Energy-saving flat glass and preparation method thereof

Abstract

This invention relates to an energy-saving flat glass and its preparation method, belonging to the field of glass material technology. The flat glass is composed of the following components by weight percentage: 62.0–70.0% SiO2, 3.0–4.0% Al2O3, 9.0–11.0% Na2O, 1.0–2.0% K2O, 7.0–8.5% CaO, 3.0–4.0% MgO, 0.05–0.15% SrO, 0.5–2.0% B2O3, 6.0–8.0% BaO, and 0–0.15% Fe2O3. 3.0-1.0% SO3, wherein the total weight percentage of CaO and BaO in the flat glass is not greater than 15.0%; the total weight percentage of SrO, B2O3 and BaO is not less than 7% and not greater than 9%. This invention, through the reasonable proportion of various components, enables each component to form a synergistic effect, which not only significantly reduces the melting temperature of the flat glass, but also significantly improves the phase separation problem caused by oxide segregation, greatly improving the mechanical properties, optical properties and chemical stability of the glass, which is conducive to the sustainable development and application of flat glass.

Description

Technical Field

[0001] This invention relates to the field of glass materials technology, specifically to glass composition and its preparation method, and in particular to an energy-saving flat glass and its preparation method. Background Technology

[0002] Glass, as a fundamental material, has wide applications in construction, automotive, electronics, solar energy, and many other fields. The float glass process, also known as float glass production, is a crucial manufacturing process for flat glass. Due to its excellent flatness, thickness uniformity, and optical properties, flat glass is widely used in construction, automotive, furniture, home appliances, and many other sectors. Flat glass is a significant glass variety, accounting for 60% to 70% of the total production capacity of all glass varieties. With the rapid development of the global economy and the acceleration of industrialization, the glass industry has also experienced large-scale expansion. However, while achieving remarkable success, the glass industry also faces many challenges, the most prominent being energy consumption and environmental pollution. Traditional flat glass production processes consume a large amount of energy, especially during the high-temperature melting stage, which not only increases production costs but also puts significant pressure on the environment. Furthermore, with intensifying market competition and increasingly higher consumer demands for product quality, the glass industry also needs to improve the mechanical and optical properties of its products while reducing costs to meet increasingly diversified and high-end demands.

[0003] Currently, most flat glass on the market uses traditional silicate glass formulations, whose main components include silicon dioxide (SiO2), sodium oxide (Na2O), and calcium oxide (CaO). While this glass formulation possesses good chemical stability and optical properties, it has some significant limitations in the production process. In terms of energy consumption, the melting temperature (T2, the temperature corresponding to 100 poise viscosity) in the traditional float glass manufacturing process is typically around 1435℃, and the actual controlled hot spot temperature of the glass melting furnace is generally between 1480℃ and 1550℃. Such high melting temperatures result in significant energy consumption during the melting and refining processes of flat glass. Therefore, energy costs account for approximately 40% of the overall cost of float glass. The fuels used in float glass production are mainly natural gas, heavy oil, petroleum coke, and coal gas, and this high energy consumption places a heavy energy cost burden on flat glass manufacturers.

[0004] While existing research on flat glass formulations has made some progress in reducing melting temperature and cost, most studies struggle to simultaneously meet key requirements such as significantly lower melting temperature, low-cost raw materials, and stable sourcing. Although some technologies have successfully reduced melting temperature by adding special components, this introduces rare or expensive raw materials, leading to a substantial increase in raw material costs. Other technologies, while achieving some cost control, have made significant compromises in glass performance (resulting in a decline), failing to meet the market's growing demand for high-quality glass.

[0005] Patent No. CN118973972A discloses a low-melting-point glass composition, product, and preparation method thereof; it discloses a low-melting-point glass formulation: SiO2, 5.0wt%–45.0wt%; P2O5, 22.0wt%–55.0wt%; Al2O3, 5.0wt%–22.0wt%; ZnO, 5.0wt%–30.0wt%; Na2O+K2O, 0.0wt%–20.0wt%; CaO, 2.0wt%–8.0wt%; MgO, 2.0wt%–8.0wt%. 0.0wt%; The melting temperature of this glass formulation is 1000℃~1300℃, mainly used for bottle and jar glass production. It achieves a relatively low melting temperature mainly by reducing the amount of SiO2 and introducing a large amount of P2O5 and ZnO. The glass has a relatively short material length and a high liquidus temperature, which can meet the requirements of bottle and jar molding under rapid cooling conditions. However, there is a big difference between the forming technology of flat glass and bottle and jar glass, which requires a long material length and a relatively low liquidus temperature. Therefore, the glass composition and raw material usage in this patent cannot be used for flat glass.

