Preparation method of anti-skinning high-temperature-resistant castable

Abstract

The present application relates to the technical field of castable preparation, and particularly relates to a preparation method of anti-skinning high-temperature-resistant castable, which comprises the following steps: S1, taking 50-60 parts of mullite, 20-25 parts of corundum micropowder, 3-8 parts of calcium aluminate cement, 1-3 parts of water reducing agent, 2-5 parts of silicon micropowder and 8-10 parts of modified carbon fiber as raw materials according to weight fraction; S2, pretreating the corundum micropowder; S3, loading the modified carbon fiber onto the surface of the pretreated corundum micropowder; S4, adding the mullite, water reducing agent, silicon micropowder, calcium aluminate water and corundum micropowder loaded with modified carbon fiber into a stirrer, and adding water, and obtaining the castable after stirring. The present application makes the modified carbon fiber orderly loaded on the corundum micropowder by pretreating the corundum micropowder, ensures the good combination of the corundum micropowder and the mullite, improves the toughness and thermal stability of the castable, and prevents the phenomena of skinning and falling off during the use of the castable.

Description

Technical Field

[0001] This invention relates to the field of castable preparation technology, specifically to a method for preparing an anti-scabbing, high-temperature resistant castable. Background Technology

[0002] Castable refractories are granular and powdery materials made from refractory materials with a certain amount of binder. They have high fluidity and are suitable for casting into unshaped refractories. Compared with other unshaped refractories, they have higher binder and moisture content and better fluidity, thus unshaped refractories have a wide range of applications. The materials and binders used can be selected according to the application conditions. They can be directly cast into linings or precast into blocks using casting or vibration compaction methods.

[0003] Existing high-temperature resistant castables mostly use corundum as aggregate. Although it has good high-temperature resistance, it has poor thermal stability. During use, cracks will appear on the surface of the castable. In addition, due to the production of volatile components such as alkali, chlorine and sulfur during combustion, these volatile components will repeatedly volatilize and condense under high temperature conditions. This causes these volatile components to enter the cracks and condense on the surface of the castable, forming a crust, which leads to blockage of the kiln system. Summary of the Invention

[0004] To address the above problems, this invention provides a method for preparing anti-skinning, high-temperature resistant castable.

[0005] The technical solution of this invention is: a method for preparing an anti-scabbing, high-temperature resistant castable, comprising the following steps: S1. By weight, take 50-60 parts of mullite, 20-25 parts of corundum powder, 3-8 parts of calcium aluminate cement, 1-3 parts of water-reducing agent, 2-5 parts of silica powder, and 8-10 parts of modified carbon fiber as raw materials. S2. Add corundum micro powder to ammonia water with a mass concentration of 50-60%, and ultrasonically disperse for 5-10 minutes. Then add melamine to the ammonia water, stir, and heat the ammonia water. During the heating process, gradually add silane coupling agent to the ammonia water until the temperature of the ammonia water reaches 70-80℃. Keep it at this temperature for 20-25 minutes, then stop the heating. After the ammonia water cools to room temperature, filter to obtain pretreated corundum micro powder. The mass ratio of corundum micro powder to ammonia water is 1:30-40, the amount of melamine added is 1-3% of the total mass of ammonia water, and the amount of silane coupling agent added is 0.2-0.3% of the total mass of ammonia water. S3. Load the modified carbon fiber onto the surface of the pretreated corundum powder to obtain corundum powder loaded with modified carbon fiber. S4. Add mullite, water-reducing agent, silica powder, and calcium aluminate cement to the mixer according to the stated weight proportions. After mixing for 5-10 minutes, add corundum powder loaded with modified carbon fiber to the mixer and add water accounting for 15-20% of the total mass of the raw materials. After mixing for 20-30 minutes, the castable is obtained.

