Ceramic fiberboard and preparation method thereof

Abstract

The present invention discloses a ceramic fiberboard and a preparation method thereof, belonging to the technical field of ceramic fiberboards. The present invention improves the interweaving strength between fibers in the slurry by adjusting the raw material composition, the order of adding materials, and the beating time, eliminating the need for short-cut pretreatment of the ceramic fibers, optimizing the production process, and improving production efficiency. By adding polyethylene glycol and iron sol, the various material components are more tightly bonded, thereby improving the density and strength of the product. The volume density of the ceramic fiberboard prepared by the present invention can reach 950kg / m 3 The product achieved a compressive strength of 15.3 MPa and high-temperature resistance, with a heating permanent line change of only -0.9% after 24 hours at 1600°C, and a maximum range of 1.56% of the average. The method of the present invention utilizes specific raw materials and process steps to achieve a well-balanced overall performance, improving the product's high-temperature resistance and batch-to-batch quality stability, making it highly competitive in the market.

Description

Technical Field

[0001] The present invention relates to the technical field of ceramic fiberboards, in particular to a ceramic fiberboard and a preparation method thereof. Background Art

[0002] Ceramic fiber is a fibrous, lightweight refractory material with advantages such as light weight, high-temperature resistance, good thermal stability, low thermal conductivity, low specific heat, and resistance to mechanical vibration. Therefore, it is widely used in industries such as machinery, metallurgy, chemicals, petroleum, ceramics, glass, and electronics. Ceramic fiberboard, a board material primarily composed of ceramic fiber, has seen a surge in recent years due to rising global energy prices. Its greater energy efficiency than traditional refractory materials such as insulation bricks and castables has led to its widespread application and promising development prospects.

[0003] As a composite material, ceramic fiberboard needs to mix various components during preparation to ensure that the product can obtain stable properties during subsequent use. For example, in metallurgical ladles and casting furnaces, ceramic fiberboards that are both load-bearing and heat-insulating are required, and can withstand excessive local pressure and over-temperature conditions caused by vortexes generated by liquid metal during use. The patent "CN108033756B A high-density ceramic fiberboard and its preparation method" provides a high-density ceramic fiberboard, which uses the method of cutting ceramic fibers into short pieces to process the raw materials and apply them to subsequent products. However, this process is complicated to operate and is not conducive to continuous production of the process. At the same time, since a variety of raw materials are used in the preparation of ceramic fiberboards, the composition is complex and the performance varies, there is also the problem of uneven product density. The national standard "GB / T 16400-2023 Aluminum silicate wool and its products for thermal insulation" stipulates a volume density deviation of ±15%. This is a relatively broad standard. Although qualified products from all manufacturers can meet this standard, it can only serve as a basic standard and cannot be used as a quality control requirement for high-quality products. In order to stand out from the competition with other manufacturers, it is necessary to further optimize and improve product quality. Therefore, how to apply new materials and technologies to the preparation of a ceramic fiberboard with better performance, so that the product volume density deviation is smaller, the quality is more stable, and it has a higher operating temperature and compressive strength has always been the research focus of manufacturers. Summary of the Invention

[0004] In view of the above-mentioned prior art, the object of the present invention is to provide a ceramic fiberboard and a preparation method thereof.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] In a first aspect of the present invention, a ceramic fiberboard is provided, which is made from the following raw materials in parts by weight:

[0007] 60-120 parts of zirconium-containing ceramic fiber spun cotton, 200-400 parts of high-aluminum ceramic fiber blown cotton, 20-100 parts of polycrystalline mullite fiber, 100-300 parts of wood pulp fiber slurry, 10-30 parts of high-silica chopped strands, 100-300 parts of ultrafine alumina powder, 50-200 parts of wollastonite, 10-30 parts of dolomite, 30-100 parts of cationic thermosoluble starch, 10-50 parts of polyethylene glycol, 150-500 parts of silica sol, and 30-100 parts of iron sol;

[0008] The iron sol has a density of 3-5 kg / L and a particle size of 1-100 nm.

[0009] Furthermore, the high-aluminum ceramic fiber spray cotton has a diameter of 0.5-10 μm.

[0010] Furthermore, the zirconium-containing ceramic fiber spun cotton has a diameter of 0.5-10 μm, a length of 50-200 mm, an Al2O3 content of 20-60%, and a ZrO2 content of 5-30%.