[0006] Patent No. DE10120475A1 discloses silicon oxides, such as boron, aluminum, calcium, lithium, sodium, and potassium, used in the production of low-melting-point borosilicate glass, for example, in pharmaceutical containers; the patent discloses a refractory glass material that is easy to manufacture and has a low melting point, and is highly resistant to hydrolysis, has a low processing temperature, adjustable processing viscosity, high crystallinity resistance, and low erosion when properly processed. The borosilicate glass mainly comprises: 67-77 parts SiO2, 3-10 parts Al2O3, 0.3-10 parts CaO, 5-10 parts B2O3, 0.2-0.5 parts LiO2, 2-15 parts Na2O, and 1-15 parts K2O; it may also protect the following dopants: 0-10 parts MgO, 0-10 parts BaO, 0-10 parts SrO, 0-10 parts SnO2, 0-15 parts ZnO, 0-15 parts PbO, 0-10 parts WO3, 0-10 parts TiO2, 0-10 parts NbO, 0-10 parts Ta2O5, 0-10 parts La2O3, 0-10 parts Y2O3, and 0-10 parts ZrO2. Application number CN107151096A discloses a lead-free glass for energy-saving lamps, which comprises the following components and corresponding mass ratio ranges: 60-70% SiO2, 1.5-4% Al2O3, 8-10% Na2O, 3.5-7% K2O, 0.5-1.5% LiO2, 1.5-3.5% CaO, 0.3-2.0% MgO, 7-10% BaO, 1.0-2.7% SrO, 0-1.5% B2O3, and 0-1.5% CeO2; this lead-free glass has a low coefficient of thermal expansion and a low softening temperature. It is evident that existing silicate glass materials already employ techniques to lower the melting point by adding various oxides. However, existing low-melting-point silicate glasses all contain lithium oxide, and the proportions of some oxides are not controlled, leading to the segregation of some oxides during the preparation process. This results in phase separation issues in the glass products. In other words, while the addition of various oxides can effectively lower the melting point of glass in existing technologies, it also reduces the mechanical properties and light transmittance of the glass. Therefore, it is not suitable for large-scale use in flat glass materials where high mechanical properties and light transmittance are required.

[0007] In summary, based on existing technology and market demand, there is an urgent need for a new low-melting-point flat glass material to meet the market's demand for energy-saving and emission-reducing, low-cost, high mechanical properties and high light transmittance flat glass. Summary of the Invention

[0008] The purpose of this invention is to overcome the problem of phase separation in existing low-melting-point silicate glasses and to provide an energy-saving flat glass and its preparation method.

[0009] To achieve the above-mentioned objectives, the present invention provides an energy-saving flat glass.

[0010] This invention discloses an energy-saving flat glass, which is composed of the following components by weight percentage: 62.0-70.0% SiO2, 3.0-4.0% Al2O3, 9.0-11.0% Na2O, 1.0-2.0% K2O, 7.0-8.5% CaO, 3.0-4.0% MgO, 0.05-0.15% SrO, 0.5-2.0% B2O3, 6.0-8.0% BaO, 0-0.15% Fe2O3, and 0-1.0% SO3;

[0011] In the flat glass, the total weight percentage of CaO and BaO is not greater than 15.0%; the total weight percentage of SrO, B2O3 and BaO is not less than 7% and not greater than 9%.

[0012] This invention discloses an energy-saving flat glass that, without changing the glass matrix material (SiO2, Na2O, CaO, MgO) or adding lithium oxide, utilizes various fluxing agents (SrO, B2O3, BaO) and reinforcing agents (Al2O3). 3、 By rationally combining K2O and optimizing the proportions of each component, the components can form a synergistic effect, which not only significantly reduces the melting temperature of flat glass, but also significantly improves the phase separation problem caused by oxide segregation. This greatly improves the mechanical properties, optical properties and chemical stability of the glass, thus providing a low-melting-point, high-performance flat glass, which is conducive to the sustainable development and application of flat glass.

[0013] In this invention, SiO2 is the basic component for glass formation, constructing the glass network structure and endowing it with good chemical stability, thermal stability, and mechanical strength. Al2O3, as an intermediate oxide, enhances the chemical stability and mechanical properties of the glass, and also plays a role in adjusting the melting temperature to a certain extent. Na2O and K2O are external oxides of the glass network, providing free oxygen, reducing the viscosity of the glass, making it easier to melt, and thus lowering the melting temperature. CaO and MgO, while ensuring the basic properties of the glass, have a positive impact on the chemical stability and mechanical strength of the glass, and also help to adjust the melting temperature and forming properties of the glass. SrO can optimize the structure of the glass, further reducing the melting temperature. B2O3 can reduce the surface tension of the glass, promote the clarification and homogenization of the molten glass, and also help to lower the melting temperature. BaO can increase the density and refractive index of the glass, improve the optical properties of the glass, and can work synergistically with SrO and B2O3 in reducing the melting temperature.

[0014] Preferably, in the flat glass, the mass ratio of (Na2O+K2O) to SiO2 is 1:5-6. Under the preferred mass ratio, the segregation of SiO2 phase or Na2O / K2O in the glass can be better reduced at lower temperatures, significantly reducing phase separation in the glass and improving the mechanical strength of the flat glass. More preferably, in the flat glass, the mass ratio of (Na2O+K2O) to SiO2 is 1:5.2-5.5.

[0015] Preferably, the mass ratio of Na2O to K2O in the flat glass is 5-10:1; under the preferred mass ratio condition, the chemical stability of the flat glass can be significantly improved; more preferably, the mass ratio of Na2O to K2O in the flat glass is 6-8:1; under this mass ratio condition, the chemical stability of the flat glass is improved.

