygen via nitrates during the melting stage can be advantageous, as the batch of glass raw materials in the melting tank melts to form a glass molten product, which facilitates the conversion of any fining agent (FA) used from their lower valence forms to higher valence forms (i.e., oxidation). In subsequent stages, with sufficient temperature increases, the resulting higher valence forms can be converted back to their lower valence forms by releasing oxygen.

[0070] During the melting stage, the following reactions occur or can occur: FA x O y +zO2→FA x Oy+2z

[0071] During subsequent steps, such as the clarification step, with sufficient temperature rise, the following reactions may occur or may occur: FA x O y+2z →FA x O y +zO2

[0072] In one embodiment of the method described above, the total amount of nitrous oxide in the flue gas is comprised of the proportion produced from the oxidation of nitrogen by the fuel burner and the proportion released from nitrogen species contained in the glass raw materials. Those skilled in the art will recognize that both processes may occur in the method, and that both processes may simultaneously contribute to the production of the total amount of nitrous oxide. The degree of nitrous oxide production from the oxidation of nitrogen by the fuel burner depends on the purity and / or origin of the oxygen source used. For example, oxygen obtained from electrolysis generally contains less nitrogen than oxygen obtained from an air separation process, but this also depends on the exact process and cycle conditions of the electrolysis and air separation processes. Similarly, the degree of nitrous oxide production from nitrogen species contained in the glass raw materials depends on their qualitative and quantitative presence in the glass raw materials used.

[0073] In one embodiment of the method, the proportion of nitrous oxide produced from the oxidation of nitrogen in the flue gas is less than 200 ppm(v / v), less than 100 ppm(v / v), or less than 50 ppm(v / v). In one embodiment of the method, the proportion of nitrous oxide produced from the oxidation of nitrogen is at least 1 ppm(v / v), at least 10 ppm(v / v), at least 20 ppm(v / v), or at least 30 ppm(v / v). In related embodiments of the method, the proportion of nitrous oxide produced from the oxidation of nitrogen is 1 to 200 ppm(v / v), 10 to 200 ppm(v / v), 20 to 200 ppm(v / v), 20 to 100 ppm(v / v), or 30 to 50 ppm(v / v).

[0074] In one embodiment of the method, the batch of glass raw materials contains at least 0.1% by mass of nitrate, at least 0.3% by mass of nitrate, at least 0.5% by mass of nitrate, and at least 1.0% by mass of nitrate. Optionally, the nitrate is selected from NaNO3, KNO3, Ba(NO3)2, LiNO3, Ca(NO3)2, Mg(NO3)2, and combinations thereof. In one embodiment of the method, the batch of glass raw materials contains less than 2.0% by mass of nitrate. Generally, it is desirable and advantageous to minimize the total amount of nitrous oxide released during the method. However, to obtain improved quality of the resulting glass product, it is also advantageous to allow a clarification step of the glass melt by introducing an additional clarifying agent into the batch of glass raw materials.

[0075] While it is advantageous to minimize the total amount of nitrous oxide released during the aforementioned method, one embodiment allows for a reduction in the proportion generated from nitrogen oxidation by the fuel burner, while simultaneously increasing the proportion released from nitrogen species contained in the glass raw material within the boundaries and limits specified above. Alternatively, while it is advantageous to minimize the total amount of nitrous oxide released during the aforementioned method, one embodiment allows for a reduction in the proportion generated from nitrogen species contained in the glass raw material, while simultaneously increasing the proportion produced through nitrogen oxidation by the fuel burner within the boundaries and limits specified above.

[0076] In one embodiment of the above method, reacting hydrogen with oxygen involves supplying one or more fuel gas streams to a fuel burner to form a combustion mixture in the fuel burner, wherein the combustion mixture contains at least 10% H2(v / v), at least 25% H2(v / v), at least 40% H2(v / v), at least 45% H2(v / v), at least 49% H2(v / v), or at least 49.9% H2(v / v). In one embodiment of the above method, reacting hydrogen with oxygen involves supplying one or more fuel gas streams to a fuel burner to form a combustion mixture in the fuel burner, wherein the combustion mixture contains less than 55% H2(v / v), less than 50% H2(v / v), less than 40% H2(v / v), less than 30% H2(v / v), less than 20% H2(v / v), or less than 15% H2(v / v). In one embodiment of the above method, reacting hydrogen with oxygen involves supplying one or more fuel gas streams to a fuel burner to form a combustion mixture in the fuel burner, wherein the combustion mixture contains 10% to 55% H2(v / v), 25% to 50% H2(v / v), 40% to 50% H2(v / v), 45% to 50% H2(v / v), 45% to 50% H2(v / v), or 49.9% to 50% H2(v / v).