[0011] Furthermore, the high-silica chopped strands have a length of 2-20 mm and a diameter of 2-20 μm, wherein the SiO2 content is not less than 80%.

[0012] Furthermore, the polycrystalline mullite fiber has a diameter of 1-10 μm and a length of 1-50 mm.

[0013] Furthermore, the ultrafine alumina powder has a particle size of 50-200 nm.

[0014] Furthermore, the wollastonite has a particle size of 2000-8000 mesh.

[0015] Furthermore, the dolomite has a particle size of 2000-8000 mesh.

[0016] Furthermore, the compressive strength of the ceramic fiberboard is 5-20 MPa and the bulk density is 600-1200 kg / m 3 .

[0017] A second aspect of the present invention provides a method for preparing the ceramic fiberboard, comprising the following steps:

[0018] (1) adding zirconium-containing ceramic fiber spinning cotton, high-aluminum ceramic fiber blowing cotton, polycrystalline mullite fiber, wood pulp fiber slurry and high-silica chopped strands into water in sequence and beating;

[0019] (2) adding ultrafine alumina powder, wollastonite and dolomite to the liquid after beating in step (1), and dispersing and beating;

[0020] (3) adding cationic thermosoluble starch and polyethylene glycol to the pulped liquid in step (2) and mixing uniformly;

[0021] (4) adding silica sol and iron sol to the mixed liquid in step (3) for flocculation, and then forming the flocculated slurry into a wet blank, and drying it to obtain a ceramic fiberboard.

[0022] Beneficial effects of the present invention:

[0023] In the present invention, the high-aluminum ceramic fiber spray cotton used refers to the fiber prepared by the spraying method, which has the characteristics of fine fiber diameter and short fiber length. The zirconium-containing ceramic fiber spun cotton refers to the fiber prepared by the spun method, which has the characteristics of long fiber, thick fiber diameter and high strength. Polycrystalline mullite fiber helps to improve the stability of ceramic fiber board at high temperature. The addition of high-silica short-cut fibers acts as a reinforcing fiber at room temperature to prevent cracking, while not affecting the refractoriness of high-density ceramic fiber board. The fillers selected are the barren materials alumina ultrafine powder, wollastonite and the plastic material dolomite. The two types of fillers, plastic materials and barren materials, are used and matched in appropriate proportions. While improving the density and strength of the product, cracking in the wet blank drying stage can be avoided. When the ceramic powder is pressed and molded, the binders used include organic binders and inorganic binders. The organic binder cationic thermosoluble starch and polyethylene glycol mixture has good bonding properties and plasticity, and can effectively bond the ceramic powder together to form a solid molded part. Inorganic binders silica sol and iron sol have high sintering activity and chemical stability. They can react chemically with ceramic powder at high temperature to form a dense binding phase, thereby improving the density and mechanical properties of the molded parts.

[0024] The present invention adjusts the order of adding materials and controls the beating time to obtain a slurry with a reasonable combination of long fibers and short fibers, coarse fibers and fine fibers, thereby improving the interweaving strength between the fibers in the slurry, thereby eliminating the need for short-cut pretreatment of the ceramic fibers, optimizing the production process, and improving production efficiency; by adding polyethylene glycol and iron sol, the material is dispersed evenly and stably, which not only makes the various material components more closely bonded, reduces the resilience of the wet blank after pressing, and increases the density of the wet blank and dry blank after forming, but also improves the density and strength of the final product after high-temperature sintering during subsequent actual use. It avoids the common problem of uneven distribution of raw materials due to floating materials, resulting in different heat resistance of different parts of the fiberboard, partial cracking, and reduced heat resistance of the overall product. The ceramic fiberboard resistant to high temperatures of 1600°C prepared by the present invention has a volume density of up to 950kg / m 3The compressive strength reaches 15.3 MPa, and the rate of change of the permanent line after 24 hours of insulation at 1600°C is only -0.9%. Ten samples were tested, and the maximum range was 1.56% of the average, improving the quality consistency of batch products. The volume density deviation is far lower than the ±15% requirement specified in the national standard GB / T 16400-2023, "Aluminum Silicate Wool for Thermal Insulation and Its Products," making it competitive with similar products on the market. DETAILED DESCRIPTION

[0025] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0026] In order to enable those skilled in the art to more clearly understand the technical solution of the present application, the technical solution of the present application will be described in detail below with reference to specific embodiments.

