Green unshaped material for liner of special steel refining furnace of aircraft carrier and preparation method of green unshaped material

Abstract

The invention relates to the technical field of refractory materials, in particular to a green amorphous material for an aircraft carrier special steel refining furnace lining and a preparation method. The green amorphous material comprises the following components in parts by weight: 50-60 parts of white corundum particles, 15-20 parts of magnesite clinker, 5-10 parts of silica powder, 5-10 parts of aluminum silicate / aluminum borate composite fibers, 3-6 parts of a binder and 1-3 parts of a water reducing agent. According to the green unshaped material, the white corundum particles serve as the aggregate and are matched with other auxiliary materials, so that the green unshaped material has good high-temperature resistance, the thermal shock resistance of the green unshaped material can be effectively improved through the aluminum silicate / aluminum borate composite fibers, and it is avoided that a lining of a refining furnace is peeled off, impurities appear in a steel ladle, and the service life of the steel ladle is prolonged. The performance of the refined special steel is influenced.

Description

Technical Field

[0001] This invention relates to the field of refractory technology, specifically to a green unshaped material for use as the lining of a special steel refining furnace for aircraft carriers and its preparation method. Background Technology

[0002] Special steel for aircraft carriers is an indispensable core material for building modern aircraft carriers, directly determining the structural strength, resistance to attack, service life, and safety of the carrier. Refining is a crucial step in the entire production process of special steel for aircraft carriers, directly determining the purity, uniformity, and final mechanical properties of the steel. Therefore, the impurity content must be strictly controlled during the refining of special steel for aircraft carriers.

[0003] The existing lining of the special steel refining furnace for aircraft carriers has poor thermal shock resistance. After long-term use, the lining material is prone to falling off. These falling off materials contain a lot of non-metallic elements, which may enter the ladle, leading to an increase in the impurity content of the special steel for aircraft carriers and ultimately affecting the performance of the special steel for aircraft carriers. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a green unshaped material for the lining of a special steel refining furnace for aircraft carriers and its preparation method.

[0005] The technical solution of the present invention is: a green unshaped material for the lining of a special steel refining furnace for aircraft carriers, characterized in that the green unshaped material comprises the following components by weight: 50-60 parts of white corundum particles, 15-20 parts of sintered magnesia, 5-10 parts of silica powder, 5-10 parts of aluminum silicate / alumina borate composite fiber, 3-6 parts of binder, and 1-3 parts of water-reducing agent.

[0006] Note: The above-mentioned green unshaped material uses white corundum particles as aggregate and is combined with other auxiliary materials to give the green unshaped material good high temperature resistance. In addition, the aluminum silicate / alumina borate composite fiber can effectively improve the thermal shock resistance of the green unshaped material, avoid the peeling of the refining furnace lining, which would lead to impurities in the ladle and affect the performance of the refined special steel.

[0007] Furthermore, the white corundum particles, by weight, comprise: 30-34 parts of coarse particles with a diameter of 3-5 mm, 8-10 parts of medium particles with a diameter of 1-2 mm, and 12-16 parts of fine particles with a diameter of 0.1-0.5 mm.

[0008] Note: The white fused alumina particles with the above particle size distribution can increase the density of green amorphous material, reduce the porosity within the green amorphous material, and ensure the strength of the green amorphous material.

[0009] Furthermore, the binder is calcium aluminate cement or aluminum dihydrogen phosphate.

[0010] Note: The above-mentioned binder can bind the various components in the green amorphous material together, ensuring the strength of the green amorphous material.

[0011] Furthermore, the water-reducing agent is sodium lignosulfonate or sodium hexametaphosphate.

[0012] Note: The above-mentioned water-reducing agent can reduce water consumption while ensuring the flowability of green amorphous materials.

