Glass clarifying auxiliary agent and preparation method thereof

Abstract

The invention discloses a glass clarifying auxiliary agent and a preparation method thereof, and the glass clarifying auxiliary agent comprises the following raw materials by mass: 60-80% of sodium sulfate, 5-20% of cerium oxide and 10-25% of calcium fluoride. Due to the synergistic effect of all the components, the clarifying effect is excellent in the mixing and melting process with the main raw materials for glass, and the prepared glass product has high transmittance and is suitable for preparation and application of high-transmittance glass for flat plates, automobiles, photovoltaics and the like.

Description

Technical Field

[0001] This invention relates to a glass clarifying agent and its preparation method, belonging to the field of glass preparation technology. Background Technology

[0002] The raw materials used in glassmaking typically include quartz sand, soda ash, and limestone. The purity of these raw materials has a significant impact on the color and transmittance of the glass, especially the Fe content. 2+ The color of the glass is most severely affected. At the same time, during the high-temperature melting process, air bubbles introduced by water vapor, salts, and refractory materials are difficult to remove, which can easily cause bubble defects and thus affect the glass's transmittance and safety performance.

[0003] For example, ultra-clear glass for solar energy applications requires extremely high transmittance, playing a crucial role in photovoltaic modules and significantly impacting their photoelectric conversion efficiency. During the glass melting process, the refractory materials are subject to significant corrosion, which substantially affects the transmittance of the glass products. Therefore, improving the glass melting efficiency is also critical.

[0004] Therefore, developing a highly efficient glass clarifying agent is of great significance. Summary of the Invention

[0005] At least to address one of the problems existing in the prior art, the present invention provides a glass clarifying agent and its preparation method. Through the synergistic effect of sodium sulfate, cerium oxide and calcium fluoride, the clarifying effect is excellent during the mixing and melting process with the main raw materials for glass, and the prepared glass products have high transmittance, which is suitable for the preparation of high-transmittance glass for flat panels, automobiles, photovoltaics and other applications.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a glass clarifying agent comprising the following raw materials, in mass percentage: sodium sulfate 60-80%, cerium oxide 5-20%, and calcium fluoride 10-25%.

[0007] Preferably, the glass clarifying agent is prepared by drying, grinding, mixing, sieving, and vacuum drying sodium sulfate, cerium oxide, and calcium fluoride.

[0008] Preferably, the glass clarifying agent has a particle size greater than 1500 mesh.

[0009] Preferably, the glass clarifying agent is used by mixing the glass clarifying agent with the main raw material for glass, and then melting it at high temperature to prepare glass products.

[0010] Preferably, the glass clarifying agent accounts for 0.3 to 0.8% of the mass of the main raw material for glass.

[0011] Preferably, the main raw material for glass is a main raw material for glass that is melted at 1400~1600℃.

[0012] This invention also provides a method for preparing a glass clarifying agent, comprising the following steps: (1) Weigh the raw materials according to the mass percentage: sodium sulfate, cerium oxide and calcium fluoride, place them in a drying oven to dry, and obtain the dried raw materials; (2) Place the dried raw materials in a horizontal ball mill for ball milling and mixing, and then sieve to obtain a mixture; (3) Place the mixture in a vacuum drying oven for vacuum drying, cool to room temperature, and package to obtain glass additive.

[0013] Preferably, in step (1), the drying conditions are: temperature 100~150℃, time 1~10h.

[0014] Preferably, in step (2), the ball milling mixing conditions are: rotation speed 40~100 rpm, time 2~6h.

[0015] Preferably, in step (2), the sieving conditions are: a 1500-mesh sieve is used.

[0016] Preferably, in step (3), the vacuum drying conditions are: temperature 100~200℃, time 2~8h.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The glass clarifying agent of the present invention uses sodium sulfate, which forms gases such as sulfur trioxide and oxygen during the glass melting process, causing the tiny bubbles introduced by the main glass raw materials to gradually grow larger and then be removed; at the same time, it works synergistically with cerium oxide to effectively oxidize the ferrous ions that cannot be completely removed by raw materials such as quartz sand into ferric ions with weaker coloring ability, thereby improving the transmittance of the glass.

[0018] 2. The glass clarifying agent of the present invention also uses calcium fluoride, which can significantly reduce the viscosity and surface tension of the glass melt during the melting process, help remove bubbles, clarify the glass, and significantly improve the melting effect of the glass, reduce the melting time, and reduce the negative impact of glass melt corroding refractory materials.

