CN111747423B - Preparation method of ultrapure sodium silicate - Google Patents
Preparation method of ultrapure sodium silicate Download PDFInfo
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- CN111747423B CN111747423B CN202010574715.3A CN202010574715A CN111747423B CN 111747423 B CN111747423 B CN 111747423B CN 202010574715 A CN202010574715 A CN 202010574715A CN 111747423 B CN111747423 B CN 111747423B
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/20—Silicates
- C01B33/32—Alkali metal silicates
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/34—Silicon-containing compounds
- C08K3/36—Silica
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K9/00—Use of pretreated ingredients
- C08K9/04—Ingredients treated with organic substances
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- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L83/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers
- C08L83/04—Polysiloxanes
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- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
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- C01P2006/80—Compositional purity
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- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K2201/00—Specific properties of additives
- C08K2201/011—Nanostructured additives
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- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2205/00—Polymer mixtures characterised by other features
- C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
- C08L2205/025—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
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- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2205/00—Polymer mixtures characterised by other features
- C08L2205/03—Polymer mixtures characterised by other features containing three or more polymers in a blend
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Abstract
The invention discloses a preparation method of ultrapure sodium silicate, which relates to the technical field of inorganic materials, and the invention takes fly ash as a preparation raw material of sodium silicate, thereby not only realizing reasonable utilization of fly ash, but also avoiding resource waste and environmental pollution caused by waste of fly ash; the consumption of the quartz sand is reduced by replacing the quartz sand, and the sustainable development is facilitated; and the purity of the prepared sodium silicate is high and reaches more than 99.5 percent, so the prepared sodium silicate can be regarded as the ultrapure sodium silicate, and then the prepared sodium silicate is applied to the field of rubber through the preparation of nano silicon dioxide, and has a reinforcing effect on rubber.
Description
The technical field is as follows:
the invention relates to the technical field of inorganic materials, in particular to a preparation method of ultrapure sodium silicate.
Background art:
sodium silicate, commonly known as sodium silicate, and its aqueous solution, commonly known as water glass, has the chemical formula of Na 2 O.nSiO 2 Belongs to soluble inorganic silicate. Sodium silicate is the most valuable filler in the soap industry, functions as a building, preservative, foam stabilizing in synthetic detergents, and can also be used as a filler in paper making, as a binder in the foundry industry, and for the manufacture of silica gels and silica gels, and is also an important raw material for the production of silica.
At present, the common preparation raw materials of sodium silicate are quartz sand and soda ash, the quartz sand at the present stage has the characteristics of sufficient source and low price, but because the quartz sand belongs to natural resources, the reduction of the consumption of the quartz sand is beneficial to sustainable development.
The fly ash is used as a raw material, the silicon dioxide contained in the fly ash is separated and purified, and then the silicon dioxide and the soda ash are subjected to melting reaction to prepare the sodium silicate, wherein the purity of the prepared sodium silicate is up to 99%, so that the reasonable utilization of the fly ash is realized, and the waste of resources is avoided.
The invention content is as follows:
the invention aims to solve the technical problem of providing a preparation method of ultrapure sodium silicate, which takes fly ash as a raw material, and generates the sodium silicate by fusion reaction with soda ash after purification, thereby realizing reasonable utilization of the fly ash and reducing the consumption of quartz sand.
The technical problem to be solved by the invention is realized by adopting the following technical scheme:
a preparation method of ultrapure sodium silicate takes fly ash as a raw material, and comprises the following specific preparation steps:
(1) Dispersing the fly ash in water, then dropwise adding a sulfuric acid solution to adjust the pH value to 3-5, heating and stirring, filtering, washing filter residues with water, drying, and crushing to obtain silicon micro powder;
(2) Uniformly mixing the silicon micro powder and the soda ash, then sending the mixture into a horse shoe flame kiln, calcining the mixture at a high temperature in an air atmosphere to perform a melting reaction, quenching the mixture with water after the reaction is finished, and drying the mixture to obtain a sodium silicate crude product;
(3) And (3) crushing the sodium silicate crude product into particles, then sending the particles into a high-pressure reaction kettle, introducing high-temperature steam for dissolving, filtering, and taking filtrate to obtain the ultrapure sodium silicate solution.
The mass concentration of the sulfuric acid solution is 5-30%.
