CN114773070A - Preparation method of alumina continuous fiber by using aluminum carboxylate sol as precursor - Google Patents
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Abstract
The application discloses a preparation method of alumina continuous fibers by taking aluminum carboxylate sol as a precursor, which comprises the following steps: (1) preparing aluminum carboxylate sol; (2) preparing a spinnable aluminum carboxylate precursor sol; (3) preparing alumina gel fiber; (4) and (3) ceramization of the alumina gel fiber. The preparation method can obtain the high-strength alumina continuous fiber which has long continuous filament collecting distance, high tensile strength, excellent high temperature resistance and excellent weavability.
Description
Technical Field
The application relates to a preparation method of alumina continuous fibers by taking aluminum carboxylate sol as a precursor, belonging to the technical field of inorganic nonmetallic materials.
Background
The alumina continuous fiber is a novel fiber material with corrosion resistance, high temperature resistance, high modulus and high strength, has wide commercial prospect and has great strategic significance in the fields of aerospace, war industry and the like. Alumina fibers are composed primarily of alumina, which contains a certain amount of other components, such as silica, magnesia, zirconia, ferric oxide, yttria, boria, and the like.
At present, most of alumina continuous fibers with excellent performance adopt a sol-gel method, namely, an alcohol or aqueous solution of aluminum salt is used as a raw material, an aluminum sol containing abundant linear structure polymers is prepared through hydrolytic polymerization, and then the alumina fibers are prepared through aging and heat treatment. At present, the precursor sol of the alumina fiber mainly comprises three types: aluminum chloride sol, aluminum nitrate sol, and aluminum carboxylate sol. Aluminum chloride sol is prepared by using aluminum powder and aluminum chloride as aluminum sources, and controlling the molar ratio of the aluminum powder to the aluminum chloride. Tan et al prepared a sol from aluminum powder and aluminum chloride by controlling the molar ratio of aluminum content to water, and prepared an aluminum chloride sol having good spinnability when the molar ratio of aluminum powder to aluminum chloride was 3.4 to 3.8 (see: J.Sol-Gel Sci.Technol.2010,53,378).
US3322865 discloses a method for preparing alumina fiber using aluminum chloride sol as precursor, which comprises heating and filtering aluminum filament and aluminum chloride to obtain stable aluminum chloride sol, and dry spinning to obtain alumina short fiber. This method is difficult to be used in actual production because the aluminum chloride sol causes corrosion of equipment in the actual spinning process. Okada et al investigated the effect of the molar ratio of aluminum powder to aluminum nitrate on the aluminum sol by reacting the aluminum powder with aluminum nitrate and prepared a sol with good spinnability (see: j. europ. center. soc.1988,18,1879). Wujianfeng et al obtained a more stable alumina sol by adding ammonia water to an aluminum nitrate solution and then back-dissolving with nitric acid (see: ceramics letters 2007,3, 155). The gel fiber prepared from the aluminum nitrate sol can release harmful nitrogen oxides in the ceramic sintering process, and causes pollution to the environment.
Liu et al prepared an aluminum carboxylate sol by dispersing aluminum powder in formic acid, acetic acid and deionized water, reacted at 95 ℃ and obtained alumina fibers having smooth surfaces and uniform diameters by dry spinning, but did not discuss the strength and other relevant properties of the fibers (see: mater. Res. express 2019,6, 045207). US patent document 4047965 prepares an aluminum carboxylate sol having spinnability using basic aluminum formate solution, silica sol, lactic acid and corn syrup, but it is expensive and difficult to popularize in actual production. Chinese patent document CN110004521B discloses an aluminum carboxylate sol prepared from amorphous alumina, formic acid and acetic acid, but does not discuss the strength performance of the obtained fiber, and the method has the problem of high breakage rate when preparing continuous fiber, and continuous fiber with high strength cannot be obtained in the actual spinning process.