[0027] The test materials used in the embodiments of the present invention that are not specifically described are all conventional test materials in the field and can be purchased through commercial channels. The high-aluminum ceramic fiber spray cotton used in the present invention has an average diameter of 4 μm and an average length of 75 mm, purchased from Zhejiang Aoka Refractory Materials Co., Ltd., model AK-61; zirconium-containing ceramic fiber spun cotton has a diameter of 3 μm, an Al2O3 content of 36%, and a ZrO2 content of 15%, purchased from Zhejiang Aoka Refractory Materials Co., Ltd., model AK-41; high-silica chopped strands have a length of 6 mm and a diameter of 6 μm, wherein the SiO2 content is not less than 94%, purchased from Nanjing Tianyuan Fiberglass Composite Materials Co., Ltd., model SCD-06-S; polycrystalline mullite fiber has a diameter of 4 μm and a length of 15 mm, purchased from Zhejiang Jiang Jiahua Crystal Fiber Co., Ltd., model T-1600 fiber cotton; ultrafine alumina powder with a particle size of 100 nm, purchased from Nanjing Baoket New Materials Co., Ltd., model PAT-G10A; wollastonite with a particle size of 5000 mesh, purchased from Guangdong Yuanlei Powder Co., Ltd.; dolomite with a particle size of 4000 mesh, purchased from Hebei Poyuan Mineral Products Trading Co., Ltd.; polyethylene glycol was purchased from Guangzhou Jincheng Chemical Co., Ltd., model PEG-300; iron sol, i.e., iron hydroxide colloid, with a density of 3.5 kg / L and a particle size of 90 nm, was prepared by the conventional boiling water method of adding a saturated solution of ferric chloride to boiling distilled water.

[0028] The method for testing the performance of ceramic fiberboard in the present invention is as follows:

[0029] The volume density and heating permanent linear change rate of high-density ceramic fiberboard are tested using the "GB / T17911-2018 Test Method for Refractory Fiber Products";

[0030] The compressive strength test adopts the method of "GB / T13480-2014 Determination of compression properties of thermal insulation products for building use".

[0031] Example 1

[0032] Ceramic fiberboard is prepared by the following method:

[0033] (1) 400 kg of waste paper was fully soaked in water for 30 hours, 4 tons of water was added to the pulper, and the pulp was beaten for 25 minutes. Water was added to dilute the pulp to prepare a wood pulp fiber slurry with a mass fraction of 5%, which was then taken out for later use.

[0034] (2) Add 6 tons of water to the pulper, add 90 kg of zirconium-containing ceramic fiber spinning cotton, and beat for 11 minutes; add 320 kg of high-aluminum ceramic fiber blowing cotton, and beat for 12 minutes; add 50 kg of polycrystalline mullite fiber, and beat for 13 minutes; add 180 kg of wood pulp fiber slurry prepared in step (1), and beat for 9 minutes.

[0035] (3) Add 18 kg of high-silica chopped strands into the pulper and beat for 6 minutes.

[0036] (4) Add 150 kg of ultrafine alumina powder, 100 kg of wollastonite, and 20 kg of dolomite into a pulper and beat for 7 minutes.

[0037] (5) Add 60 kg of cationic thermosoluble starch and 20 kg of polyethylene glycol to the pulper, dilute with water until the solid mass fraction in the slurry is 5%, and stir for 16 minutes.

[0038] (6) Add 320 kg of 25% silica sol and 60 kg of iron sol into the pulper and stir for 18 minutes to mix them evenly in the slurry and to flocculate the components in the slurry.

[0039] (7) Add water to dilute the slurry to a solid mass fraction of 4%.

[0040] (8) The diluted slurry is formed into a wet blank through a vacuum suction filtration device, and then pressed into a corresponding thickness and density in a hydraulic press, and transported to a drying room for drying. After drying, a high-density ceramic fiberboard resistant to high temperatures of 1600°C is produced.

[0041] The performance of the ceramic fiberboard prepared in Example 1 of the present invention was tested, and the results were as follows:

[0042] The volume density of the ceramic fiberboard prepared in Example 1 of the present invention is 972 kg / m 3 , compressive strength is 13.6MPa, and the heating permanent line change rate after keeping warm at 1600℃ for 24 hours is -1.7%.

[0043] At the same time, the volume density (kg / m 3 ) were tested, and the results are shown in Table 1.