[0013] Furthermore, the preparation method of the aluminum silicate / aluminum borate composite fiber includes the following steps: S1. Polyacrylonitrile fibers are placed in an ethanol solution and ultrasonically dispersed for 10-20 minutes to obtain a dispersion. Then, tetraethyl orthosilicate is added to the dispersion, and the pH value of the dispersion is adjusted to 2-3 using dilute hydrochloric acid. After standing for 1-2 hours, polyacrylonitrile fibers loaded with silica gel are obtained. The mass ratio of polyacrylonitrile fibers, tetraethyl orthosilicate, and ethanol solution is 1:0.2-0.3:4-5. S2. Add boric acid and aluminum nitrate to deionized water and stir for 10-15 minutes to obtain the first mixture; the mass ratio of boric acid, aluminum nitrate and deionized water is 1:1.0-1.2:5-6. S4. The polyacrylonitrile fibers loaded with silica gel are immersed in the first mixture 2 to 4 times. After immersion, the impregnated polyacrylonitrile fibers are obtained. The immersion time for each time is 10 to 20 minutes. After each immersion, the polyacrylonitrile fibers loaded with silica gel are dried at 70 to 80°C for 20 to 30 minutes. S4. The impregnated polyacrylonitrile fibers are placed in a sintering furnace for sintering. During the sintering process: first, the temperature inside the sintering furnace is raised to 300-350℃ at a heating rate of 10-12℃ / min, and then held for 1-1.5 hours; then, the temperature inside the sintering furnace is raised to 600-650℃ at a heating rate of 7-9℃ / min, and then held for 2-3 hours; then, the temperature inside the sintering furnace is raised to 900-950℃ at a heating rate of 4-6℃ / min, and then the heating of the sintering furnace is stopped, allowing the temperature inside the sintering furnace to drop to 780-820℃; then, the temperature inside the sintering furnace is raised to 1050-1200℃ at a heating rate of 1-3℃ / min, and then held for 2-4 hours to obtain aluminum silicate / alumina borate composite fibers.

[0014] Explanation: The above preparation method uses polyacrylonitrile fiber as a template, loads silica gel on the polyacrylonitrile fiber, and then impregnates it to allow boric acid and aluminum nitrate to enter the pores of the silica gel. Through sintering, the polyacrylonitrile fiber is decomposed and transformed into aluminum silicate / alumina borate composite fiber. The aluminum silicate / alumina borate composite fiber can improve the thermal shock resistance of green amorphous material, prevent the green amorphous material from falling off, and at the same time improve the heat insulation effect of green amorphous material, reducing heat loss in refining furnace.

[0015] Furthermore, the mass concentration of the ethanol solution is 50-70%.

[0016] Note: The above-mentioned concentration of ethanol solution has good dispersibility and can effectively disperse polyacrylonitrile fibers.

[0017] Furthermore, the mass concentration of the dilute hydrochloric acid is 10-20%.

[0018] Note: The dilute hydrochloric acid of the above mass concentration can ensure the hydrolysis rate of tetraethyl orthosilicate, allowing the surface of polyacrylonitrile fibers to be fully loaded with silica gel.

[0019] On the other hand, the present invention also provides a method for preparing green unshaped material for the lining of a special steel refining furnace for aircraft carriers, characterized by comprising the following steps: 1) Add white corundum particles, sintered magnesia, silica powder, and aluminum silicate / alumina borate composite fibers into a mixer and mix for 10-15 minutes to obtain dry material; 2) Add water at a mass of 5-10% to the dry material, then add the binder and water-reducing agent into the mixer and continue mixing for 20-30 minutes to obtain green amorphous material.

[0020] Explanation: The preparation method of this invention involves mixing the main materials as dry materials, then adding water and additives to the dry materials for mixing, thereby obtaining green amorphous material. This ensures the uniformity and fluidity of the green amorphous material's composition, giving it excellent casting performance.

[0021] The beneficial effects of this invention are: (1) The green amorphous material of the present invention uses white corundum particles as aggregate and is combined with other auxiliary materials to make the green amorphous material have good high temperature resistance. The aluminum silicate / alumina borate composite fiber can effectively improve the thermal shock resistance of the green amorphous material, avoid the peeling of the refining furnace lining, which leads to impurities in the ladle and affects the performance of the refined special steel.