Disclosure of Invention
In order to solve the problems, the preparation method of the alumina continuous fiber using the aluminum carboxylate sol as the precursor is provided, and the preparation method can obtain the high-strength alumina continuous fiber which has long continuous filament receiving distance, high tensile strength and excellent high-temperature resistance and weavability.
According to one aspect of the present application, there is provided a method for preparing alumina continuous fibers using an aluminum carboxylate sol as a precursor, comprising the steps of:
(1) preparation of an aluminum carboxylate Sol
Adding a mixed solution of micromolecular carboxylic acid into the amorphous aluminum hydroxide turbid liquid, stirring and centrifugally filtering to prepare aluminum carboxylate sol with the solid content of 2-10%, and taking Al as the aluminum carboxylate sol2O3Counting;
(2) preparation of spinnable aluminium carboxylate precursor sol
Adding silica sol into the aluminum carboxylate sol obtained in the step (1), then adding a drying control agent and a reaction auxiliary agent, uniformly mixing to obtain mixed sol, and heating and aging the mixed sol to obtain spinnable aluminum carboxylate precursor sol;
(3) preparation of alumina gel fiber
Carrying out dry spinning on the spinnable aluminum carboxylate precursor sol prepared in the step (2) to obtain alumina gel fibers;
(4) ceramization of alumina gel fibers
And (4) moving the alumina gel fiber prepared in the step (3) into a furnace, gradually raising the temperature and preserving the heat in three stages, and finally obtaining the alumina continuous fiber.
Optionally, in the step (1), the solid content of the amorphous aluminum hydroxide suspension is 5-15%, and Al (OH)3Counting; the molar ratio of the small molecular carboxylic acid to the aluminum hydroxide in the step (1) is (1-2): 1.
Optionally, the mixed solution of small-molecule carboxylic acids in step (1) is a mixed solution of at least three of formic acid, acetic acid, propionic acid and n-butyric acid.
Optionally, the ratio of the total weight of formic acid and acetic acid to the weight of propionic acid and/or n-butyric acid in the mixed solution of the small-molecule carboxylic acid is (3-4): (1.6-2.5).
Optionally, the drying control agent is at least one or more of glycerol, erythritol, ethylene glycol, dimethylformamide, diethylene glycol, glucose, polyvinyl alcohol (PVA), polyethylene oxide (PEO), polyvinylpyrrolidone (PVP), hydroxyethyl cellulose, lactic acid, tartaric acid, and citric acid;
the reaction auxiliary agent is at least one or more of ethylene glycol, diethylene glycol, glucose, hydroxyethyl cellulose, lactic acid, tartaric acid and citric acid.
Optionally, the aging temperature in the step (2) is 30-60 ℃, and the vacuum degree in the aging process is 0.093-0.1 MPa.
Preferably, the viscosity of the spinnable aluminum carboxylate precursor sol in the step (2) is 20-800 Pa.s.
Optionally, the parameters of the dry spinning in the step (3) are that the ambient temperature is 20-42 ℃ and the ambient humidity is 15-65%.
Preferably, the parameters of the dry spinning in the step (3) further comprise that the number of spinneret holes is 100-800, the aperture is 0.05-0.20 mm, and the filament winding speed is 60-140 m/min.
Optionally, in the first stage in the step (4), the temperature is raised to 200-300 ℃ at a rate of 1-5 ℃/min, and the temperature is maintained for 1-2 hours.
Optionally, in the second stage of the step (4), the temperature is raised to 600-750 ℃ at a rate of 0.5-3 ℃/min, and the temperature is maintained for 0.5-2 h.
Optionally, in the third stage in the step (4), the temperature is increased to 1200-1400 ℃ at a rate of 8-10 ℃/min, and the temperature is maintained for 0.5-1.5 h.
Benefits of the present application include, but are not limited to:
1. according to the preparation method of the alumina continuous fiber with the aluminum carboxylate sol as the precursor, the aluminum carboxylate sol prepared by the sol-gel method is simple to operate and low in cost, the polymerization degree of the sol is improved, the spinning performance and the stability are better, and the industrial production is easy to realize.