[0077] In one embodiment of the method described above, the method includes the step of electrolyzing H2O to obtain hydrogen and oxygen, where at least some of the hydrogen and some of the oxygen are sent to a fuel burner. This is advantageous because the electrolyzed H2 / O2 mixture has only a very low N2 content, which reduces the generation of nitrous oxide in the flue gas. Thus, by supplying nitrogen-free fuel and oxidizer, the formation of thermal nitrogen oxides is reduced. A further advantage of this embodiment is the avoidance of out-of-process O2 supply, for example, through air separation techniques (Linde process, pressure swing adsorption).

[0078] In one embodiment, the method relies solely on hydrogen and oxygen produced through the electrolysis of H2O, i.e., more than 99% (v / v) of the total volume of hydrogen and oxygen. Electrolysis powered by renewable energy inherently reduces the environmental impact and carbon footprint associated with the manufacturing of glass products. Alternatively, electrolysis could be powered by nuclear energy, which results in the CO2-neutral production of hydrogen. However, this energy source is not sustainable due to radioactive waste.

[0079] It is generally advantageous if the method relies solely on hydrogen and oxygen produced by the electrolysis of H2O. Specifically, the method may rely at least 80%, at least 90%, at least 95%, at least 99%, or at least 99.9% (in (v / v) of the total volume of hydrogen and oxygen) on hydrogen and oxygen produced by the electrolysis of H2O. In this regard, those skilled in the art recognize that hydrogen and oxygen can also be obtained and / or produced by other sources or means, such as air distillation for oxygen and steam reforming for hydrogen. Firstly, no CO2 is produced during the heating of the glass raw materials and / or glass molten materials using at least one fuel burner, and optionally during the melting of batches of glass raw materials in a melting tank to form the glass molten material. Reduced CO2 production as part of the method also reduces the amount of CO2 in the glass molten material and the final glass product, and also reduces the number and size of bubbles in the glass molten material and the final glass product. Secondly, as mentioned above, the use of hydrogen and oxygen (only) produced through the electrolysis of H2O reduces and / or avoids the generation of nitrous oxide during the process resulting from the (thermal) combustion of N2, because N2 is hardly present in the hydrogen and oxygen obtained through the electrolysis of H2O.

[0080] A glass molten material or glass composition may contain one or more fining agents, sometimes referred to as refining agents. The fining agents may be selected from polyvalent metal oxides, halides, sulfates, and combinations thereof. In one embodiment, the fining agent is selected from the list of arsenic oxide, antimony oxide, tin oxide, cerium oxide, chlorides, sulfates, and combinations thereof. Fining agents are advantageously used to reduce the amount of bubbles in the glass molten material and the final glass product. Generally, fining agents assist in the process of expelling any gases or bubbles from the glass molten material, such as CO2 bubbles and O2 bubbles. Fining agents further assist and influence the overall oxidation state in the glass molten material and the resulting glass product, and consequently, Fe 2+ Fe 3+ It influences and helps establish a desirable ratio value for [the given value].

[0081] At the clarification temperature, which is above the melting temperature, any, or at least most, of the gases remaining in the glass molten are expelled. Each clarifying agent decomposes at a specific temperature, forming gases and creating bubbles in the glass molten. Due to the partial pressure difference, any gases present in the molten material diffuse into these bubbles, which grow and rise to the top of the molten material. To make this process economically viable, the clarification temperature range uses high temperatures similar to those during glass melting to produce a sufficiently low viscosity in the glass molten material, which facilitates and / or accelerates the rise of the bubbles.