The mass ratio of the silicon micropowder to the soda ash is 2-3:1.
The temperature of the melting reaction is 1450-1550 ℃.
The temperature of the high-temperature steam is 145-160 ℃, and the pressure is 0.4-0.6MPa.
The chemical reaction formula of sodium silicate is: na (Na) 2 CO 3 +nSiO 2 →Na 2 O.nSi0 2 +CO 2 ↑
As the fly ash contains Si0 in addition to 2 In addition, it also contains Fe 2 O 3 、Al 2 O 3 And small amounts of other non-metals and metal oxides, and in order to remove these impurities, the invention uses sulfuric acid for preliminary separation, which impurities are largely able to react with sulfuric acid to form water-soluble sulfates, while SiO 2 Does not react with sulfuric acid, so that the filter residue obtained in the step (1) mainly contains SiO 2 。
The invention also utilizes high-temperature steam to dissolve the sodium silicate generated by the melting reaction to obtain a sodium silicate solution, and impurities introduced by the filter residue prepared in the step (1) can be further removed through the operation, so that the purity of the sodium silicate in the final product is improved.
The invention also utilizes the ultrapure sodium silicate solution prepared by the technical scheme to prepare the rubber reinforcing agent, and the specific technical scheme is as follows:
(1) Adding an ultrapure sodium silicate solution into a reaction kettle, introducing preheated carbon dioxide gas, carrying out heat preservation reaction, after the reaction is finished, decompressing, transferring the reaction liquid into an aging tank, aging, filtering, and washing a filter cake with water;
(2) Adding water into the filter cake for pulping, then dropwise adding a sulfuric acid solution, adjusting the pH value of the slurry to 4-7, filtering, washing the filter cake with water, and drying to obtain nano silicon dioxide;
(3) Dissolving 4-fluorobenzothiazole-2-methanol in dimethylformamide, heating and stirring, adding nano silicon dioxide, continuously heating and stirring, cooling, adding water and stirring to form a precipitate, stopping adding water when the precipitate is not increased any more, filtering, washing with water, and drying to obtain the rubber reinforcing agent.
In the step (1), the preheating temperature of the carbon dioxide gas is 40-60 ℃, the reaction temperature is 70-90 ℃, the reaction pressure is 0.01-0.5MPa, and the aging time is 0.5-2h.
The mass concentration of the sulfuric acid solution in the step (2) is 5-30%, and the pH value is preferably 5-6.
In the step (3), the mass ratio of the 4-fluorobenzothiazole-2-methanol to the nano silicon dioxide is 0.5-5, and the heating and stirring temperature is 100-120 ℃.
According to the invention, 4-fluorobenzothiazole-2-methanol is used as a modifier, and as the surface of the nano silicon dioxide contains a large amount of hydroxyl, 4-fluorobenzothiazole-2-methanol is grafted to the surface of the nano silicon dioxide through a hydrogen bond, so that the rubber reinforcing agent is prepared to optimize the reinforcing effect of the nano silicon dioxide. The prior art and common knowledge in the field do not give any suggestion on the technology of preparing the rubber reinforcing agent by using 4-fluorobenzothiazole-2-methanol as the nano silica modifier.
The invention has the beneficial effects that: the fly ash is used as the preparation raw material of the sodium silicate, so that the reasonable utilization of the fly ash is realized, and the resource waste and the environmental pollution caused by the waste of the fly ash are avoided; the consumption of the quartz sand is reduced by replacing the quartz sand, and the sustainable development is facilitated; and the purity of the prepared sodium silicate is high and reaches more than 99.5 percent, so the prepared sodium silicate can be regarded as the ultrapure sodium silicate, and then the prepared sodium silicate is applied to the field of rubber through the preparation of nano silicon dioxide, and has a reinforcing effect on rubber.
The specific implementation mode is as follows:
in order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further described with the specific embodiments.