2. According to the preparation method of the alumina continuous fiber with the aluminum carboxylate sol as the precursor, the aluminum carboxylate sol prepared from amorphous aluminum hydroxide and micromolecular carboxylic acid, propionic acid and n-butyl acid groups have stronger coordination capacity in aluminum oligomers as coordination groups, the aluminum oligomers are favorably formed in the aging process, and the propionic acid and n-butyl acid groups have longer chain structures compared with formate groups and acetate groups, so that the aluminum polymer with a long linear structure can be formed, and the prepared alumina gel fiber has good spinnability and stretchability.
3. According to the preparation method of the alumina continuous fiber with the aluminum carboxylate sol as the precursor, the limited drying control agent and the limited reaction auxiliary agent are added, so that the rapid volatilization of the moisture and the carboxylic acid in the gel fiber can be prevented, the internal and external structures of the gel fiber are protected, the defects are avoided, the structure of the gel fiber is effectively protected, the flexible continuous gel fiber with the fine diameter of thousands of meters can be obtained under the appropriate environment, the prepared alumina continuous fiber has excellent spinning continuity and stability, the gel fiber does not need to be dried and pretreated, the continuous fiber can be directly calcined, and the industrial continuous production is easy to realize.
4. According to the preparation method of the alumina continuous fiber with the aluminum carboxylate sol as the precursor, the alumina continuous fiber prepared by calcining the specific raw material components in three stages by using a specific temperature curve is uniform in diameter, smooth in surface and free of defects, compact in internal structure, 7-10 mu m in fiber monofilament diameter, 2.1GPa in monofilament tensile strength and 180GPa in modulus, and is a high-strength alumina continuous fiber with excellent high-temperature resistance and weavability.
Drawings
The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:
FIG. 1 is an XRD spectrum of an alumina continuous fiber prepared in example 1 of the present application;
FIG. 2 is an optical photograph of the alumina continuous gel fiber prepared in example 1 of the present application;
FIG. 3 is an SEM photograph of alumina continuous fibers prepared in example 1 of the present application;
FIG. 4 is a high magnification SEM photograph of alumina continuous fibers prepared in example 1 of the present application;
FIG. 5 is a high magnification SEM photograph of a cross section of the alumina continuous fiber prepared in example 1 of the present application.
Detailed Description
The present application will be described in detail with reference to examples, but the present application is not limited to these examples.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The reagents or starting materials used in the present invention can be purchased from conventional sources, and unless otherwise specified, the reagents or starting materials used in the present invention can be used in a conventional manner in the art or in accordance with the product specification. In addition, any methods and materials similar or equivalent to those described herein can be used in the methods of the present invention. The preferred methods and materials described in this patent are for illustrative purposes only.
The following examples and comparative examples use an amorphous aluminum hydroxide suspension and a silica sol which is a silica sol of type DY-12C of Hibiscus rosa-sinensis, Qingdao, as commercially available products.
