Preparation method of high-quality sodium silicate
Through high-temperature calcination method and graft modification technology, the problem of directly preparing high-purity sodium silicate in the prior art was solved, and the preparation of high-purity sodium silicate and its high-performance application as a binder were realized.
Patent Information
- Application Number
- CN202411725952.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-28
- Publication Date
- 2025-03-14
AI Technical Summary
It is difficult to directly prepare high-purity sodium silicate through quartz sand in the prior art, resulting in the purity of sodium silicate that cannot meet the high quality requirements.
High-purity quartz sand is mixed with soda ash by high-temperature calcination to prepare solid sodium silicate, and then dissolve it into a sodium silicate solution. Through the graft modification method, high-performance modified sodium silicate is prepared using methyltriallyl silane and an initiator.
The preparation of high-purity sodium silicate is achieved, which has good adhesion and high bond strength as a binder, and the hygroscopic resistance of liquid sodium silicate is improved.
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of inorganic silicate processing, and in particular to a method for preparing high-quality sodium silicate. Background Art
[0002] Sodium silicate, commonly known as sodium silicate, has a chemical formula of Na 2 O·nSiO 2 . Industrial sodium silicate is divided into two categories: liquid sodium silicate and solid sodium silicate. Liquid sodium silicate is colorless, transparent, yellow-green, blue-gray or slightly reddish, while solid sodium silicate is colorless, slightly colored, translucent or transparent block glass. Liquid sodium silicate is an important raw material for making glass. It can increase the hardness and toughness of glass, and can also improve the transparency and heat resistance of glass. Liquid sodium silicate is widely used in building materials such as cement, gypsum, and bricks. It can improve the toughness and water resistance of materials and prevent groundwater erosion. Liquid sodium silicate is an auxiliary agent in the textile printing and dyeing process. It can enhance the adhesion of dyes on fibers and improve dyeing effects and color fastness. Liquid sodium silicate is used as a water treatment agent to reduce water hardness and reduce scale formation. The main use of solid sodium silicate is to make liquid sodium silicate. Liquid sodium silicate is called water glass in the industry. In addition, there are new types of water glass such as potassium water glass, sodium potassium water glass, and lithium silicate.
[0003] At present, the main methods for industrial production of sodium silicate include wet process (liquid phase process) and dry process (solid phase process). The wet process is to mix quartz sand and liquid caustic soda (NaOH) in a certain proportion and add them into an autoclave, and use steam to heat the reaction to directly produce liquid water glass. The reaction formula is: 2NaOH+SiO 2 =Na 2 SiO 3 +H 2 O. The dry process is to mix quartz sand and soda ash (Na 2 CO 3 ) are mixed in a certain proportion and heated to about 1400°C in a reverberatory furnace to generate molten sodium silicate. The reaction formula is: Na 2 CO 3 +SiO 2 =Na 2 SiO 3 +CO 2 .
[0004] Normally, the purity of sodium silicate is required to be above 99%, and the purity of high-quality sodium silicate can reach above 99.5%. When manufacturing glass and ceramics, the purity of sodium silicate is required to be even higher. At present, quartz sand is generally used as the raw material for preparing sodium silicate, which has the advantages of wide sources, low cost, and environmental friendliness. However, quartz sand contains not only SiO 2 , also contains Fe 2 O3 、Al 2 O 3 ,MgO,CaO,P 2 O 5 and organic matter and other impurities, so the sodium silicate prepared directly using quartz sand as raw material has low purity and cannot meet the requirements of high-quality sodium silicate. Summary of the invention
[0005] The technical problem to be solved by the present invention is to provide a method for preparing high-quality sodium silicate. High-purity quartz sand is used as a raw material. Solid sodium silicate is first prepared by a high-temperature calcination method. The solid sodium silicate is then dissolved to prepare a sodium silicate solution. The sodium silicate is then grafted and modified. The modified sodium silicate can be used as a binder and has good adhesion to a substrate and high bonding strength.
[0006] The technical problem to be solved by the present invention is achieved by adopting the following technical solutions:
[0007] The present invention provides a method for preparing high-quality sodium silicate, comprising the following preparation steps:
[0008] (1) mixing high-purity quartz sand and soda ash, calcining at high temperature, cooling, and crushing to obtain solid sodium silicate;
[0009] (2) dissolving solid sodium silicate in water to obtain a sodium silicate solution;
[0010] (3) adding methyl triallylsilane and an initiator to the sodium silicate solution, heating the solution for reaction, and obtaining a modified sodium silicate solution.
[0011] Furthermore, the SiO in the high-purity quartz sand in step (1) 2 The content is above 99.9%. Preferably, the SiO 2 The content is above 99.99%.