Example 1
Preparation of ultrapure sodium silicate:
(1) Dispersing 3kg of fly ash in 10kg of water, then dropwise adding a sulfuric acid solution with the mass concentration of 25% to adjust the pH value to 4, heating to 80 ℃, stirring for 3 hours, filtering, washing filter residues with water, drying in an oven at 80 ℃, and crushing to obtain silicon micropowder;
(2) Uniformly mixing 2kg of silicon micropowder and 1kg of soda ash, then sending the mixture into a horse shoe flame kiln, calcining the mixture at high temperature in the air atmosphere to perform fusion reaction, wherein the calcining temperature is 1500 ℃, the calcining time is 8 hours, water quenching is performed after the reaction is finished, and the mixture is dried in an oven at 80 ℃ to obtain a sodium silicate crude product;
(3) And (3) crushing the sodium silicate crude product into particles, then sending the particles into a high-pressure reaction kettle, introducing high-temperature steam for dissolving, wherein the temperature of saturated steam is 145 ℃, filtering, and taking filtrate to obtain the ultrapure sodium silicate solution.
Example 2
Preparation of ultrapure sodium silicate:
(1) Dispersing 3kg of fly ash in 10kg of water, then dropwise adding a sulfuric acid solution with the mass concentration of 25% to adjust the pH value to 3, heating to 80 ℃, stirring for 4 hours, filtering, washing filter residues with water, drying in an oven at 80 ℃, and crushing to obtain silicon micropowder;
(2) Uniformly mixing 2kg of silicon micropowder and 1kg of soda ash, then sending the mixture into a horse shoe flame kiln, calcining the mixture at high temperature in the air atmosphere to perform fusion reaction, wherein the calcining temperature is 1500 ℃, the calcining time is 8 hours, water quenching is performed after the reaction is finished, and the mixture is dried in an oven at 80 ℃ to obtain a sodium silicate crude product;
(3) And (3) crushing the sodium silicate crude product into particles, then sending the particles into a high-pressure reaction kettle, introducing high-temperature steam for dissolving, wherein the temperature of saturated steam is 145 ℃, filtering, and taking filtrate to obtain the ultrapure sodium silicate solution.
The ultrapure sodium silicate solutions prepared in examples 1 and 2 were concentrated to remove water and dried, and the purity of the sodium silicate contained therein was measured to be 99.54% and 99.68%, respectively.
Example 3
Preparation of rubber reinforcing agent:
(1) Adding 1kg of the ultrapure sodium silicate solution prepared in the example 1 into a reaction kettle, introducing carbon dioxide gas preheated to 50 ℃, carrying out heat preservation reaction for 3h at the temperature of 85 ℃ under the pressure of 0.1MPa, releasing pressure after the reaction is finished, transferring the reaction liquid into an aging tank, aging for 1h, filtering, and washing a filter cake with water;
(2) Adding water with the weight 5 times that of the filter cake to prepare pulp, then dropwise adding a sulfuric acid solution with the mass concentration of 25%, adjusting the pH value of the pulp to 6, filtering, washing the filter cake with water, and drying to obtain nano silicon dioxide;
(3) Dissolving 4g of 4-fluorobenzothiazole-2-methanol in dimethylformamide, heating to 110 ℃, preserving heat and stirring for 10min, adding 20g of nano-silica, continuing heating to 110 ℃, preserving heat and stirring for 2h, cooling, adding water and stirring to form precipitates, stopping adding water when the precipitates are not increased any more, filtering, washing with water, and drying in an oven at 80 ℃ to obtain the rubber reinforcing agent.
Comparative example 1
Comparative example 1 differs from example 3 in that 4-fluorobenzothiazole-2-methanol was replaced with the same amount of silane coupling agent KH560.
Comparative example 2
Comparative example 2 is different from example 3 in that the nano silica prepared in the step (2) is directly used as a rubber reinforcing agent.
The raw materials were prepared according to the raw material ratio in table 1, and the rubber reinforcing agents prepared in example 3, comparative example 1 and comparative example 2 were used as reinforcing agents.
TABLE 1
All the raw materials in the table 1 are added into a double-roll mill to be mixed for 30min at 85 ℃, then the mixture is heated to 100 ℃, vacuumized for 30min at the vacuum degree of-0.08 MPa, and vulcanized on a flat vulcanizing machine at the vulcanization condition of 155 ℃ for 90min to obtain the rubber material.
Determining the tensile strength and the elongation at break by referring to the standard GB/T528-2009 determination of tensile stress strain performance of vulcanized rubber or thermoplastic rubber; standard GB/T1687.1-2016 determination of temperature rise and fatigue resistance in flexure tests for vulcanizates part 1: the basic principle "shows the temperature rise, and the measurement results are shown in Table 2.