[0022] (2) The present invention loads silica gel on polyacrylonitrile fibers and then allows boric acid and aluminum nitrate to enter the pores of silica gel. Through sintering, the polyacrylonitrile fibers are decomposed and transformed into aluminum silicate / alumina borate composite fibers, thereby improving the thermal shock resistance and heat insulation performance of green amorphous materials, preventing the green amorphous materials from falling off and reducing heat loss in refining furnaces.

[0023] (3) The preparation method of the present invention is to mix the main material as dry material, and then add water and additives to the dry material to mix it to obtain green amorphous material, ensuring the uniformity and fluidity of the green amorphous material composition, so that the green amorphous material has good casting performance. Detailed Implementation

[0024] 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.

[0025] Example 1: Green unshaped material for the lining of a special steel refining furnace for aircraft carriers. The green unshaped material, by weight, includes the following components: 55 parts white fused alumina particles, 18 parts sintered magnesia, 8 parts silica powder, 8 parts aluminum silicate / alumina borate composite fiber, 5 parts binder, and 2 parts water-reducing agent; the binder is calcium aluminate cement, and the water-reducing agent is sodium lignosulfonate; the white fused alumina particles, by weight, include: 32 parts coarse particles with a particle size of 3-5 mm, 9 parts medium particles with a particle size of 1-2 mm, and 14 parts fine particles with a particle size of 0.1-0.5 mm. The preparation method of the aluminum silicate / aluminum borate composite fiber includes the following steps: S1. Polyacrylonitrile fibers were placed in an ethanol solution and ultrasonically dispersed for 15 minutes to obtain a dispersion. Tetraethyl orthosilicate was then added to the dispersion, and the pH of the dispersion was adjusted to 2.5 using dilute hydrochloric acid. After standing for 1.5 hours, polyacrylonitrile fibers loaded with silica gel were obtained. The mass ratio of polyacrylonitrile fibers, tetraethyl orthosilicate, and ethanol solution was 1:0.25:4.5; the mass concentration of the ethanol solution was 60%; and the mass concentration of the dilute hydrochloric acid was 15%. S2. Add boric acid and aluminum nitrate to deionized water and stir for 12 minutes to obtain the first mixture; the mass ratio of boric acid, aluminum nitrate and deionized water is 1:1.1:5.5. S4. The polyacrylonitrile fibers loaded with silica gel are immersed in the first mixture three times. After immersion, the impregnated polyacrylonitrile fibers are obtained. The immersion time for each time is 15 minutes. After each immersion, the polyacrylonitrile fibers loaded with silica gel are dried at 75°C for 25 minutes. S4. The impregnated polyacrylonitrile fibers are placed in a sintering furnace for sintering. During the sintering process: the temperature inside the sintering furnace is first raised to 330℃ at a heating rate of 11℃ / min, and then held for 1.25h; then the temperature inside the sintering furnace is raised to 630℃ at a heating rate of 8℃ / min, and then held for 2.5h; then the temperature inside the sintering furnace is raised to 930℃ at a heating rate of 5℃ / min, then the heating of the sintering furnace is stopped, and the temperature inside the sintering furnace is reduced to 800℃; then the temperature inside the sintering furnace is raised to 1100℃ at a heating rate of 2℃ / min, and then held for 3h to obtain aluminum silicate / alumina borate composite fibers. The preparation method of the above-mentioned green amorphous material includes the following steps: 1) Add white corundum particles, sintered magnesia, silica powder, and aluminum silicate / alumina borate composite fibers into a mixer and mix for 12 minutes to obtain dry material; 2) Add water at 8% of its mass to the dry material, then add the binder and water-reducing agent into the mixer and continue mixing for 25 minutes to obtain green amorphous material.

[0026] Example 2: This example is basically the same as Example 1, except that the green amorphous material, by weight, includes the following components: 50 parts white corundum particles, 15 parts sintered magnesia, 5 parts silica powder, 5 parts aluminum silicate / alumina borate composite fiber, 3 parts binder, and 1 part water-reducing agent.

[0027] Example 3: This example is basically the same as Example 1, except that the green amorphous material, by weight, includes the following components: 60 parts white corundum particles, 20 parts sintered magnesia, 10 parts silica powder, 10 parts aluminum silicate / alumina borate composite fiber, 6 parts binder, and 3 parts water-reducing agent.