[0044] Table 1 Detection of volume density differences of ceramic fiberboard prepared in Example 1

[0045]

[0046]

[0047] The average volume density of the above 10 samples is 963.8 kg / m 3 , the maximum range is 17kg / m 3 The maximum range is 1.76% of the average value, and the volume density deviation is far lower than the ±15% requirement specified in the national standard GB / T 16400-2023 "Aluminum silicate wool and its products for insulation".

[0048] Example 2

[0049] Ceramic fiberboard is prepared by the following method:

[0050] (1) 350 kg of waste paper was fully soaked in water for 30 hours, 4 tons of water was added to the pulper, and the pulp was beaten for 25 minutes. The pulp was diluted with water to prepare a wood pulp fiber slurry with a mass fraction of 5%, which was then taken out for later use.

[0051] (2) Add 6 tons of water to the pulper, add 80 kg of zirconium-containing ceramic fiber spinning cotton, and beat for 11 minutes; add 4000 kg of high-aluminum ceramic fiber blowing cotton, and beat for 12 minutes; add 40 kg of polycrystalline mullite fiber, and beat for 13 minutes; add 200 kg of wood pulp fiber slurry prepared in step (1), and beat for 9 minutes.

[0052] (3) Add 16 kg of high-silica chopped strands into the pulper and beat for 6 minutes.

[0053] (4) Add 170 kg of ultrafine alumina powder, 80 kg of wollastonite, and 25 kg of dolomite into the pulper and beat for 7 minutes.

[0054] (5) Add 60 kg of cationic thermosoluble starch and 20 kg of polyethylene glycol to the pulper, dilute with water until the solid mass fraction in the slurry is 5%, and stir for 16 minutes.

[0055] (6) Add 320 kg of 25% silica sol and 60 kg of iron sol into the pulper and stir for 18 minutes to mix them evenly in the slurry and to flocculate the components in the slurry.

[0056] (7) Add water to dilute the slurry to a solid mass fraction of 4%.

[0057] (8) The diluted slurry is formed into a wet blank through a vacuum suction filtration device, and then pressed into a corresponding thickness and density in a hydraulic press, and transported to a drying room for drying. After drying, a high-density ceramic fiberboard resistant to high temperatures of 1600°C is produced.

[0058] The performance of the ceramic fiberboard prepared in Example 2 of the present invention was tested, and the results were as follows:

[0059] The volume density of the ceramic fiberboard prepared in Example 2 of the present invention is 984 kg / m 3 , compressive strength is 15.3MPa, and the heating permanent line change rate after keeping warm at 1600℃ for 24 hours is -0.9%.

[0060] At the same time, the volume density (kg / m 3 ) were tested, and the results are shown in Table 1.

[0061] Table 2: Volume density difference detection of ceramic fiberboard prepared in Example 2

[0062]

[0063] The average volume density of the above 10 samples is 960 kg / m 3 , the maximum range is 15kg / m 3 The maximum range is 1.56% of the average value, and the volume density deviation is far lower than the ±15% requirement specified in the national standard GB / T 16400-2023 "Aluminum silicate wool and its products for insulation".

[0064] Comparative Example 1

[0065] The difference between this comparative example and Example 1 is that no iron sol and polyethylene glycol are added. The ceramic fiber board is prepared by the following method:

[0066] (1) 400 kg of waste paper was fully soaked in water for 30 hours, 4 tons of water was added to the pulper, and the pulp was beaten for 25 minutes. Water was added to dilute the pulp to prepare a wood pulp fiber slurry with a mass fraction of 5%, which was then taken out for later use.

[0067] (2) Add 6 tons of water to the pulper, add 90 kg of zirconium-containing ceramic fiber spinning cotton, and beat for 11 minutes; add 320 kg of high-aluminum ceramic fiber blowing cotton, and beat for 12 minutes; add 50 kg of polycrystalline mullite fiber, and beat for 13 minutes; add 180 kg of wood pulp fiber slurry prepared in step (1), and beat for 9 minutes.

[0068] (3) Add 18 kg of high-silica chopped strands into the pulper and beat for 6 minutes.

[0069] (4) Add 150 kg of ultrafine alumina powder, 100 kg of wollastonite, and 20 kg of dolomite into a pulper and beat for 7 minutes.

[0070] (5) Add 60 kg of cationic thermosoluble starch to the pulper, dilute with water until the solid mass fraction in the slurry is 5%, and stir for 16 minutes.

