High-performance ceramic fiber filter tube and preparation method thereof

Abstract

The invention discloses a high-performance ceramic fiber filter tube and a preparation method thereof, and belongs to the technical field of ceramic fiber filter tubes, the high-performance ceramic fiber filter tube comprises the following raw materials by weight: 72-85 parts of modified aluminosilicate fiber, 1.5-5 parts of a binder, 13-20 parts of a pore-enlarging agent, 0.5-3 parts of magnesium sulfate and 400 parts of water; the modified aluminum silicate fiber is modified by magnesium salt, so that magnesium oxide is attached to the surface of the aluminum silicate fiber. According to the invention, starting from the core material aluminosilicate fiber of the ceramic filter tube, the aluminosilicate fiber is subjected to surface modification, and the fusion degree of the strength structure and the ceramic fiber filter tube is improved, so that the strength of the ceramic filter tube is improved, and the tube breakage phenomenon in the transportation, installation and operation processes is improved. In the preparation process of the ceramic fiber filter tube, a magnesium sulfate solution is added, magnesium sulfate reacts with magnesium oxide attached to the surfaces of aluminum silicate fibers to generate a magnesium oxysulfate gelling agent, and the strength of the ceramic fiber filter tube is improved.

Description

Technical Field

[0001] This invention belongs to the field of ceramic fiber filter tube technology, specifically relating to a high-performance ceramic fiber filter tube and its preparation method. Background Technology

[0002] Ceramic fiber filter tubes, as a high-quality and efficient filtration material, are widely used in flue gas purification processes in chemical, environmental protection, and energy fields due to their excellent high-temperature resistance, chemical stability, and good filtration efficiency. They can be used as adsorption filter media or catalyst carriers. In particular, their outstanding potential in air pollution control has been demonstrated in the "co-treatment technology of dust, sulfur, and nitrate synergistically using composite ceramic fiber filter tubes for medium- and low-temperature flue gas in industrial kilns".

[0003] These filter tubes are typically made primarily of aluminosilicate fiber, supplemented with binders, pore expanders, and other auxiliary materials. They are formed into an inorganic composite material with a multi-layered gradient pore structure through a vacuum filtration molding process. They can withstand long-term operating temperatures exceeding 500℃, exhibit excellent shock resistance, and possess stable chemical properties, making them highly suitable for filtration and catalytic reaction environments under high-temperature and highly corrosive flue gas conditions.

[0004] However, due to the large length of ceramic fiber filter tubes, typically reaching 3 meters and some even 4 meters, they face significant mechanical strength challenges during transportation, on-site installation, and actual operation. Improper packaging or handling during logistics can easily lead to filter tube breakage; under complex working conditions, the filter tubes also face the risk of structural damage or even breakage due to factors such as temperature fluctuations, airflow impact, and vibration. To improve the overall mechanical properties of ceramic fiber filter tubes and reduce the breakage rate, several reinforcement schemes have been proposed in the existing technology. Patent application CN119656738A discloses using nickel foam as a support skeleton, integrally molding the ceramic filter tube matrix onto both sides of the nickel foam support skeleton, reducing the risk of filter tube breakage during transportation and use; patent application CN117797556A discloses adding strength-modifying materials during the filter tube manufacturing process. As the calcination temperature of the tube blank increases, a closed glass membrane forms at the edge of the modified material to protect the strength material, thereby improving the bending strength of the ceramic filter tube. However, the above-mentioned methods for improving strength all start with auxiliary materials other than the core material, and it is impossible to know whether the final ceramic fiber filter tube has a high degree of compatibility with the auxiliary materials. Summary of the Invention

[0005] The purpose of this invention is to provide a high-performance ceramic fiber filter tube and its preparation method, so as to solve the problem of easy breakage of ceramic filter tubes.

[0006] The objective of this invention can be achieved through the following technical solutions: The first aspect of this application provides a high-performance ceramic fiber filter tube, which, by weight, comprises the following raw materials: 72-85 parts of modified aluminosilicate fiber, 1.5-5 parts of binder, 13-20 parts of pore expander, 0.5-3 parts of magnesium sulfate, and 400 parts of water; wherein the modified aluminosilicate fiber is modified with magnesium salt, so that magnesium oxide is attached to the surface of the aluminosilicate fiber.

