Ceramic fiber reinforced silicon carbide repair material, its preparation method and application

Abstract

The application discloses a ceramic fiber reinforced silicon carbide repair material and a preparation method and application thereof, and belongs to the technical field of refractory repair materials. The material comprises, in terms of weight parts, 5-20 parts of a fiber composite filler, 20-40 parts of mullite aggregate, 20-40 parts of a silicon carbide reinforcing phase, 5-20 parts of a ceramic filler, 15-30 parts of calcium aluminate, 5-20 parts of brown corundum, 10-30 parts of a binder, 5-30 parts of water and 0.1-5 parts of a dispersing agent; wherein the fiber composite filler is composed of silicon-based ceramic fibers and aluminum silicate fibers; the mullite aggregate is composed of mullite with different particle sizes in an equal mass ratio; and the silicon carbide reinforcing phase is composed of silicon carbide with different particle sizes in an equal mass ratio. The material is used to overcome the technical problems of short service life, low wear resistance and poor thermal shock resistance of the material used in the inclined channel area of a dry quenching furnace.

Description

Technical Field

[0001] This invention belongs to the field of refractory repair materials technology, specifically relating to a ceramic fiber reinforced silicon carbide repair material, its preparation method, and its application. Background Technology

[0002] Dry quenching technology utilizes inert gas in a closed system to cool high-temperature red-hot coke, effectively recovering heat energy and reducing emissions of pollutants such as phenol and cyanide wastewater and dust. However, the operating conditions in the inclined section of the dry quenching furnace are harsh. It must withstand the static load of the upper masonry and the dynamic stress from the coke flow over extended periods. Frequent temperature fluctuations cause severe thermal shock, leading to internal thermal stress in the materials. Simultaneously, the high-speed circulating gas carries coke particles, severely eroding the surface of the refractory material. Therefore, the refractory material in the inclined section must simultaneously meet the requirements of high thermal shock resistance (≥50 cycles, 1100℃ water cooling) and high wear resistance (volume wear rate ≤5 cm). 3 With its excellent high-temperature flexural strength (≥15 MPa, 1400℃) and 1000 rpm, the performance of the material directly affects the maintenance cycle and operating cost of the dry quenching furnace. If the material life is insufficient, it will lead to frequent furnace shutdowns for maintenance, increasing production costs and reducing production efficiency. Currently, mullite-silicon carbide bricks (30 wt%~35 wt% Al2O3, 25 wt%~35 wt% SiC) are commonly used in inclined sections. However, in actual operation, this material has the following problems: the Fe2O3 (1.5 wt%~3.0 wt%) contained in mullite reacts with the reducing gases (CO, H2) in the dry quenching furnace: Fe2O3+3CO→2Fe+3CO2, Fe2O3+3H2→2Fe+3H2O. The generated Fe catalyzes the Boudouard reaction (2CO→C+CO2), leading to the deposition of free carbon, which makes the internal structure of the material loose, increases the porosity (by 5%~8%), and reduces the thermal shock resistance (<15 cycles) and wear resistance. After long-term operation, the surface of the material peels off more quickly, the wear rate increases by 30%~50%, and the maintenance cycle is shortened to 18~24 months, which seriously affects the stable operation of the dry quenching furnace. Currently, pure SiC bricks have poor thermal shock resistance, a high coefficient of thermal expansion, and are prone to corrosion with CO to generate SiO gas under high-temperature conditions. Therefore, there is an urgent need to develop a new type of refractory repair material with high thermal shock resistance and erosion resistance, which can quickly and efficiently repair damaged mullite-silicon carbide bricks in inclined sections to extend their service life, reduce the frequency of major repairs, and minimize costs as much as possible.

[0003] To address the aforementioned technical problems, Chinese invention patent application CN102173845A discloses a nitride ceramic fiber reinforced inorganic non-metallic composite material and its preparation method. However, this method requires weaving the finished nitride fibers and then processing them in a vacuum or inert atmosphere, increasing initial investment costs. For example, Chinese invention patent application CN109761611A discloses a fiber-reinforced microporous silicon nitride composite silicon carbide brick and its preparation method. This material significantly improves the wear and corrosion resistance of materials used in furnaces, but the microporous structure and uniform fiber dispersion require precise control of sintering conditions (such as temperature profiles and atmosphere protection), placing high demands on equipment and technology. Furthermore, Chinese invention patent application CN103833391A discloses a method for preparing silicon nitride composite silicon carbide bricks, using industrial silica sand as the silicon source and simultaneously employing nano-rare earth oxides. The scarcity of these materials severely hinders large-scale use and promotion. For example, Chinese invention patent application CN114956829A discloses a method of using a silicon carbide / metallic silicon mixture recycled from polycrystalline silicon waste as a raw material to produce silicon nitride-bonded silicon carbide bricks. Although this reduces the manufacturing cost of the raw materials, the impact of other substances in the waste on the service life of the bricks is unclear, posing potential risks.

[0004] Therefore, it is very important to seek a new type of refractory repair material with high thermal shock resistance and erosion resistance to improve the service life of refractory bricks in the inclined section and reduce maintenance costs. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a ceramic fiber reinforced silicon carbide repair material, its preparation method and application, which is used to overcome the technical problems of short service life, low wear resistance and poor thermal shock resistance of the materials used in the inclined section of the dry quenching furnace.

[0006] To achieve the above objectives, the present invention employs the following technical solution: This invention provides a ceramic fiber reinforced silicon carbide repair material. The raw materials for preparing the ceramic fiber reinforced silicon carbide repair material, by weight, include: 5-20 parts of fiber composite filler, 20-40 parts of mullite aggregate, 20-40 parts of silicon carbide reinforcing phase, 5-20 parts of ceramic filler, 15-30 parts of calcium aluminate, 5-20 parts of brown corundum, 10-30 parts of binder, 5-30 parts of water, and 0.1-5 parts of dispersant; wherein the fiber composite filler is composed of silicon-based ceramic fibers and aluminosilicate fibers in a mass ratio of (1.8-2):1. The mullite aggregate is composed of equal mass ratios of 20-30 mesh mullite, 30-60 mesh mullite, and 60-100 mesh mullite; the silicon carbide reinforcing phase is composed of equal mass ratios of 30-40 mesh silicon carbide, 95-105 mesh silicon carbide, and 320-330 mesh silicon carbide. The raw materials for preparing the silicon-based ceramic fiber include: 5-15 parts of polyvinylpyrrolidone, 10 parts of a mixed solution, 5-20 parts of water glass, and 0.1-5 parts of hydrochloric acid; wherein the mixed solution is composed of water and ethanol.

[0007] In one embodiment, the method for preparing the silicon-based ceramic fiber includes the following steps: Polyvinylpyrrolidone was dissolved in the mixed solution and stirred evenly at room temperature. Then, it was stirred continuously in a water bath until it was evenly dispersed to obtain solution A. Prepare solution B by mixing water glass and hydrochloric acid; Solution A and solution B are mixed thoroughly and stirred continuously to obtain solution C; Silicon-based ceramic fibers were obtained by spinning with solution C followed by calcination.

[0008] In one embodiment, the volume ratio of water to ethanol in the mixed solution is (3-3.2):2.

[0009] More preferably, the volume ratio of water to ethanol in the mixed solution is 3:2; the volume ratio of water glass to hydrochloric acid is 5:1; and the mass ratio of solution A to solution B is 1:1.

[0010] In one embodiment, the temperature of the water bath is 80℃-85℃; in the spinning process, the feed speed is 8μL / min-8.5μL / min, and the distance from the receiving end is 10cm-15cm; in the calcination process, the temperature is 600℃-900℃, and the time is 2h-4h.

[0011] In one embodiment, the ceramic filler is one or more of nano-ceramic hollow microspheres or nano-glass hollow microspheres.

[0012] In one embodiment, the adhesive is a silica-based adhesive or a phosphate-based adhesive.

[0013] In one embodiment, the silicate-based adhesive is one or more of water-based inorganic potassium silicate resin, water-based inorganic sodium silicate resin, and water-based inorganic lithium silicate resin; the phosphate-based adhesive is aluminum dihydrogen phosphate.

[0014] In one embodiment, the dispersant is anionic polyacrylamide.

[0015] This invention also provides a method for preparing a ceramic fiber reinforced silicon carbide repair material, comprising the following steps: Preparation of silicon-based ceramic fibers; Silicon-based ceramic fibers were treated with active plasma; the treated silicon-based ceramic fibers were dispersed in a first portion of water, and then aluminum silicate fibers were added and mixed uniformly to obtain a fiber composite filler. Mullite aggregate and silicon carbide reinforcing phase are mixed to prepare the repair material skeleton; The repair filler is prepared by simultaneously mixing ceramic filler, calcium aluminate and brown fused alumina. The fiber composite filler, the repair material skeleton and the repair filler are mixed to obtain a homogeneous material; The adhesive is mixed with the second part of water and then added to the mixture. At the same time, a dispersant is added to disperse the mixture, thus obtaining a ceramic fiber reinforced silicon carbide repair material. The amount of water used in the first part is 20%-30% of the weight of water in the raw materials for preparing the ceramic fiber reinforced silicon carbide repair material; The sum of the weights of the first portion of water and the second portion of water is equal to the weight of water in the raw materials for preparing the ceramic fiber reinforced silicon carbide repair material.

[0016] The present invention also provides the application of the aforementioned ceramic fiber reinforced silicon carbide repair material in a dry quenching furnace.