[0082] In one embodiment of the method described above, the method further comprises the steps of releasing oxygen from nitrates in the glass molten and / or oxidizing at least one polyvalent fining agent in the glass molten. This combination is advantageous because the oxygen is distributed in-situ and homogeneously in the glass molten, enabling efficient oxidation of the polyvalent fining agent. Polyvalent elements present in the molten often contribute to color depending on their concentration and their oxidation state. As a general rule of thumb, polyvalent elements in their best possible oxidation state do not have d or s electrons in their molecular orbitals that contribute to UV or visible light-induced transitions. Therefore, oxidizing at least one polyvalent element in the glass molten makes it possible to establish a desirable redox state in the glass molten, and in particular, makes it possible for the polyvalent element to oxidize to its best redox state, thus avoiding any color effect on the resulting glass product.

[0083] In one embodiment of this disclosure, a molten glass and / or glass product has a light transmittance of at least 50%, preferably at least 60%, more preferably at least 70%, and most preferably at least 80%, measured over a wavelength range of 400–800 nm and at a reference glass thickness of 1 mm. In other words, if a glass product is manufactured from the glass composition, and a sample of the glass product has a thickness of 1 mm, then the glass product has a light transmittance of at least 50%, preferably at least 60%, more preferably at least 70%, and most preferably at least 80%, measured over a wavelength range of 400–800 nm. This feature does not mean that the glass product has a thickness of 1 mm. The 1 mm thickness is used as a reference for comparison. The transmittance may be measured at, for example, 2 mm, and the transmittance at 1 mm may be calculated using the Lambert-Beer law.

[0084] In one embodiment of this disclosure, the glass molten material and / or the glass product is heated at a temperature above 1580°C for 10 2Having a viscosity of dPas and / or the glass molten material having at least a portion of 10 2.5 It is heated to a sufficiently high temperature because it has a viscosity of less than dPas. Advantageously, 10 2.5 Glass melts with a viscosity of less than dPas allow for the escape of any residual gases within the glass melt. This is particularly advantageous when fining agents are used as part of the glass raw material, because their decomposition (at certain temperatures) leads to gas formation. Due to the partial pressure difference, any gases present in the melt diffuse into bubbles of the fining agent, which grow and rise to the top of the melt. At sufficiently low viscosity of the glass melt, the rise of bubbles to the top of the glass melt becomes easier and / or accelerated.

[0085] In one embodiment of this disclosure, the glass product is a sheet, wafer, plate, tube, rod, ingot, or block. Optionally, the glass molten material and / or the glass product each have a total carbon content of less than 310 ppm based on the mass of carbon atoms, relative to the mass of the glass product or glass molten material. In a further embodiment, the glass molten material and / or the glass product each have a total carbon content of less than 160 ppm, less than 80 ppm, or less than 30 ppm based on the mass of carbon atoms, relative to the mass of the glass product or glass molten material. In a further embodiment, the glass molten material and / or the glass product each have a total carbon content of at least 1 ppm, at least 2 ppm, at least 3 ppm, or at least 5 ppm based on the mass of carbon atoms, relative to the mass of the glass product or glass molten material. In the relevant embodiments, the glass molten and / or the glass product each has a total carbon content of 1 to 310 ppm, 2 to 160 ppm, 3 to 80 ppm, or 5 to 30 ppm based on the mass of carbon atoms, relative to the mass of the glass product or glass molten. A glass molten and / or glass product having a total carbon content limited as described herein, based on the mass of carbon atoms, relative to the mass of the glass product, is advantageous in that it has fewer bubbles and / or fewer CO2 bubbles in the (obtained) glass product. For example, the glass product may contain fewer than two bubbles per 10 kg of glass, each having a size of 100 μm or larger and a CO2 content greater than 5% of the total volume of gas in the bubbles. In a particular embodiment, the glass product may be bubble-free, each having a size of 100 μm or larger and a CO2 content greater than 5% of the total volume of gas in the bubbles, relative to the mass of the glass product or glass molten. For example, the glass product may contain fewer than two bubbles per 10 kg of glass, each having a size of 100 μm or larger and a CO2 content exceeding 10% of the total volume of gas in the bubbles.In a particular embodiment, the glass product may be bubble-free, having a size of 100 μm or larger per 10 kg of glass and a CO2 content exceeding 10% of the total volume of gas in the bubbles.

[0086] In one embodiment of the method, heating the glass raw material and / or glass molten includes heating the glass molten mass using one or more electrodes. In another embodiment of the method, heating the glass raw material and / or glass molten includes directly introducing most of the thermal energy into the glass molten. For example, the glass molten can be directly heated using one or more electrodes. One or more electrodes can be positioned partially or entirely within or on the wall of the molten tank. One or more electrodes can be positioned partially or entirely within or on the bottom plate of the molten tank. In one embodiment, one or more electrodes constitute a portion of the wall and / or the bottom plate of the molten tank.