[0019] 3. The glass clarifying agent of the present invention has few and simple raw materials, does not introduce excessive alkali metal oxides and other high expansion materials, avoids affecting the expansion coefficient of glass, and thus improves the safety performance of glass.

[0020] 4. In the process of preparing glass clarifying additives, this invention effectively improves the mixing uniformity of glass clarifying additives by controlling the particle size of each component, and can significantly improve the clarifying effect.

[0021] 5. The clarifying agent prepared by this invention is easy to store and does not exhibit moisture absorption or clumping. Detailed Implementation

[0022] The following is a clear and complete description of the technical solutions in the implementation of this invention. The described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents, instruments, or components used without specified manufacturers are all conventional products that can be purchased commercially.

[0023] The main raw material for glass in this invention is a main raw material for glass that can be melted at 1400~1600℃. It is based on quartz sand, soda ash, and limestone, or may be supplemented with auxiliary materials such as feldspar, alumina, and colorants to optimize performance.

[0024] Example 1 A glass clarifying agent comprises the following raw materials, in mass percentage: 60% sodium sulfate, 18% cerium oxide and 22% calcium fluoride.

[0025] The preparation method of this glass clarifying agent includes the following steps: (1) Weigh the raw materials according to the above mass percentages: sodium sulfate, cerium oxide and calcium fluoride, and dry them in a drying oven at 100°C for 10 hours to obtain the dried raw materials; (2) Place the dried raw materials in a horizontal ball mill and ball mill them at a speed of 40 rpm for 6 hours. Then pass the mixture through a 1500-mesh sieve to obtain the mixture. (3) Place the mixture in a vacuum drying oven at 100°C and dry it for 8 hours. Cool it to room temperature and seal it to obtain the glass additive.

[0026] The method of using the glass clarifying agent prepared in Example 1 above is as follows: after the glass clarifying agent is mixed evenly with the main raw material for glass, 0.5% of the mass of the main raw material for glass clarifying agent is melted at 1400℃. The total melting time t (h) is shown in Table 1 to prepare a glass substrate.

[0027] Tests showed that: 1) A 5cm glass strip was used to test the coefficient of thermal expansion (CTE) (×10). -6 / ℃); 2) Prepare a glass substrate with a thickness of 0.3 mm and an area of ​​1 square meter and observe the number of bubbles D (N / bubble) using an optical microscope; 3) Prepare a glass substrate with a thickness of 3 mm and test the transmittance (T%) in the visible light region. The results are shown in Table 1.

[0028] Example 2 A glass clarifying agent comprises the following raw materials, in mass percentage: sodium sulfate 77%, cerium oxide 6%, and calcium fluoride 17%.

[0029] The preparation method of this glass clarifying agent includes the following steps: (1) Weigh the raw materials according to the above mass percentages: sodium sulfate, cerium oxide and calcium fluoride, and dry them in a drying oven at 130°C for 4 hours to obtain the dried raw materials; (2) Place the dried raw materials in a horizontal ball mill and ball mill them at a speed of 90 rpm for 2 hours. Then pass the mixture through a 1500-mesh sieve to obtain the mixture. (3) Place the mixture in a vacuum drying oven at 180°C for 3 hours, cool it to room temperature, and package it to obtain the glass additive.

[0030] The method of using the glass clarifying agent prepared in Example 2 is as follows: after the glass clarifying agent is mixed evenly with the same glass main raw material as in Example 1, 0.6% of the mass of the glass clarifying agent main raw material is melted at 1400℃. The total melting time t (h) is shown in Table 1 to prepare a glass substrate.

[0031] Tests showed that: 1) A 5cm glass strip was used to test the coefficient of thermal expansion (CTE) (×10). -6 / ℃); 2) Prepare a glass substrate with a thickness of 0.3 mm and an area of ​​1 square meter and observe the number of bubbles D (N / bubble) using an optical microscope; 3) Prepare a glass substrate with a thickness of 3 mm and test the transmittance (T%) in the visible light region. The results are shown in Table 1.

[0032] Example 3 A glass clarifying agent comprises the following raw materials, in mass percentage: 70% sodium sulfate, 10% cerium oxide and 20% calcium fluoride.