[0017] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a ceramic fiber-reinforced silicon carbide repair material. In this material, mullite aggregate serves as the core framework, silicon carbide reinforcing phase as the key functional reinforcing phase, and ceramic filler and brown corundum as functional auxiliary components. The aluminosilicate fibers in the fiber composite filler possess excellent thermal insulation properties, effectively reducing the material's thermal conductivity and mitigating thermal shock caused by sudden temperature changes in the inclined zone. The silicon-based ceramic fibers are prepared using water glass (silicon source), hydrochloric acid (catalyst), and polyvinylpyrrolidone (thickener). They exhibit high temperature resistance and high toughness, significantly improving the material's thermal shock stability and flexural strength, effectively reducing wear, mitigating thermal shock, and extending the material's service life. The water glass in the silicon-based ceramic fibers hydrolyzes under hydrochloric acid catalysis, generating flexible silicon-oxygen bonds (Si-R) that can partially replace the rigid silicon-oxygen bridge bonds (Si-O-Si) in traditional ceramics, forming a three-dimensional network structure that combines rigidity and flexibility. This molecular-scale flexible design endows the silicon-based ceramic fibers with excellent compressive elasticity and macroscopic flexibility. These flexible bonds, while playing a cross-linking role and providing structural strength, also enhance the overall mechanical properties of the material. Polyvinylpyrrolidone (PVP) acts as both a thickener and a template. The nanoscale defects formed during calcination passivate crack tips. Combined with the control of the spinning process using a mixed solution, it effectively improves the brittleness of ceramic materials and significantly enhances their thermal shock resistance. Silicon-based ceramic fibers contain numerous active silanol groups on their surface, which can chemically react with the matrix binder to form strong chemical bonds. This transforms the fiber-matrix bonding from mechanical interlocking to chemical bonding. Stress is dissipated through crack bridging and fiber pull-out mechanisms, effectively avoiding the peeling and severe wear caused by weak interfacial bonding in traditional fibers. When combined with aluminosilicate fibers, this fiber forms a functionally complementary system, simultaneously providing thermal insulation and structural reinforcement, achieving a good balance between thermal insulation and mechanical properties. Silicon-based ceramic fibers, with silicon dioxide as the main component, are free of impurities easily corroded by reducing gases, fundamentally avoiding the structural loosening problem caused by carbon deposition. Furthermore, a dense, self-passivating protective film forms on the surface at high temperatures, blocking the intrusion of corrosive media and improving the material's high-temperature chemical stability. As a ceramic material, this silicon-based ceramic fiber is inherently resistant to high temperatures and is fully adapted to the operating environment of a dry quenching furnace. The silicon-based ceramic fiber prepared by electrospinning technology yields a product with a uniform structure, giving it high strength, high toughness, and excellent high-temperature resistance.

[0018] Mullite, due to its high melting point (~1850℃), excellent high-temperature structural stability, outstanding creep resistance, and low coefficient of thermal expansion, was selected as the core refractory skeleton for repair materials. It ensures the material maintains fundamental thermal stability and structural integrity under the high-temperature environment of a dry quenching furnace. To achieve the densest particle packing, a blend of three particle sizes—20-30 mesh (coarse), 30-60 mesh (medium), and 60-100 mesh (fine)—is used. Coarse particles form the macroscopic skeleton, providing primary structural support and resistance to thermal stress. Too small a proportion leads to insufficient skeleton strength and easy overall deformation at high temperatures, while too large a proportion results in insufficient fine powder filling, a loose structure, and a decrease in bulk density and strength at both room and high temperatures. Medium and fine particles fill the gaps between coarse particles, making the structure more compact. Fine particles further fill the secondary voids between medium and coarse particles and can better contact the binder, improving sintering activity and mid-temperature strength. The three-graded granules, through a synergistic process of "skeleton-filler-densification," increase the mechanical interlocking and contact points between particles, resulting in high bulk density and excellent initial strength in the repair material after application. The 1:1:1 mass ratio achieves an optimal balance between bulk density, workability, and post-sintering strength, forming a skeleton that is both strong and dense.

[0019] In this system, silicon carbide serves as a high-performance reinforcing phase, not as the main structural component. It primarily strengthens the mullite aggregate through its excellent physicochemical properties, achieving a Mohs hardness of over 9.2. This significantly improves the material's wear resistance, while maintaining stable strength at high temperatures. It effectively distributes loads and inhibits crack propagation. During high-temperature use, its surface oxidizes to form a dense SiO2 glass film, effectively preventing further internal oxidation. This film also reacts with corrosive media such as molten alkali metal salts to form a high-viscosity layer, significantly enhancing resistance to chemical corrosion. Similar to mullite, silicon carbide is graded in three meshes: 30-40 mesh (coarse), 95-105 mesh (medium), and 320-330 mesh (fine) to achieve optimal filling effect, ensuring uniform dispersion in the matrix and the formation of a reinforcing network. A 1:1:1 mass ratio fully leverages the reinforcing effect of silicon carbide. Excessively coarse particles lead to uneven dispersion, while excessively fine particles cause agglomeration and increase costs. This ratio results in the optimal overall strength and wear resistance of the material.

[0020] Ceramic filler is used to adjust the thermal insulation function. Its closed hollow structure creates numerous static air cavities, greatly extending the heat conduction path and effectively reducing the thermal conductivity of the material. This provides additional thermal insulation protection for the dry quenching furnace shell, preventing overheating deformation, cracking, and damage. When the amount of ceramic filler added is less than 5 parts, the improvement in thermal insulation effect is not significant; if it exceeds 20 parts, it will severely disrupt the continuity of the matrix structure, significantly reduce the material's bulk density, mechanical strength, and corrosion resistance, becoming a weak point in the structure and ultimately leading to a significant shortening of the repair layer's lifespan. Therefore, the range of 5-20 parts achieves the optimal balance between thermal insulation performance and structural strength.

[0021] Brown fused alumina possesses excellent toughness, high hardness, and good thermal shock resistance. The introduction of brown fused alumina further enhances overall wear resistance. More importantly, its coefficient of thermal expansion matches well with that of the main materials such as mullite, and its inherent toughness allows it to effectively dissipate heat stress through mechanisms such as crack deflection and bridging, improving the material's resistance to sudden temperature changes. An addition of 5-20 parts of brown fused alumina is sufficient to form an effective toughening network in the matrix, significantly improving thermal shock resistance and wear resistance. Adding less than 5 parts has limited effect; adding more than 20 parts can alter the main phase composition of the material, potentially adversely affecting high-temperature chemical stability and being uneconomical. Detailed Implementation

[0022] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions mentioned in the specification are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0023] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0024] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0025] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0026] This invention provides a ceramic fiber reinforced silicon carbide repair material, its preparation method, and its application.

[0027] The first aspect of this invention provides a ceramic fiber reinforced silicon carbide repair material. The raw materials for preparing this material, by weight, include: 5-20 parts of fiber composite filler, 20-40 parts of mullite aggregate, 20-40 parts of silicon carbide reinforcing phase, 5-20 parts of ceramic filler, 15-30 parts of calcium aluminate, 5-20 parts of brown corundum, 10-30 parts of binder, 5-30 parts of water, and 0.1-5 parts of dispersant; wherein the fiber composite filler is composed of silicon-based ceramic fibers and aluminosilicate fibers in a mass ratio of (1.8-2):1.

[0028] The mullite aggregate is composed of equal mass ratios of 20-30 mesh mullite, 30-60 mesh mullite, and 60-100 mesh mullite; the silicon carbide reinforcing phase is composed of equal mass ratios of 30-40 mesh silicon carbide, 95-105 mesh silicon carbide, and 320-330 mesh silicon carbide.

[0029] The raw materials for preparing the silicon-based ceramic fiber, by weight, include: 5-15 parts of polyvinylpyrrolidone, 10 parts of a mixed solution, 5-20 parts of water glass and 0.1-5 parts of hydrochloric acid; wherein the mixed solution is prepared by mixing water and ethanol in a volume ratio of (3-3.2):2.

[0030] More preferably, the ceramic fiber reinforced silicon carbide repair material comprises, by weight, 5-15 parts of fiber composite filler, 24-30 parts of mullite aggregate, 21-24 parts of silicon carbide reinforcing phase, 5-7 parts of ceramic filler, 15-20 parts of calcium aluminate, 5-7 parts of brown corundum, 13-24 parts of binder, 5-9.5 parts of water, and 0.5-2 parts of dispersant; wherein the fiber composite filler is composed of silicon-based ceramic fibers and aluminosilicate fibers in a mass ratio of 2:1.

[0031] More preferably, the silicon carbide reinforcing phase is composed of equal mass ratios of 36-mesh silicon carbide, 100-mesh silicon carbide, and 325-mesh silicon carbide.

[0032] More preferably, the raw materials for preparing the silicon-based ceramic fiber, by weight, include: 5-10 parts of polyvinylpyrrolidone, 10 parts of a mixed solution, 5-15 parts of water glass, and 0.5-5 parts of hydrochloric acid; wherein the mixed solution is prepared by mixing water and ethanol in a volume ratio of 3:2.

[0033] The specific descriptions of each raw material in the aforementioned ceramic fiber reinforced silicon carbide repair material are as follows: Both mullite aggregate and silicon carbide reinforcing phase adopt a multi-mesh gradient compound design: by weight, coarse-grained particles constitute the core skeleton structure of the repair material, while fine-grained particles fill the gaps as fillers. The two work together to enhance the overall strength and wear resistance of the repair material. The amount of mullite aggregate and silicon carbide reinforcing phase can be selected as 20-40 parts, with the preferred amount of mullite aggregate being 24-30 parts and the preferred amount of silicon carbide reinforcing phase being 21-24 parts.

[0034] The mullite aggregate is blended in three sizes: 20-30 mesh mullite, 30-60 mesh mullite, and 60-100 mesh mullite. For example, the weight percentages of the three are 10 parts, 10 parts, and 10 parts respectively (equal mass ratio). The silicon carbide reinforcing phase is blended in three sizes: 36 mesh silicon carbide, 100 mesh silicon carbide, and 325 mesh silicon carbide. For example, the weight percentages of the three are 10 parts, 10 parts, and 10 parts respectively (equal mass ratio).