[0016] To achieve the above-mentioned objectives, the present invention further provides a method for preparing energy-saving flat glass, comprising the following steps:

[0017] (1) Based on the weight percentage of each component in the above-mentioned flat glass, determine the raw materials and their dosage, and crush the raw materials separately, mix the crushed raw materials to obtain a mixture; the raw materials include quartz sand, dolomite, limestone, feldspar, soda ash, sodium borate, barite and strontium carbonate;

[0018] (2) The mixture is put into a glass melting furnace for melting; during the melting process, oxidation clarification and homogenization are carried out to obtain glass liquid; wherein, the oxidation clarification and homogenization methods include: adding a clarifying agent and stirring and bubbling; wherein, the bubbling is carried out by introducing oxygen-containing gas for bubbling.

[0019] (3) The glass melt is formed by the float glass process and then annealed to obtain energy-saving flat glass.

[0020] The present invention discloses a method for preparing energy-saving flat glass, which uses a variety of raw ores as raw materials and employs targeted refining, oxidation clarification and homogenization treatments based on the impurities and other problems existing in the raw ores. This method achieves a breakthrough in directly preparing high-performance flat glass from raw ores, significantly saving raw material costs and energy consumption, reducing emissions, and is suitable for large-scale production of the energy-saving flat glass of the present invention.

[0021] Preferably, in step (1), the particle size of barite is 100-200 mesh; the particle size of sodium borate is 30-200 mesh; the preferred particle size range gives the glass melt a better clarification effect and better quality, which is beneficial to reducing energy consumption.

[0022] Preferably, in step (2), the hot spot temperature of the melting furnace is set to 1360-1370℃ during the melting process. The preferred temperature range can ensure that the raw materials react and melt fully, and is lower than the melting temperature of traditional float glass, thus achieving the purpose of energy saving.

[0023] Preferably, the clarifying agent is sodium sulfate, and the dosage is 1-3% of the mass of the molten glass. The combination of the preferred clarifying agent and the bubbling treatment can significantly improve the clarification effect on the molten glass, resulting in better glass performance.

[0024] Among them, the oxygen bubbling clarification treatment can significantly reduce the sulfur content (mainly introduced by barite) in the glass, ensuring that the color of the flat glass does not deviate; preferably, the amount of oxygen gas introduced (as oxygen) is 0.8-1.2 ml / min·100g (that is, 0.8-1.2 ml of oxygen is introduced per minute in every 100g of glass melt); the bubbling time is based on achieving the clarification requirements.

[0025] Preferably, the oxygen-containing gas is air or oxygen; most preferably, the oxygen-containing gas is oxygen with a purity of 95% or higher; directly introducing oxygen results in better oxidation and clarification.

[0026] Preferably, the stirring speed is 13-15 r / min; the preferred stirring speed can achieve better clarification and homogenization effects (the conventional stirring speed is only 10-12 r / min, which has poor clarification and homogenization effects on the glass melt of the present invention and takes longer).

[0027] Preferably, the number of bubbles in the molten glass is no more than 5 per m. 3 Furthermore, the diameter of the bubbles should not exceed 1 mm; under the preferred parameter conditions, the clarification quality of the glass melt is the best, and the resulting product has better performance.

[0028] Preferably, the temperature difference between different regions in the molten glass is less than 0.5℃; the preferred temperature difference indicates better homogenization of the molten glass, less segregation of components, and better product performance.

[0029] Preferably, in step (3), the cooling rate of the glass is controlled at 5-10℃ / min during the forming process. The preferred cooling rate can reduce the internal stress and component segregation in the glass, which is beneficial to improving the performance of the product.

[0030] Preferably, the annealing temperature is 520-550℃; the preferred annealing temperature results in flat glass with better performance.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] 1. The energy-saving flat glass of this invention, without changing the glass matrix material (sodium-calcium-silicon glass, SiO2, Na2O, CaO, MgO) and without adding lithium oxide, utilizes various fluxing components (SrO, B2O3, BaO) and reinforcing components (Al2O3). 3、 By rationally combining K2O and optimizing the proportion of each component, the components can form a synergistic effect, significantly reducing the melting temperature of flat glass (melting temperature T2 is reduced to 1350-1370℃, which is 70-90℃ lower than the melting temperature of conventional float glass of 1430-1440℃).

[0033] 2. The energy-saving flat glass of this invention significantly improves the phase separation problem caused by oxide segregation, greatly enhancing the mechanical properties (Young's modulus not less than 76.5 GPa, shear modulus not less than 31.0 GPa, Poisson's ratio between 0.20 and 0.23), optical properties (average visible light transmittance >85% (6mm)), and chemical stability (tin penetration depth not greater than 33μm; resistance to HCl corrosion not greater than 0.12 mg / cm², resistance to mixed alkali corrosion not greater than 0.095 mg / cm²), thus providing a low-melting-point, high-performance flat glass, which is beneficial to the sustainable development and application of flat glass.

[0034] 3. The method for preparing energy-saving flat glass of the present invention uses a variety of raw ores (especially barite) as raw materials, and adopts targeted refining, oxidation clarification and homogenization treatments according to the impurities and other problems existing in the raw ores. This achieves a breakthrough in directly preparing high-performance flat glass from raw ores, significantly saving raw material costs and energy consumption, and reducing emissions.