[0071] (6) Add 320 kg of silica sol with a mass fraction of 25% into the pulper and stir for 18 minutes to mix it evenly in the slurry and to flocculate the various components in the slurry.

[0072] (7) Add water to dilute the slurry to a solid mass fraction of 4%.

[0073] (8) The diluted slurry is formed into a wet blank through a vacuum suction filtration device, and then pressed into a corresponding thickness and density in a hydraulic press, and transported to a drying room for drying. After drying, a high-density ceramic fiberboard resistant to high temperatures of 1600°C is produced.

[0074] The performance of the ceramic fiberboard prepared in Comparative Example 1 of the present invention was tested, and the results were as follows:

[0075] The volume density of the ceramic fiberboard prepared in Comparative Example 1 of the present invention is 914 kg / m 3 , compressive strength 5.7MPa, heating permanent line change rate after keeping warm at 1600℃ for 24 hours is -2.5%.

[0076] At the same time, the volume density (kg / m 3 ) were tested, and the results are shown in Table 3.

[0077] Table 3 Volume density difference detection of ceramic fiberboard prepared in Comparative Example 1

[0078]

[0079]

[0080] The average volume density of the above 10 samples is 958 kg / m 3 , the maximum range is 99kg / m 3 , the maximum range is 10.33% of the mean.

[0081] Comparative Example 2

[0082] The difference between this comparative example and Example 1 is that no iron sol is added. The ceramic fiber board is prepared by the following method:

[0083] (1) 400 kg of waste paper was fully soaked in water for 30 hours, 4 tons of water was added to the pulper, and the pulp was beaten for 25 minutes. Water was added to dilute the pulp to prepare a wood pulp fiber slurry with a mass fraction of 5%, which was then taken out for later use.

[0084] (2) Add 6 tons of water to the pulper, add 90 kg of zirconium-containing ceramic fiber spinning cotton, and beat for 11 minutes; add 320 kg of high-aluminum ceramic fiber blowing cotton, and beat for 12 minutes; add 50 kg of polycrystalline mullite fiber, and beat for 13 minutes; add 180 kg of wood pulp fiber slurry prepared in step (1), and beat for 9 minutes.

[0085] (3) Add 18 kg of high-silica chopped strands into the pulper and beat for 6 minutes.

[0086] (4) Add 150 kg of ultrafine alumina powder, 100 kg of wollastonite, and 20 kg of dolomite into a pulper and beat for 7 minutes.

[0087] (5) Add 60 kg of cationic thermosoluble starch and 20 kg of polyethylene glycol to the pulper, dilute with water until the solid mass fraction in the slurry is 5%, and stir for 16 minutes.

[0088] (6) Add 320 kg of silica sol with a mass fraction of 25% into the pulper and stir for 18 minutes to mix it evenly in the slurry and to flocculate the various components in the slurry.

[0089] (7) Add water to dilute the slurry to a solid mass fraction of 4%.

[0090] (8) The diluted slurry is formed into a wet blank through a vacuum suction filtration device, and then pressed into a corresponding thickness and density in a hydraulic press, and transported to a drying room for drying. After drying, a high-density ceramic fiberboard resistant to high temperatures of 1600°C is produced.

[0091] The performance of the ceramic fiberboard prepared in Comparative Example 2 of the present invention was tested, and the results were as follows:

[0092] The volume density of the ceramic fiberboard prepared in Comparative Example 2 of the present invention is 926 kg / m 3 , compressive strength 7.8MPa, heating permanent line change rate after keeping warm at 1600℃ for 24 hours is -2.2%.

[0093] At the same time, the volume density (kg / m 3 ) were tested, and the results are shown in Table 4.

[0094] Table 4 Comparative Example 2 Preparation of Ceramic Fiberboard Volume Density Difference Detection

[0095]

[0096]

[0097] The average volume density of the above 10 samples is 949.7 kg / m 3 , the maximum range is 72kg / m 3 , the maximum range is 7.58% of the mean.

[0098] Comparative Example 3

[0099] The difference between this comparative example and Example 1 is that polyethylene glycol is not added. The ceramic fiber board is prepared by the following method:

[0100] (1) 400 kg of waste paper was fully soaked in water for 30 hours, 4 tons of water was added to the pulper, and the pulp was beaten for 25 minutes. Water was added to dilute the pulp to prepare a wood pulp fiber slurry with a mass fraction of 5%, which was then taken out for later use.