TABLE 2
| Group number | Tensile strength/MPa | Elongation at break/%) | Temperature rise/. Degree.C |
| Example 3 | 36.8 | 625 | 10 |
| Comparative example 1 | 32.4 | 597 | 18 |
| Comparative example 2 | 27.3 | 540 | 25 |
As can be seen from the table 2, the reinforcing agent prepared by using the 4-fluorobenzothiazole-2-methanol as the nano-silica modifier can better optimize the mechanical property and the fatigue resistance of the prepared rubber material.
The foregoing shows and describes the general principles and broad features of the present invention and advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (8)
1. The method for preparing the rubber reinforcing agent by using the ultrapure sodium silicate solution is characterized by comprising the following specific technical scheme:
(1) Adding an ultrapure sodium silicate solution into a reaction kettle, introducing preheated carbon dioxide gas, carrying out heat preservation reaction, after the reaction is finished, decompressing, transferring the reaction liquid into an aging tank, aging, filtering, and washing a filter cake with water;
(2) Adding water into the filter cake for pulping, then dropwise adding a sulfuric acid solution, adjusting the pH value of the slurry to 4-7, filtering, washing the filter cake with water, and drying to obtain nano silicon dioxide;
(3) Dissolving 4-fluorobenzothiazole-2-methanol in dimethylformamide, heating and stirring, adding nano silicon dioxide, continuing heating and stirring, cooling, adding water and stirring to form precipitates, stopping adding water when the precipitates are not increased any more, filtering, washing with water, and drying to obtain a rubber reinforcing agent;
the ultrapure sodium silicate solution is prepared from fly ash as a raw material by the following specific steps:
(1) Dispersing the fly ash in water, then dropwise adding a sulfuric acid solution to adjust the pH value to 3-5, heating and stirring, filtering, washing filter residues with water, drying, and crushing to obtain silicon micro powder;
(2) Uniformly mixing the silicon micropowder and soda ash, then sending the mixture into a horse shoe flame kiln, calcining the mixture at high temperature in air atmosphere to perform melting reaction, quenching the mixture with water after the reaction is finished, and drying the mixture to obtain a crude product of sodium silicate;
(3) And (3) crushing the sodium silicate crude product into particles, then sending the particles into a high-pressure reaction kettle, introducing high-temperature steam for dissolving, filtering, and taking filtrate to obtain the ultrapure sodium silicate solution.
2. The method of claim 1, wherein: the mass concentration of the sulfuric acid solution is 5-30%.
3. The method of claim 1, wherein: the mass ratio of the silicon micropowder to the soda ash is 2-3:1.
4. The method of claim 1, wherein: the temperature of the melting reaction is 1450-1550 ℃.
5. The method of claim 1, wherein: the temperature of the high-temperature steam is 145-160 ℃, and the pressure is 0.4-0.6MPa.
6. The method of claim 1, wherein: in the step (1), the preheating temperature of the carbon dioxide gas is 40-60 ℃, the reaction temperature is 70-90 ℃, the reaction pressure is 0.01-0.5MPa, and the aging time is 0.5-2h.
7. The method of claim 1, wherein: the mass concentration of the sulfuric acid solution in the step (2) is 5-30%, and the pH value is preferably 5-6.
8. The method of claim 1, wherein: in the step (3), the mass ratio of the 4-fluorobenzothiazole-2-methanol to the nano silicon dioxide is 0.5-5, and the heating and stirring temperature is 100-120 ℃.
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| GB813453A (en) * | 1954-12-14 | 1959-05-13 | Columbia Southern Chem Corp | Silica pigments |
| GB2464136A (en) * | 2008-10-06 | 2010-04-07 | Dsi Dimona Silica Ind Ltd | A dispersible silica characterised by DBP absorption capacity |
| JP2011012131A (en) * | 2009-06-30 | 2011-01-20 | Sumitomo Rubber Ind Ltd | Rubber composition for tire and pneumatic tire |
| CN102424392A (en) * | 2011-09-11 | 2012-04-25 | 中国科学院过程工程研究所 | Method for preparing white carbon black cogeneration nanometer calcium carbonate by integrally utilizing micro silicon powder |
| CN102936016B (en) * | 2012-11-12 | 2014-06-18 | 山西大学 | Method for preparing soluble glass by using waste residues with aluminum extracted by coal gangue |
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