[0028] Example 4: This example is basically the same as Example 1, except that the white corundum particles include, by weight, 30 parts of coarse particles with a particle size of 3-5 mm, 8 parts of medium particles with a particle size of 1-2 mm, and 12 parts of fine particles with a particle size of 0.1-0.5 mm.

[0029] Example 5: This example is basically the same as Example 1, except that the white corundum particles include, by weight, 34 parts of coarse particles with a particle size of 3-5 mm, 10 parts of medium particles with a particle size of 1-2 mm, and 16 parts of fine particles with a particle size of 0.1-0.5 mm.

[0030] Example 6: This example is basically the same as Example 1, except that dilute hydrochloric acid is used to adjust the pH of the dispersion to 2.

[0031] Example 7: This example is basically the same as Example 1, except that dilute hydrochloric acid is used to adjust the pH of the dispersion to 3.

[0032] Example 8: This example is basically the same as Example 1, except that the mass ratio of polyacrylonitrile fiber, tetraethyl orthosilicate, and ethanol solution is 1:0.2:4.

[0033] Example 9: This example is basically the same as Example 1, except that the mass ratio of polyacrylonitrile fiber, tetraethyl orthosilicate, and ethanol solution is 1:0.3:5.

[0034] Example 10: This example is basically the same as Example 1, except that the mass ratio of boric acid, aluminum nitrate and deionized water is 1:1.0:5.

[0035] Example 11: This example is basically the same as Example 1, except that the mass ratio of boric acid, aluminum nitrate and deionized water is 1:1.2:6.

[0036] Example 12: This example is basically the same as Example 1, except that the polyacrylonitrile fibers loaded with silicone gel are impregnated twice in the first mixture.

[0037] Example 13: This example is basically the same as Example 1, except that the polyacrylonitrile fibers loaded with silicone gel are impregnated in the first mixture 4 times.

[0038] Example 14: This example is basically the same as Example 1, except that during the sintering process: the temperature inside the sintering furnace is first raised to 330°C at a heating rate of 10°C / min; then the temperature inside the sintering furnace is raised to 630°C at a heating rate of 7°C / min; then the temperature inside the sintering furnace is raised to 930°C at a heating rate of 4°C / min; and then the temperature inside the sintering furnace is raised to 1100°C at a heating rate of 1°C / min.

[0039] Example 15: This example is basically the same as Example 1, except that during the sintering process: the temperature inside the sintering furnace is first raised to 330°C at a heating rate of 12°C / min; then the temperature inside the sintering furnace is raised to 630°C at a heating rate of 9°C / min; then the temperature inside the sintering furnace is raised to 930°C at a heating rate of 6°C / min; and then the temperature inside the sintering furnace is raised to 1100°C at a heating rate of 3°C / min.

[0040] Example 16: This example is basically the same as Example 1, except that the temperature inside the sintering furnace is first raised to 300°C at a heating rate of 11°C / min; then raised to 600°C at a heating rate of 8°C / min; then raised to 900°C at a heating rate of 5°C / min; then the heating of the sintering furnace is stopped, and the temperature inside the sintering furnace is reduced to 780°C; then the temperature inside the sintering furnace is raised to 1050°C at a heating rate of 2°C / min.

[0041] Example 17: This example is basically the same as Example 1, except that the temperature inside the sintering furnace is first raised to 350°C at a heating rate of 11°C / min; then raised to 650°C at a heating rate of 8°C / min; then raised to 950°C at a heating rate of 5°C / min; then the heating of the sintering furnace is stopped, and the temperature inside the sintering furnace is reduced to 820°C; then the temperature inside the sintering furnace is raised to 1200°C at a heating rate of 2°C / min.

[0042] Comparative Example 1: Referring to Example 1, the aluminum silicate / alumina borate composite fiber was replaced with aluminum silicate fiber and aluminum borate fiber mixed in a 1:1 mass ratio.

[0043] Comparative Example 2: Referring to Example 1, boric acid was not added to the first mixture.