[0101] (2) Add 6 tons of water to the pulper, add 90 kg of zirconium-containing ceramic fiber spinning cotton, and beat for 11 minutes; add 320 kg of high-aluminum ceramic fiber blowing cotton, and beat for 12 minutes; add 50 kg of polycrystalline mullite fiber, and beat for 13 minutes; add 180 kg of wood pulp fiber slurry prepared in step (1), and beat for 9 minutes.

[0102] (3) Add 18 kg of high-silica chopped strands into the pulper and beat for 6 minutes.

[0103] (4) Add 150 kg of ultrafine alumina powder, 100 kg of wollastonite, and 20 kg of dolomite into a pulper and beat for 7 minutes.

[0104] (5) Add 60 kg of cationic thermosoluble starch to the pulper, dilute with water until the solid mass fraction in the slurry is 5%, and stir for 16 minutes.

[0105] (6) Add 320 kg of 25% silica sol and 60 kg of iron sol into the pulper and stir for 18 minutes to mix them evenly in the slurry and to flocculate the components in the slurry.

[0106] (7) Add water to dilute the slurry to a solid mass fraction of 4%.

[0107] (8) The diluted slurry is formed into a wet blank through a vacuum suction filtration device, and then pressed into a corresponding thickness and density in a hydraulic press, and transported to a drying room for drying. After drying, a high-density ceramic fiberboard resistant to high temperatures of 1600°C is produced.

[0108] The performance of the ceramic fiberboard prepared in Comparative Example 3 of the present invention was tested, and the results were as follows:

[0109] The volume density of the ceramic fiberboard prepared in Comparative Example 3 of the present invention is 932 kg / m3 , compressive strength 8.3MPa, heating permanent line change rate after keeping warm at 1600℃ for 24 hours is -1.9%.

[0110] At the same time, the volume density (kg / m 3 ) were tested, and the results are shown in Table 5.

[0111] Table 5 Volume density difference detection of ceramic fiberboard prepared in comparative example 3

[0112]

[0113]

[0114] The average volume density of the above 10 samples is 921.9 kg / m 3 , the maximum range is 77kg / m 3 , the maximum range is 8.35% of the mean.

[0115] Comparative Example 4

[0116] The difference between this comparative example and Example 1 is that no binder (cationic thermosoluble starch, polyethylene glycol, silica sol or iron sol) is added, and the preparation method is as follows:

[0117] (1) 400 kg of waste paper was fully soaked in water for 30 hours, 4 tons of water was added to the pulper, and the pulp was beaten for 25 minutes. Water was added to dilute the pulp to prepare a wood pulp fiber slurry with a mass fraction of 5%, which was then taken out for later use.

[0118] (2) Add 6 tons of water to the pulper, add 90 kg of zirconium-containing ceramic fiber spinning cotton, and beat for 11 minutes; add 320 kg of high-aluminum ceramic fiber blowing cotton, and beat for 12 minutes; add 50 kg of polycrystalline mullite fiber, and beat for 13 minutes; add 180 kg of wood pulp fiber slurry prepared in step (1), and beat for 9 minutes.

[0119] (3) Add 18 kg of high-silica chopped strands into the pulper and beat for 6 minutes.

[0120] (4) Add 150 kg of ultrafine alumina powder, 100 kg of wollastonite, and 20 kg of dolomite into a pulper and beat for 7 minutes.

[0121] (5) Add water to dilute the slurry to a solid mass fraction of 4%.

[0122] (6) The diluted slurry is formed into a wet blank through a vacuum suction filtration device, and then pressed to a corresponding thickness and density in a hydraulic press, and transported to a drying room for drying.

[0123] Since comparative example 4 does not add a binder (cationic thermosoluble starch, polyethylene glycol, silica sol or iron sol), its bonding performance is poor, and defects such as cracks and breakages occur in the wet blank stage and after drying, making it impossible to form a complete blank and thus failing to become a qualified product.

[0124] Comparative Example 5

[0125] The difference between this comparative example 5 and Example 1 is that no barren raw materials (ultrafine alumina powder and wollastonite) are added, that is, only dolomite is added in step (4). The preparation method is as follows:

[0126] (1) 400 kg of waste paper was fully soaked in water for 30 hours, 4 tons of water was added to the pulper, and the pulp was beaten for 25 minutes. Water was added to dilute the pulp to prepare a wood pulp fiber slurry with a mass fraction of 5%, which was then taken out for later use.