Example 1 alumina continuous fibers 1#
(1) Preparation of an aluminum carboxylate Sol
100kg of a suspension of amorphous aluminum hydroxide having a solids content of 5% are weighed out, in terms of Al (OH)3To this, a mixed solution of 1.62kg of formic acid, 1.50kg of acetic acid, 1.17kg of propionic acid and 1.1kg of n-butyric acid mixed uniformly was added, stirred and subjected to centrifugal filtration to obtain an aluminum carboxylate sol having a solid content of 3.11% and containing Al2O3Counting;
(2) preparation of spinnable aluminum carboxylate precursor sol
Adding 7.29kg of silica sol with the solid content of 20% into the aluminum carboxylate solution obtained in the step (1), adding a mixed solution which is prepared from 375g of glycerol and 124g of glycol and has the mass fraction of 50%, and uniformly stirring to obtain mixed sol; putting the mixed sol into a rotary evaporation bottle, setting the aging temperature to be 45 ℃, the vacuum degree of the rotary evaporation bottle to be 0.098MPa, and aging until the viscosity is 342 pas to obtain a spinnable aluminum carboxylate precursor sol;
(3) preparation of alumina gel fiber by dry spinning
And (3) carrying out dry spinning on the spinnable aluminum carboxylate precursor sol prepared in the step (2), wherein the parameters in the spinning process are as follows: the environment temperature is 32 ℃, the environment humidity is 40%, the number of spinneret orifices is 200, the aperture is 0.1mm, and the filament collecting speed is 80 m/min;
(4) ceramization of alumina gel fibers
Quickly transferring the alumina gel fiber prepared in the step (3) into a furnace, heating to 270 ℃ at the speed of 1 ℃/min, and preserving heat for 1h at the temperature; heating to 600 deg.C at a speed of 2 deg.C/min, and maintaining at the temperature for 1 h; heating to 1200 deg.C at a rate of 10 deg.C/min, and maintaining the temperature for 1.5h to obtain alumina continuous fiber No. 1.
The finally obtained alumina continuous fiber 1# can be continuously wound for thousands of meters, the diameter is 8.8-9.7 mu m, and the fiber shrinkage rate is about 48%; the fiber has compact inside, smooth appearance, monofilament strength of 2.1GPa, obvious gamma-Al main crystal phase as shown in figure 12O3。
A plain optical photograph of the alumina continuous fiber 1# is shown in fig. 2, an SEM photograph of the alumina continuous fiber 1# is shown in fig. 3, a high magnification SEM photograph is shown in fig. 4, and a high magnification SEM photograph of a fiber cross section is shown in fig. 5. As can be seen from the above pictures, the alumina continuous fiber 1# obtained by the preparation method defined in the present application has smooth outer surface, dense inner part, and few defects and pores, which also provides a basis for the high strength of the alumina continuous fiber.
Example 2 alumina continuous fibers No. 2
(1) Preparation of an aluminum carboxylate sol
100kg of a suspension of amorphous aluminum hydroxide having a solids content of 5% are weighed out, and Al (OH)3To this, a mixed solution of 2.11kg of formic acid, 1.80kg of acetic acid and 1.88kg of n-butyric acid was added, and the mixture was stirred and centrifuged to obtain an aluminum carboxylate sol having a solid content of 2.93% and containing Al2O3Counting;
steps (2) to (4) are the same as steps (2) to (4) in example 1.
The finally obtained alumina continuous fiber 2# can be continuously wound for thousands of meters, the diameter is 9.1-9.7 mu m, and the fiber shrinkage rate is about 48%; the fiber has compact inside, smooth surface, 1.97GPa of monofilament strength, and gamma-Al as the main crystal phase2O3。
Example 3 alumina continuous fibers 3#
Step (1) is the same as step (1) of example 1;
(2) preparation of spinnable aluminium carboxylate precursor sol
Adding 7.29kg of silica sol with the solid content of 20% into the aluminum carboxylate solution obtained in the step (1), adding a mixed solution with the mass fraction of 50% prepared from 750g of ethylene glycol and 103g of glucose, and uniformly stirring to obtain a mixed sol; putting the mixed sol into a rotary evaporation bottle, setting the aging temperature to be 45 ℃, the vacuum degree of the rotary evaporation bottle to be 0.098MPa, and aging until the viscosity is 388 Pa.s to obtain a spinnable aluminum carboxylate precursor sol;
the steps (3) to (4) are the same as in example 1.