[0087] In one embodiment of the method described above, heating the glass raw material and / or glass molten material may depend at least 30%, at least 40%, at least 50%, or at least 60% (of the total amount of thermal energy) on hydrogen and oxygen produced by the electrolysis of H2O, and additionally on the use of one or more electrodes. Optionally, heating the glass raw material and / or glass molten material may depend solely on hydrogen and oxygen produced by the electrolysis of H2O, and the use of one or more electrodes.

[0088] For example, if more energy is required near the surface of the molten glass, longer electrodes can be used. In one embodiment, heating the molten glass may include heating with one or more electrodes extending upward from the bottom of the melting chamber to at least 50%, preferably at least 60%, at least 70%, or at least 80% of the depth of the molten glass. Optionally, one or more electrodes may extend from the bottom of the melting chamber to 100%, 95%, or 90% of the depth of the molten glass. Optionally, one or more electrodes may extend from the bottom of the melting chamber to 50%–100%, 60%–95%, or 70%–90% of the depth of the molten glass. In one embodiment of the method, the amount of thermal energy introduced into the molten glass using at least one fuel burner is at least 30% (of the total amount of thermal energy).

[0089] In one embodiment of the above method, the amount of thermal energy introduced into the glass molten material using one or more electrodes exceeds 10% of the total amount of thermal energy introduced into the glass molten material in the melting tank.

[0090] In one embodiment of the method described above, the method includes the step of removing bubbles from the glass molten material. Removing bubbles from the molten material can be done in the melting tank and optionally outside the melting tank, for example, in a separate container. The separate container may be a clarification container. Bubbles can be removed from the molten material using chemical and / or physical methods. In one embodiment, removing bubbles from the molten material includes allowing bubbles to rise to the surface of the glass molten material in the melting tank. In another embodiment, bubbles are removed from the molten material by allowing them to rise to the surface of the glass molten material in the melting tank and then further removing them in a separate container. Thanks to the improved method of this invention, bubble removal in the melting tank contributes to achieving excellent bubble quality in the glass product. In a further embodiment, the method includes the step of removing bubbles from the glass molten material in the melting tank and / or in a separate clarification tank after the glass molten material produced in the melting tank has been withdrawn. The temperature of the glass molten material in the clarification container may be higher than the highest temperature of the glass molten material in the melting tank. In one embodiment, the method of this invention does not involve vacuum clarification and / or bubbling of the molten material. In an alternative embodiment, the method of this invention includes vacuum clarification and / or bubbling of the molten material.

[0091] In a second embodiment, the present invention relates to a glass product made of Fe 2+ Fe 3+ The present invention relates to a glass product having a ratio value of less than 0.2, less than 0.15, less than 0.10, or less than 0.05, and having fewer than 80 bubbles in the range of 0.1 mm to 0.2 mm in size per 10 kg of glass, and / or fewer than 2 bubbles in size greater than 0.2 mm per 10 kg of glass.

[0092] In one embodiment, the glass product is made by melting glass at 1100°C and then adding 1 cm³ of glass. 3 5 x 10 19 CO2 bar of molecules less than -1 The glass product exhibits a CO2 solubility and / or has a total carbon content of less than 310 ppm based on the mass of carbon atoms relative to the mass of the glass product.

[0093] In one embodiment, the glass product has a total carbon content of less than 310 ppm, less than 160 ppm, less than 80 ppm, or less than 30 ppm based on the mass of carbon atoms relative to the mass of the glass product. Optionally, the glass product has a total carbon content of at least 1 ppm, at least 2 ppm, at least 3 ppm, or at least 5 ppm based on the mass of carbon atoms relative to the mass of the glass product. In related embodiments, the glass product has a total carbon content of 1 to 310 ppm, 2 to 160 ppm, 3 to 80 ppm, or 5 to 30 ppm based on the mass of carbon atoms relative to the mass of the glass product. Glass products having a total carbon content limited as described herein, based on the mass of carbon atoms relative to the mass of the glass product, are advantageous in that they have fewer bubbles and / or fewer CO2 bubbles in the (obtained) glass product.