[0006] Explanation: The above-mentioned castable involves pretreating corundum micro powder to load melamine onto the powder. The amino groups on the melamine can undergo a condensation reaction with formaldehyde loaded at one end of the modified carbon fiber, resulting in the orderly loading of the modified carbon fiber onto the corundum micro powder. This allows the corundum micro powder to bond well with the mullite phase. Furthermore, during the use of the castable, due to the high temperature conditions, the melamine can act as a nitrogen source, reacting with the alumina in the corundum micro powder to convert it into aluminum nitride. The aluminum nitride connects the corundum micro powder and carbon fiber, improving the toughness and thermal stability of the castable, reducing thermal stress and cracks caused by temperature changes, preventing crack propagation, and preventing phenomena such as skinning and peeling during the use of the castable.

[0007] Further, in step S1, the water-reducing agent is sodium lignosulfonate or sodium allyl sulfonate.

[0008] Note: The above-mentioned water-reducing agent can improve the bonding performance of castables, reduce porosity, and reduce the amount of water used in the mixing process.

[0009] Furthermore, in step S1, the particle size of the corundum micro powder is 10~20μm.

[0010] Note: Limiting the particle size of corundum powder ensures that it can fully fill the pores within the mullite, reducing the porosity of the castable.

[0011] Furthermore, in step S1, the length of the modified carbon fiber is 1~3mm.

[0012] Note: Limiting the length of modified carbon fibers ensures uniform distribution of the carbon fibers and avoids aggregation and entanglement caused by excessive length.

[0013] Further, in step S1, the method for preparing the modified carbon fiber includes the following steps: S1-1. Add carbon fiber to anhydrous ethanol and ultrasonically disperse for 5-10 minutes to obtain a carbon fiber suspension; wherein the mass ratio of carbon fiber to anhydrous ethanol is 1:30-50. S1-2. Use a sprayer to spray the carbon fiber suspension onto the substrate. The nozzle of the sprayer is perpendicular to the substrate, so that the carbon fibers are vertically aligned onto the substrate. The spraying rate of the carbon fiber suspension is 50~60 ml / cm². 2 ; S1-3. The substrate is horizontally hoisted and lowered, and the carbon fibers on the substrate are successively immersed in dilute sulfuric acid with a mass concentration of 10-15% and formaldehyde aqueous solution with a mass concentration of 20-30% for modification treatment; wherein the immersion time in dilute sulfuric acid is 4-5 minutes and the immersion time in formaldehyde aqueous solution is 10-15 minutes. S1-4. Repeat step S1-3 2-4 times, and each time shorten the immersion time in dilute sulfuric acid by 30-40 seconds compared to the previous time, and extend the immersion time in formaldehyde aqueous solution by 1-2 minutes compared to the previous time. Then scrape the carbon fiber off the substrate to obtain the modified carbon fiber.

[0014] Explanation: The modified carbon fiber described above is produced by spraying carbon fibers unidirectionally onto a substrate. Subsequently, one end of the carbon fiber is alternately immersed in dilute sulfuric acid and formaldehyde aqueous solution. The dilute sulfuric acid oxidizes the carbon fiber, causing one end of the carbon fiber to be loaded with hydroxyl groups. The hydroxyl groups then undergo a hydroxylation reaction with formaldehyde, resulting in one end of the carbon fiber being loaded with formaldehyde. The dilute sulfuric acid accelerates the hydroxylation reaction rate of formaldehyde. Gradually shortening the immersion time in the dilute sulfuric acid can prevent excessive oxidation of the carbon fiber and avoid the reaction between formaldehyde and dilute sulfuric acid. Gradually extending the immersion time in the formaldehyde aqueous solution can ensure that the carbon fiber is fully loaded with formaldehyde.

[0015] Furthermore, in steps S1-2, the distance between the nozzle of the sprayer and the substrate is 20-30cm, the spraying pressure is 0.2-0.4MPa, and the spraying speed is 60-100cm / s.

[0016] Note: Limiting the spraying parameters of the sprayer ensures that the carbon fibers are vertically aligned onto the substrate, preventing them from tangling together.