[0012] Furthermore, the SiO 2 The molar ratio of soda ash to sodium carbonate is 1:(1.2~2). If the amount of soda ash is too little, SiO 2 The reaction is incomplete; if too much soda ash is used, it will lead to soda ash waste and increase costs.
[0013] Furthermore, the high temperature calcination in step (1) is carried out at a temperature of 1300-1400° C. and for a time of 0.5-2 hours. Quartz sand and soda ash are calcined at high temperature to generate molten sodium silicate.
[0014] Furthermore, during the high temperature calcination in step (1), CO is recovered simultaneously. 2 By recycling CO 2To avoid the negative impact of the sodium silicate production process on the environment, and also to speed up the reaction rate.
[0015] Furthermore, the dissolution in step (2) is stirring dissolution or ultrasonic dissolution. The stirring method can be mechanical stirring or magnetic stirring. The dissolution process is carried out at room temperature or under heating conditions, depending on the solubility of the solid sodium silicate. Preferably, the frequency of the ultrasonic dissolution is 20 to 40 kHz, the power is 100 to 500 W, the temperature is 50 to 60° C., and the time is 5 to 30 min.
[0016] Furthermore, the mass ratio of the solid sodium silicate to water in step (2) is 1:(10-20). Using water as a diluent is a convenient and economical choice, and the concentration of the sodium silicate solution can be adjusted as needed by adding an appropriate amount of water to achieve the desired dilution effect.
[0017] Furthermore, the initiator in step (3) is a water-soluble initiator, including but not limited to at least one of dicumyl peroxide, hydrogen peroxide, and ammonium persulfate. The amount of the initiator used is 0.05 to 0.5% of the monomer mass.
[0018] Furthermore, the amount of methyltriallylsilane used in step (3) is 50-100% of the mass of the solid sodium silicate in step (2). If the amount of methyltriallylsilane used is too small, the effect of improving the bonding performance of sodium silicate will not be obvious; if the amount of methyltriallylsilane used is too large, not only will the bonding performance of sodium silicate not be further significantly improved, but the cost will be increased. Therefore, it is necessary to reasonably control the amount of methyltriallylsilane used.
[0019] The invention adopts methyl triallylsilane to graft and modify sodium silicate, realizes the combination of inorganic silicon material and organic silicon material, aims to improve the adhesion of liquid sodium silicate on substrates such as paper, plastic, rubber, metal, etc. when used as a binder and to solidify sand molds in casting, and at the same time improve the moisture absorption resistance of liquid sodium silicate.
[0020] The beneficial effects of the present invention are:
[0021] 1. The present invention uses high-purity quartz sand as raw material, which fundamentally reduces the impurity content in the sodium silicate product, and does not require cumbersome purification operations for the prepared sodium silicate product;
[0022] 2. The present invention first prepares solid sodium silicate by high-temperature calcination of high-purity quartz sand, then dissolves the solid sodium silicate in water to prepare a sodium silicate solution, and then grafts and modifies the sodium silicate. The obtained modified sodium silicate can be used as a binder for a variety of substrates, not only has good adhesion to the substrate, but also has high bonding strength, and can also improve the anti-hygroscopicity of liquid sodium silicate. DETAILED DESCRIPTION
[0023] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below in conjunction with specific embodiments.
[0024] The SiO in the high-purity quartz sand used in the following examples and comparative examples is 2 The content is 99.995% and the particle size is 100-200 mesh.
[0025] Example 1
[0026] (1) Mix high-purity quartz sand with 150g of soda ash and calcine at 1400℃ for 1h. 2 The molar ratio with soda ash is 1:1.5, and CO is recovered during high-temperature calcination. 2 , cooled, and crushed to obtain solid sodium silicate.
[0027] (2) 100 g of the solid sodium silicate prepared in step (1) was ultrasonically dissolved in water, the mass ratio of solid sodium silicate to water being 1:15, the ultrasonic frequency being 28 kHz, the ultrasonic power being 300 W, the ultrasonic temperature being 55° C., and the ultrasonic time being 15 min, to obtain a sodium silicate solution.
[0028] (3) Add 50 g of methyltriallylsilane and 0.3 g of diisopropylbenzene peroxide to the sodium silicate solution prepared in step (2), raise the temperature to 70° C. and react for 8 h to obtain a modified sodium silicate solution.
[0029] Example 2
[0030] (1) Mix high-purity quartz sand with 150g of soda ash and calcine at 1400℃ for 2h. 2 The molar ratio with soda ash is 1:2, and CO is recovered during high-temperature calcination. 2 , cooled, and crushed to obtain solid sodium silicate.