[0094] In one embodiment, the glass product has fewer than 80 bubbles in the size range of 0.1 mm to 0.2 mm per 10 kg of glass, fewer than 40 bubbles in the size range of 0.1 mm to 0.2 mm per 10 kg of glass, fewer than 10 bubbles in the size range of 0.1 mm to 0.2 mm per 10 kg of glass, fewer than 5 bubbles in the size range of 0.1 mm to 0.2 mm per 10 kg of glass, or fewer than 2 bubbles in the size range of 0.1 mm to 0.2 mm per 10 kg of glass, and / or fewer than 2 bubbles larger than 0.2 mm per 10 kg of glass. In one embodiment, the glass product has fewer than 5 bubbles in the size range of 0.1 mm to 0.2 mm per 10 kg of glass. In one embodiment, the glass product has fewer than 2 bubbles in the size range of 0.1 mm to 0.2 mm per 10 kg of glass. In a related embodiment, the glass product has fewer than two bubbles having an equivalent spherical diameter of 250 μm or more, 200 μm or more, or 150 μm or more. The characteristic number of bubbles per unit mass of glass does not mean that the glass product of this disclosure has a weight of at least 10 kg. Rather, a number of bubbles for 10 kg can be easily measured in lighter glass products. Optionally, the glass product has a mass of at least 1 g, at least 10 g, at least 100 g, or at least 250 g. In one embodiment, the glass product may have a mass of 100 kg or less, 25 kg or less, 10 kg or less, 5 kg or less, or 2 kg or less.

[0095] In one embodiment, the glass product is heated to a temperature of 1000 to 1600°C for 1 cm 3 2 x 10 14 CO2 bar of molecules -1 K -1 The composition has a temperature dependence of CO2 solubility that exceeds [a certain value]. In a further embodiment, the glass product is heated to a temperature of 1 cm in the range of 1000 to 1600°C. 3 5 x 10 14 CO2 bar of molecules -1 K -1 If the temperature exceeds 1 cm, or within a temperature range of 1000-1600°C 31 x 10 15 CO2 bar of molecules -1 K -1 The composition has a temperature dependence of CO2 solubility that exceeds 1 cm. In a related embodiment, the temperature dependence of CO2 solubility is within a temperature range of 1000 to 1600°C. 3 1 x 10 18 CO2 bar of molecules less than -1 K -1 , within a temperature range of 1000~1600℃, 1cm 3 1 x 10 17 CO2 bar of molecules less than -1 K -1 , or 1 cm within a temperature range of 1000~1600℃ 3 5 x 10 16 CO2 bar of molecules less than -1 K -1 In a related embodiment, the glass product is heated to a temperature of 1000 to 1600°C for 1 cm 3 2 x 10 14 CO2 bar of molecules -1 K -1 ~1cm 3 1 x 10 18 CO2 bar of molecules -1 K -1 , within a temperature range of 1000~1600℃, 1cm 3 5 x 10 14 CO2 bar of molecules -1 K -1 ~1cm 3 1 x 10 17 CO2 bar of molecules -1 K -1 , or 1 cm within a temperature range of 1000~1600℃ 3 1 x 10 15 CO2 bar of molecules -1 K -1 ~1cm 3 5 x 10 16 CO2 bar of molecules -1 K -1The composition has a temperature dependence of CO2 solubility. This temperature dependence of CO2 solubility is advantageous because it provides optimally degassed glass products within a temperature range of 1300 to 1650°C.

[0096] In one embodiment, the glass product is and / or can be obtained by the method described herein.

[0097] In one embodiment of the glass product, the composition is heated at a temperature above 1580°C. 2 It exhibits viscosity in dPas. Advantageously, at temperatures above 1580°C, it is 10 2 Glass products having a viscosity of dPas allow for the escape of any gases released during the production of the glass molten material in the manufacturing method of this disclosure. It is particularly advantageous when a fining agent is used as part of the glass raw material, because their decomposition (at a certain temperature) leads to the formation of gases. Due to the partial pressure difference, any gases present in the molten material diffuse into bubbles of the fining agent, which grow and rise to the top of the glass molten material. With a sufficiently low viscosity of the glass molten material, it becomes easier and / or accelerates the rise of bubbles to the top of the glass molten material.