[0035] Calcium aluminate, preferably 325 mesh, is used as an inorganic binder. It undergoes a hydration reaction with a portion of the water in the main formulation at a weight ratio of 5:3. The resulting hydrated calcium aluminate crystals provide significant early strength to the repair material and exhibit rapid hardening, meeting the construction requirements for rapid repair of dry-quenching furnaces while effectively reducing overall material costs. The amount of calcium aluminate used can be selected from 15-30 parts, preferably 15-20 parts.

[0036] Brown fused alumina, as an auxiliary component for wear resistance and toughening, is preferably 200-mesh brown fused alumina. Due to its excellent high hardness and thermal shock resistance, it can further enhance the erosion and wear resistance and resistance to sudden temperature changes of the repair material. Together with silicon carbide reinforcement and fiber composite fillers, it forms a multi-layered wear-resistant and toughening system. The amount of brown fused alumina can be selected from 5 to 20 parts, preferably 5 to 7 parts.

[0037] The ceramic filler uses one or more of commercially available nano-ceramic hollow microspheres or nano-glass hollow microspheres, preferably 200-mesh ceramic filler. The special treatment process of the heat-insulating filler can improve its high-temperature resistance and surface properties. In this embodiment of the invention, nano-ceramic hollow microspheres containing inert gas, produced by Lantek Environmental Protection Technology Co., Ltd., are preferred. Their internal closed static air cavity can significantly extend the heat conduction path and effectively reduce the material's thermal conductivity. The amount of ceramic filler can be selected from 5-20 parts, preferably 5-7 parts.

[0038] The adhesive employs an inorganic high-temperature resistant system, specifically a silicate-based adhesive or a phosphate-based adhesive. The silicate-based adhesive is selected from one or more of water-based inorganic potassium silicate resin, water-based inorganic sodium silicate resin, and water-based inorganic lithium silicate resin. The phosphate-based adhesive is aluminum dihydrogen phosphate. The technical specifications for the silicate-based adhesive are a modulus greater than 4.0 and a viscosity less than 50 mPa. In this embodiment of the invention, a nano-sized silicate solution with a modulus of 4.5, produced by Henan Yilu Chemical Technology Co., Ltd., is used. The amount of adhesive used can be selected as 10-30 parts, preferably 13-24 parts.

[0039] The dispersant is anionic polyacrylamide, and the dosage can be selected from 0.1 to 5 parts, preferably 0.5 to 2 parts.

[0040] The fiber composite filler is composed of aluminosilicate fibers and silicon-based ceramic fibers. The aluminosilicate fibers possess excellent thermal insulation, electrical insulation, corrosion resistance, high-temperature chemical stability, and mechanical strength, effectively reducing the overall thermal conductivity of the material. The self-made silicon-based ceramic fibers, after active plasma surface treatment, can serve as a reinforcing bonding phase in the matrix, further improving the thermal shock stability and flexural strength of the silica bricks while reducing thermal conductivity. In this embodiment of the invention, aluminosilicate fibers produced by Hebei Meifeng Chemical Building Materials Co., Ltd. and self-made silicon-based ceramic fibers are used. The amount of fiber composite filler can be selected from 5-20 parts, preferably 5-15 parts.

[0041] Water glass, used as the silicon source for silicon-based ceramic fibers, is preferably an industrial-grade product with a modulus of 3.5, which can undergo catalytic hydrolysis under both acidic and alkaline conditions. The amount of water glass used can be 5-20 parts, preferably 5-15 parts.

[0042] Hydrochloric acid, as an acidic catalyst for the hydrolysis of water glass, can precisely control the rate of the hydrolysis and condensation reaction of water glass. A 1 mol / L hydrochloric acid solution is used. The amount of hydrochloric acid can be selected from 0.1 to 5 parts, preferably 0.5 to 5 parts.

[0043] Polyvinylpyrrolidone (PVP) acts as a good thickener and template, further increasing the solution viscosity and spinnability during the preparation of silicon-based ceramic fibers. During calcination, it gradually decomposes and carbonizes, forming uniformly distributed nanoscale pores within the fibers, which can blunt crack tips and further improve fiber toughness. The amount of PPVP used can be selected as 5-15 parts, preferably 5-10 parts.

[0044] Furthermore, a method for preparing silicon-based ceramic fibers is also provided, comprising the following steps: S1: Dissolve polyvinylpyrrolidone in the mixed solution, stir evenly at room temperature (e.g., 25℃), and then stir continuously at 150 r / min in a water bath at 80℃-85℃ until uniformly dispersed to obtain solution A. S2: Mix water glass and hydrochloric acid, stir evenly at 25°C, and prepare solution B; S3: Mix solution A and solution B thoroughly and stir continuously for 2 hours to obtain solution C; S4: Silicon-based ceramic fibers are obtained by spinning with solution C and then calcining. The treated fibers can be bent at will and then restored to their original shape. They have good flexibility and can be stored at room temperature.

[0045] The spinning process specifically involves: using a 10mL syringe to draw solution C, placing solution C on the propulsion device of a DP30 spinning equipment at a propulsion speed of 8μL / min-8.5μL / min, and a distance of 10cm-15cm from the receiving end. The positive electrode is connected to the flat end of the syringe, and the negative electrode is connected to the receiving end. After the equipment is powered on, the spinning process begins. Under the action of the propulsion device, droplets gather at the front end of the syringe and form a fiber bundle with a diameter of approximately 1μm under the action of high voltage. The ejected fiber bundle is collected at the receiving end to form a fiber membrane.

[0046] The calcination treatment specifically involves calcining at 600℃-900℃ for 2-4 hours to remove residual polymer templates from the fibers.

[0047] In one embodiment, the volume ratio of water to ethanol in the mixed solution is (3-3.2):2.

[0048] More preferably, the volume ratio of water to ethanol in the mixed solution is 3:2; the volume ratio of water glass to hydrochloric acid is 5:1; and solution A and solution B are mixed evenly at a mass ratio of 1:1.

[0049] This invention provides a method for preparing a ceramic fiber reinforced silicon carbide repair material, comprising the following steps: Preparation of S100 silicon-based ceramic fibers: Silicon-based ceramic fibers are prepared using steps S1-S4.

[0050] Preparation of S200 and fiber composite fillers: Silicon-based ceramic fibers prepared by S100 are placed into PDC type 32G In the plasma instrument of size 2, the sealed chamber was evacuated to a vacuum of 10. -3 Pa-10 -5 The fiber surface was physically bombarded for 10 minutes using high-energy particles in the plasma and the action of oxygen-containing active groups. This removed organic contaminants from the fiber surface and introduced oxygen-containing polar groups, significantly improving the hydrophilicity of the silicon-based ceramic fibers. After treatment, the power and gas sources were turned off, and the fiber was slowly removed from the chamber. The first portion of water, accounting for 20%-30% of the weight of water in the raw materials for preparing the silicon carbide repair material reinforced with ceramic fibers, was used to completely immerse the plasma-treated silicon-based ceramic fibers. The mixture was stirred to ensure full contact and pre-dispersion between the silicon-based ceramic fibers and the water. Then, it was placed together with the aluminosilicate fibers into a Scientz-type container. Simultaneous dispersion was performed in an IID cell disruptor, and the mixture was treated at 25 kHz and 25°C for 5 minutes to ensure that the two fibers were evenly dispersed and fully compounded in water, thus obtaining a fiber composite filler.

[0051] S300, Preparation of the repair material skeleton: 20 30 mesh, 30 60 mesh, 60 Mullite of 100 mesh is compounded in a weight ratio of 1:1:1 to form mullite aggregate, and silicon carbide of 30-40 mesh, 95-105 mesh, and 320-330 mesh is compounded in a weight ratio of 1:1:1 to form silicon carbide reinforcing phase. The above mullite aggregate and silicon carbide reinforcing phase are placed together in a planetary ball mill and mixed at a speed of 1000 r / min for 2 hours. By combining multiple particle sizes, the skeleton support effect is enhanced, and the repair material skeleton is obtained. By adjusting the mixing ratio and fineness of the two, the support effect of the skeleton is enhanced, thereby strengthening the strength of the repair material.

[0052] S400, Preparation of Repair Filler: Ceramic filler, calcium aluminate and brown corundum are mixed simultaneously at a speed of 1500 r / min for 1 hour. By adjusting the mixing ratio and fineness of each fine powder, the filling properties of the fine powder are enhanced to obtain the repair filler.

[0053] Preparation of S500 ceramic fiber reinforced silicon carbide repair material: The fiber composite filler obtained from S200, the repair material skeleton obtained from S300, and the repair filler obtained from S400 are mixed together for 30 minutes to obtain a homogeneous material; the ratio of the adhesive to the second part of water is pre-adjusted, wherein the amount of the second part of water accounts for 70%-80% of the weight of water in the raw materials for preparing ceramic fiber reinforced silicon carbide repair material, and is added to the homogeneous material, along with a dispersant, and dispersed at 500 r / min for 30 minutes using an electric disperser. After mixing, a ceramic fiber reinforced silicon carbide repair material that can be used for repairing the inclined zone of a dry quenching furnace is obtained.

[0054] In summary, the inclined section is subjected to rapid temperature changes and thermal shock and abrasion from falling coke over a long period, making the refractory lining highly susceptible to damage, leading to decreased lining strength and shortened service life. Therefore, this invention provides a composite material that can withstand harsh conditions such as high temperature, abrasion, and thermal shock. This material uses mullite aggregate as a structural framework to ensure the stability and refractoriness of the main body, silicon carbide to form a reinforcing network to improve the material's strength and erosion resistance, ceramic fillers to optimize thermal insulation, and brown fused alumina to enhance the material's toughness and thermal shock resistance. Simultaneously, the multi-size particle gradation creates a dense synergy, achieving close packing and laying the foundation for the material's high strength and impermeability; the complementary cooperation of the functional components forms a functional synergy, enabling the repair material to simultaneously resist multiple destructive effects such as high temperature, abrasion, and thermal shock.