[0033] The preparation method of this glass clarifying agent includes the following steps: (1) Weigh the raw materials according to the above mass percentages: sodium sulfate, cerium oxide and calcium fluoride, and dry them in a drying oven at 120°C for 8 hours to obtain the dried raw materials; (2) Place the dried raw materials in a horizontal ball mill and ball mill them at a speed of 55 rpm for 5 hours. Then pass the mixture through a 1500-mesh sieve to obtain the mixture. (3) Place the mixture in a vacuum drying oven at 150°C and dry it for 5 hours. Then cool it to room temperature and seal it to obtain the glass additive.

[0034] The method of using the glass clarifying agent prepared in Example 3 is as follows: after the glass clarifying agent is mixed evenly with the same glass main raw material as in Example 1, 0.7% of the mass of the glass clarifying agent main raw material is melted at 1400℃. The total melting time t (h) is shown in Table 1 to prepare a glass substrate.

[0035] Tests showed that: 1) A 5cm glass strip was used to test the coefficient of thermal expansion (CTE) (×10). -6 / ℃); 2) Prepare a glass substrate with a thickness of 0.3 mm and an area of ​​1 square meter and observe the number of bubbles D (N / bubble) using an optical microscope; 3) Prepare a glass substrate with a thickness of 3 mm and test the transmittance (T%) in the visible light region. The results are shown in Table 1.

[0036] Example 4 A glass clarifying agent comprises the following raw materials, in mass percentage: 65% sodium sulfate, 10% cerium oxide and 25% calcium fluoride.

[0037] The preparation method of this glass clarifying agent includes the following steps: (1) Weigh the raw materials according to the above mass percentages: sodium sulfate, cerium oxide and calcium fluoride, and dry them in a drying oven at 140°C for 6 hours to obtain the dried raw materials; (2) Place the dried raw materials in a horizontal ball mill and ball mill them at a speed of 70 rpm for 3.5 hours. Then pass the mixture through a 1500-mesh sieve to obtain the mixture. (3) Place the mixture in a vacuum drying oven at 130°C for 6.5 hours, cool it to room temperature, and package it to obtain the glass additive.

[0038] The method of using the glass clarifying agent prepared in Example 4 above is as follows: after the glass clarifying agent is mixed evenly with the same glass raw material as in Example 1, 0.8% of the mass of the glass clarifying agent raw material is melted at 1400℃. The total melting time t (h) is shown in Table 1 to prepare a glass substrate.

[0039] Tests showed that: 1) A 5cm glass strip was used to test the coefficient of thermal expansion (CTE) (×10). -6 / ℃); 2) Prepare a glass substrate with a thickness of 0.3 mm and an area of ​​1 square meter and observe the number of bubbles D (N / bubble) using an optical microscope; 3) Prepare a glass substrate with a thickness of 3 mm and test the transmittance (T%) in the visible light region. The results are shown in Table 1.

[0040] Example 5 A glass clarifying agent comprises the following raw materials, in mass percentage: 70% sodium sulfate, 20% cerium oxide and 10% calcium fluoride.

[0041] The preparation method of this glass clarifying agent includes the following steps: (1) Weigh the raw materials according to the above mass percentages: sodium sulfate, cerium oxide and calcium fluoride, and dry them in a drying oven at 150°C for 2 hours to obtain the dried raw materials; (2) Place the dried raw materials in a horizontal ball mill and ball mill them at a speed of 80 rpm for 2.5 hours. Then pass the mixture through a 1500-mesh sieve to obtain the mixture. (3) Place the mixture in a vacuum drying oven at 170°C and dry it for 3 hours. Then cool it to room temperature and seal it to obtain the glass additive.

[0042] The method of using the glass clarifying agent prepared in Example 5 is as follows: after the glass clarifying agent is mixed evenly with the same glass raw material as in Example 1, 0.4% of the mass of the glass clarifying agent raw material is melted at 1400℃. The total melting time t (h) is shown in Table 1 to prepare a glass substrate.

[0043] Tests showed that: 1) A 5cm glass strip was used to test the coefficient of thermal expansion (CTE) (×10). -6 / ℃); 2) Prepare a glass substrate with a thickness of 0.3 mm and an area of ​​1 square meter and observe the number of bubbles D (N / bubble) using an optical microscope; 3) Prepare a glass substrate with a thickness of 3 mm and test the transmittance (T%) in the visible light region. The results are shown in Table 1.

[0044] Example 6 A glass clarifying agent comprises the following raw materials, in mass percentage: 80% sodium sulfate, 5% cerium oxide and 15% calcium fluoride.