[0035] 4. The method for preparing energy-saving flat glass of the present invention, based on the properties of each oxide component in the glass, significantly improves the clarification effect of the glass melt by optimizing the preparation process and parameters of the flat glass, greatly improves the phase separation problem of the glass, and significantly improves the performance of the obtained flat glass. Detailed Implementation

[0036] To more clearly describe the inventive objectives, technical solutions, and advantages of the present invention in specific embodiments, a detailed description will be provided below in conjunction with the solutions in specific embodiments of the present invention. The specific technical solutions involved in the following specific embodiments are merely for the purpose of clearly and completely describing the innovative technical solutions of the present invention. They are only a part of the specific implementation methods that the present invention can adopt, not all embodiments, and should not be construed as limiting the innovative solutions of the present invention. Any solution that adopts the same inventive concept as the present invention should be included within the protection scope of the present invention.

[0037] For those skilled in the art, when understanding the solutions described in the specific embodiments of the present invention, conventional technical manuals in the field can be consulted. At the same time, appropriate understandings or adjustments can be made to the places where the above terms appear, so as to deduce the same or similar technical solutions without creative effort.

[0038] In a specific embodiment of the present invention, the thickness of the produced flat glass is 6mm.

[0039] Examples 1-13

[0040] An energy-saving flat glass, the weight percentages of its components are shown in Table 1; its specific preparation method is as follows:

[0041] (1) Based on the weight percentage of each component in the above-mentioned flat glass, determine the raw materials and their usage, and pulverize the raw materials (quartz sand, dolomite, limestone, feldspar, soda ash, sodium borate, barite and strontium carbonate) respectively (the particle size of barite is 150 mesh; the particle size of sodium borate is 100 mesh; the others are 50 mesh), mix the pulverized raw materials to obtain a mixture;

[0042] (2) The mixture is put into a glass melting furnace for melting (the hot spot temperature of the melting furnace is set to 1366℃); during the melting process, oxidation clarification and homogenization are carried out (2% sodium sulfate is added, and the mixture is stirred at a speed of 14r / min; oxygen is introduced for bubbling at 1.0ml / min·100g) to obtain clear glass melt (the number of bubbles is no more than 5 / m). 3 (And the diameter of the bubbles is no greater than 1 mm, and the temperature difference between regions is less than 0.5℃).

[0043] (3) The glass melt is formed by the float glass process (cooling rate is controlled at 8℃ / min), and then annealed (temperature is 530℃) to obtain energy-saving flat glass.

[0044] Table 1. (Design) weight percentages of each component in the flat glass of Examples 1-13

[0045]

[0046] Example 14

[0047] An energy-saving flat glass, whose component weight percentages are the same as in Example 1, is prepared by the following method:

[0048] (1) Based on the weight percentage of each component in the above-mentioned flat glass, determine the raw materials and their usage, and pulverize the raw materials (quartz sand, dolomite, limestone, feldspar, soda ash, sodium borate, barite and strontium carbonate) respectively (the particle size of barite is 100 mesh; the particle size of sodium borate is 200 mesh, and the others are 50 mesh). Mix the pulverized raw materials to obtain a mixture.

[0049] (2) The mixture is put into a glass melting furnace for melting (the hot spot temperature of the melting furnace is set to 1360℃); during the melting process, oxidation clarification and homogenization are carried out (3% sodium sulfate is added, and stirring is performed at a speed of 13r / min; oxygen is introduced for bubbling at 0.8ml / min·100g) to obtain clear glass melt (the number of bubbles is no more than 5 / m). 3 (And the diameter of the bubbles is no greater than 1 mm, and the temperature difference between regions is less than 0.5℃).

[0050] (3) The glass melt is formed by the float glass process (cooling rate is controlled at 10℃ / min), and then annealed (temperature is 520℃) to obtain energy-saving flat glass.

[0051] Example 15

[0052] An energy-saving flat glass, whose component weight percentages are the same as in Example 1, is prepared by the following method:

[0053] (1) Based on the weight percentage of each component in the above-mentioned flat glass, determine the raw materials and their usage, and pulverize the raw materials (quartz sand, dolomite, limestone, feldspar, soda ash, sodium borate, barite and strontium carbonate) respectively (the particle size of barite is 200 mesh; the particle size of sodium borate is 30 mesh, and the others are 50 mesh). Mix the pulverized raw materials to obtain a mixture.

[0054] (2) The mixture is put into a glass melting furnace for melting (the hot spot temperature of the melting furnace is set at 1370℃); during the melting process, oxidation clarification and homogenization are carried out (0.5% sodium sulfate is added, and the mixture is stirred at a speed of 15r / min; oxygen is introduced for bubbling at 1.2ml / min·100g) to obtain clear glass melt (the number of bubbles is no more than 5 / m). 3 (And the diameter of the bubbles is no greater than 1 mm, and the temperature difference between regions is less than 0.5℃).

[0055] (3) The glass melt is formed by the float glass process (cooling rate is controlled at 5℃ / min), and then annealed (temperature is 550℃) to obtain energy-saving flat glass.

[0056] Comparative Examples 1-12

[0057] A type of flat glass, the weight percentages of its components are shown in Table 2; its specific preparation method is as follows:

[0058] (1) Based on the weight percentage of each component in the above-mentioned flat glass, determine the raw materials and their usage, and pulverize the raw materials (quartz sand, dolomite, limestone, feldspar, soda ash, sodium borate, barite and strontium carbonate) respectively (the particle size of barite is 150 mesh; the particle size of sodium borate is 100 mesh, and the others are 50 mesh). Mix the pulverized raw materials to obtain a mixture.