[0017] Further, in step S3, the method for loading modified carbon fibers onto the surface of pretreated corundum micropowder includes the following steps: S3-1. Add the pretreated corundum micro powder and modified carbon fiber to petroleum ether according to the stated weight parts, and ultrasonically disperse for 10-15 minutes to obtain a mixture; wherein, the solid-liquid ratio in the mixture is 1:20-30. S3-2. Adjust the pH of the mixture to 4-6 using dilute hydrochloric acid with a mass concentration of 10-15%. Then, heat the mixture once to raise the temperature to 70-80℃ and keep it at that temperature for 1-2 hours. After the temperature is maintained, heat the mixture a second time to raise the temperature to 100-110℃ and keep it at that temperature for 2-3 hours. Then, filter to obtain corundum micro powder loaded with modified carbon fiber.

[0018] Explanation: The above loading method is based on the fact that one end of the carbon fiber is loaded with formaldehyde and the corundum powder is loaded with melamine. Under acidic conditions, the aldehyde group of formaldehyde can undergo a condensation reaction with the amino group of melamine, so that one end of the carbon fiber can be stably loaded on the corundum powder.

[0019] Furthermore, the heating rate for the first heating is 10~12℃ / min, and the heating rate for the second heating is 3~5℃ / min.

[0020] Note: Limiting the heating rate of the first and second heating cycles ensures that formaldehyde and melamine react fully and cure, thus guaranteeing the bonding strength between carbon fiber and melamine.

[0021] The beneficial effects of this invention are: (1) This invention pre-treats corundum powder to load melamine onto the corundum powder. The amino groups on the melamine can undergo a condensation reaction with the formaldehyde loaded at one end of the modified carbon fiber, so that the modified carbon fiber is orderly loaded onto the corundum powder, ensuring good bonding between the corundum powder and mullite, improving the toughness and thermal stability of the castable, reducing thermal stress and cracks caused by temperature changes, avoiding crack propagation, and preventing skinning and peeling during the use of the castable.

[0022] (2) In this invention, carbon fibers are sprayed onto a substrate in a unidirectional arrangement by a spraying method. Then, one end of the carbon fiber is alternately immersed in dilute sulfuric acid and formaldehyde aqueous solution. The dilute sulfuric acid can oxidize the carbon fiber, so that one end of the carbon fiber is loaded with hydroxyl groups. Subsequently, the hydroxyl groups will undergo a hydroxylation reaction with formaldehyde, so that one end of the carbon fiber is loaded with formaldehyde. Detailed Implementation

[0023] To further illustrate the methods and effects of this invention, the technical solution of this invention will be clearly and completely described below in conjunction with experiments.