[0055] If the content of the components exceeds the specified range, it will have significant negative effects: for example, an imbalance in the particle size distribution of the skeleton will lead to a decrease in bulk density, insufficient strength, or poor workability; excessive addition of ceramic fillers will seriously degrade the strength and durability of the material and easily form a weak and vulnerable layer; excessive addition of brown fused alumina will not only increase costs and introduce excess chemical components, but will also cause the improvement of the core refractory performance to enter the range of diminishing marginal benefits.

[0056] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined in this application.

[0057] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0058] The technical solution of the present invention will be described in detail below with reference to specific embodiments. These embodiments do not constitute a limitation on the present invention.

[0059] Example 1: A ceramic fiber reinforced silicon carbide repair material, by weight, comprises: 6 parts of fiber composite filler, 24 parts of mullite aggregate, 21 parts of silicon carbide reinforcing phase, 5 parts of ceramic filler, 15 parts of calcium aluminate, 5 parts of brown corundum, 24 parts of binder, 9.5 parts of water, and 0.5 parts of dispersant. The fiber composite filler is composed of silicon-based ceramic fibers and aluminosilicate fibers in a mass ratio of 2:1.

[0060] The raw materials for preparing silicon-based ceramic fibers include: 5 parts polyvinylpyrrolidone, 10 parts mixed solution (water to ethanol volume ratio 3:2), 5 parts water glass and 0.5 parts hydrochloric acid.

[0061] The mullite aggregate consists of 8 parts each of equal mass of 20-mesh mullite, 60-mesh mullite, and 90-mesh mullite; the silicon carbide reinforcing phase consists of 7 parts each of equal mass of 36-mesh silicon carbide, 100-mesh silicon carbide, and 325-mesh silicon carbide; the ceramic filler is nano-ceramic hollow microspheres; the binder is water-based inorganic potassium silicate resin; and the dispersant is anionic polyacrylamide.

[0062] A method for preparing a ceramic fiber reinforced silicon carbide repair material includes the following steps: S1001, Preparation of silicon-based ceramic fibers: Polyvinylpyrrolidone was dissolved in a mixture of water and ethanol and stirred at 25°C until homogeneous. The solution was then continuously stirred in an 80°C water bath until uniformly dispersed; this solution is denoted as solution A. Water glass was dissolved in hydrochloric acid and stirred until homogeneous to obtain solution B. Solution A and solution B were mixed at a mass ratio of 1:1 to obtain solution C. Solution C was drawn into a 10mL syringe and placed in the feed device of a DP30 spinning apparatus at a feed rate of 8μL / min and a distance of 10cm from the receiving end. The positive electrode was connected to the flat end of the syringe, and the negative electrode was connected to the receiving end. After the equipment was powered on, the spinning process began. Under the action of the feeder, droplets gathered at the tip of the syringe and formed fiber bundles with a diameter of approximately 1μm under the action of high voltage. The ejected fiber bundles were collected at the receiving end to form a fiber membrane, which was then calcined at 600°C for 2 hours to remove residual polymers from the fibers, thus obtaining silicon-based ceramic fibers.

[0063] S1002, Preparation of fiber composite filler: Silicon-based ceramic fibers are placed in PDC model 32G In the plasma instrument of size 2, the sealed chamber was evacuated to a vacuum of 10. - 3 Pa, the fiber surface is physically bombarded with active plasma for 10 minutes, and the fiber is removed; take 20% of the weight of water in the raw materials for preparing ceramic fiber reinforced silicon carbide repair material, and completely immerse the plasma-treated silicon-based ceramic fiber in it and stir to pre-disperse it. Then, the pre-dispersed silicon-based ceramic fiber and aluminosilicate fiber are put into the Scientz model. In the cell disruptor of IID, the two types of fibers are simultaneously dispersed and treated for 5 minutes at 25KHz power and 25℃ to ensure that they are evenly dispersed and fully compounded in water, thus producing fiber composite filler.

[0064] S1003, Preparation of the repair material skeleton: Mullite aggregate and silicon carbide reinforcing phase were placed together in a planetary ball mill and mixed at a speed of 1000 r / min for 2 hours to obtain the repair material skeleton.

[0065] S1004, Preparation of repair filler: The ceramic filler, calcium aluminate and brown corundum were mixed at a speed of 1500 r / min for 1 hour to obtain the repair filler.

[0066] S1005, Preparation of ceramic fiber reinforced silicon carbide repair material: The above-mentioned fiber composite filler, repair material skeleton and repair filler are mixed and mixed evenly with an electric disperser for 30 minutes at a speed of 300 r / min; binder and second part of water are added, wherein the amount of second part of water accounts for 80% of the weight of water in the raw materials for preparing ceramic fiber reinforced silicon carbide repair material. At the same time, dispersant is added and dispersed with an electric disperser at a speed of 500 r / min for 30 minutes. After mixing evenly, ceramic fiber reinforced silicon carbide repair material is obtained.

[0067] Example 2: A ceramic fiber reinforced silicon carbide repair material, by weight, comprises: 9 parts fiber composite filler, 24 parts mullite aggregate, 21 parts silicon carbide reinforcing phase, 7 parts ceramic filler, 17 parts calcium aluminate, 5 parts brown corundum, 17 parts binder, 9.5 parts water, and 0.5 parts dispersant. The fiber composite filler is composed of silicon-based ceramic fibers and aluminosilicate fibers in a mass ratio of 2:1.

[0068] The raw materials for preparing silicon-based ceramic fibers include: 5 parts polyvinylpyrrolidone, 10 parts mixed solution (water to ethanol volume ratio 3:2), 5 parts water glass and 0.5 parts hydrochloric acid.

[0069] The mullite aggregate consists of 8 parts each of equal mass of 30-mesh mullite, 60-mesh mullite, and 100-mesh mullite; the silicon carbide reinforcing phase consists of 7 parts each of equal mass of 36-mesh silicon carbide, 100-mesh silicon carbide, and 325-mesh silicon carbide; the ceramic filler is nano-ceramic hollow microspheres; the binder is water-based inorganic potassium silicate resin; and the dispersant is anionic polyacrylamide.

[0070] A method for preparing a ceramic fiber reinforced silicon carbide repair material includes the following steps: S2001, Preparation of silicon-based ceramic fibers: Polyvinylpyrrolidone was dissolved in a mixture of water and ethanol and stirred at 25°C until homogeneous. The solution was then continuously stirred in an 85°C water bath until uniformly dispersed; this solution is denoted as solution A. Water glass was dissolved in hydrochloric acid and stirred until homogeneous to obtain solution B. Solution A and solution B were mixed at a mass ratio of 1:1 to obtain solution C. Solution C was drawn into a 10mL syringe and placed in the feed device of a DP30 spinning apparatus at a feed speed of 8.5μL / min and a distance of 15cm from the receiving end. The positive electrode was connected to the flat end of the syringe, and the negative electrode was connected to the receiving end. After the equipment was powered on, the spinning process began. Under the action of the feeder, droplets gathered at the tip of the syringe and formed fiber bundles with a diameter of approximately 1μm under the action of high voltage. The ejected fiber bundles were collected at the receiving end to form a fiber membrane, which was then calcined at 900°C for 4 hours to remove residual polymers from the fibers, thus obtaining silicon-based ceramic fibers.

[0071] S2002, Preparation of fiber composite filler: Silicon-based ceramic fibers are placed in PDC model 32G In the plasma instrument of size 2, the sealed chamber was evacuated to a vacuum of 10. - 5 Pa, the fiber surface is physically bombarded with active plasma for 10 minutes, and the fiber is removed; take 30% of the weight of water in the raw materials for preparing ceramic fiber reinforced silicon carbide repair material, and completely immerse the plasma-treated silicon-based ceramic fiber in it and stir to pre-disperse it. Then, the pre-dispersed silicon-based ceramic fiber and aluminosilicate fiber are put into the Scientz model. In the cell disruptor of IID, the two types of fibers are simultaneously dispersed and treated for 5 minutes at 25KHz power and 25℃ to ensure that they are evenly dispersed and fully compounded in water, thus producing fiber composite filler.

[0072] S2003, Preparation of the repair material skeleton: Mullite aggregate and silicon carbide reinforcing phase were placed together in a planetary ball mill and mixed at a speed of 1000 r / min for 2 hours to obtain the repair material skeleton.

[0073] S2004, Preparation of Repair Filler: The ceramic filler, calcium aluminate and brown corundum were mixed at a speed of 1500 r / min for 1 hour to obtain the repair filler.

[0074] S2005, Preparation of ceramic fiber reinforced silicon carbide repair material: The above-mentioned fiber composite filler, repair material skeleton and repair filler are mixed and mixed evenly with an electric disperser for 30 minutes at a speed of 300 r / min; binder and second part of water are added, wherein the amount of second part of water accounts for 70% of the weight of water in the raw materials for preparing ceramic fiber reinforced silicon carbide repair material. At the same time, dispersant is added and dispersed with an electric disperser at a speed of 500 r / min for 30 minutes. After mixing evenly, ceramic fiber reinforced silicon carbide repair material is obtained.

[0075] Example 3: A ceramic fiber reinforced silicon carbide repair material, by weight, comprises: 12 parts of fiber composite filler, 24 parts of mullite aggregate, 21 parts of silicon carbide reinforcing phase, 6 parts of ceramic filler, 20 parts of calcium aluminate, 7 parts of brown corundum, 13 parts of binder, 6.5 parts of water, and 0.5 parts of dispersant. The fiber composite filler is composed of silicon-based ceramic fibers and aluminosilicate fibers in a mass ratio of 2:1.

[0076] The raw materials for preparing silicon-based ceramic fibers include: 5 parts polyvinylpyrrolidone, 10 parts mixed solution (water to ethanol volume ratio 3:2), 5 parts water glass and 0.5 parts hydrochloric acid.