[0045] The preparation method of this glass clarifying agent includes the following steps: (1) Weigh the raw materials according to the above mass percentages: sodium sulfate, cerium oxide and calcium fluoride, and dry them in a drying oven at 150°C for 1 hour to obtain the dried raw materials; (2) Place the dried raw materials in a horizontal ball mill and ball mill them at a speed of 100 rpm for 2 hours. Then pass the mixture through a 1500-mesh sieve to obtain the mixture. (3) Place the mixture in a vacuum drying oven at 200°C and dry it for 2 hours. Then cool it to room temperature and seal it to obtain the glass additive.

[0046] The method of using the glass clarifying agent prepared in Example 6 above is as follows: after the glass clarifying agent is mixed evenly with the same glass main raw material as in Example 1, 0.3% of the mass of the glass clarifying agent main raw material is melted at 1400℃. The total melting time t (h) is shown in Table 1 to prepare a glass substrate.

[0047] Tests showed that: 1) A 5cm glass strip was used to test the coefficient of thermal expansion (CTE) (×10). -6 / ℃); 2) Prepare a glass substrate with a thickness of 0.3 mm and an area of ​​1 square meter and observe the number of bubbles D (N / bubble) using an optical microscope; 3) Prepare a glass substrate with a thickness of 3 mm and test the transmittance (T%) in the visible light region. The results are shown in Table 1.

[0048] Comparative Example 1 A glass clarifying agent and its preparation method differ from Example 1 in that step (3) is omitted, the agent is passed through a 1500-mesh sieve, cooled to room temperature, and then packaged to obtain the glass clarifying agent. The rest are exactly the same, and the test results are shown in Table 1.

[0049] Comparative Example 2 A glass clarifying agent and its preparation method differ from Example 2 in that: in step (2), the dried raw material is placed in a horizontal ball mill and ball-milled at a speed of 90 rpm for 1 hour, and then passed through a 1000-mesh sieve to obtain a mixture; The rest are exactly the same, and the test results are shown in Table 1.

[0050] Comparative Example 3 A glass clarifying agent and its preparation method differ from Example 3 in that: (1) Weigh the raw materials according to the above mass percentages: sodium sulfate, cerium oxide and calcium fluoride, place them in a horizontal ball mill, and ball mill them at a speed of 55 rpm for 5 hours. Then pass them through a 1500-mesh sieve to obtain the mixture. (2) Place the mixture in a vacuum drying oven at 150°C and vacuum dry for 5 hours. Cool to room temperature and seal to obtain glass additives. The rest are exactly the same, and the test results are shown in Table 1.

[0051] Comparative Example 4 A glass clarifying agent and its preparation method differ from Example 4 in that: sodium sulfate 55%, cerium oxide 20%, and calcium fluoride 25%; The rest are exactly the same, and the test results are shown in Table 1.

[0052] Comparative Example 5 A glass clarifying agent and its preparation method differ from Example 5 in that: sodium sulfate 73%, cerium oxide 20%, and calcium fluoride 7%; The rest are exactly the same, and the test results are shown in Table 1.

[0053] Comparative Example 6 A glass clarifying agent and its preparation method, which differ from Example 6 in that: sodium sulfate 80%, cerium oxide 4%, and calcium fluoride 16%; The rest are exactly the same, and the test results are shown in Table 1.

[0054] Comparative Example 7 A glass clarifying agent and its preparation method differ from Example 3 in that: sodium sulfate 70%, cerium hydroxide 10%, and calcium fluoride 20% are used. The rest are exactly the same, and the test results are shown in Table 1.

[0055] Table 1 Performance Test Results

[0056] As can be seen from Table 1 above, the glass clarifying agent prepared by the present invention, when mixed with the main raw materials for glass, results in glass products with a smaller coefficient of expansion, fewer bubbles, and higher transmittance.

[0057] Compared with Examples 1-6, the glass clarifying additive formulation, component content, and preparation process of the present invention result in a significant difference in the performance of the glass prepared by using the glass clarifying additive in the main raw materials for glass production; specifically as follows: The raw materials of Comparative Example 1 were dried, ball-milled, and sieved, but not vacuum dried. This is because the heat generated during mechanical mixing, stirring, and impact makes it easy to adsorb water vapor from the air during the cooling process to room temperature. As a result, the glass clarifying additive cannot be well dispersed in the entire powder system during the mixing process with the main glass raw materials, resulting in poor clarification effect of the glass products, manifested as low transmittance and a large number of bubbles.