[0059] (2) The mixture is put into a glass melting furnace for melting (the hot spot temperature of the melting furnace is set to 1366℃); during the melting process, oxidation clarification and homogenization are carried out (stirring at a speed of 14r / min; oxygen is introduced for bubbling at 1.0ml / min·100g) to obtain clear glass liquid (the number of bubbles is no more than 5 / m). 3 (And the diameter of the bubbles is no greater than 1 mm, and the temperature difference between regions is less than 0.5℃).

[0060] (3) The glass melt is formed by the float glass process (cooling rate controlled at 8℃ / min), and then annealed (temperature is 530℃) to obtain flat glass.

[0061] Table 2. Design weight percentage of each component in the flat glass of Comparative Examples 1-12

[0062]

[0063] Comparative Example 13

[0064] A flat glass, the weight percentages of its components are the same as in Example 1; its specific preparation method is as follows:

[0065] (1) Based on the weight percentage of each component in the above-mentioned flat glass, determine the raw materials and their usage, and pulverize the raw materials (quartz sand, dolomite, limestone, feldspar, soda ash, sodium borate, barite and strontium carbonate) respectively (the particle size of barite is 80 mesh; the particle size of sodium borate is 100 mesh, and the others are 50 mesh). Mix the pulverized raw materials to obtain a mixture.

[0066] (2) The mixture is put into a glass melting furnace for melting (the hot spot temperature of the melting furnace is set to 1366℃); during the melting process, oxidation clarification and homogenization are carried out (2% sodium sulfate is added, and the mixture is stirred at a speed of 14r / min; oxygen is introduced for bubbling at 1.0ml / min·100g) to obtain clear glass melt (the number of bubbles is no more than 5 / m). 3(And the diameter of the bubbles is no greater than 1 mm, and the temperature difference between regions is less than 0.5℃).

[0067] (3) The glass melt is formed by the float glass process (cooling rate controlled at 8℃ / min), and then annealed (temperature is 530℃) to obtain flat glass.

[0068] Comparative Example 14

[0069] A flat glass, the weight percentages of its components are the same as in Example 1; its specific preparation method is as follows:

[0070] (1) Based on the weight percentage of each component in the above-mentioned flat glass, determine the raw materials and their usage, and pulverize the raw materials (quartz sand, dolomite, limestone, feldspar, soda ash, sodium borate, barite and strontium carbonate) respectively (the particle size of barite is 250 mesh; the particle size of sodium borate is 100 mesh, and the others are 50 mesh). Mix the pulverized raw materials to obtain a mixture.

[0071] (2) The mixture is put into a glass melting furnace for melting (the hot spot temperature of the melting furnace is set to 1366℃); during the melting process, oxidation clarification and homogenization are carried out (2% sodium sulfate is added, and the mixture is stirred at a speed of 14r / min; oxygen is introduced for bubbling at 1.0ml / min·100g) to obtain clear glass melt (the number of bubbles is no more than 5 / m). 3 (And the diameter of the bubbles is no greater than 1 mm, and the temperature difference between regions is less than 0.5℃).

[0072] (3) The glass melt is formed by the float glass process (cooling rate controlled at 8℃ / min), and then annealed (temperature is 530℃) to obtain flat glass.

[0073] Comparative Example 15

[0074] A flat glass, the weight percentages of its components are the same as in Example 1; its specific preparation method is as follows:

[0075] (1) Based on the weight percentage of each component in the above-mentioned flat glass, determine the raw materials and their usage, and pulverize the raw materials (quartz sand, dolomite, limestone, feldspar, soda ash, sodium borate, barite and strontium carbonate) respectively (the particle size of barite is 150 mesh; the particle size of sodium borate is 250 mesh, and the others are 50 mesh). Mix the pulverized raw materials to obtain a mixture.

[0076] (2) The mixture is put into a glass melting furnace for melting (the hot spot temperature of the melting furnace is set to 1366℃); during the melting process, oxidation clarification and homogenization are carried out (2% sodium sulfate is added, and the mixture is stirred at a speed of 14r / min; oxygen is introduced for bubbling at 1.0ml / min·100g) to obtain clear glass melt (the number of bubbles is no more than 5 / m). 3 (And the diameter of the bubbles is no greater than 1 mm, and the temperature difference between regions is less than 0.5℃).

[0077] (3) The glass melt is formed by the float glass process (cooling rate controlled at 8℃ / min), and then annealed (temperature is 530℃) to obtain flat glass.

[0078] Comparative Example 16

[0079] A flat glass, the weight percentages of its components are the same as in Example 1; its specific preparation method is as follows:

[0080] (1) Based on the weight percentage of each component in the above-mentioned flat glass, determine the raw materials and their usage, and pulverize the raw materials (quartz sand, dolomite, limestone, feldspar, soda ash, sodium borate, barite and strontium carbonate) respectively (the particle size of barite is 150 mesh; the particle size of sodium borate is 20 mesh, and the others are 50 mesh). Mix the pulverized raw materials to obtain a mixture.

[0081] (2) The mixture is put into a glass melting furnace for melting (the hot spot temperature of the melting furnace is set to 1366℃); during the melting process, oxidation clarification and homogenization are carried out (2% sodium sulfate is added, and the mixture is stirred at a speed of 14r / min; oxygen is introduced for bubbling at 1.0ml / min·100g) to obtain clear glass melt (the number of bubbles is no more than 5 / m). 3 (And the diameter of the bubbles is no greater than 1 mm, and the temperature difference between regions is less than 0.5℃).