The finally obtained alumina continuous fiber 3# can be continuously wound for thousands of meters, the diameter is 9.3-9.8 mu m, and the fiber shrinkage rate is about 48%; the fiber has compact interior and smooth appearance, the monofilament strength is 1.89GPa, and the main crystal phase of the fiber is gamma-Al2O3。
Example 4 alumina continuous fibers 4#
Step (1) is the same as step (1) of example 2, and step (2) is the same as step (2) of example 3;
(3) preparation of alumina gel fiber by dry spinning
And (3) carrying out dry spinning on the spinnable aluminum carboxylate precursor sol prepared in the step (2), wherein the parameters in the spinning process are that the ambient temperature is 27 ℃, the ambient humidity is 35%, the number of spinneret holes is 400, the aperture is 0.08mm, and the filament winding speed is 120 m/min.
Step (4) is the same as step (4) of example 1.
The finally obtained alumina continuous fiber No. 4 can be continuously wound for thousands of meters, the diameter is 8.9-9.7 mu m, and the fiber shrinkage rate is about 47%; the fiber has compact inside, smooth surface, 1.92GPa of monofilament strength, and gamma-Al as the main crystal phase2O3。
Example 5 alumina continuous fibers 5#
Step (1) is the same as step (1) of example 2, step (2) is the same as step (2) of example 3, and step (3) is the same as step (3) of example 1;
(4) ceramization of alumina gel fibers
Quickly transferring the alumina gel fiber prepared in the step (3) into a furnace, heating to 200 ℃ at the speed of 0.5 ℃/min, and preserving heat for 1h at the temperature; then heating to 660 ℃ at the speed of 1.5 ℃/min, and preserving the heat for 1.5h at the temperature; heating to 1200 deg.C at a rate of 10 deg.C/min, and maintaining the temperature for 1 hr to obtain alumina continuous fiber No. 5.
The finally obtained alumina continuous fiber No. 5 can be continuously wound for thousands of meters, the diameter is 9.3-9.7 mu m, and the fiber shrinkage rate is about 48 percent; the fiber has compact inside, smooth surface, monofilament strength of 1.88GPa, and main crystal phase of gamma-Al2O3。
Example 6 alumina continuous fibers 6#
Step (1) is the same as step (1) of example 1;
(2) preparation of spinnable aluminum carboxylate precursor sol
Adding 7.29kg of silica sol with the solid content of 20% into the aluminum carboxylate solution obtained in the step (1), adding 443g of ethylene glycol and 200g of diethylene glycol to prepare a mixed solution with the mass fraction of 50%, and uniformly stirring to obtain a mixed sol; putting the mixed sol into a rotary evaporation bottle, setting the aging temperature to be 45 ℃, the vacuum degree of the rotary evaporation bottle to be 0.098MPa, and aging until the viscosity is 388 Pa.s to obtain a spinnable aluminum carboxylate precursor sol;
steps (3) to (4) are the same as steps (3) to (4) of example 1.
The finally obtained alumina continuous fiber No. 6 can be continuously wound for thousands of meters, the diameter is 9.0-10.2 mu m, and the fiber shrinkage rate is about 47%; the fiber has compact inside, smooth surface, 1.76GPa of monofilament strength, and gamma-Al as the main crystal phase2O3。
Comparative example 1 alumina continuous fiber 7#
(1) Preparation of an aluminum carboxylate Sol
100kg of a suspension of amorphous aluminum hydroxide having a solids content of 5% are weighed out, and Al (OH)3To this, a mixed solution of 2.65kg of formic acid and 2.74kg of acetic acid which were mixed uniformly was added, stirred and centrifuged to obtain an aluminum carboxylate sol having a solid content of 3.08% as Al2O3And (6) counting.
Steps (2) to (4) are the same as steps (2) to (4) of example 1.
The diameter of the finally prepared aluminum oxide continuous fiber 7# is 9.4-10.6 microns, the fiber shrinkage rate is about 50%, the strength of a fiber monofilament is 1.21GPa, the strength of the fiber monofilament is reduced compared with that of the fiber monofilament prepared in the embodiment 1, the fiber monofilament is easy to break in the fiber spinning process, the spinning continuity is poor, and the fiber cannot be collected.