[0024] Example 1: A method for preparing a high-temperature resistant, anti-scabbing castable, comprising the following steps: S1. By weight, take 55 parts of mullite, 22 parts of corundum powder, 5 parts of calcium aluminate cement, 2 parts of water-reducing agent, 4 parts of silica powder, and 9 parts of modified carbon fiber as raw materials; wherein, the water-reducing agent is sodium lignosulfonate, the particle size of corundum powder is 10~20μm, and the length of modified carbon fiber is 2mm. S2. Add corundum micro powder to 55% ammonia solution and ultrasonically disperse for 8 minutes. Then add melamine to the ammonia solution, stir, and heat the ammonia solution. During the heating process, gradually add silane coupling agent to the ammonia solution until the ammonia solution reaches 75°C. Keep the solution at this temperature for 22 minutes and then stop heating. After the ammonia solution cools to room temperature, filter to obtain pretreated corundum micro powder. The mass ratio of corundum micro powder to ammonia solution is 1:35. The amount of melamine added accounts for 2% of the total mass of ammonia solution, and the amount of silane coupling agent added accounts for 0.25% of the total mass of ammonia solution. KH-550 is used as the silane coupling agent. S3. Load the modified carbon fiber onto the surface of the pretreated corundum powder to obtain corundum powder loaded with modified carbon fiber. S4. Add mullite, water-reducing agent, silica powder, and calcium aluminate cement to the mixer according to the weight proportions. After mixing for 8 minutes, add corundum powder loaded with modified carbon fiber to the mixer and add water accounting for 18% of the total mass of raw materials. After mixing for 25 minutes, the castable is obtained. The preparation method of modified carbon fiber includes the following steps: S1-1. Add carbon fiber to anhydrous ethanol and ultrasonically disperse for 8 minutes to obtain a carbon fiber suspension; wherein the mass ratio of carbon fiber to anhydrous ethanol is 1:40. S1-2. Use a sprayer to spray the carbon fiber suspension onto the substrate. The nozzle of the sprayer is perpendicular to the substrate, so that the carbon fibers are vertically aligned onto the substrate. The spraying rate of the carbon fiber suspension is 55 ml / cm². 2 The distance between the sprayer nozzle and the substrate is 25cm, the spraying pressure is 0.3MPa, and the spraying speed is 80cm / s. S1-3. The substrate is horizontally hoisted and lowered, so that the carbon fibers on the substrate are successively immersed in a 12% dilute sulfuric acid solution and a 25% formaldehyde solution for modification treatment; the immersion time in the dilute sulfuric acid solution is 4.5 min, and the immersion time in the formaldehyde solution solution is 13 min. S1-4. Repeat step S1-3 three times, and each time the immersion time in dilute sulfuric acid is shortened by 35 seconds compared to the previous time, and the immersion time in formaldehyde aqueous solution is extended by 1.5 minutes compared to the previous time. Then scrape the carbon fiber off the substrate to obtain the modified carbon fiber. Step S3, the loading method for loading modified carbon fibers onto the surface of pretreated corundum micro powder includes the following steps: S3-1. Add the pretreated corundum micro powder and modified carbon fiber to petroleum ether according to the stated weight proportions, and ultrasonically disperse for 13 minutes to obtain a mixture; wherein, the solid-liquid ratio in the mixture is 1:25. S3-2. The pH of the mixture was adjusted to 5 using 12% dilute hydrochloric acid. The mixture was then heated once to 75°C and held at that temperature for 1.5 hours. After holding at that temperature, the mixture was heated a second time to 105°C and held at that temperature for 2.5 hours. The mixture was then filtered to obtain corundum micro powder loaded with modified carbon fibers. The heating rate for the first heating was 11°C / min, and the heating rate for the second heating was 4°C / min.

[0025] Example 2: This example is basically the same as Example 1, except that 50 parts by weight of mullite, 20 parts by weight of corundum powder, 3 parts by weight of calcium aluminate cement, 1 part by weight of water-reducing agent, 2 parts by weight of silica powder, and 8 parts by weight of modified carbon fiber are selected as raw materials.

[0026] Example 3: This example is basically the same as Example 1, except that 60 parts by weight of mullite, 25 parts by weight of corundum powder, 8 parts by weight of calcium aluminate cement, 3 parts by weight of water-reducing agent, 5 parts by weight of silica powder, and 10 parts by weight of modified carbon fiber are selected as raw materials.

[0027] Example 4: This example is basically the same as Example 1, except that the amount of melamine added accounts for 1% of the total mass of ammonia water.

[0028] Example 5: This example is basically the same as Example 1, except that the amount of melamine added accounts for 3% of the total mass of ammonia water.

[0029] Example 6: This example is basically the same as Example 1, except that the amount of silane coupling agent added accounts for 0.2% of the total mass of ammonia water.

[0030] Example 7: This example is basically the same as Example 1, except that the amount of silane coupling agent added accounts for 0.3% of the total mass of ammonia water.

[0031] Example 8: This example is basically the same as Example 1, except that the carbon fibers on the substrate are successively immersed in a 10% dilute sulfuric acid solution and a 20% formaldehyde solution for modification.

[0032] Example 9: This example is basically the same as Example 1, except that the carbon fibers on the substrate are successively immersed in a 15% dilute sulfuric acid solution and a 30% formaldehyde solution for modification.

[0033] Example 10: This example is basically the same as Example 1, except that steps S1-3 are repeated twice.

[0034] Example 11: This example is basically the same as Example 1, except that steps S1-3 are repeated 4 times.

[0035] Example 12: This example is basically the same as Example 1, except that the immersion time in dilute sulfuric acid is shortened by 30 seconds each time, and the immersion time in formaldehyde aqueous solution is extended by 1 minute each time.