[0098] In one embodiment, the glass product is a sheet, wafer, plate, tube, rod, ingot, or block.

[0099] In one embodiment, the carbon dioxide footprint of the glass product is less than 500g of CO2 per kilogram of glass. In another embodiment, the carbon dioxide footprint of the glass product is less than 400g, less than 300g, less than 200g, less than 100g, or even 0g of CO2 per kilogram of glass. For example, a glass product with a zero carbon dioxide footprint may be manufactured using only energy from renewable resources, such as biofuels, hydrogen, or electricity from renewable resources. The carbon dioxide footprint refers to CO2 emissions resulting from Scope 1 emissions under the GHG protocol. In this regard, it refers to the CO2 emissions per kilogram of glass material, caused by burning fossil fuels during the manufacture of the glass product and released by carbon-containing raw materials.

[0100] Detailed description of the drawing Figure 1 shows the dry measurement (i.e., H2O is condensed before gas analysis) of flue gas compositions derived from household gas combustion and hydrogen combustion, using oxygen from air fractionation (95.5 vol% O2, 2 vol% N2, 2.5 vol% Ar). The measured dry flue gas composition is recalculated to its original wet composition based on the mass balance of combustion. The experimental setup has separate melting and clarification sections, allowing for separate flue gas analysis in both sections. NO x The ratio is multiplied by 100 and measured on the same vertical coordinate system. [Examples]

[0101] Manufacturing methods for glass products The glass products described were manufactured according to the following procedure: Batches of glass raw materials were mixed and melted in a continuous dioecious melting tank consisting of a melting section and a clarifying section. Each section had a volume of approximately 40 liters. Three different compositions related to the glass products were investigated: A) one glass-ceramic, B) one pharmaceutical-grade glass, and C) one optical glass.

[0102] [Table 9]

[0103] The melting temperature and clarification temperature (range) were specifically adapted for the corresponding glass products.

[0104] [Table 10]

[0105] The glass raw materials and glass molten materials were heated by using one fuel burner for each section, i.e., two separate burners for the melting section and the clarifying section, and by additional electric heating. The two burners could be operated independently using natural gas, hydrogen, or a defined mixture of hydrogen and natural gas. For electric heating, a Pt20Rh plate electrode was used. Two electrodes (with dimensions of 225 × 225 × 3 mm) and one heating circuit were used in the melting section. Four electrodes (with dimensions of 125 × 125 × 3 mm) and one heating circuit were used in the clarifying section. After an average residence time of 18.3 hours (A), 16.5 hours (B), or 18.6 hours (C) in both the melting and clarifying sections, the glass molten material was withdrawn from the clarifying section by a Pt10 / Rh drain.

[0106] The three different glass compositions contain an initial amount of iron, e.g., Fe2O3, expressed in mol% and ppm relative to the batch of glass raw materials. After the glass raw materials are melted and processed to become molten glass and the final glass product, Fe 2+ and Fe 3+ The amounts of both species are determined spectroscopically and expressed in mol%, and the ratio value X between the two species is also determined. red (Fe 2+ / Fe 3+ It is expressed as ).

[0107] [Table 11]

[0108] CO2 solubility CO2 solubility was measured by vacuum thermal extraction after saturation or equilibration at a defined CO2 partial pressure (see Christopher Charles Tournour's PhD dissertation, "Solubility and Diffusion of Gases in Glasses and Melts," Alfred University, New York, 2004, Chapters 3.2-3.4). For this purpose, apparatus for saturating glass and melts under controlled temperature and pressure was used. The apparatus consisted of 1-1 / 2 inch stainless steel vacuum fittings with copper gasket seals. The saturation chamber was either quartz glass or mullite tube, depending on the saturation temperature used. Gas was supplied to the sample through a 1 / 4 inch stainless steel tube. Swagelock® fittings were used throughout the apparatus. The saturation chamber was evacuated by a direct-drive mechanical pump, and the pump pressure was monitored by a thermocouple pressure gauge. A vertical sliding electric resistance furnace was used to heat the quartz glass saturation chamber, while a fixed electric resistance furnace had to be used for mullite tubes, as there was a greater chance of thermal shock to the material. The temperature of the glass in the quartz glass tube was monitored using a K-type thermocouple placed inside a 1-inch sample, while the system pressure was monitored using a digital pressure gauge. The temperature inside the mullite tube was monitored using a K-type thermocouple, and the sample was removed before saturation to allow sufficient space for the crucible to descend into the tube. The system pressure was monitored using a digital pressure gauge.