[0077] The mullite aggregate consists of 8 parts each of 20-mesh mullite, 30-mesh mullite, and 60-mesh mullite of equal mass; the silicon carbide reinforcing phase consists of 7 parts each of 30-mesh silicon carbide, 95-mesh silicon carbide, and 320-mesh silicon carbide of equal mass; the ceramic filler is nano-ceramic hollow microspheres; the binder is water-based inorganic potassium silicate resin; and the dispersant is anionic polyacrylamide.

[0078] The preparation method and parameters in this embodiment are the same as those in Example 1.

[0079] Example 4: A ceramic fiber reinforced silicon carbide repair material, by weight, comprises: 9 parts fiber composite filler, 27 parts mullite aggregate, 24 parts silicon carbide reinforcing phase, 7 parts ceramic filler, 17 parts calcium aluminate, 5 parts brown corundum, 15 parts binder, 5 parts water, and 1 part dispersant. The fiber composite filler is composed of silicon-based ceramic fibers and aluminosilicate fibers in a mass ratio of 2:1.

[0080] The raw materials for preparing silicon-based ceramic fibers include: 5 parts polyvinylpyrrolidone, 10 parts mixed solution (water to ethanol volume ratio 3:2), 5 parts water glass and 0.5 parts hydrochloric acid.

[0081] The mullite aggregate consists of 9 parts each of equal mass of 30-mesh mullite, 60-mesh mullite, and 100-mesh mullite; the silicon carbide reinforcing phase consists of 8 parts each of equal mass of 40-mesh silicon carbide, 105-mesh silicon carbide, and 330-mesh silicon carbide; the ceramic filler is nano-ceramic hollow microspheres; the binder is water-based inorganic potassium silicate resin; and the dispersant is anionic polyacrylamide.

[0082] The preparation method and parameters in this embodiment are the same as those in Example 1.

[0083] Example 5: A ceramic fiber reinforced silicon carbide repair material, by weight, comprises: 9 parts fiber composite filler, 27 parts mullite aggregate, 24 parts silicon carbide reinforcing phase, 5 parts ceramic filler, 17 parts calcium aluminate, 5 parts brown corundum, 15 parts binder, 7 parts water, and 1 part dispersant. The fiber composite filler is composed of silicon-based ceramic fibers and aluminosilicate fibers in a mass ratio of 2:1.

[0084] The raw materials for preparing silicon-based ceramic fibers include: 5 parts polyvinylpyrrolidone, 10 parts mixed solution (water to ethanol volume ratio 3:2), 5 parts water glass and 0.5 parts hydrochloric acid.

[0085] The mullite aggregate consists of 9 parts each of equal mass of 30-mesh mullite, 60-mesh mullite, and 100-mesh mullite; the silicon carbide reinforcing phase consists of 8 parts each of equal mass of 36-mesh silicon carbide, 100-mesh silicon carbide, and 325-mesh silicon carbide; the ceramic filler is nano-ceramic hollow microspheres; the binder is water-based inorganic potassium silicate resin; and the dispersant is anionic polyacrylamide.

[0086] The preparation method and parameters in this embodiment are the same as those in Example 1.

[0087] Example 6: A ceramic fiber reinforced silicon carbide repair material, by weight, comprises: 9 parts fiber composite filler, 30 parts mullite aggregate, 21 parts silicon carbide reinforcing phase, 5 parts ceramic filler, 17 parts calcium aluminate, 5 parts brown corundum, 15 parts binder, 7 parts water, and 1 part dispersant. The fiber composite filler is composed of silicon-based ceramic fibers and aluminosilicate fibers in a mass ratio of 2:1.

[0088] The raw materials for preparing silicon-based ceramic fibers include: 5 parts polyvinylpyrrolidone, 10 parts mixed solution (water to ethanol volume ratio 3:2), 5 parts water glass and 0.5 parts hydrochloric acid.

[0089] The mullite aggregate consists of 10 parts each of equal mass of 30-mesh mullite, 60-mesh mullite, and 100-mesh mullite; the silicon carbide reinforcing phase consists of 7 parts each of equal mass of 36-mesh silicon carbide, 100-mesh silicon carbide, and 325-mesh silicon carbide; the ceramic filler is nano-ceramic hollow microspheres; the binder is water-based inorganic potassium silicate resin; and the dispersant is anionic polyacrylamide.

[0090] The preparation method and parameters in this embodiment are the same as those in Example 1.

[0091] Example 7: A ceramic fiber reinforced silicon carbide repair material, by weight, comprises: 9 parts fiber composite filler, 24 parts mullite aggregate, 21 parts silicon carbide reinforcing phase, 7 parts ceramic filler, 16 parts calcium aluminate, 5 parts brown corundum, 18 parts binder, 8 parts water, and 2 parts dispersant. The fiber composite filler is composed of silicon-based ceramic fibers and aluminosilicate fibers in a mass ratio of 2:1.

[0092] The raw materials for preparing silicon-based ceramic fibers include: 5 parts polyvinylpyrrolidone, 10 parts mixed solution (water to ethanol volume ratio 3:2), 5 parts water glass and 0.5 parts hydrochloric acid.

[0093] The mullite aggregate consists of 8 parts each of equal mass of 30-mesh mullite, 60-mesh mullite, and 100-mesh mullite; the silicon carbide reinforcing phase consists of 7 parts each of equal mass of 36-mesh silicon carbide, 100-mesh silicon carbide, and 325-mesh silicon carbide; the ceramic filler is nano-ceramic hollow microspheres; the binder is water-based inorganic potassium silicate resin; and the dispersant is anionic polyacrylamide.

[0094] The preparation method and parameters in this embodiment are the same as those in Example 1.

[0095] Example 8 A ceramic fiber reinforced silicon carbide repair material, by weight, comprises: 5 parts fiber composite filler, 20 parts mullite aggregate, 20 parts silicon carbide reinforcing phase, 5 parts ceramic filler, 30 parts calcium aluminate, 5 parts brown corundum, 10 parts binder, 9.5 parts water, and 0.1 parts dispersant. The fiber composite filler is composed of silicon-based ceramic fibers and aluminosilicate fibers in a mass ratio of 1.8:1.

[0096] The raw materials for preparing silicon-based ceramic fibers include: 15 parts of polyvinylpyrrolidone, 10 parts of a mixed solution (water to ethanol volume ratio 3.2:2), 20 parts of water glass, and 0.1 parts of hydrochloric acid.

[0097] The mullite aggregate consists of equal masses of 30-mesh mullite, 60-mesh mullite, and 100-mesh mullite, each in 6.67 parts; the silicon carbide reinforcing phase consists of equal masses of 36-mesh silicon carbide, 100-mesh silicon carbide, and 325-mesh silicon carbide, each in 6.67 parts; the ceramic filler is nano-ceramic hollow microspheres; the binder is water-based inorganic potassium silicate resin; and the dispersant is anionic polyacrylamide.

[0098] The preparation method and parameters in this embodiment are the same as those in Example 1.

[0099] Example 9 A ceramic fiber reinforced silicon carbide repair material, by weight, comprises: 20 parts of fiber composite filler, 40 parts of mullite aggregate, 40 parts of silicon carbide reinforcing phase, 20 parts of ceramic filler, 15 parts of calcium aluminate, 20 parts of brown corundum, 30 parts of binder, 30 parts of water, and 5 parts of dispersant. The fiber composite filler is composed of silicon-based ceramic fibers and aluminosilicate fibers in a mass ratio of 2:1.

[0100] The raw materials for preparing silicon-based ceramic fibers include: 5 parts polyvinylpyrrolidone, 10 parts mixed solution (water to ethanol volume ratio 3:2), 5 parts water glass and 5 parts hydrochloric acid.

[0101] The mullite aggregate consists of equal masses of 30-mesh mullite, 60-mesh mullite, and 100-mesh mullite, each in 13.33 parts; the silicon carbide reinforcing phase consists of equal masses of 36-mesh silicon carbide, 100-mesh silicon carbide, and 325-mesh silicon carbide, each in 13.33 parts; the ceramic filler is nano-ceramic hollow microspheres; the binder is water-based inorganic potassium silicate resin; and the dispersant is anionic polyacrylamide.

[0102] The preparation method and parameters in this embodiment are the same as those in Example 1.

[0103] Example 10 A ceramic fiber reinforced silicon carbide repair material, by weight, comprises: 15 parts fiber composite filler, 24 parts mullite aggregate, 21 parts silicon carbide reinforcing phase, 5 parts ceramic filler, 17 parts calcium aluminate, 5 parts brown corundum, 15 parts binder, 9.5 parts water, and 0.5 parts dispersant. The fiber composite filler is composed of silicon-based ceramic fibers and aluminosilicate fibers in a mass ratio of 2:1.

[0104] The raw materials for preparing silicon-based ceramic fibers include: 10 parts of polyvinylpyrrolidone, 10 parts of a mixed solution (water to ethanol volume ratio 3:2), 15 parts of water glass, and 0.5 parts of hydrochloric acid.

[0105] The mullite aggregate consists of 8 parts each of equal mass of 30-mesh mullite, 60-mesh mullite, and 100-mesh mullite; the silicon carbide reinforcing phase consists of 7 parts each of equal mass of 36-mesh silicon carbide, 100-mesh silicon carbide, and 325-mesh silicon carbide; the ceramic filler is nano-ceramic hollow microspheres; the binder is water-based inorganic potassium silicate resin; and the dispersant is anionic polyacrylamide.

[0106] The preparation method and parameters in this embodiment are the same as those in Example 1.