[0007] In some possible implementations, 76-82 parts of modified aluminosilicate fiber, 2-4 parts of binder, 17-19 parts of pore expander, 1-2 parts of magnesium sulfate, and 400 parts of water are used.

[0008] In some possible implementations, 80 parts of modified aluminosilicate fiber, 2 parts of binder, 17 parts of pore expander, 1 part of magnesium sulfate, and 400 parts of water are used.

[0009] In some possible implementations, the aluminosilicate fiber has a diameter of 3~8μm and a length of 12~250mm.

[0010] In some possible implementations, the magnesium salt is at least one of magnesium sulfate, magnesium nitrate, magnesium chloride, magnesium acetate, and magnesium bromide; preferably, it is at least one of magnesium sulfate, magnesium nitrate, and magnesium acetate.

[0011] In some possible implementations, the binder is at least one of carboxymethyl cellulose, high-temperature sealant-JD-9768, water glass, transparent dispersion of nano-silica (VK-S01), aluminum sol, aluminum phosphate, and aluminum dihydrogen phosphate; The pore-expanding agent is at least one of cellulose, nut shell powder, polyethylene wax powder, ammonium bicarbonate, ammonium carbonate, magnesium powder, and sodium chloride.

[0012] In some possible implementations, modified aluminosilicate fibers are prepared through the following steps: S1: Mix ethanol and water evenly, add 3wt% magnesium salt and stir until completely dissolved, then add cellulose aluminosilicate and stir. S2: Add sodium hydroxide dropwise to the mixed solution of aluminosilicate fiber and magnesium salt to adjust the pH to 10-12, and stir slowly until the magnesium salt is completely precipitated and aged for 2-3 hours; S3: Filter the above mixture to obtain magnesium hydroxide-attached aluminosilicate fibers, wash with water until neutral, and dry; S4: The dried aluminosilicate fiber mixture is calcined at high temperature and then naturally cooled to room temperature to obtain modified aluminosilicate fiber.

[0013] In some possible implementations, the volume ratio of ethanol to water in S1 is (0~2):(8~10), preferably (0~1):(9~10), and more preferably, the volume ratio of ethanol to water in S1 is 0.5:9.5.

[0014] Preferably, the pH in S2 is adjusted to 11-12; In some possible implementations, the drying process in S3 involves heating to 105°C at a rate of 1-10°C / min. Preferably, the heating rate in S3 is 1-5°C / min, and more preferably, it is 2°C / min.

[0015] In some possible implementations, the high-temperature calcination temperature in S4 is 350-500℃, with a preferred calcination temperature of 400℃.

[0016] The second aspect of this application provides a method for preparing a high-performance ceramic fiber filter tube, comprising the following steps: Modified aluminum silicate fiber is added to water and stirred to disperse it into a mixed solution. A binder is added to the mixed solution and stirred until the binder is fully dispersed. A pore expander is added and stirred to disperse the pore expander. Magnesium sulfate is added and stirred until the magnesium sulfate dissolves. The mixture is then poured into a mold, vacuum filtered under negative pressure, and dried to obtain a high-performance ceramic fiber filter tube.

[0017] The beneficial effects of this invention are: This invention starts with the core material of ceramic filter tubes, aluminosilicate fiber. By modifying the surface of aluminosilicate fiber, the integration of the strength structure with the ceramic fiber filter tube is improved, thereby enhancing the strength of the ceramic filter tube and reducing the occurrence of tube breakage during transportation, installation, and operation.

[0018] This invention uses magnesium salts to modify aluminosilicate fibers, causing magnesium oxide to adhere to the surface of the aluminosilicate fibers. During the preparation of the ceramic fiber filter tube, a magnesium sulfate solution is added, causing the magnesium sulfate and the magnesium oxide adhering to the surface of the aluminosilicate fibers to react and produce a magnesium oxysulfate gelling agent. The magnesium oxysulfate gelling agent is an air-hardening material and is weakly alkaline, which has a stronger selective adsorption capacity for acidic substances in the air or exhaust gas. Over time, it reacts with water vapor, CO2, SO2 and other substances in the air to form a crystalline structure, increasing the strength of the ceramic fiber filter tube. Attached Figure Description

[0019] The invention will now be further described with reference to the accompanying drawings.