[0109] The molten sample is saturated by placing a glass cube (2-4 grams) in a Pt / 5Au crucible. The crucible is then inserted into a platinum stand suspended from the top of the saturation chamber by platinum wire. This configuration is then lowered into a mullite tube, which is attached to the saturation system and surrounded by a furnace preheated to approximately 1100°C. While the sample is equilibrated at this temperature, the tube is evacuated in 100 Torr increments to remove the ambient atmosphere and any residual gases and bubbles in the molten material. The vacuuming must be done slowly to avoid foaming of the molten material from these gas sources. The furnace temperature is then changed to the desired saturation temperature, and the remelted sample is equilibrated at this new temperature. Once equilibrated, the saturation chamber is filled with the appropriate gas to the desired pressure. The molten material is held at the temperature and pressure for a sufficient amount of time to reach equilibrium, after which the crucible is rapidly removed from the saturation chamber and quenched in water, thereby freezing the dissolved gases within the sample.

[0110] The detection of gases generated from the sample was performed using a quadrupole mass spectrometer or a residual gas analyzer (RGA). The gas was introduced into the RGA through a throttle valve that controlled the gas flow rate from the sample to the mass spectrometer. A port was also provided for introducing gas from a standard volume container to calibrate the system and determine the absolute solubility of the gas.

[0111] The glass and molten material are degassed by placing the sample in a new platinum crucible that has not been previously exposed to saturated gas. This crucible is then lowered into a quartz glass tube attached to the degassing apparatus. Before loading the sample into the chamber, the quartz glass tube is degassed under vacuum to ensure that the only gas detected by the RGA is from the sample. The system is operated for approximately 10 minutes. -7The furnace was evacuated to Torr to remove the ambient atmosphere, and background data for 5 minutes was collected using RGA. Then, a furnace preheated to the desired degassing temperature was placed over the sample. The glass molten material was degassed at 950°C. The sample was held at the temperature for a sufficiently long time for all the dissolved gases to diffuse from the glass or molten material and enter the mass spectrometer.

[0112] Carbon content The carbon content was quantified by IR gas analysis after combustion, in accordance with DIN 51085:2015-01, which describes the quantification of a similar sulfur content after combustion.

[0113] Iron content The iron content was quantified by spectroscopic analysis of the final glass product in accordance with DIN 51001:2003-08. Specifically, in the final glass product, Fe 2+ Fe 3+ The ratio to was quantified by deconvolution of the UV / Vis transmission spectrum.

[0114] Electrolysis of H2O The process of electrolyzing H2O to obtain hydrogen and oxygen, and then supplying at least a portion of the hydrogen and at least a portion of the oxygen to a fuel burner, was carried out by proton exchange membrane (PEM) electrolysis.

[0115] Analysis of flue gas composition The flue gas consists of the combustion products of the corresponding fuel gas, imitation air, gases released from the glass raw material mixture, and O2 purge gas used by the furnace chamber probe. Complete combustion into CO2 and H2O is assumed. NO x The formation is calculated based on nitrogen combustion and assuming that only nitric oxide is formed, i.e., using thermal NO, also known as Zeldovitch NO. Nitrate forms a special case where both NO and NO2 are produced, i.e., two different reactions occur: Na2NO3 → Na2O + NO2 Na2NO3 → Na2O + NO + 1 / 2O2 The resulting flue gas was dried to remove water, and each component of the flue gas was measured using IR spectroscopy for CO2, a paramagnetic O2 analyzer for O2, and a chemiluminescence sensor for NO. Before NO measurement, all NO x Seeds NO x It was reduced to NO by a converter.

[0116] By taking into account the underlying composition, hydrogen gas, or mixtures thereof, the moist flue gas composition can be derived using theoretical formulas for the combustion of natural gas.