[0107] Example 11 A ceramic fiber reinforced silicon carbide repair material, by weight, comprises: 9 parts fiber composite filler, 24 parts mullite aggregate, 21 parts silicon carbide reinforcing phase, 7 parts ceramic filler, 17 parts calcium aluminate, 5 parts brown corundum, 17 parts binder, 9.5 parts water, and 0.5 parts dispersant. The fiber composite filler is composed of silicon-based ceramic fibers and aluminosilicate fibers in a mass ratio of 2:1.

[0108] The raw materials for preparing silicon-based ceramic fibers include: 5 parts polyvinylpyrrolidone, 10 parts mixed solution (water to ethanol volume ratio 3:2), 5 parts water glass and 0.5 parts hydrochloric acid.

[0109] The mullite aggregate consists of 8 parts each of equal mass of 30-mesh mullite, 60-mesh mullite, and 100-mesh mullite; the silicon carbide reinforcing phase consists of 7 parts each of equal mass of 36-mesh silicon carbide, 100-mesh silicon carbide, and 325-mesh silicon carbide; the ceramic filler is nano-glass hollow microspheres; the binder is water-based inorganic potassium silicate resin; and the dispersant is anionic polyacrylamide.

[0110] The preparation method and parameters in this embodiment are the same as those in Example 1.

[0111] Example 12 A ceramic fiber reinforced silicon carbide repair material, by weight, comprises: 9 parts fiber composite filler, 24 parts mullite aggregate, 21 parts silicon carbide reinforcing phase, 7 parts ceramic filler, 17 parts calcium aluminate, 5 parts brown corundum, 17 parts binder, 9.5 parts water, and 0.5 parts dispersant. The fiber composite filler is composed of silicon-based ceramic fibers and aluminosilicate fibers in a mass ratio of 2:1.

[0112] The raw materials for preparing silicon-based ceramic fibers include: 5 parts polyvinylpyrrolidone, 10 parts mixed solution (water to ethanol volume ratio 3:2), 5 parts water glass and 0.5 parts hydrochloric acid.

[0113] The mullite aggregate consists of 8 parts each of equal mass of 30-mesh mullite, 60-mesh mullite, and 100-mesh mullite; the silicon carbide reinforcing phase consists of 7 parts each of equal mass of 36-mesh silicon carbide, 100-mesh silicon carbide, and 325-mesh silicon carbide; the ceramic filler is nano-ceramic hollow microspheres; the binder is water-based inorganic sodium silicate resin; and the dispersant is anionic polyacrylamide.

[0114] The preparation method and parameters in this embodiment are the same as those in Example 1.

[0115] Example 13 A ceramic fiber reinforced silicon carbide repair material, by weight, comprises: 9 parts fiber composite filler, 24 parts mullite aggregate, 21 parts silicon carbide reinforcing phase, 7 parts ceramic filler, 17 parts calcium aluminate, 5 parts brown corundum, 17 parts binder, 7 parts water, and 0.5 parts dispersant. The fiber composite filler is composed of silicon-based ceramic fibers and aluminosilicate fibers in a mass ratio of 2:1.

[0116] The raw materials for preparing silicon-based ceramic fibers include: 5 parts polyvinylpyrrolidone, 10 parts mixed solution (water to ethanol volume ratio 3:2), 5 parts water glass and 0.5 parts hydrochloric acid.

[0117] The mullite aggregate consists of equal masses of 30-mesh mullite, 60-mesh mullite, and 100-mesh mullite, each in 8 parts; the silicon carbide reinforcing phase consists of equal masses of 36-mesh silicon carbide, 100-mesh silicon carbide, and 325-mesh silicon carbide, each in 7 parts; the ceramic filler is nano-ceramic hollow microspheres; the binder is aluminum dihydrogen phosphate; and the dispersant is anionic polyacrylamide.

[0118] The preparation method and parameters in this embodiment are the same as those in Example 1.

[0119] Comparative Example 1: A castable for repairing damaged support parts of a dry quenching furnace bracket is composed of the following raw materials in parts by weight: 20 parts of fused mullite particles with a particle size of 3-5 mm, 25 parts of fused dense corundum with a particle size of 3-8 mm, 10 parts of zirconium corundum particles with a particle size of 1-3 mm, 15 parts of sintered corundum particles with a particle size of 0-1 mm, 10 parts of silicon carbide micro powder with a particle size of <2 μm, 10 parts of aluminate cement, 5 parts of polypropylene fiber, 0.25 parts of urea, and 4.75 parts of water.

[0120] The construction method is as follows: First, a heat-resistant stainless steel anchoring component is inserted into the damaged area. Asphalt paint is applied to the surface of the anchoring component. Then, a mold is fixed on the anchoring component that has been coated with asphalt paint. The above-mentioned proportioned castable is poured into the mold by vibration to form a dense lining. After natural curing for 10 to 16 hours, the lining is demolded. Finally, it is baked at 150°C and can be put into production and use.

[0121] The shortcomings of this comparative scheme are: cold construction must be carried out after the furnace is shut down and cooled, requiring welding of anchors, formwork, pouring, long-term curing and baking, resulting in a long overall repair period and making it unsuitable for rapid hot repair in dry-quench furnace production conditions; moreover, the way polypropylene fibers and urea decompose and leave pores during the baking process is detrimental to the high-temperature density and erosion resistance of the final lining.

[0122] Comparative Example 2: A liquid grouting material for hot repair of cracks in coke oven walls, by weight, is composed of the following raw materials: 30 parts water glass; 50 parts solid filler, which consists of 30 parts mullite, 15 parts refractory clay, and 5 parts quartz sand; and 20 parts additives, which consist of 6 parts sodium hexametaphosphate, 11 parts penetrant JFC, and 3 parts defoamer silicone oil.

[0123] The preparation method is as follows: (1) Add mullite, refractory clay and quartz sand to a mixer with a rotation speed of 100 r / min and mix for 10 min until uniform to obtain solid filler; (2) Add sodium hexametaphosphate, penetrant JFC and defoamer silicone oil to a mixer with a speed of 150 r / min and mix for 5 min until uniform to obtain the additive; (3) Add the additive obtained in step (2) to water glass and stir at 200 r / min until uniform. Then add the solid filler obtained in step (1) while stirring at 300 r / min. After the addition is complete, continue stirring until the mixture is uniform, and the liquid grouting material for hot repair of cracks in coke oven walls is obtained.

[0124] The comparative scheme has the following shortcomings: using water glass as a binder, it is easy to form a low-melting-point glass phase at high temperatures, resulting in insufficient volume stability and high-temperature erosion resistance of the repair body under long-term high-temperature service conditions; the solid filler is mainly mullite, refractory clay and quartz sand, lacking dense corundum raw materials with high thermal shock resistance, resulting in limited high-temperature mechanical strength and resistance to slag erosion; in addition, the retention rate of liquid grouting material in wider cracks and the degree of densification of the repair body are relatively low, affecting the service life of the repaired area.

[0125] Comparative Example 3 (Mullite aggregate gradation deviation) The repair material provided in this comparative example differs from that in Example 1 in that the mullite aggregate is composed of 20-mesh, 60-mesh, and 90-mesh mullite in a mass ratio of 1:2:1, while the rest of the formula and preparation method are exactly the same as in Example 1.

[0126] The repair material provided in this comparative example is inferior to that provided in Example 1. This is because the core purpose of the three-gradation material with equal mass ratio in this invention is to achieve the densest particle packing. Coarse particles form a continuous macroscopic skeleton, medium particles fill the gaps between coarse particles, and fine particles fill secondary voids. In this comparative example, the proportion of coarse particles is insufficient, failing to form a stable load-bearing skeleton; the proportion of fine particles is also insufficient, failing to fully fill the voids, resulting in a decrease in material packing density and a significant increase in internal porosity. Pores become stress concentration points and crack propagation channels, while also providing intrusion paths for corrosive media, ultimately leading to a comprehensive decline in mechanical properties and durability.

[0127] Comparative Example 4 (Silicon carbide-reinforced phase gradation deviation) The repair material provided in this comparative example differs from that in Example 1 in that the silicon carbide reinforcing phase is composed of 36-mesh, 100-mesh, and 325-mesh silicon carbide in a mass ratio of 2:2:3. The rest of the formulation and preparation method are exactly the same as in Example 1.

[0128] The repair material provided in this comparative example is inferior to that provided in Example 1. This is because silicon carbide, as a reinforcing phase, requires the uniform dispersion of particles of different sizes to form a three-dimensional continuous reinforcing network. In this comparative example, the proportion of fine-grained silicon carbide is too high, which easily leads to agglomeration and prevents uniform dispersion in the matrix; the proportion of coarse-grained silicon carbide is insufficient, failing to effectively share the load and suppress the propagation of macroscopic cracks. Agglomerated fine particles become weak points in the structure, easily fractured under stress, resulting in a significant decrease in the material's wear resistance and thermal shock stability.

[0129] Comparative Example 5 (Single-size mullite aggregate) The repair material provided in this comparative example differs from that in Example 1 in that all the mullite aggregate used is 60-mesh single-particle-size mullite, while the rest of the formula and preparation method are exactly the same as in Example 1.

[0130] The repair material provided in this comparative example is inferior to that provided in Example 1. This is because the single-size particles cannot achieve close packing, resulting in numerous interconnected large pores between the particles, leading to a loose material structure and low bulk density. These large pores not only significantly reduce the material's mechanical strength but also allow high-temperature gases and corrosive media to easily penetrate the material, accelerating oxidation and carbon deposition processes. During thermal shock, severe stress concentration occurs at the large pores, causing rapid crack propagation and ultimately resulting in extremely poor thermal shock stability, making the material completely unable to withstand the frequent temperature fluctuations of the dry quenching furnace.

[0131] Comparative Example 6 (Single-size silicon carbide reinforced phase) The repair material provided in this comparative example differs from that in Example 1 in that the silicon carbide reinforcing phase is entirely composed of 100-mesh single-particle-size silicon carbide, while the rest of the formulation and preparation method are exactly the same as in Example 1.