[0044] Comparative Example 3: Referring to Example 1, no aluminum nitrate was added to the first mixture.

[0045] Comparative Example 4: Referring to Example 1, the temperature inside the sintering furnace was raised to 1100°C at a heating rate of 5°C / min during sintering.

[0046] Comparative Example 5: Referring to Example 1, after the temperature inside the sintering furnace rises to 930°C, it is not allowed to wait until the temperature inside the sintering furnace drops to 800°C.

[0047] Experimental Example: To investigate the influence of preparation parameters of each embodiment on the performance of green amorphous materials, the green amorphous materials prepared in each embodiment were made into 150mm×25mm×25mm test blocks. The test blocks were then baked at 110℃ for 24 hours. The flexural strength of the test blocks from each embodiment was then tested, followed by 5 cycles of thermal shock. The flexural strength retention rate of the test blocks from each embodiment was then tested. The thermal shock cycling method involved holding the test blocks at 1100℃ for 30 minutes, followed by water cooling. The specific investigation is as follows: Experiment Example 1: Investigating the Influence of Components on the Properties of Green Amorphous Materials Using Examples 1, 2, 3, 4, 5 and Comparative Example 1 as experimental comparisons, the performance of green amorphous materials with different compositions is shown in Table 1 below: Table 1. Performance of Green Amorphous Materials with Different Compositions

[0048] As shown in Table 1, compared with Examples 1, 2, and 3, the green amorphous material of Example 1 has the highest flexural strength and flexural strength retention rate, indicating that the green amorphous material of Example 1 has better strength and thermal shock resistance. This may be because the green amorphous material of Example 1 has a more uniform structure, so the green amorphous material selected in Example 1 has better performance components.

[0049] Compared with Examples 1, 4, and 5, the green amorphous material in Example 1 has the highest flexural strength and flexural strength retention rate, indicating that the green amorphous material in Example 1 has better strength and thermal shock resistance. This may be because the green amorphous material in Example 1 is more compact and has fewer pores under the white fused alumina particle size distribution. Therefore, the white fused alumina particle size distribution selected in Example 1 is better.

[0050] Compared with Comparative Example 1, in Example 1, after replacing the aluminum silicate / alumina borate composite fiber with a mixture of aluminum silicate and aluminum borate fibers, the flexural strength and flexural strength retention rate of the green amorphous material both decreased. This indicates that the performance of the aluminum silicate / alumina borate composite fiber can effectively improve the performance of the green amorphous material. Therefore, the green amorphous material selected in Example 1 has better performance components.

[0051] 2. Investigate the effect of pH value of dispersion on the properties of green amorphous materials. Using Examples 1, 6, and 7 as experimental comparisons, the performance of the green amorphous material under different pH values ​​of the dispersion is shown in Table 2 below: Table 2. Performance of green amorphous material at different pH values ​​of dispersion.

[0052] As shown in Table 2, compared with Examples 1, 6, and 7, the green amorphous material of Example 1 has the highest flexural strength and flexural strength retention rate, indicating that the green amorphous material of Example 1 has better strength and thermal shock resistance. This may be because the hydrolysis rate of tetraethyl orthosilicate at the pH value of the dispersion in Example 1 is moderate, so the pH value of the dispersion selected in Example 1 is better.

[0053] 3. Investigate the effect of the ratio of polyacrylonitrile fiber to tetraethyl orthosilicate on the properties of green unshaped materials. Using Examples 1, 8, and 9 as comparative experiments, the properties of green amorphous materials with different ratios of polyacrylonitrile fiber and tetraethyl orthosilicate are shown in Table 3 below: Table 3. Properties of green amorphous materials with different ratios of polyacrylonitrile fiber and tetraethyl orthosilicate

[0054] As shown in Table 3, compared with Examples 1, 8, and 9, the green amorphous material of Example 1 has the highest flexural strength and flexural strength retention rate, indicating that the green amorphous material of Example 1 has better strength and thermal shock resistance. This may be because the polyacrylonitrile fiber to tetraethyl orthosilicate ratio in Example 1 can fully load the silicone gel. Therefore, the polyacrylonitrile fiber to tetraethyl orthosilicate ratio selected in Example 1 is better.