[0127] (2) Add 6 tons of water to the pulper, add 90 kg of zirconium-containing ceramic fiber spinning cotton, and beat for 11 minutes; add 320 kg of high-aluminum ceramic fiber blowing cotton, and beat for 12 minutes; add 50 kg of polycrystalline mullite fiber, and beat for 13 minutes; add 180 kg of wood pulp fiber slurry prepared in step (1), and beat for 9 minutes.

[0128] (3) Add 18 kg of high-silica chopped strands into the pulper and beat for 6 minutes.

[0129] (4) Add 20 kg of dolomite into the pulper and beat for 7 minutes.

[0130] (5) Add 60 kg of cationic thermosoluble starch and 20 kg of polyethylene glycol to the pulper, dilute with water until the solid mass fraction in the slurry is 5%, and stir for 16 minutes.

[0131] (6) Add 320 kg of 25% silica sol and 60 kg of iron sol into the pulper and stir for 18 minutes to mix them evenly in the slurry and to flocculate the components in the slurry.

[0132] (7) Add water to dilute the slurry to a solid mass fraction of 4%.

[0133] (8) The diluted slurry is formed into a wet blank through a vacuum suction filtration device, and then pressed to a corresponding thickness and density in a hydraulic press, and transported to a drying room for drying.

[0134] Since comparative example 5 does not add lean raw materials (ultrafine alumina powder and wollastonite), the plastic filler undergoes dehydration shrinkage and curling deformation during the drying process, resulting in a large number of cracks and severe warping in the dried ceramic fiberboard, making it unqualified product.

[0135] Comparative Example 6

[0136] The difference between this comparative example 6 and example 1 is that no plastic raw material (dolomite) is added, that is, only ultrafine alumina powder and wollastonite are added in step (4). The preparation method is as follows:

[0137] (1) 400 kg of waste paper was fully soaked in water for 30 hours, 4 tons of water was added to the pulper, and the pulp was beaten for 25 minutes. Water was added to dilute the pulp to prepare a wood pulp fiber slurry with a mass fraction of 5%, which was then taken out for later use.

[0138] (2) Add 6 tons of water to the pulper, add 90 kg of zirconium-containing ceramic fiber spinning cotton, and beat for 11 minutes; add 320 kg of high-aluminum ceramic fiber blowing cotton, and beat for 12 minutes; add 50 kg of polycrystalline mullite fiber, and beat for 13 minutes; add 180 kg of wood pulp fiber slurry prepared in step (1), and beat for 9 minutes.

[0139] (3) Add 18 kg of high-silica chopped strands into the pulper and beat for 6 minutes.

[0140] (4) Add 150 kg of ultrafine alumina powder and 100 kg of wollastonite into the pulper and beat for 7 minutes.

[0141] (5) Add 60 kg of cationic thermosoluble starch and 20 kg of polyethylene glycol to the pulper, dilute with water until the solid mass fraction in the slurry is 5%, and stir for 16 minutes.

[0142] (6) Add 320 kg of 25% silica sol and 60 kg of iron sol into the pulper and stir for 18 minutes to mix them evenly in the slurry and to flocculate the components in the slurry.

[0143] (7) Add water to dilute the slurry to a solid mass fraction of 4%.

[0144] (8) The diluted slurry is formed into a wet blank through a vacuum suction filtration device, and then pressed to a corresponding thickness and density in a hydraulic press, and transported to a drying room for drying.

[0145] Since no plastic raw material (dolomite) was added in Comparative Example 6, the material was too loose and had poor water filterability, and the wet blank could not be formed. The wet blank forming thickness was further reduced to 10 mm. Although the wet blank could be barely formed, cracks appeared on the surface of the wet blank during the pressing process, and thus it could not become a qualified product.