Claims

1. A method for manufacturing a glass product, comprising: melting a batch of glass frits in a melting tank to form a glass melt; heating the glass frit and / or the glass melt using at least one fuel burner, withdrawing the glass melt from the melting tank; - Obtaining glass products wherein the fuel burner heats the glass frit and / or the glass melt by reacting hydrogen and oxygen, and the glass product comprises Fe 2+ Fe 3+ The method of claim 1, wherein the ratio of

2. CO in the glass melt 2 The melting point is 1100°C and 1 cm of glass melt. 3 5 x 10 per 19 Less than 100 molecules of CO 2 bar -1 and / or CO in the glass melt 2 The temperature dependence of solubility is 1 cm within the temperature range of 1000 to 1600°C. 3 2 x 10 per 14 molecule CO 2 bar -1 K -1 Exceeding The method of claim 1.

3. 2. The method of claim 1, wherein the amount of carbonate in the batch of frit is less than 15 wt.%.

4. 10. The method of claim 1, wherein, at least temporarily, the fuel burner is operated at an oxygen-to-fuel equivalence ratio λ greater than 1.01 and preferably less than or equal to 1.

35.

5. the total amount of nitrous oxide in the flue gases resulting from the melting and heating steps is less than 500 ppm (v / v) relative to the total volume of said flue gases; the total amount of nitrous oxide is made up of a proportion resulting from the oxidation of nitrogen by said fuel burner and a proportion released from nitrogen species contained in the glass frit, the proportion of nitrous oxide resulting from the oxidation of nitrogen is less than 200 ppm (v / v) relative to the total volume of flue gas; and / or the batch of glass frits contains at least 0.1% by weight of nitrates, The method of claim 1.

6. reacting hydrogen and oxygen includes delivering one or more fuel gas streams to the fuel burner to form a combustion mixture within the fuel burner, the combustion mixture containing at least 10% H 2 (v / v), ・ H 2 Electrolyzing O to obtain hydrogen and oxygen, and sending at least a portion of the hydrogen and at least a portion of the oxygen to the fuel burner; and / or the amount of thermal energy introduced into the glass melt using the at least one fuel burner is at least 30% relative to the total amount of thermal energy introduced into the glass melt; The method of claim 1.

7. Releasing oxygen from at least one nitrate in the glass melt, and / or oxidizing at least one polyvalent fining agent in the glass melt; The method of claim 1 further comprising:

8. the glass melt is heated to a temperature above 1580°C for 10 2 and / or The glass melt is at least partially melted to a temperature of 1000°C. 2.5 heated to a temperature high enough to have a viscosity of 0.05 dPas or less, The method of claim 1.

9. the glass product is a sheet, wafer, plate, tube, rod, ingot or block; and / or the glass product has a total carbon content, based on the mass of carbon atoms, of less than 310 ppm relative to the mass of the glass product; The method of claim 1.

10. 10. The method of claim 1, wherein heating the glass frit and / or the glass melt comprises heating a glass melt mass using one or more electrodes.

11. 11. The method of claim 10, wherein the amount of thermal energy introduced into the glass melt using the one or more electrodes is greater than 10% of the total amount of thermal energy introduced into the glass melt in the melting tank.

12. 12. A glass product comprising a composition optionally obtained and / or obtainable by the method of any one of claims 1 to 11, said glass product comprising Fe 2+ Fe 3+ less than 0.2, or less than 0.05, and the glass product has less than 80 bubbles within the size range of 0.1 mm to 0.2 mm per 10 kg of glass and / or less than 2 bubbles greater than 0.2 mm per 10 kg of glass.

13. The composition is melted in a glass melt of 1 cm at 1100°C. 3 5 x 10 per 19 Less than 100 molecules of CO 2 bar -1 CO 2 13. The glass article of claim 12, wherein the glass article exhibits solubility and / or the glass article has a total carbon content of less than 310 ppm based on the mass of carbon atoms, relative to the mass of the glass article.

14. The composition can be heated to 1 cm within a temperature range of 1000 to 1600°C. 3 2 x 10 per 14 molecule of CO 2 bar -1 K -1 CO exceeding 2 13. The glass article of claim 12, having a temperature dependence of solubility.

15. The composition is 2 13. The glass product of claim 12, exhibiting a viscosity of dPas.

16. 13. The glass article of claim 12, which is a sheet, wafer, plate, tube, rod, ingot or block.

17. CO of 100 μm or larger per 10 kg of glass and more than 10% of the total volume of gas in bubbles 2 13. The glass product of claim 12, comprising less than two bubbles having a content of 100% or less.

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