Comparative example 2 alumina continuous fiber No. 8#
(1) Preparation of an aluminum carboxylate Sol
100kg of a suspension of amorphous aluminum hydroxide having a solids content of 5% are weighed out, and Al (OH)3To this, a mixed solution of 2.45kg of formic acid, 2.58kg of acetic acid and 480g of n-butyric acid mixed uniformly was added, stirred and centrifuged to obtain an aluminum carboxylate sol having a solid content of 2.8% and containing Al2O3And (6) counting.
Steps (2) to (4) are the same as steps (2) to (4) of example 1.
The diameter of the finally prepared alumina continuous fiber 8# is 9.4-9.9 mu m, the fiber shrinkage rate is about 48%, the strength of a fiber monofilament is 1.42GPa, the strength of the fiber monofilament is reduced compared with that of the fiber monofilament in example 1, and the strength of the fiber monofilament is improved compared with that of comparative example 1, but the fiber monofilament is easy to break in the fiber spinning process, the spinning continuity is poor, and only hundreds of meters of filament can be collected.
Comparative example 3 alumina continuous fiber 9#
Step (1) is the same as step (1) of example 1;
(2) preparation of spinnable aluminium carboxylate precursor sol
Adding 7.29kg of silica sol with the solid content of 20% into the aluminum carboxylate solution obtained in the step (1), and then uniformly stirring to obtain mixed sol; putting the mixed sol into a rotary evaporation bottle, setting the aging temperature to be 45 ℃, the vacuum degree of the rotary evaporation bottle to be 0.098MPa, and aging until the viscosity is 368 Pa.s to obtain a spinnable aluminum carboxylate precursor sol;
steps (3) to (4) are the same as steps (3) to (4) of example 1.
The diameter of the finally prepared alumina continuous fiber 9# is 9.6-10.6 mu m, and the fiber shrinkage rate is about 48%; the fiber is compact in interior and smooth in appearance, the strength of the monofilament is 1.74GPa, but yarn breakage is easily caused in the spinning process, the spinning continuity is poor, and yarn collection cannot be realized.
From the above examples 1-6, it can be seen that the alumina continuous fiber obtained by the preparation method defined in the present application can continuously take up several kilometers, the fiber diameter is 7-10 μm, the length reaches 1500m, the monofilament strength can reach 2.1GPa, the modulus can reach 180GPa, and the fiber has excellent strength and weavability.
From comparative examples 1 to 3, it can be seen that the filament strength and spinning continuity of the finally obtained fiber are poor with only formic acid and acetic acid in the small molecular carboxylic acid of comparative example 1, and the filament strength and spinning continuity of the finally obtained fiber are poor with the n-butyric acid addition amount of comparative example 2 being less than the range defined in the present application, and that the filament strength of the alumina continuous fiber is remarkably enhanced and the spinning continuity thereof is also improved when the small molecular carboxylic acid is mixedly added as compared with the alumina continuous fiber obtained by adding only formic acid and acetic acid.
In comparative example 3, no drying control agent and no reaction auxiliary agent were used, and the finally obtained fiber had poor spinning continuity and could not be collected.
The above description is only an example of the present application, and the protection scope of the present application is not limited by these specific examples, but is defined by the claims of the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the technical idea and principle of the present application should be included in the protection scope of the present application.
Claims (10)
1. A method for preparing alumina continuous fibers by taking aluminum carboxylate sol as a precursor is characterized by comprising the following steps:
(1) preparation of an aluminum carboxylate Sol
Adding a mixed solution of micromolecular carboxylic acid into the amorphous aluminum hydroxide suspension, stirring, centrifuging and filtering to obtain aluminum carboxylate sol with the solid content of 2-10%, and adding Al2O3Counting;
(2) preparation of spinnable aluminum carboxylate precursor sol
Adding silica sol into the aluminum carboxylate sol obtained in the step (1), then adding a drying control agent and a reaction auxiliary agent, uniformly mixing to obtain mixed sol, and heating and aging the mixed sol to obtain spinnable aluminum carboxylate precursor sol;
(3) preparation of alumina gel fiber
Carrying out dry spinning on the spinnable aluminum carboxylate precursor sol prepared in the step (2) to obtain alumina gel fibers;
(4) ceramization of alumina gel fibers
And (4) moving the alumina gel fiber prepared in the step (3) into a furnace, gradually raising the temperature and preserving the heat in three stages, and finally obtaining the alumina continuous fiber.