[0031] (2) 100 g of the solid sodium silicate prepared in step (1) was ultrasonically dissolved in water, the mass ratio of solid sodium silicate to water being 1:10, the ultrasonic frequency being 20 kHz, the ultrasonic power being 500 W, the ultrasonic temperature being 50° C., and the ultrasonic time being 10 min, to obtain a sodium silicate solution.
[0032] (3) Add 80 g of methyltriallylsilane and 0.5 g of diisopropylbenzene peroxide to the sodium silicate solution prepared in step (2), raise the temperature to 80° C. and react for 8 h to obtain a modified sodium silicate solution.
[0033] Example 3
[0034] (1) Mix high-purity quartz sand with 150g of soda ash and calcine at 1350℃ for 1.5h. 2 The molar ratio with soda ash is 1:1.8, and CO is recovered during high-temperature calcination. 2 , cooled, and crushed to obtain solid sodium silicate.
[0035] (2) 100 g of the solid sodium silicate prepared in step (1) was ultrasonically dissolved in water, the mass ratio of solid sodium silicate to water being 1:20, the ultrasonic frequency being 40 kHz, the ultrasonic power being 100 W, the ultrasonic temperature being 55° C., and the ultrasonic time being 30 min, to obtain a sodium silicate solution.
[0036] (3) Add 100 g of methyltriallylsilane and 0.5 g of hydrogen peroxide to the sodium silicate solution prepared in step (2), raise the temperature to 75° C. and react for 8 h to obtain a modified sodium silicate solution.
[0037] Example 4
[0038] (1) Mix high-purity quartz sand with 150g of soda ash and calcine at 1300℃ for 0.5h. 2 The molar ratio with soda ash is 1:1.2, and CO is recovered during high-temperature calcination. 2 , cooled, and crushed to obtain solid sodium silicate.
[0039] (2) 100 g of the solid sodium silicate prepared in step (1) was ultrasonically dissolved in water, the mass ratio of solid sodium silicate to water was 1:15, the ultrasonic frequency was 28 kHz, the ultrasonic power was 200 W, the ultrasonic temperature was 60° C., and the ultrasonic time was 20 min to obtain a sodium silicate solution.
[0040] (3) Add 100 g of methyltriallylsilane and 0.5 g of ammonium persulfate to the sodium silicate solution prepared in step (2), raise the temperature to 70° C. and react for 8 h to obtain a modified sodium silicate solution.
[0041] Example 5
[0042] (1) Mix high-purity quartz sand with 150g of soda ash and calcine at 1400℃ for 1h. 2 The molar ratio with soda ash is 1:2, and CO is recovered during high-temperature calcination. 2 , cooled, and crushed to obtain solid sodium silicate.
[0043] (2) 100 g of the solid sodium silicate prepared in step (1) was ultrasonically dissolved in water, the mass ratio of solid sodium silicate to water being 1:15, the ultrasonic frequency being 40 kHz, the ultrasonic power being 400 W, the ultrasonic temperature being 55° C., and the ultrasonic time being 15 min, to obtain a sodium silicate solution.
[0044] (3) Add 100 g of methyltriallylsilane and 0.5 g of diisopropylbenzene peroxide to the sodium silicate solution prepared in step (2), raise the temperature to 80° C. and react for 8 h to obtain a modified sodium silicate solution.
[0045] Comparative Example 1
[0046] The method of Example 1 was followed, except that ethyl acrylate was used instead of methyl triallylsilane.
[0047] (1) Mix high-purity quartz sand with 150g of soda ash and calcine at 1400℃ for 1h. 2 The molar ratio with soda ash is 1:1.5, and CO is recovered during high-temperature calcination. 2 , cooled, and crushed to obtain solid sodium silicate.
[0048] (2) 100 g of the solid sodium silicate prepared in step (1) was ultrasonically dissolved in water, the mass ratio of solid sodium silicate to water being 1:15, the ultrasonic frequency being 28 kHz, the ultrasonic power being 300 W, the ultrasonic temperature being 55° C., and the ultrasonic time being 15 min, to obtain a sodium silicate solution.
[0049] (3) Add 50 g of ethyl acrylate and 0.3 g of diisopropylbenzene peroxide to the sodium silicate solution prepared in step (2), raise the temperature to 70° C. and react for 8 h to obtain a modified sodium silicate solution.
[0050] Comparative Example 2
[0051] The method of Example 1 was followed, except that ethyl acrylate and acrylic acid were used instead of methyl triallylsilane.