[0020] Figure 1 This is a SEM image of the high-performance ceramic fiber filter tube in Embodiment 1 of the present invention; Figure 2 This is a SEM image of the modified aluminosilicate fiber of Example 1 of the present invention; Figure 3 This is a SEM image of the ceramic fiber filter tube in Comparative Example 1 of the present invention. Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] The following is a detailed description of a high-performance ceramic fiber filter tube and its preparation method according to an embodiment of this application.

[0023] This application implements a first aspect to provide a high-performance ceramic fiber filter tube, which, by weight, comprises the following raw materials: 72-85 parts of modified aluminosilicate fiber, 1.5-5 parts of binder, 13-20 parts of pore expander, 0.5-3 parts of magnesium sulfate, and 400 parts of water; wherein the modified aluminosilicate fiber is modified with magnesium salt, so that magnesium oxide is attached to the surface of the aluminosilicate fiber.

[0024] In some possible embodiments, the mixture contains 76-82 parts of modified aluminosilicate fiber, 2-4 parts of binder, 17-19 parts of pore expander, 1-2 parts of magnesium sulfate, and 400 parts of water.

[0025] In some possible embodiments, the mixture comprises 80 parts modified aluminosilicate fiber, 2 parts binder, 18 parts pore expander, 1 part magnesium sulfate, and 400 parts water.

[0026] In some possible embodiments, the aluminosilicate fiber has a diameter of 3~8μm and a length of 12~250mm.

[0027] In some possible embodiments, the magnesium salt is at least one of magnesium sulfate, magnesium nitrate, magnesium chloride, magnesium acetate, and magnesium bromide; Preferably, it is at least one of magnesium sulfate, magnesium nitrate, and magnesium acetate.

[0028] In some possible embodiments, the binder is at least one of carboxymethyl cellulose, JD-9768, water glass, transparent dispersion of nano-silica, aluminum sol, aluminum phosphate, and aluminum dihydrogen phosphate; The pore-expanding agent is at least one of cellulose, nut shell powder, polyethylene wax powder, ammonium bicarbonate, ammonium carbonate, magnesium powder, and sodium chloride.

[0029] In some possible embodiments, the modified aluminosilicate fibers are prepared by the following steps: S1: Mix ethanol and water evenly, add magnesium salt and stir until completely dissolved, then add cellulose aluminosilicate and stir. S2: Add sodium hydroxide dropwise to the mixed solution of aluminosilicate fiber and magnesium salt to adjust the pH to 10-12, and stir slowly until the magnesium salt is completely precipitated and aged for 2-3 hours; S3: Filter the above mixture to obtain magnesium hydroxide-attached aluminosilicate fibers, wash with water until neutral, and dry; S4: The dried aluminosilicate fiber mixture is calcined at high temperature and then naturally cooled to room temperature to obtain modified aluminosilicate fiber.

[0030] In some possible embodiments, the volume ratio of ethanol to water in S1 is (0~2):(8~10), preferably, the volume ratio of ethanol to water is (0~1):(9~10), and more preferably, the volume ratio of ethanol to water in S1 is 0.5:9.5.

[0031] Preferably, the pH in S2 is adjusted to 11-12; In some possible embodiments, the drying process in S3 involves heating to 105°C at a rate of 1-10°C / min. Preferably, the heating rate in S3 is 1-5°C / min, and more preferably 2°C / min. In some possible implementations, the high-temperature calcination temperature in S4 is 350-500℃, with a preferred calcination temperature of 400℃.

[0032] This application implements a second aspect of providing a method for preparing a high-performance ceramic fiber filter tube, comprising the following steps: Modified aluminum silicate fiber is added to water and stirred to disperse it into a mixed solution. A binder is added to the mixed solution and stirred until the binder is fully dispersed. A pore expander is added and stirred to disperse the pore expander. Magnesium sulfate is added and stirred until the magnesium sulfate dissolves. The mixture is then poured into a mold, vacuum filtered under negative pressure, and dried to obtain a high-performance ceramic fiber filter tube.