[0082] (3) The glass melt is formed by the float glass process (cooling rate controlled at 8℃ / min), and then annealed (temperature is 530℃) to obtain flat glass.

[0083] Comparative Example 17

[0084] A flat glass, the weight percentages of its components are the same as in Example 1; its specific preparation method is as follows:

[0085] (1) Based on the weight percentage of each component in the above-mentioned flat glass, determine the raw materials and their usage, and pulverize the raw materials (quartz sand, dolomite, limestone, feldspar, soda ash, sodium borate, barite and strontium carbonate) respectively (the particle size of barite is 150 mesh; the particle size of sodium borate is 100 mesh, and the others are 50 mesh). Mix the pulverized raw materials to obtain a mixture.

[0086] (2) The mixture is put into a glass melting furnace for melting (the hot spot temperature of the melting furnace is set to 1366℃); during the melting process, oxidation clarification and homogenization are carried out (2% sodium sulfate is added, and the mixture is stirred at a speed of 14r / min; no oxygen is introduced) to obtain clear glass melt (the number of bubbles is no more than 5 / m). 3 (And the diameter of the bubbles is no greater than 1 mm, and the temperature difference between regions is less than 0.5℃).

[0087] (3) The glass melt is formed by the float glass process (cooling rate controlled at 8℃ / min), and then annealed (temperature is 530℃) to obtain flat glass.

[0088] Comparative Example 18

[0089] A flat glass, the weight percentages of its components are the same as in Example 1; its specific preparation method is as follows:

[0090] (1) Based on the weight percentage of each component in the above-mentioned flat glass, determine the raw materials and their usage, and pulverize the raw materials (quartz sand, dolomite, limestone, feldspar, soda ash, sodium borate, barite and strontium carbonate) respectively (the particle size of barite is 150 mesh; the particle size of sodium borate is 100 mesh, and the others are 50 mesh). Mix the pulverized raw materials to obtain a mixture.

[0091] (2) The mixture is put into a glass melting furnace for melting (the hot spot temperature of the melting furnace is set at 1366℃); during the melting process, oxidation clarification and homogenization are carried out (2% sodium sulfate is added, and stirring is performed at a speed of 14r / min; oxygen is introduced for bubbling, and the oxygen introduction rate is only 0.7ml / min·100g), to obtain clear glass melt (the number of bubbles is no more than 5 / m). 3 (And the diameter of the bubbles is no greater than 1 mm, and the temperature difference between regions is less than 0.5℃).

[0092] (3) The glass melt is formed by the float glass process (cooling rate controlled at 8℃ / min), and then annealed (temperature is 530℃) to obtain flat glass.

[0093] Comparative Example 19

[0094] A flat glass, the weight percentages of its components are the same as in Example 1; its specific preparation method is as follows:

[0095] (1) Based on the weight percentage of each component in the above-mentioned flat glass, determine the raw materials and their usage, and pulverize the raw materials (quartz sand, dolomite, limestone, feldspar, soda ash, sodium borate, barite and strontium carbonate) respectively (the particle size of barite is 150 mesh; the particle size of sodium borate is 100 mesh, and the others are 50 mesh). Mix the pulverized raw materials to obtain a mixture.

[0096] (2) The mixture is put into a glass melting furnace for melting (the hot spot temperature of the melting furnace is set to 1366℃); during the melting process, oxidation clarification and homogenization are carried out (stirring at a speed of 14r / min; oxygen is introduced for bubbling at 1.0ml / min·100g) to obtain clear glass liquid (the number of bubbles is no more than 5 / m). 3 (And the diameter of the bubbles is no greater than 1 mm, and the temperature difference between regions is less than 0.5℃).

[0097] (3) The glass melt is formed by the float glass process (cooling rate controlled at 8℃ / min), and then annealed (temperature is 530℃) to obtain flat glass.

[0098] Comparative Example 20

[0099] A flat glass, the weight percentages of its components are the same as in Example 1; its specific preparation method is as follows:

[0100] (1) Based on the weight percentage of each component in the above-mentioned flat glass, determine the raw materials and their usage, and pulverize the raw materials (quartz sand, dolomite, limestone, feldspar, soda ash, sodium borate, barite and strontium carbonate) respectively (the particle size of barite is 150 mesh; the particle size of sodium borate is 100 mesh, and the others are 50 mesh). Mix the pulverized raw materials to obtain a mixture.

[0101] (2) The mixture is put into a glass melting furnace for melting (the hot spot temperature of the melting furnace is set at 1366℃); during the melting process, oxidation clarification and homogenization are carried out (2% of sodium sulfate, sodium nitrate and carbon powder (existing conventional clarifying agent) are added in a mass ratio of 1:67:0.17, and the mixture is stirred at a speed of 14r / min) to obtain clear glass melt (the number of bubbles is no more than 5 / m). 3 (And the diameter of the bubbles is no greater than 1 mm, and the temperature difference between regions is less than 0.5℃).

[0102] (3) The glass melt is formed by the float glass process (cooling rate controlled at 8℃ / min), and then annealed (temperature is 530℃) to obtain flat glass.