[0036] Example 13: This example is basically the same as Example 1, except that the immersion time in dilute sulfuric acid is shortened by 40 seconds each time, and the immersion time in formaldehyde aqueous solution is extended by 2 minutes each time.

[0037] Example 14: This example is basically the same as Example 1, except that the mixture is heated once to raise the temperature of the mixture to 70°C and kept at that temperature for 1 hour.

[0038] Example 15: This example is basically the same as Example 1, except that the mixture is heated once to raise the temperature of the mixture to 80°C and kept at that temperature for 2 hours.

[0039] Example 16: This example is basically the same as Example 1, except that after the heat preservation is completed, the mixture is heated a second time to raise the temperature of the mixture to 100°C and kept warm for 2 hours.

[0040] Example 17: This example is basically the same as Example 1, except that after the heat preservation is completed, the mixture is heated a second time to raise the temperature of the mixture to 110°C and kept warm for 3 hours.

[0041] Comparative Example 1: Referring to Example 1, the modified carbon fiber was replaced with unmodified carbon fiber.

[0042] Comparative Example 2: Referring to Example 1, no pretreatment was performed on the corundum micro powder.

[0043] Comparative Example 3: Referring to Example 1, the immersion time in dilute sulfuric acid and the immersion time in formaldehyde aqueous solution did not change.

[0044] Comparative Example 4: Referring to Example 1, the temperature of the mixture was directly raised to 105°C and kept at that temperature for 2.5 hours.

[0045] Experimental Example: To investigate the influence of parameters from each embodiment on the performance of the castable, test blocks were made from the castables prepared in each embodiment. The test blocks were then calcined at 1550℃ for 3 hours, and the performance of each test block was tested. The specific investigation is as follows: Experiment Example 1: Investigating the Influence of Castable Refractory Composition on Castable Refractory Properties Using Examples 1-3 and Comparative Example 1 as experimental comparisons, the performance of castables with different compositions is shown in Table 1 below: Table 1. Performance of castables with different compositions

[0046] As shown in Table 1, compared with Examples 1, 2 and 3, the castable of Example 1 has the highest compressive strength and the smallest linear change rate after firing, indicating that the castable of Example 1 has the highest strength and the best thermal stability. Therefore, the castable composition selected in Example 1 is the optimal. Compared with Comparative Example 1, the compressive strength of the castable decreased and the linear shrinkage rate after firing increased after using unmodified carbon fiber in Example 1. This may be because the modified carbon fiber is more uniformly distributed and has the best bonding performance with mullite. Therefore, the modified carbon fiber selected in Example 1 is a better choice in principle.

[0047] Experimental Example 2: The Influence of Pretreatment Parameters of Corundum Micropowder on Castable Properties Using Examples 1, 4-7, and Comparative Example 2 as experimental comparisons, the castable properties under different pretreatment parameters of corundum micro powder are shown in Table 2 below: Table 2. Castable properties under different pretreatment parameters of corundum micro powder

[0048] As shown in Table 2, compared with Examples 1, 4, and 5, the compressive strength of the castable gradually increased and the linear change rate after firing gradually decreased with the increase of melamine addition, until the compressive strength of Example 1 reached the highest and the linear change rate after firing was the lowest. With the continued increase of melamine addition, the compressive strength and linear change rate after firing of the castable began to show no significant change. This may be because the melamine that can be loaded on the corundum micro powder reached its maximum value. Therefore, from the perspective of cost, the melamine addition amount selected in Example 1 is optimal. Compared with Examples 1, 6, and 7, the castable of Example 1 has the highest compressive strength and the smallest linear change rate after firing, indicating that the castable of Example 1 has the highest strength and the best thermal stability. This may be because too much silane coupling agent leads to the formation of too much coupling agent layer on the surface of corundum particles, which affects the bonding performance between melamine and corundum powder. Therefore, the amount of silane coupling agent added in Example 1 is optimal. Compared with Comparative Example 2, in Example 1, the compressive strength of the castable decreased and the linear shrinkage rate after firing increased without pretreatment of the corundum powder. This may be because the lack of pretreatment of the corundum powder prevents the surface of the corundum powder from being fully and orderly loaded with carbon fibers, and the bonding performance between the corundum powder and the carbon fibers deteriorates. Therefore, the corundum powder pretreatment method selected in Example 1 is better.