[0033] The following is a detailed description with reference to specific examples.

[0034] Example 1

[0035] This embodiment provides a high-performance ceramic fiber filter tube, the preparation method of which includes the following steps: Step S1: Mix ethanol and water in a volume ratio of 0.5:9.5, add 3wt% magnesium nitrate, then add aluminum silicate fiber to the mixed solution and stir until evenly dispersed; Step S2: Adjust the pH of the mixed solution in step S1 with 0.1 mol / L sodium hydroxide to maintain it between 11 and 12, and stir to precipitate magnesium ions in the solution. Step S3: Filter to obtain magnesium hydroxide-attached aluminosilicate fibers, wash with water until neutral, and place in an oven to dry at 105°C with a heating rate of 2°C / min. Step S4: Calcine the dried aluminosilicate fibers at 400℃ for 4 hours, and then allow them to cool naturally to obtain modified aluminosilicate fibers.

[0036] By weight, 80 parts of modified aluminum silicate fiber were added to 400 parts of water and stirred to disperse; 2 parts of nano silica transparent dispersion VK-S01 were added to the above mixed solution and stirred thoroughly; 17 parts of ammonium bicarbonate were added to the above mixed solution and stirred further; then 1 part of magnesium sulfate was added. The obtained mixed solution was injected into a mold, filtered under negative pressure, and dried to obtain a high-performance ceramic fiber filter tube. The ceramic fiber filter tube was then subjected to SEM (scanning electron microscopy). Figure 1 As shown in the figure, the SEM image of the modified aluminosilicate fiber is as follows. Figure 2 As shown.

[0037] Example 2

[0038] High-performance ceramic fiber filter tube solutions: Compared with Example 1, in the modified aluminum silicate fiber step S1 of Example 2, only the aqueous solution was used as the solvent to dissolve magnesium nitrate, and the other conditions remained unchanged.

[0039] Example 3

[0040] High-performance ceramic fiber filter tube solutions: Compared with Example 1, in the modified aluminum silicate fiber step S1 of Example 3, the volume ratio of ethanol to water was 1.5:8.5, and the other conditions remained unchanged.

[0041] Example 4

[0042] High-performance ceramic fiber filter tube solutions: Compared with Example 1, in the modified aluminum silicate fiber step S1 of Example 4, the amount of magnesium nitrate used was 2wt%, and the other conditions remained unchanged.

[0043] Example 5

[0044] High-performance ceramic fiber filter tube solutions: Compared with Example 1, in the modified aluminum silicate fiber step S2 of Example 5, the solution pH adjustment step was maintained at 10, and the other conditions remained unchanged.

[0045] Example 6

[0046] High-performance ceramic fiber filter tube solutions: Compared with Example 1, in step S4 of the modified aluminosilicate fiber in Example 6, the calcination temperature was selected as 500℃, while the other conditions remained unchanged.

[0047] Example 7

[0048] High-performance ceramic fiber filter tube solutions: Compared with Example 1, in the modified aluminum silicate fiber step S3 of Example 7, the heating rate was 10℃ / min, and the other conditions remained unchanged.

[0049] Example 8

[0050] High-performance ceramic fiber filter tube solutions: Compared with Example 1, in the modified aluminosilicate fiber of Example 8, magnesium sulfate was used instead of magnesium nitrate; The filter tube was prepared as follows: 72 parts of modified aluminum silicate fiber were added to 400 parts of water and stirred to disperse; 4 parts of aluminum sol were added to the above mixed solution and stirred thoroughly; 19 parts of cellulose were added to the above mixed solution and stirred continuously; then 2 parts of magnesium sulfate were added, and the other conditions remained unchanged.

[0051] Example 9

[0052] High-performance ceramic fiber filter tube solutions: Compared with Example 1, the filter tube preparation process of Example 9 is as follows: 85 parts of modified aluminum silicate fiber are added to 400 parts of water and stirred to disperse; 1.5 parts of aluminum sol are added to the above mixed solution and stirred thoroughly; 13 parts of cellulose are added to the above mixed solution and stirred continuously; then 0.5 parts of magnesium sulfate are added, and the other conditions remain unchanged.