[0146] In the present invention, the high-aluminum ceramic fiber spray cotton used refers to the fiber prepared by the spraying method, which has the characteristics of fine fiber diameter and short fiber length. The zirconium-containing ceramic fiber spun cotton refers to the fiber prepared by the spun method, which has the characteristics of long fiber, thick fiber diameter and high strength. Polycrystalline mullite fiber helps to improve the stability of ceramic fiber board at high temperature. The addition of high-silica short-cut fibers acts as a reinforcing fiber at room temperature to prevent cracking, while not affecting the refractoriness of high-density ceramic fiber board. The fillers selected are the barren materials alumina ultrafine powder, wollastonite and the plastic material dolomite. The two types of fillers, plastic materials and barren materials, are used and matched in appropriate proportions. While improving the density and strength of the product, cracking in the wet blank drying stage can be avoided. When the ceramic powder is pressed and molded, the binders used include organic binders and inorganic binders. The organic binder cationic thermosoluble starch and polyethylene glycol mixture has good bonding properties and plasticity, and can effectively bond the ceramic powder together to form a solid molded part. Inorganic binders silica sol and iron sol have high sintering activity and chemical stability. They can react chemically with ceramic powder at high temperature to form a dense binding phase, thereby improving the density and mechanical properties of the molded parts.

[0147] The present invention adjusts the order of adding materials and controls the beating time to obtain a slurry with a reasonable combination of long fibers and short fibers, coarse fibers and fine fibers, thereby improving the interweaving strength between the fibers in the slurry, thereby eliminating the need for short-cut pretreatment of the ceramic fibers, optimizing the production process, and improving production efficiency; by adding polyethylene glycol and iron sol, the material is dispersed evenly and stably, which not only makes the various material components more closely bonded, reduces the resilience of the wet blank after pressing, and increases the density of the wet blank and dry blank after forming, but also improves the density and strength of the final product after high-temperature sintering during subsequent actual use. It avoids the common problem of uneven distribution of raw materials due to floating materials, resulting in different heat resistance of different parts of the fiberboard, partial cracking, and reduced heat resistance of the overall product. The ceramic fiberboard resistant to high temperatures of 1600°C prepared by the present invention has a volume density of up to 950kg / m 3 The compressive strength reaches 15.3 MPa, and the rate of change of the permanent line after 24 hours of insulation at 1600°C is only -0.9%. Ten samples were tested, and the maximum range was 1.56% of the average, improving the quality consistency of batch products. The volume density deviation is far lower than the ±15% requirement specified in the national standard GB / T 16400-2023, "Aluminum Silicate Wool for Thermal Insulation and Its Products," making it competitive with similar products on the market.

[0148] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A ceramic fiberboard, characterized in that: Made from the following raw materials in parts by weight: 60-120 parts of zirconium-containing ceramic fiber spun cotton, 200-400 parts of high-aluminum ceramic fiber blown cotton, 20-100 parts of polycrystalline mullite fiber, 100-300 parts of wood pulp fiber slurry, 10-30 parts of high-silica chopped strands, 100-300 parts of ultrafine alumina powder, 50-200 parts of wollastonite, 10-30 parts of dolomite, 30-100 parts of cationic thermosoluble starch, 10-50 parts of polyethylene glycol, 150-500 parts of silica sol, and 30-100 parts of iron sol; The iron sol has a density of 3-5 kg / L and a particle size of 1-100 nm; The high-aluminum ceramic fiber spray cotton has a diameter of 0.5-10 μm; The zirconium-containing ceramic fiber spinning cotton has a diameter of 0.5-10 μm, a length of 50-200 mm, an Al2O3 content of 20-60%, and a ZrO2 content of 5-30%. The high-silica chopped strands have a length of 2-20 mm and a diameter of 2-20 μm, wherein the SiO2 content is not less than 80%; The polycrystalline mullite fiber has a diameter of 1-10 μm and a length of 1-50 mm; The ultrafine alumina powder has a particle size of 50-200 nm; The wollastonite has a particle size of 2000-8000 mesh; The dolomite has a particle size of 2000-8000 mesh; The compressive strength of ceramic fiberboard is 5-20MPa and the bulk density is 600-1200kg / m 3 .

2. The method for preparing the ceramic fiberboard according to claim 1, characterized in that: The following steps are involved: (1) adding zirconium-containing ceramic fiber spinning cotton, high-aluminum ceramic fiber blowing cotton, polycrystalline mullite fiber, wood pulp fiber slurry and high-silica chopped strands into water in sequence and beating; (2) adding ultrafine alumina powder, wollastonite and dolomite to the liquid after beating in step (1), and dispersing and beating; (3) adding cationic thermosoluble starch and polyethylene glycol to the pulped liquid in step (2) and mixing uniformly; (4) adding silica sol and iron sol to the mixed liquid in step (3) for flocculation, and then forming the flocculated slurry into a wet blank, and drying it to obtain a ceramic fiberboard.

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