[0103] Comparative Example 21

[0104] A flat glass, the weight percentages of its components are the same as in Example 1; its specific preparation method is as follows:

[0105] (1) Based on the weight percentage of each component in the above-mentioned flat glass, determine the raw materials and their usage, and pulverize the raw materials (quartz sand, dolomite, limestone, feldspar, soda ash, sodium borate, barite and strontium carbonate) respectively (the particle size of barite is 150 mesh; the particle size of sodium borate is 100 mesh, and the others are 50 mesh). Mix the pulverized raw materials to obtain a mixture.

[0106] (2) The mixture is put into a glass melting furnace for melting (the hot spot temperature of the melting furnace is set to 1366℃); during the melting process, oxidation clarification and homogenization are carried out (2% sodium sulfate is added, and the mixture is stirred at a speed of 14r / min; oxygen is introduced for bubbling at 1.0ml / min·100g) to obtain clear glass melt (the number of bubbles is no more than 5 / m). 3 (And the diameter of the bubbles is no greater than 1 mm, and the temperature difference between regions is less than 0.5℃).

[0107] (3) The glass melt is formed by the float glass process (cooling rate is controlled at 8℃ / min), and then annealed (temperature is 500℃) to obtain flat glass.

[0108] Comparative Example 22

[0109] A flat glass, the weight percentages of its components are the same as in Example 1; its specific preparation method is as follows:

[0110] (1) Based on the weight percentage of each component in the above-mentioned flat glass, determine the raw materials and their usage, and pulverize the raw materials (quartz sand, dolomite, limestone, feldspar, soda ash, sodium borate, barite and strontium carbonate) respectively (the particle size of barite is 150 mesh; the particle size of sodium borate is 100 mesh, and the others are 50 mesh). Mix the pulverized raw materials to obtain a mixture.

[0111] (2) The mixture is put into a glass melting furnace for melting (the hot spot temperature of the melting furnace is set to 1366℃); during the melting process, oxidation clarification and homogenization are carried out (2% sodium sulfate is added, and the mixture is stirred at a speed of 14r / min; oxygen is introduced for bubbling at 1.0ml / min·100g) to obtain clear glass melt (the number of bubbles is no more than 5 / m). 3 (And the diameter of the bubbles is no greater than 1 mm, and the temperature difference between regions is less than 0.5℃).

[0112] (3) The glass melt is formed by the float glass process (cooling rate is controlled at 4℃ / min), and then annealed (temperature is 530℃) to obtain flat glass.

[0113] Comparative Example 23

[0114] A flat glass, the weight percentages of its components are the same as in Example 1; its specific preparation method is as follows:

[0115] (1) Based on the weight percentage of each component in the above-mentioned flat glass, determine the raw materials and their usage, and pulverize the raw materials (quartz sand, dolomite, limestone, feldspar, soda ash, sodium borate, barite and strontium carbonate) respectively (the particle size of barite is 150 mesh; the particle size of sodium borate is 100 mesh, and the others are 50 mesh). Mix the pulverized raw materials to obtain a mixture.

[0116] (2) The mixture is put into a glass melting furnace for melting (the hot spot temperature of the melting furnace is set to 1366℃); during the melting process, oxidation clarification and homogenization are carried out (2% sodium sulfate is added, and the mixture is stirred at a speed of 14r / min; oxygen is introduced for bubbling at 1.0ml / min·100g) to obtain clear glass melt (the number of bubbles is no more than 5 / m). 3 (And the diameter of the bubbles is no greater than 1 mm, and the temperature difference between regions is less than 0.5℃).

[0117] (3) The glass melt is formed by the float glass process (cooling rate controlled at 12℃ / min), and then annealed (temperature is 530℃) to obtain flat glass.

[0118] Comparative Example 24

[0119] A commercially available ordinary flat glass (6mm);

[0120] The specific composition is: 72% silicon dioxide, 2% aluminum oxide, 9% calcium oxide, 3% magnesium oxide, 7% sodium oxide and 7% potassium oxide.

[0121] The specific preparation method is as follows:

[0122] (1) Based on the weight percentage of each component in the above flat glass, determine the raw materials and their usage, and crush the raw materials (quartz sand, dolomite, limestone, feldspar, soda ash) into 50 mesh. Mix the crushed raw materials to obtain a mixture.

[0123] (2) The mixture is put into a glass melting furnace for melting (the hot spot temperature of the melting furnace is set at 1435℃); during the melting process, oxidation clarification and homogenization treatment are carried out (2% of sodium sulfate, sodium nitrate and carbon powder in a mass ratio of 1:67:0.17 are added and stirred at a speed of 14r / min) to obtain clear glass melt (the number of bubbles is no more than 5 / m). 3 (And the diameter of the bubbles is no greater than 1 mm, and the temperature difference between regions is less than 0.5℃).

[0124] (3) The glass melt is formed by the float glass process (cooling rate controlled at 8℃ / min), and then annealed (temperature is 530℃) to obtain flat glass.

[0125] Comparative Example 25

[0126] A flat glass is prepared using the formulation scheme in Example 1 of patent DE10120475A1.

[0127] Comparative Example 26

[0128] A flat glass is prepared using the formulation scheme in Example 1 of patent CN107151096A.