[0053] Comparative Example 1

[0054] This comparative example provides a ceramic fiber filter tube, and its preparation method includes the following steps: By weight, 80 parts of aluminosilicate fiber were added to 400 parts of water and stirred to disperse; 2 parts of nano-silica transparent dispersion (VK-S01) were added to the above mixed solution and stirred thoroughly; 17 parts of ammonium bicarbonate were added to the above mixed solution and stirred continuously; then magnesium oxide (3 wt% of aluminosilicate fiber) and 1 part of magnesium sulfate were added in sequence. The obtained mixed solution was injected into a mold, filtered under negative pressure, and dried to obtain a ceramic fiber filter tube. The ceramic fiber filter tube was then subjected to SEM analysis. Figure 3 As shown.

[0055] Compared to the case where magnesium oxide was attached to the surface of aluminum silicate fiber in Example 1, in Comparative Example 1, magnesium oxide was added directly. The addition step was to add 1 part of magnesium sulfate after the aluminum silicate fiber, binder and pore expander were mixed, and then stir thoroughly.

[0056] Comparative Example 2

[0057] This comparative example provides a ceramic fiber filter tube: Compared with Example 1, in Comparative Example 2, the amount of magnesium oxide added was 2 wt%, and the other conditions remained unchanged.

[0058] Comparative Example 3

[0059] This comparative example provides a ceramic fiber filter tube: Compared with Example 1, in Comparative Example 3, the amount of magnesium oxide added was 4 wt%, and the other conditions remained unchanged.

[0060] Comparative Example 4

[0061] This comparative example provides a ceramic fiber filter tube: Compared with Example 1, in Comparative Example 4, the amount of magnesium oxide added was 3 wt%, magnesium sulfate was not added, and the other conditions remained unchanged.

[0062] Comparative Example 5

[0063] This comparative example provides a ceramic fiber filter tube: Compared with Example 1, in Comparative Example 5, no magnesium oxide was added, 1 part magnesium sulfate was added, and the other conditions remained unchanged.

[0064] Comparative Example 6

[0065] This comparative example is compared with Example 9. Unmodified aluminum silicate fiber was used, magnesium salt was added in the form of magnesium oxide, and the amount of magnesium sulfate was 0.5 parts. The other steps remained unchanged.

[0066] Comparative Example 7

[0067] This comparative example provides a ceramic fiber filter tube: Compared with Example 1, in Comparative Example 7, neither magnesium oxide nor magnesium sulfate was added, and all other conditions remained unchanged.

[0068] All embodiments and comparative examples were tested according to the C-ring compressive strength and pressure drop test method in JB / T 14662-2023, and the results are shown in Tables 1-2: Table 1: Compressive Strength Values ​​of C-ring

[0069] Table 2: Pressure Drop Values

[0070] As shown in Tables 1 and 2, while directly adding magnesium oxide and magnesium sulfate during filter tube molding can improve the compressive strength of the C-ring to some extent, it significantly increases the resistance of the filter tube, leading to a greater pressure differential, which is detrimental to actual working conditions. After standing for 7 days, the C-ring strength and pressure differential of the modified filter tube improved somewhat; after standing for 15 days, the changes in C-ring strength and pressure drop were not significant, indicating that the effect of the magnesium oxysulfate gelling agent on the filter tube gradually weakened. This is mainly because the magnesium oxysulfate gelling agent is an air-hardening material. It adsorbs components such as water, carbon dioxide, and sulfur dioxide in ambient air and hardens through physicochemical processes. Its core reaction is the hydration reaction of magnesium oxide and magnesium sulfate to form a crystalline structure. Over time, the adsorption capacity gradually weakens, and the increase in strength gradually slows down.

[0071] The difference between the comparative and the examples lies in whether the core material, aluminosilicate fiber, has been modified with magnesium salts. According to the test results, aluminosilicate fiber modified with in-situ magnesium salts exhibits superior strength and pressure drop compared to directly added aluminosilicate fiber. Based on the composition of the magnesium sulfate-oxygenate gelling agent, the ratio of magnesium oxide to magnesium sulfate is 3:1; therefore, excessive or insufficient magnesium sulfate is detrimental to the gelling agent's strengthening effect on the filter tube.