[0052] (1) Mix high-purity quartz sand with 150g of soda ash and calcine at 1400℃ for 1h. 2 The molar ratio with soda ash is 1:1.5, and CO is recovered during high-temperature calcination. 2 , cooled, and crushed to obtain solid sodium silicate.
[0053] (2) 100 g of the solid sodium silicate prepared in step (1) was ultrasonically dissolved in water, the mass ratio of solid sodium silicate to water being 1:15, the ultrasonic frequency being 28 kHz, the ultrasonic power being 300 W, the ultrasonic temperature being 55° C., and the ultrasonic time being 15 min, to obtain a sodium silicate solution.
[0054] (3) Add 25 g of ethyl acrylate, 25 g of acrylic acid and 0.3 g of diisopropylbenzene peroxide to the sodium silicate solution prepared in step (2), raise the temperature to 70° C. and react for 8 h to obtain a modified sodium silicate solution.
[0055] Comparative Example 3
[0056] The method of Example 1 was followed, except that the sodium silicate was not graft-modified.
[0057] (1) Mix high-purity quartz sand with 150g of soda ash and calcine at 1400℃ for 1h. 2 The molar ratio with soda ash is 1:1.5, and CO is recovered during high-temperature calcination. 2 , cooled, and crushed to obtain solid sodium silicate.
[0058] (2) 100 g of the solid sodium silicate prepared in step (1) was ultrasonically dissolved in water, the mass ratio of solid sodium silicate to water being 1:15, the ultrasonic frequency being 28 kHz, the ultrasonic power being 300 W, the ultrasonic temperature being 55° C., and the ultrasonic time being 15 min, to obtain a sodium silicate solution.
[0059] The modified sodium silicate solutions prepared in Examples 1 to 5 and Comparative Examples 1 to 2 and the sodium silicate solution prepared in Comparative Example 3 were concentrated under reduced pressure at 55°C to a solid content of 30% to obtain a binder. The binder was mixed with standard sand (70 mesh, SiO 2 The content is 98.5%) and then mixed evenly and injected into the mold. The amount of binder is 3% of the mass of standard sand. After compaction, demoulding is carried out, and it is dried at 150℃ for 30 minutes and then hardened at room temperature for 24 hours. The sample preparation and compressive strength test are carried out according to GB / T 2684-2009, and the residual strength test is carried out after the sample is heated to 600℃ and kept warm for 30 minutes. The results are shown in Table 1.
[0060] Table 1 Compressive strength of samples
[0061]
[0062]
[0063] It can be seen from Table 1 that, compared with Comparative Examples 1 to 3, the modified sodium silicate solutions prepared in Examples 1 to 5 are more suitable as molding sand binders, with high bonding strength and good disintegration properties.
[0064] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.
Claims
1. A method for preparing high-quality sodium silicate, characterized in that: The preparation method comprises the following preparation steps: (1) mixing high-purity quartz sand and soda ash, calcining at high temperature, cooling, and crushing to obtain solid sodium silicate; (2) dissolving solid sodium silicate in water to obtain a sodium silicate solution; (3) adding methyl triallylsilane and an initiator to the sodium silicate solution, heating the solution for reaction, and obtaining a modified sodium silicate solution.
2. The preparation method according to claim 1, characterized in that: The SiO2 content in the high-purity quartz sand in step (1) is above 99.9%.
3. The preparation method according to claim 2, characterized in that: The SiO2 content in the high-purity quartz sand is above 99.99%.
4. The preparation method according to claim 1, characterized in that: The molar ratio of SiO2 to soda ash in the high-purity quartz sand in step (1) is 1:(1.2-2).
5. The preparation method according to claim 1, characterized in that: The high temperature calcination in step (1) is carried out at a temperature of 1300 to 1400° C. and for a time of 0.5 to 2 hours.
6. The preparation method according to claim 1, characterized in that: CO2 is recovered simultaneously during the high-temperature calcination process in step (1).
7. The preparation method according to claim 1, characterized in that: The dissolving in step (2) is stirring dissolving or ultrasonic dissolving; Preferably, the frequency of the ultrasonic dissolution is 20-40 kHz, the power is 100-500 W, the temperature is 50-60° C., and the time is 5-30 min.
8. The preparation method according to claim 1, characterized in that: The mass ratio of the solid sodium silicate to water in step (2) is 1:(10-20).
9. The preparation method according to claim 1, characterized in that: The initiator in step (3) is a water-soluble initiator, selected from at least one of dicumyl peroxide, hydrogen peroxide, and ammonium persulfate.
10. The preparation method according to claim 1, characterized in that: The amount of methyltriallylsilane used in step (3) is 50-100% of the mass of the solid sodium silicate in step (2).