[0055] 4. Investigate the effect of the composition of the first mixture on the properties of green amorphous materials. Using Examples 1, 10, and 11, as well as Comparative Examples 2 and 3, as experimental comparisons, the performance of the green amorphous material under different components of the first mixture is shown in Table 4 below: Table 4 Performance of Green Amorphous Material under Different Components of the First Mixture

[0056] As shown in Table 4, compared with Examples 1, 10, and 11, the green amorphous material of Example 1 has the highest flexural strength and flexural strength retention rate, indicating that the green amorphous material of Example 1 has better strength and thermal shock resistance. This may be because the polyacrylonitrile fiber loaded with silicone gel under the first mixture component of Example 1 can fully load boric acid and aluminum nitrate. Therefore, the first mixture component selected in Example 1 is better.

[0057] Compared with Comparative Examples 2 and 3, in Example 1, the flexural strength and flexural strength retention rate of the green amorphous material decreased after boric acid or aluminum nitrate were not added to the first mixture. This may be because the performance of aluminum silicate / alumina borate composite fiber decreased after boric acid or aluminum nitrate was not added. Therefore, the composition of the first mixture selected in Example 1 is better.

[0058] 5. Investigate the effect of the number of impregnations of silica gel-loaded polyacrylonitrile fibers on the properties of green amorphous materials. Using Examples 1, 12, and 13 as comparative experiments, the properties of green amorphous materials of polyacrylonitrile fibers loaded with silica gel under different impregnation cycles are shown in Table 5 below: Table 5. Performance of green amorphous materials made from polyacrylonitrile fibers loaded with silica gel after different impregnation cycles.

[0059] As shown in Table 5, compared with Examples 1, 12, and 13, the flexural strength and flexural strength retention rate of the green amorphous material gradually increased with the increase of the number of impregnations. However, with the continued increase of the number of impregnations, the flexural strength and flexural strength retention rate of the green amorphous material began to show no significant change. Therefore, from the perspective of time cost, the number of impregnations of the polyacrylonitrile fiber loaded with silicone gel selected in Example 1 is better.

[0060] 6. Investigate the influence of sintering parameters on the properties of green amorphous materials. Using Examples 1, 14, 15, 16, and 17, as well as Comparative Examples 4 and 5, as experimental comparisons, the properties of green amorphous materials under different sintering parameters are shown in Table 6 below: Table 6. Properties of green amorphous materials under different sintering parameters

[0061] As shown in Table 6, compared with Examples 1, 14, and 15, the green amorphous material of Example 1 has the highest flexural strength and flexural strength retention rate, indicating that the green amorphous material of Example 1 has better strength and thermal shock resistance. This may be because the aluminum silicate / alumina borate composite fiber structure is the most stable and has the highest strength at the heating rate of Example 1. Therefore, the heating rate selected in Example 1 is the optimal one.

[0062] Compared with Examples 1, 16, and 17, the green amorphous material of Example 1 has the highest flexural strength and flexural strength retention rate, indicating that the green amorphous material of Example 1 has better strength and thermal shock resistance. This may be because the aluminum silicate / alumina borate composite fiber structure is the most stable and has the highest strength at the sintering temperature of Example 1. Therefore, the sintering temperature selected in Example 1 is the optimal one.

[0063] Compared with Examples 1 and 4, after the heating rate was kept constant during sintering, the flexural strength and flexural strength retention rate of the green amorphous material both decreased. This may be because the polyacrylonitrile fiber was not fully decomposed by the heating rate, resulting in the aluminum silicate / alumina borate composite fiber not being fully converted. Therefore, the sintering method selected in Example 1 is better.

[0064] Compared with Examples 1 and 5, the flexural strength and flexural strength retention rate of the green amorphous material decreased during sintering without waiting for the temperature inside the sintering furnace to drop. This may be because not waiting for the temperature inside the sintering furnace to drop caused defects inside the aluminum silicate / alumina borate composite fiber. Therefore, the sintering method selected in Example 1 is better.