[0132] The repair material provided in this comparative example is inferior to that provided in Example 1. This is because single-particle fine-diameter silicon carbide has a large specific surface area, is prone to agglomeration, and has a large sintering shrinkage rate, making it susceptible to microcracks during curing and high-temperature use. Furthermore, single-particle-diameter silicon carbide cannot fill the gaps of varying sizes between mullite aggregates, resulting in limited reinforcement and an inability to form a continuous three-dimensional reinforcing network. This leads to a significant decrease in the material's high-temperature flexural strength and abrasion resistance, making it unable to effectively resist the erosion and wear of coke particles.

[0133] Comparative Example 7 (using only aluminum silicate fiber) The repair material provided in this comparative example differs from that in Example 1 in that the fiber composite filler consists entirely of 6 parts aluminosilicate fiber, without the addition of self-made silicon-based ceramic fiber, and the silicon-based ceramic fiber preparation and plasma treatment steps are omitted. The remaining formulation and preparation method are exactly the same as in Example 1.

[0134] The repair material provided in this comparative example is inferior to the repair material provided in Example 1. This is because this comparative example only uses a single aluminosilicate fiber as the reinforcing phase and does not add the self-made silicon-based ceramic fiber of the present invention, which has obvious performance defects: the bonding force between the aluminosilicate fiber and the matrix is ​​weak, and it is easy to peel off during service, causing serious wear; it is prone to crystal transformation and pulverization under long-term high temperature, and has poor thermal shock stability and high temperature strength retention rate, and is prone to cracking and peeling when the temperature changes suddenly; in addition, the alumina component is easily corroded by acid and alkali media, which leads to the destruction of the fiber skeleton and ultimately causes the material to fail rapidly.

[0135] Comparative Example 8 (using only self-made silicon-based ceramic fibers) The repair material provided in this comparative example differs from that in Example 1 in that the fiber composite filler consists entirely of 6 parts of self-made silicon-based ceramic fiber, without the addition of aluminum silicate fiber. The rest of the formulation and preparation method are exactly the same as in Example 1.

[0136] The repair material provided in this comparative example is inferior to that provided in Example 1 because it only uses self-made silicon-based ceramic fibers without combining other fibers. This solution has shortcomings in thermal conductivity, and its thermal insulation advantage is not prominent. Although the thermal conductivity is lower than that of the aluminosilicate fibers in Comparative Example 7, it is still significantly higher than that of the fiber composite system in this invention, indicating that the thermal insulation advantage of a single silicon-based ceramic fiber is not fully utilized. Its wear resistance and acid / alkali corrosion resistance are only at a moderate level, far inferior to the wear-free and corrosion-free state of Example 1, and its performance is prone to degradation after long-term use. There is still room for improvement in thermal shock stability and high / low temperature fastness. Although it is better than Comparative Example 7, it is significantly lower than the fiber composite example, posing a risk of microcrack propagation under repeated temperature shocks, resulting in insufficient long-term service reliability.

[0137] Comparative Example 9 (deviation in mass ratio of fiber composite filler) The repair material provided in this comparative example differs from that in Example 1 in that the fiber composite filler is composed of silicon-based ceramic fibers and aluminum silicate fibers in a mass ratio of 1:1 (3 parts silicon-based ceramic fibers and 3 parts aluminum silicate fibers). The rest of the formulation and preparation method are exactly the same as in Example 1.

[0138] The repair material provided in this comparative example is inferior to that provided in Example 1. This is because the (1.8-2):1 mass ratio determined in this invention is to achieve the optimal balance between thermal insulation and mechanical properties. In this comparative example, the proportion of silicon-based ceramic fibers is insufficient, failing to form a sufficiently high-strength three-dimensional reinforcing network; the proportion of aluminosilicate fibers is too high, resulting in a slight improvement in thermal insulation performance, but a decrease in overall strength and abrasion resistance. This leads to the material being prone to wear and cracking when subjected to coke erosion and thermal shock, resulting in a shortened service life.

[0139] Comparative Example 10 (without plasma surface treatment) The repair material provided in this comparative example differs from that in Example 1 in that the active plasma surface treatment step of silicon-based ceramic fibers is omitted, while the rest of the formulation and preparation method are exactly the same as in Example 1.

[0140] The repair material provided in this comparative example is inferior to that provided in Example 1. This is because the surface of the untreated silicon-based ceramic fibers contains residual organic contaminants and cannot introduce sufficient active hydroxyl groups. It can only form a weak mechanical intercalation with the matrix, unable to form a chemical bond. Under stress, the fibers are easily pulled out of the matrix, completely losing their crack bridging and stress dissipation functions, leading to a significant deterioration in the overall mechanical properties of the material. The weak interface between the fiber and the matrix forms numerous interconnected microcracks and pores. These defects become high-speed channels for heat conduction, completely destroying the thermal insulation effect of the fiber composite system and significantly increasing the material's thermal conductivity. Furthermore, the weak interface also becomes a channel for corrosive media to penetrate, resulting in a decrease in the material's bond strength, thermal shock stability, and corrosion resistance.

[0141] Comparative Example 11 (commercially available silicon-based ceramic fiber substitute) The repair material provided in this comparative example differs from that in Example 1 in that commercially available quartz fiber (ordinary silicon-based ceramic fiber) is used instead of the self-made silicon-based ceramic fiber, with a dosage of 4 parts, and the preparation step of the self-made silicon-based ceramic fiber is omitted. The rest of the formula and preparation method are exactly the same as those in Example 1.

[0142] The repair material provided in this comparative example is inferior to that provided in Example 1. This is because the self-made silicon-based ceramic fiber of this invention, through a unique formulation and electrospinning process, forms a three-dimensional network structure that combines rigidity and flexibility, containing uniformly distributed nanoscale pores that can effectively passivate crack tips. In contrast, commercially available quartz fibers are prepared by melt spinning, resulting in a dense and brittle structure lacking the aforementioned flexible structure and nanopores. Even after the same plasma treatment, their surface-active hydroxyl content is still lower than that of the self-made fiber, leading to insufficient chemical bonding with the matrix. This results in a significantly inferior toughening effect compared to the self-made fiber, and a substantial decrease in the material's high-temperature strength, thermal shock stability, and wear resistance.

[0143] Comparative Example 12 (without added brown fused alumina component) The repair material provided in this comparative example differs from that in Example 1 in that no brown fused alumina auxiliary toughening and wear-resistant components were added; the rest of the formulation and preparation method are exactly the same as in Example 1.

[0144] The repair material provided in this comparative example is inferior to that provided in Example 1. This is because brown fused alumina possesses high hardness, excellent toughness, and a thermal expansion coefficient that matches well with the host material. It can effectively dissipate heat stress through mechanisms such as crack deflection and bridging, and form a multi-layered wear-resistant system with the silicon carbide reinforcing phase. Without brown fused alumina, the wear resistance and thermal shock resistance of the material decrease significantly, and it cannot effectively resist the high-speed erosion of coke particles and frequent temperature fluctuations.

[0145] Comparative Example 13 (Ceramic filler addition amount below the lower limit) The repair material provided in this comparative example differs from that in Example 1 in that the amount of ceramic filler added is 3 parts (lower than the lower limit of the range of 5-20 parts specified in this invention), while the rest of the formula and preparation method are exactly the same as in Example 1.

[0146] The repair material provided in this comparative example is inferior to that provided in Example 1. This is because the thermal insulation effect of the ceramic filler (nano-ceramic hollow microspheres) depends on its internal closed static air cavity. When the amount added is less than 5 parts, the number of hollow microspheres is insufficient, and a continuous and effective thermal insulation network cannot be formed in the matrix. The heat conduction path is difficult to be effectively blocked, and the thermal insulation effect is affected.

[0147] Comparative Example 14 (Ceramic filler addition exceeds the upper limit) The repair material provided in this comparative example differs from that in Example 1 in that the amount of ceramic filler added is 25 parts (higher than the upper limit of the range of 5-20 parts specified in this invention), while the rest of the formula and preparation method are exactly the same as in Example 1.

[0148] The repair material provided in this comparative example is inferior to that provided in Example 1 because the strength of ceramic hollow microspheres is much lower than that of matrix components such as mullite and silicon carbide. When the addition amount exceeds 20 parts, a large number of hollow microspheres will severely disrupt the continuity of the matrix structure, forming numerous weak interfaces, resulting in a significant decrease in the material's bulk density, mechanical strength, and erosion resistance. Under the influence of coke erosion and thermal shock, hollow microspheres are prone to breakage, becoming the starting point for crack initiation and propagation, ultimately leading to rapid wear, cracking, and detachment of the repair layer, and a significantly shortened service life.

[0149] Comparative Example 15 (brown fused alumina content below the lower limit) The repair material provided in this comparative example differs from that in Example 1 in that the amount of brown fused alumina added is 3 parts (lower than the lower limit of the range of 5-20 parts specified in this invention), while the rest of the formula and preparation method are exactly the same as in Example 1.

[0150] The repair material provided in this comparative example is inferior to that provided in Example 1. This is because the high hardness and excellent toughness of brown fused alumina are crucial for the material's wear resistance and thermal shock resistance. When the addition amount is less than 5 parts, the number of brown fused alumina particles is insufficient to form an effective toughening and wear-resistant network in the matrix, and it cannot form a multi-layered synergistic protection with the silicon carbide reinforcing phase. This leads to a decrease in the material's ability to resist high-speed erosion by coke particles. At the same time, during thermal shock, it cannot effectively dissipate heat stress through mechanisms such as crack deflection and bridging, resulting in reduced thermal shock stability.

[0151] Comparative Example 16 (brown fused alumina content exceeds the upper limit) The repair material provided in this comparative example differs from that in Example 1 in that the amount of brown fused alumina added is 25 parts (higher than the upper limit of the range of 5-20 parts specified in this invention), while the rest of the formula and preparation method are exactly the same as in Example 1.