[0058] The raw materials of Comparative Example 2 were mixed for a shorter time in the horizontal ball mill, resulting in poor mixing uniformity and slightly larger particle size, which could only pass through a 1000-mesh sieve. Consequently, the clarification effect of the glass products was poor after the glass clarifying additive was mixed with the main glass raw materials.

[0059] Before mixing the components of Comparative Example 3 in the horizontal ball mill, no pretreatment drying operation was performed. Because the raw materials are very easy to absorb moisture during storage, they were placed in the horizontal ball mill without drying, resulting in obvious agglomeration and reduced mixing uniformity. This led to an increase in the expansion coefficient of the glass products and an increase in the number of local bubbles.

[0060] The glass clarifying agent in Comparative Example 4 introduced a smaller amount of sodium sulfate. Although the introduction of less alkali metal oxide ensured the safety performance of the glass, the sulfur trioxide and oxygen content released when it decomposes above 1300℃ is low, which cannot effectively remove bubbles and reduces transmittance.

[0061] In Comparative Example 5, the glass clarifying additive introduced a low amount of calcium fluoride, resulting in very high viscosity of the glass after high-temperature melting. The bubbles rose slowly in the high-viscosity melt and were removed slowly. At the same time, due to the high viscosity of the melt, the surface tension was high and the melting time was long. However, the refractory material of the furnace wall penetrated into the glass melt in large quantities, further introducing bubbles and increasing the viscosity of the glass melt, leading to an increase in the number of bubbles.

[0062] The glass clarifying agent of Comparative Example 6 contains a small amount of cerium oxide, which decomposes to produce less oxygen. The ferrous ions brought in by raw materials such as quartz sand cannot be effectively converted into ferric ions with lower coloring ability, resulting in a decrease in transmittance. Furthermore, the reduced amount of oxygen cannot promote the removal of small bubbles in the glass melt, leading to an increase in the number of bubbles.

[0063] The glass clarifying agent in Comparative Example 7 used cerium hydroxide, which affected the glass's coefficient of thermal expansion and could not be effectively converted into ferric ions with lower coloring power, resulting in a further decrease in its transmittance. Furthermore, it could not promote the removal of small bubbles in the molten glass, leading to an increase in the number of bubbles.

[0064] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit and essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0065] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A glass clarifying agent, characterized in that, The ingredients include the following raw materials, by mass percentage: sodium sulfate 60-80%, cerium oxide 5-20%, and calcium fluoride 10-25%; The glass clarifying agent is prepared by drying, grinding, mixing, sieving, and vacuum drying sodium sulfate, cerium oxide, and calcium fluoride.

2. The glass clarifying agent according to claim 1, characterized in that, The glass clarifying agent has a particle size greater than 1500 mesh.

3. The glass clarifying agent according to claim 1, characterized in that, The method of using the glass clarifying agent is as follows: after the glass clarifying agent is mixed evenly with the main raw material for glass, it is then melted at high temperature to prepare glass products.

4. The glass clarifying agent according to claim 3, characterized in that, The glass clarifying additive accounts for 0.3 to 0.8% of the mass of the main raw materials for glass.

5. A glass clarifying agent according to claim 3, characterized in that, The main raw material for glass is a main raw material for glass that is melted at 1400~1600℃.

6. A method for preparing the glass clarifying agent according to any one of claims 1 to 5, characterized in that, Includes the following steps: (1) Weigh the raw materials according to the mass percentage: sodium sulfate, cerium oxide and calcium fluoride, place them in a drying oven to dry, and obtain the dried raw materials; (2) Place the dried raw materials in a horizontal ball mill for ball milling and mixing, and then sieve to obtain a mixture; (3) Place the mixture in a vacuum drying oven for vacuum drying, cool to room temperature, and package to obtain glass additive.

7. The method for preparing a glass clarifying agent according to claim 6, characterized in that, In step (1), the drying conditions are: temperature 100~150℃, time 1~10h.

8. The method for preparing a glass clarifying agent according to claim 6, characterized in that, In step (2), the ball milling mixing conditions are: rotation speed 40~100 rpm, time 2~6h.

9. A method for preparing a glass clarifying agent according to claim 6, characterized in that, In step (2), the sieving conditions are: a 1500-mesh sieve is selected.

10. A method for preparing a glass clarifying agent according to claim 6, characterized in that, In step (3), the vacuum drying conditions are: temperature 100~200℃, time 2~8h.

Images