[0129] Experimental Example 1

[0130] The time required for the glass melt to clarify and homogenize to meet the requirements during the preparation of flat glass in Examples 1-15 and Comparative Examples 1-26 was statistically analyzed. The visible light transmittance (GB11614—2022), Young's modulus (GB / T 37780-2019), shear modulus (GB / T 37780-2019), Poisson's ratio (GB / T 37780-2019), resistance to HCl corrosion (GB / T 15728-2021), resistance to mixed alkali corrosion (GB / T 6580-2021), and tin penetration depth (GB / T 36406-2018) of the prepared flat glass were tested. The results are shown in Tables 3 and 4.

[0131] Table 3. Relevant experimental data of flat glass in Examples 1-15

[0132]

[0133] Table 4. Relevant experimental data of flat glass in Comparative Examples 1-26

[0134]

[0135] Comparative analysis of the data in Tables 3 and 4 shows that, without changing the glass matrix material or adding lithium oxide, this invention optimizes the proportion of each component through the rational combination of various fluxing and reinforcing components, enabling each component to form a synergistic effect. This not only significantly reduces the melting temperature of the flat glass but also significantly improves the phase separation problem caused by oxide segregation, greatly enhancing the mechanical, optical, and chemical properties of the glass. Any adjustment to the proportion of components in the formula or the preparation process parameters will lead to a significant reduction in a certain property of the glass, which is detrimental to its application.

[0136] Experiment Example 2

[0137] The flat glass prepared in Example 1 and Comparative Examples 17-20 was subjected to color testing (GB / T 20147.4-2023), and the test results are shown in Table 5:

[0138] Table 5 Color Detection Results Data

[0139]

[0140] Note: L* represents transparency; a* represents the red-green axis chromaticity coordinates; b* represents the yellow-blue axis chromaticity coordinates.

[0141] Comparative analysis of the data in Table 5 shows that while using barite as a raw material for flat glass in this application can significantly reduce the melting temperature of the glass, if the "clarifying agent + oxygen bubbling" method is not used for clarification treatment, but instead traditional methods such as using only a clarifying agent (Comparative Example 17), only introducing oxygen (Comparative Example 19), or insufficient oxygen introduction (Comparative Example 18), the sulfur content in the prepared flat glass will be significantly increased, resulting in a yellowish color, reduced transparency, and reduced visible light transmittance. While using a composite clarifying agent (Comparative Example 20) can also achieve a good clarification effect and produce a correct glass color, it increases the cost of the clarifying agent raw materials, leads to higher nitrogen oxide emissions, increases the environmental burden, and significantly increases the time required for clarification and homogenization treatment.

[0142] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An energy-saving flat glass, characterized by, It consists of the following components by weight percentage: 62.0–70.0% SiO2, 3.0–4.0% Al2O3, 9.0–11.0% Na2O, 1.0–2.0% K2O, 7.0–8.5% CaO, 3.0–4.0% MgO, 0.05–0.15% SrO, 0.5–2.0% B2O3, 6.0–8.0% BaO, 0–0.15% Fe2O3, 0–1.0% SO3; In the flat glass, the total weight percentage of CaO and BaO is not greater than 15.0%; the total weight percentage of SrO, B2O3 and BaO is not less than 7% and not greater than 9%.

2. The flat glass according to claim 1, characterized in that, In the flat glass, the mass ratio of (Na2O+K2O) to SiO2 is 1:5-6.

3. The flat glass according to claim 2, characterized in that, In the flat glass, the mass ratio of (Na2O+K2O) to SiO2 is 1:5.2-5.

5.

4. The flat glass according to claim 1, characterized in that, In the flat glass, the mass ratio of Na2O to K2O is 5-10:

1.

5. The flat glass according to claim 4, characterized in that, In the flat glass, the mass ratio of Na2O to K2O is 6-8:

1.

6. A method for preparing the energy-saving flat glass according to any one of claims 1-5, characterized in that, Includes the following steps: (1) Based on the weight percentage of each component in the above-mentioned flat glass, determine the raw materials and their usage, and pulverize the raw materials respectively, and mix the pulverized raw materials to obtain a mixture; the raw materials include quartz sand, dolomite, limestone, feldspar, soda ash, sodium borate, barite, and strontium carbonate; (2) The mixture is put into a glass melting furnace for melting; During the melting process, oxidation clarification and homogenization treatments are performed to obtain molten glass; wherein the oxidation clarification and homogenization treatment methods include: adding a clarifying agent and performing stirring and bubbling treatment; wherein the bubbling treatment is performed by introducing oxygen-containing gas for bubbling. (3) The glass melt is formed by the float glass process and then annealed to obtain energy-saving flat glass.

7. The method for preparing flat glass according to claim 6, characterized in that, In step (1), the particle size of barite is 100-200 mesh; the particle size of sodium borate is 30-200 mesh.

8. The method for preparing flat glass according to claim 6, characterized in that, In step (2), the oxygen-containing gas is introduced at a rate of 0.8-1.2 ml / min·100g.

9. The method for preparing flat glass according to claim 6, characterized in that, In step (2), the number of bubbles in the glass liquid is not more than 5 / m 3 , and the diameter of the bubbles is not more than 1 mm.

10. The method for preparing flat glass according to claim 6, characterized in that, In step (2), the temperature difference between different regions in the molten glass is less than 0.5℃.

11. The method for preparing flat glass according to claim 6, characterized in that, In step (3), the cooling rate of the glass is controlled at 5-10℃ / min during the forming process.

12. The method for preparing flat glass according to claim 6, characterized in that, In step (3), the annealing temperature is 520-550℃.

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