[0152] The repair material provided in this comparative example is inferior to that provided in Example 1. This is because although the coefficient of thermal expansion of brown fused alumina matches that of the main materials such as mullite and silicon carbide, there are still slight differences. When the amount added exceeds 20 parts, excessive brown fused alumina will change the main phase composition of the material, leading to an increase in the overall coefficient of thermal expansion and generating greater internal stress during sudden temperature changes. At the same time, the small amount of impurities contained in brown fused alumina are prone to react in the reducing atmosphere of the dry quenching furnace, reducing the high-temperature chemical stability of the material. In addition, excessive addition of brown fused alumina will significantly increase the material cost, and the improvement in performance will enter the diminishing marginal benefit range, making it uneconomical.

[0153] The repair materials prepared in the embodiments and comparative examples of this invention can be directly applied to the gaps and surfaces of damaged refractory bricks without the need for any base material. Before application, it is only necessary to ensure that the surface to be repaired is free of significant loose powder. After repair, the material surface forms a film quickly and dries rapidly. To ensure effectiveness or meet testing requirements, the material must be allowed to fully cure naturally for at least 48 hours before use or performance testing. High-temperature drying can accelerate the drying rate and shorten the drying time, but it cannot guarantee that the material's interior is completely and thoroughly dried.

[0154] Performance testing methods: Thermal conductivity test: The thermal conductivity of the ceramic fiber reinforced silicon carbide repair material was measured using a thermal conductivity meter.

[0155] Adhesion strength test: The repair materials provided in the examples and comparative examples were applied to the surface of ordinary carbon steel sheets. After drying for 48 hours, the adhesion strength between the coating and the substrate was measured using an adhesion strength tester.

[0156] High-temperature resistance test: The normal operating temperature range inside the dry quenching furnace is 300℃-1000℃, and the repair material of this invention can meet the requirements under this condition. The repair material is applied to the surface of the actual refractory brick and subjected to a high-temperature sintering test at 1500℃. The surface of the repair layer is observed to see if there are any abnormal phenomena such as cracking, peeling, flaking, or blistering.

[0157] Thermal shock stability test: The repair materials provided in the examples and comparative examples were coated on the surface of the refractory bricks and dried for 48 hours before testing. The samples were placed in a muffle furnace and calcined at 900°C for 20 minutes, followed by rapid cooling using a water cooling method. The effect of the number of rapid cooling cycles on surface cracking was recorded. The number of rapid cooling cycles at which surface cracking occurred was recorded as the thermal shock stability test result, which served as the thermal shock stability index of the sample.

[0158] High and low temperature cycling fastness test: simulating the actual working conditions inside a dry quenching furnace, refractory bricks coated with repair material were placed inside the muffle furnace for high and low temperature cycling calcination for 25 days. After removing the samples, the residual bond strength of the coating was measured using an adhesive strength tester, and the wear condition of the coating surface was observed.

[0159] Acid and alkali corrosion resistance test: The repair materials provided in the examples and comparative examples were coated on the surface of ordinary carbon steel sheets and tested after drying for 48 hours. The samples were first immersed in a 10% sulfuric acid solution for 24 hours, then rinsed and immersed in a 10% sodium hydroxide solution for 24 hours. After removing the samples, rinsing and drying them, the appearance of the coating was checked, and any blistering, peeling, flaking, corrosion, or rust was observed.

[0160] The basic performance test results of the repair materials prepared in the above embodiments and comparative examples are shown in Tables 1 and 2 below: Table 1 Performance test results of Examples 1 to 13

[0161] Table 2 Performance test results of Comparative Examples 1 to 16

[0162] Based on the operating characteristics and actual usage requirements of the dry quenching furnace, the performance of the embodiments and comparative examples of the present invention were compared and tested, and the results are as follows: The thermal conductivity of the repair material provided in this embodiment is significantly lower than that of the repair material provided in the comparative example, indicating that the repair material has excellent thermal insulation effect, which can effectively reduce heat loss in the dry quenching furnace and reduce energy consumption. The bonding strength of the repair material provided in this embodiment is significantly higher than that of the repair material provided in the comparative example, indicating that the material has a stronger interfacial bonding force with the refractory brick matrix, which can effectively prevent the repair layer from falling off during use. The high temperature resistance and high and low temperature cycle fastness of the repair material provided in this embodiment are significantly better than those of the repair material provided in the comparative example, which can fully meet the long-term working temperature requirements of the dry quenching furnace of 300℃-1000℃, and can still maintain structural integrity under frequent temperature fluctuation conditions. The thermal shock stability of the repair material provided in this embodiment is significantly better than that of the repair material provided in the comparative example, which can withstand the thermal shock of high temperature and rapid cooling, avoiding cracking and peeling of the repair layer due to sudden temperature changes, and can meet the thermal shock conditions required in the actual production of the dry quenching furnace. The acid and alkali corrosion resistance comparison test results show that the acid and alkali corrosion resistance of the repair material provided in this embodiment is significantly better than that of the repair material provided in the comparative example, which can resist the complex chemical corrosion environment in the dry quenching furnace and extend the service life of the repair layer.

[0163] In summary, in response to the harsh operating conditions such as rapid temperature changes in the inclined zone of the dry quenching furnace and thermal shock and wear caused by the falling coke, this invention provides a repair material prepared through the screening, gradation design and synergistic compounding of various components. This material effectively solves the problems of easy damage, low strength and short service life of existing refractory lining materials.

[0164] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of this invention.

Claims

1. A ceramic fiber reinforced silicon carbide repair material, characterized in that, The raw materials for preparing the ceramic fiber reinforced silicon carbide repair material, by weight, include: 5-20 parts of fiber composite filler, 20-40 parts of mullite aggregate, 20-40 parts of silicon carbide reinforcing phase, 5-20 parts of ceramic filler, 15-30 parts of calcium aluminate, 5-20 parts of brown corundum, 10-30 parts of binder, 5-30 parts of water, and 0.1-5 parts of dispersant; wherein the fiber composite filler is composed of silicon-based ceramic fibers and aluminosilicate fibers in a mass ratio of (1.8-2):

1. The mullite aggregate is composed of equal mass ratios of 20-30 mesh mullite, 30-60 mesh mullite, and 60-100 mesh mullite; the silicon carbide reinforcing phase is composed of equal mass ratios of 30-40 mesh silicon carbide, 95-105 mesh silicon carbide, and 320-330 mesh silicon carbide. The raw materials for preparing the silicon-based ceramic fiber include: 5-15 parts of polyvinylpyrrolidone, 10 parts of a mixed solution, 5-20 parts of water glass, and 0.1-5 parts of hydrochloric acid; wherein the mixed solution is composed of water and ethanol.

2. The ceramic fiber reinforced silicon carbide repair material according to claim 1, characterized in that, The method for preparing the silicon-based ceramic fiber includes the following steps: Polyvinylpyrrolidone was dissolved in the mixed solution and stirred evenly at room temperature. Then, it was stirred continuously in a water bath until it was evenly dispersed to obtain solution A. Prepare solution B by mixing water glass and hydrochloric acid; Solution A and solution B are mixed thoroughly and stirred continuously to obtain solution C; Silicon-based ceramic fibers were obtained by spinning with solution C followed by calcination.

3. The ceramic fiber reinforced silicon carbide repair material according to claim 2, characterized in that, The volume ratio of water to ethanol in the mixed solution is (3-3.2):

2.

4. The ceramic fiber reinforced silicon carbide repair material according to claim 2, characterized in that, The water bath temperature is 80℃-85℃; in the spinning process, the feed speed is 8μL / min-8.5μL / min, and the distance from the receiving end is 10cm-15cm; in the calcination process, the temperature is 600℃-900℃, and the time is 2h-4h.

5. The ceramic fiber reinforced silicon carbide repair material according to claim 1, characterized in that, The ceramic filler is one or more of nano-ceramic hollow microspheres or nano-glass hollow microspheres.

6. The ceramic fiber reinforced silicon carbide repair material according to claim 1, characterized in that, The adhesive is a silica-based adhesive or a phosphate-based adhesive.

7. The ceramic fiber reinforced silicon carbide repair material according to claim 6, characterized in that, The silica-based adhesive is one or more of water-based inorganic potassium silicate resin, water-based inorganic sodium silicate resin, and water-based inorganic lithium silicate resin; the phosphate-based adhesive is aluminum dihydrogen phosphate.

8. The ceramic fiber reinforced silicon carbide repair material according to claim 1, characterized in that, The dispersant is anionic polyacrylamide.

9. A method for preparing a ceramic fiber reinforced silicon carbide repair material according to any one of claims 1 to 8, characterized in that, Includes the following steps: Preparation of silicon-based ceramic fibers; Silicon-based ceramic fibers were treated using active plasma. The treated silicon-based ceramic fibers were dispersed in the first part of water, and then aluminum silicate fibers were added and mixed evenly to obtain a fiber composite filler. Mullite aggregate and silicon carbide reinforcing phase are mixed to prepare the repair material skeleton; The repair filler is prepared by simultaneously mixing ceramic filler, calcium aluminate and brown fused alumina. The fiber composite filler, the repair material skeleton and the repair filler are mixed to obtain a homogeneous material; The adhesive is mixed with the second part of water and then added to the mixture. At the same time, a dispersant is added to disperse the mixture, thus obtaining a ceramic fiber reinforced silicon carbide repair material. The amount of water used in the first part is 20%-30% of the weight of water in the raw materials for preparing the ceramic fiber reinforced silicon carbide repair material; The sum of the weights of the first portion of water and the second portion of water is equal to the weight of water in the raw materials for preparing the ceramic fiber reinforced silicon carbide repair material.

10. The application of a ceramic fiber reinforced silicon carbide repair material in a dry quenching furnace, characterized in that, The ceramic fiber reinforced silicon carbide repair material described in any one of claims 1 to 8 is used.

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