Claims

1. A green unshaped material for the lining of a special steel refining furnace for aircraft carriers, characterized in that, Green unshaped material, by weight, includes the following components: 50-60 parts white corundum particles, 15-20 parts sintered magnesia, 5-10 parts silica powder, 5-10 parts aluminum silicate / alumina borate composite fiber, 3-6 parts binder, and 1-3 parts water-reducing agent.

2. The green unshaped material for the lining of a special steel refining furnace for aircraft carriers according to claim 1, characterized in that, The white corundum particles, by weight, comprise: 30-34 parts of coarse particles with a diameter of 3-5 mm, 8-10 parts of medium particles with a diameter of 1-2 mm, and 12-16 parts of fine particles with a diameter of 0.1-0.5 mm.

3. The green unshaped material for the lining of a special steel refining furnace for aircraft carriers according to claim 1, characterized in that, The binder is calcium aluminate cement or aluminum dihydrogen phosphate.

4. The green unshaped material for the lining of a special steel refining furnace for aircraft carriers according to claim 1, characterized in that, The water-reducing agent is sodium lignosulfonate or sodium hexametaphosphate.

5. The green unshaped material for the lining of a special steel refining furnace for aircraft carriers according to claim 1, characterized in that, The preparation method of the aluminum silicate / aluminum borate composite fiber includes the following steps: S1. Polyacrylonitrile fibers are placed in an ethanol solution and ultrasonically dispersed for 10-20 minutes to obtain a dispersion. Then, tetraethyl orthosilicate is added to the dispersion, and the pH value of the dispersion is adjusted to 2-3 using dilute hydrochloric acid. After standing for 1-2 hours, polyacrylonitrile fibers loaded with silica gel are obtained. The mass ratio of polyacrylonitrile fibers, tetraethyl orthosilicate, and ethanol solution is 1:0.2-0.3:4-5. S2. Add boric acid and aluminum nitrate to deionized water and stir for 10-15 minutes to obtain the first mixture; the mass ratio of boric acid, aluminum nitrate and deionized water is 1:1.0-1.2:5-6. S4. The polyacrylonitrile fibers loaded with silica gel are immersed in the first mixture 2 to 4 times. After immersion, the impregnated polyacrylonitrile fibers are obtained. The immersion time for each time is 10 to 20 minutes. After each immersion, the polyacrylonitrile fibers loaded with silica gel are dried at 70 to 80°C for 20 to 30 minutes. S4. The impregnated polyacrylonitrile fibers are placed in a sintering furnace for sintering. During the sintering process: first, the temperature inside the sintering furnace is raised to 300-350℃ at a heating rate of 10-12℃ / min, and then held for 1-1.5 hours; then, the temperature inside the sintering furnace is raised to 600-650℃ at a heating rate of 7-9℃ / min, and then held for 2-3 hours; then, the temperature inside the sintering furnace is raised to 900-950℃ at a heating rate of 4-6℃ / min, and then the heating of the sintering furnace is stopped, allowing the temperature inside the sintering furnace to drop to 780-820℃; then, the temperature inside the sintering furnace is raised to 1050-1200℃ at a heating rate of 1-3℃ / min, and then held for 2-4 hours to obtain aluminum silicate / alumina borate composite fibers.

6. The green unshaped material for the lining of a special steel refining furnace for aircraft carriers according to claim 5, characterized in that, In step S1, the mass concentration of the ethanol solution is 50-70%.

7. The green unshaped material for the lining of a special steel refining furnace for aircraft carriers according to claim 5, characterized in that, In step S1, the mass concentration of the dilute hydrochloric acid is 10-20%.

8. The method for preparing green unshaped material for the lining of a special steel refining furnace for aircraft carriers according to any one of claims 1 to 7, characterized in that, Includes the following steps: 1) Add white corundum particles, sintered magnesia, silica powder, and aluminum silicate / alumina borate composite fibers into a mixer and mix for 10-15 minutes to obtain dry material; 2) Add water at a mass of 5-10% to the dry material, then add the binder and water-reducing agent into the mixer and continue mixing for 20-30 minutes to obtain green amorphous material.

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