[0072] SEM images of the comparison filter tubes ( Figure 1 , Figure 2 It can also be seen that the in-situ modified high-performance ceramic fiber filter tube has a distinct fiber structure, and the magnesium oxysulfate gelling agent mainly adheres to the surface of the fiber structure, increasing the compressive strength of the fiber through surface stacking. Filter tubes prepared by directly adding magnesium oxysulfate raw materials ( Figure 3 The fiber structure contains materials with other morphologies, and there is also a small amount of gelling agent on the fiber surface; therefore, while improving the strength of the filter tube, it also affects the airtightness of the filter tube and increases the pressure drop of the filter tube.

[0073] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0074] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-performance ceramic fiber filter tube, characterized in that, The product comprises the following raw materials by weight: 72-85 parts modified aluminosilicate fiber, 1.5-5 parts binder, 13-20 parts pore expander, 0.5-3 parts magnesium sulfate and 400 parts water; the modified aluminosilicate fiber is modified with magnesium salt, so that magnesium oxide is attached to the surface of the aluminosilicate fiber.

2. The high-performance ceramic fiber filter tube according to claim 1, characterized in that, The mixture consists of 76-82 parts modified aluminosilicate fiber, 2-4 parts binder, 17-19 parts pore expander, 1-2 parts magnesium sulfate, and 400 parts water.

3. The high-performance ceramic fiber filter tube according to claim 1, characterized in that, 80 parts modified aluminosilicate fiber, 2 parts binder, 17 parts pore expander, 1 part magnesium sulfate and 400 parts water.

4. The high-performance ceramic fiber filter tube according to claim 1, characterized in that, The aluminosilicate fibers have a diameter of 3~8μm and a length of 12~250mm.

5. A high-performance ceramic fiber filter tube according to claim 1, characterized in that, The magnesium salt is at least one of magnesium sulfate, magnesium nitrate, magnesium chloride, magnesium acetate, and magnesium bromide.

6. A high-performance ceramic fiber filter tube according to claim 1, characterized in that, The binder is at least one of carboxymethyl cellulose, high-temperature resistant sealant, water glass, nano-silica transparent dispersion, aluminum sol, aluminum phosphate, and aluminum dihydrogen phosphate; The pore-expanding agent is at least one of cellulose, nut shell powder, polyethylene wax powder, ammonium bicarbonate, ammonium carbonate, magnesium powder, and sodium chloride.

7. A high-performance ceramic fiber filter tube according to claim 1, characterized in that, The modified aluminosilicate fiber is prepared by the following steps: S1: Mix ethanol and water evenly, add 3wt% magnesium salt based on the mass of aluminum silicate and stir until completely dissolved, then add cellulose aluminosilicate and stir. S2: Add sodium hydroxide dropwise to the mixed solution of aluminosilicate fiber and magnesium salt to adjust the pH to 10-12, and stir slowly until the magnesium salt is completely precipitated and aged for 2-3 hours; S3: Filter the above mixture to obtain magnesium hydroxide-attached aluminosilicate fibers, wash with water until neutral, and dry; S4: The dried aluminosilicate fiber mixture is calcined at high temperature and then naturally cooled to room temperature to obtain modified aluminosilicate fiber.

8. A high-performance ceramic fiber filter tube according to claim 7, characterized in that, In S1, the volume ratio of ethanol to water is (0~2):(8~10); in S3, the drying process involves heating to 105℃ at a rate of 1-10℃ / min.

9. A high-performance ceramic fiber filter tube according to claim 7, characterized in that, The high-temperature roasting temperature of S4 is 350-500℃.

10. A method for preparing a high-performance ceramic fiber filter tube, used to prepare the high-performance ceramic fiber filter tube according to any one of claims 1-9, characterized in that, Includes the following steps: Modified aluminum silicate fiber is added to water and stirred to disperse it into a mixed solution. A binder is added to the mixed solution and stirred until the binder is fully dispersed. A pore expander is added and stirred to disperse the pore expander. Magnesium sulfate is added and stirred until the magnesium sulfate dissolves. The mixture is then poured into a mold, vacuum filtered under negative pressure, and dried to obtain a high-performance ceramic fiber filter tube.

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