[0049] Experiment Example 3: Investigating the Influence of Modified Carbon Fiber Preparation Parameters on Castable Properties Using Examples 1, 8-13, and Comparative Example 3 as experimental comparisons, the castable properties under different preparation parameters of modified carbon fiber are shown in Table 3 below: Table 3. Castable properties under different pretreatment parameters of corundum micro powder

[0050] As shown in Table 3, compared with Examples 1, 8, and 9, the castable of Example 1 has the highest compressive strength and the smallest linear change rate after firing. This indicates that the castable of Example 1 has the highest strength and the best thermal stability. This may be because the carbon fiber surface is loaded with the most formaldehyde under the dilute sulfuric acid and formaldehyde aqueous solution concentration in Example 1. Therefore, the dilute sulfuric acid and formaldehyde aqueous solution concentration selected in Example 1 is the optimal one. Compared with Examples 1, 10, and 11, the castable of Example 1 has the highest compressive strength and the smallest linear change rate after firing, indicating that the castable of Example 1 has the highest strength and the best thermal stability. This may be because the carbon fiber modification effect is the best when the steps S1-3 are repeated the most times in Example 1. Therefore, the number of repetitions of steps S1-3 selected in Example 1 is optimal. Compared with Examples 1, 12, and 13, the castable of Example 1 has the highest compressive strength and the smallest linear change rate after firing, indicating that the castable of Example 1 has the highest strength and the best thermal stability. This may be because the immersion time of the dilute sulfuric acid and formaldehyde aqueous solution selected in Example 1 is optimal. Compared with Comparative Example 3, in Example 1, the compressive strength of the castable decreased and the linear shrinkage rate after firing increased after the immersion time in dilute sulfuric acid and formaldehyde aqueous solution remained unchanged. This may be because prolonged immersion in dilute sulfuric acid can lead to excessive oxidation of carbon fibers. Therefore, the modification method selected in Example 1 is optimal.

[0051] Experiment Example 4: Investigating the effect of temperature on the properties of castables when modified carbon fiber is loaded onto pretreated corundum micro powder. Using Examples 1, 14-17, and Comparative Example 4 as experimental comparisons, the castable properties at different temperatures when modified carbon fiber is loaded onto pretreated corundum micro powder are shown in Table 4 below: Table 4. Castable properties at different temperatures when modified carbon fiber is loaded onto pretreated corundum powder.

[0052] As shown in Table 4, compared with Examples 1, 14, 15, 16, and 17, both the primary heating parameters and the secondary heating parameters affect the performance of the castable. Among them, the castable of Example 1 has the highest compressive strength and the smallest linear change rate after firing, indicating that the castable of Example 1 has the highest strength and the best thermal stability. This may be because the bonding between corundum micro powder and modified carbon fiber is the best under the primary and secondary heating parameters selected in Example 1. Therefore, the primary and secondary heating parameters selected in Example 1 are both optimal. Compared with Comparative Example 4, in Example 1, the compressive strength of the castable decreased and the linear change rate after firing increased after the temperature of the mixture was directly raised to 105°C. This may be because the direct heating caused the formaldehyde and melamine to not react fully. Therefore, the heating method selected in Example 1 is optimal.