2. The method according to claim 1, wherein the amorphous aluminum hydroxide suspension in step (1) has a solid content of 5 to 15% based on Al (OH)3Counting;
the molar ratio of the small molecular carboxylic acid to the aluminum hydroxide in the step (1) is (1-2): 1.
3. The production process according to claim 1, wherein the mixed solution of small molecular carboxylic acids in the step (1) is a mixed solution of at least three of formic acid, acetic acid, propionic acid and n-butyric acid.
4. The method according to claim 1, wherein the ratio of the total weight of formic acid and acetic acid to the weight of propionic acid and/or n-butyric acid in the mixed solution of the small-molecule carboxylic acid is (3-4) to (1.6-2.5).
5. The production method according to claim 1, wherein the drying control agent is at least one or more of glycerin, erythritol, ethylene glycol, dimethylformamide, diethylene glycol, glucose, polyvinyl alcohol, polyethylene oxide, polyvinylpyrrolidone, hydroxyethylcellulose, lactic acid, tartaric acid, and citric acid;
the reaction auxiliary agent is at least one or more of ethylene glycol, diethylene glycol, glucose, hydroxyethyl cellulose, lactic acid, tartaric acid and citric acid.
6. The method according to claim 1, wherein the aging temperature in the step (2) is 30 to 60 ℃ and the degree of vacuum in the aging process is 0.093 to 0.1 MPa.
7. The preparation method according to claim 1, wherein the parameters of the dry spinning in the step (3) are that the ambient temperature is 20-42 ℃ and the ambient humidity is 15-65%.
8. The preparation method according to claim 1, wherein the first stage in the step (4) is heating to 200-300 ℃ at a rate of 1-5 ℃/min, and keeping the temperature for 1-2 h.
9. The preparation method according to claim 8, wherein the second stage in the step (4) is heating to 600-750 ℃ at a rate of 0.5-3 ℃/min, and keeping the temperature for 0.5-2 h.
10. The preparation method according to claim 9, wherein the third stage in the step (4) is to heat the mixture to 1200-1400 ℃ at a rate of 8-10 ℃/min and keep the temperature for 0.5-1.5 h.
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|---|---|---|---|---|
| US5575964A (en) * | 1993-08-19 | 1996-11-19 | Sumitomo Chemical Company, Limited | Method for producing silica-alumina fiber |
| CN101717257A (en) * | 2009-12-01 | 2010-06-02 | 西安交通大学 | Technology of preparing aluminium oxide based continuous fibers by sol-gel process |
| CN110004521A (en) * | 2019-02-28 | 2019-07-12 | 山东大学 | A kind of preparation method of spinnability silicon-aluminum sol |
| CN113860862A (en) * | 2020-11-26 | 2021-12-31 | 山东工业陶瓷研究设计院有限公司 | Preparation method of low-cost mullite fiber |
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|---|---|---|---|---|
| US5575964A (en) * | 1993-08-19 | 1996-11-19 | Sumitomo Chemical Company, Limited | Method for producing silica-alumina fiber |
| CN101717257A (en) * | 2009-12-01 | 2010-06-02 | 西安交通大学 | Technology of preparing aluminium oxide based continuous fibers by sol-gel process |
| CN110004521A (en) * | 2019-02-28 | 2019-07-12 | 山东大学 | A kind of preparation method of spinnability silicon-aluminum sol |
| CN113860862A (en) * | 2020-11-26 | 2021-12-31 | 山东工业陶瓷研究设计院有限公司 | Preparation method of low-cost mullite fiber |
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