Claims

1. A method for preparing a high-temperature resistant, anti-scabbing castable, characterized in that, Includes the following steps: S1. By weight, take 50-60 parts of mullite, 20-25 parts of corundum powder, 3-8 parts of calcium aluminate cement, 1-3 parts of water-reducing agent, 2-5 parts of silica powder, and 8-10 parts of modified carbon fiber as raw materials. The method for preparing the modified carbon fiber includes the following steps: S1-1. Add carbon fiber to anhydrous ethanol and ultrasonically disperse for 5-10 minutes to obtain a carbon fiber suspension; wherein the mass ratio of carbon fiber to anhydrous ethanol is 1:30-50. S1-2. Use a sprayer to spray the carbon fiber suspension onto the substrate. The nozzle of the sprayer is perpendicular to the substrate, so that the carbon fibers are vertically aligned onto the substrate. The spraying rate of the carbon fiber suspension is 50~60 ml / cm². 2 ; S1-3. The substrate is horizontally hoisted and lowered, and the carbon fibers on the substrate are successively immersed in dilute sulfuric acid with a mass concentration of 10-15% and formaldehyde aqueous solution with a mass concentration of 20-30% for modification treatment; wherein the immersion time in dilute sulfuric acid is 4-5 minutes and the immersion time in formaldehyde aqueous solution is 10-15 minutes. S1-4. Repeat step S1-3 2 to 4 times, and each time the immersion time in dilute sulfuric acid is shortened by 30 to 40 seconds compared to the previous time, and the immersion time in formaldehyde aqueous solution is extended by 1 to 2 minutes compared to the previous time. Then scrape the carbon fiber off the substrate to obtain the modified carbon fiber. S2. Add corundum micro powder to ammonia water with a mass concentration of 50-60%, and ultrasonically disperse for 5-10 minutes. Then, add melamine to the ammonia water, stir, and heat the ammonia water. During the heating process, gradually add silane coupling agent to the ammonia water until the temperature of the ammonia water reaches 70-80℃. Keep it at this temperature for 20-25 minutes, then stop the heating. After the ammonia water cools to room temperature, filter to obtain pretreated corundum micro powder. The mass ratio of corundum micro powder to ammonia water is 1:30-40, the amount of melamine added is 1-3% of the total mass of ammonia water, and the amount of silane coupling agent added is 0.2-0.3% of the total mass of ammonia water. S3. Load the modified carbon fiber onto the surface of the pretreated corundum powder to obtain corundum powder loaded with modified carbon fiber. The loading method for loading modified carbon fibers onto the surface of pretreated corundum micro powder includes the following steps: S3-1. Add the pretreated corundum micro powder and modified carbon fiber to petroleum ether according to the stated weight parts, and ultrasonically disperse for 10-15 minutes to obtain a mixture; wherein, the solid-liquid ratio in the mixture is 1:20-30. S3-2. Adjust the pH of the mixture to 4-6 using dilute hydrochloric acid with a mass concentration of 10-15%. Then, heat the mixture once to raise the temperature to 70-80℃ and keep it at that temperature for 1-2 hours. After the temperature is maintained, heat the mixture a second time to raise the temperature to 100-110℃ and keep it at that temperature for 2-3 hours. Then, filter to obtain corundum micro powder loaded with modified carbon fiber. S4. Add mullite, water-reducing agent, silica powder, and calcium aluminate cement to the mixer according to the stated weight proportions. After mixing for 5-10 minutes, add corundum powder loaded with modified carbon fiber to the mixer and add water accounting for 15-20% of the total mass of the raw materials. After mixing for 20-30 minutes, the castable is obtained.

2. The preparation method of the anti-scabbing high-temperature resistant castable according to claim 1, characterized in that, In step S1, the water-reducing agent is sodium lignosulfonate or sodium allyl sulfonate.

3. The preparation method of the anti-scabbing high-temperature resistant castable according to claim 1, characterized in that, In step S1, the particle size of the corundum micro powder is 10~20μm.

4. The preparation method of the anti-scabbing high-temperature resistant castable according to claim 1, characterized in that, In step S1, the length of the modified carbon fiber is 1~3mm.

5. The preparation method of the anti-scabbing high-temperature resistant castable according to claim 1, characterized in that, In steps S1-2, the distance between the nozzle of the sprayer and the substrate is 20-30cm, the spraying pressure is 0.2-0.4MPa, and the spraying speed is 60-100cm / s.

6. The preparation method of the anti-scabbing high-temperature resistant castable according to claim 1, characterized in that, The heating rate for the first heating is 10~12℃ / min, and the heating rate for the second heating is 3~5℃ / min.

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