High-purity corundum brick with high thermal shock resistance and preparation method thereof

Abstract

The invention relates to a high-purity corundum brick with high thermal shock resistance and a preparation method thereof, and belongs to the technical field of refractory materials. The high-purity corundum brick with high thermal shock resistance is prepared from the following raw materials in parts by mass: 55 to 65 parts of tabular corundum particles, 20 to 25 parts of tabular corundum fine powder, 8 to 12 parts of modified fused zirconia corundum particles, 5 to 8 parts of nano aluminum oxide powder, 2 to 3 parts of rho-aluminum oxide powder, 0.3 to 1 part of toughening agent and 0.3 to 1.5 parts of binding agent. The toughening agent increases the fracture toughness of the high-thermal-shock-resistance high-purity corundum brick through a plurality of strengthening mechanisms such as crack deflection, crack branching and microcracks, so that the high-thermal-shock-resistance high-purity corundum brick has high thermal shock resistance and mechanical properties. Meanwhile, the fused zirconia corundum has a short fiber structure through modification, and fibers can hinder linear propagation of main cracks, force the cracks to deflect and form crack branches, so that the thermal shock resistance and mechanical properties of the high-purity corundum brick with high thermal shock resistance are further enhanced.

Description

Technical Field

[0001] The invention belongs to the technical field of refractory materials, and particularly relates to a high-purity corundum brick with high thermal shock resistance and a preparation method thereof. Background Art

[0002] High-purity corundum bricks with high thermal shock resistance are high-grade refractory products made from corundum and alumina powder, with an alumina content of 99%. These bricks have extremely low impurity levels, with less than 0.3% SiO2 and 0.2% Fe2O3. These bricks can be used in demanding environments, such as Midrex reduction furnaces, where natural gas is used to reduce iron ore to reduced iron, coal-to-gas kilns, and hazardous waste kilns containing HF atmospheres. However, Fe2O3 is typically reduced to Fe3O4, FeO, and Fe in reducing atmospheres of carbon and carbon dioxide, causing cracks in the bricks, loss of structural strength, and spalling. SiO2 is reduced to SiO gas in high-temperature reducing atmospheres containing a certain amount of hydrogen, or to SiF4 in HF atmospheres, causing the bricks to become structurally loose and lose strength.

[0003] Patent application publication number CN117362015A discloses a high-purity corundum brick and its preparation method. The brick contains, by weight of the raw material oxides, 0.08-1.0% SiO2, 0.15-0.45% Na2O, 0.05-0.15% Li2O, 0.05-0.25% P2O5, 0.05-0.15% B2O3, 1.2-3.0% Cr2O3, and the remainder Al2O3 and impurities. While the high-purity corundum brick's thermal shock resistance and mechanical properties are improved by combining these raw materials, its thermal shock resistance remains relatively weak in some harsh operating conditions. Summary of the Invention

[0004] The first object of the present invention is to provide a high-purity corundum brick with high thermal shock resistance to solve the technical problem that the existing corundum bricks have poor thermal shock resistance.

[0005] The second object of the present invention is to provide a method for preparing high-purity corundum bricks with high thermal shock resistance.

[0006] In order to achieve the above objectives, the technical solution adopted by the present invention is:

[0007] A high-purity corundum brick with high thermal shock resistance comprises the following raw materials, calculated by mass: 55-65 parts of plate-shaped corundum particles, 20-25 parts of plate-shaped corundum fine powder, 8-12 parts of modified fused zirconium corundum particles, 5-8 parts of nano-alumina powder, 2-3 parts of ρ-alumina powder, 0.3-1 part of a toughening agent, and 0.3-1.5 parts of a binder.

[0008] Furthermore, the toughening agent is prepared by mixing YAlO3, SiAlON and Al2O3 to obtain a mixture, mixing the mixture with a solvent to obtain a slurry, and ball milling, drying, calcining and crushing the slurry to obtain the toughening agent.

[0009] Furthermore, the mass ratio of the YAlO3 and SiAlON is 1:15-20; the mass ratio of the YAlO3 and Al2O3 is 1:1-5; the added amount of the solvent accounts for 30-35% of the total mass of the mixture; and the solvent is ethanol.

[0010] Furthermore, the calcination step is: under inert gas, heating the temperature to 1200-1500° C. at a heating rate of 100-120° C. / h, and keeping the temperature for 2-3 hours.

[0011] Furthermore, the rotation speed of the ball mill is 350-500 r / min, the ball milling time is 2-4 hours, and the drying temperature is 80-120°C.

[0012] Furthermore, the preparation method of the modified fused zirconium corundum particles is: fused zirconium corundum, a binder, and water are uniformly mixed, and then extruded into columnar particles, and the columnar particles are fired at 1200-1500°C; the columnar particles have a diameter of 20-30 μm and a length of 40-60 μm.

[0013] Furthermore, the mass ratio of the fused zirconium corundum to the binder is 20:0.05-0.1, and the mass ratio of the fused zirconium corundum to water is 20:0.8-1; and the binder is carboxymethyl cellulose.

[0014] Furthermore, the particle size of the toughening agent is 25 to 40 μm; the binder is a sol; the plate-shaped corundum particles include 23 to 27% coarse aggregate, 55 to 70% medium aggregate and the remainder fine aggregate; the coarse aggregate includes plate-shaped corundum with a particle size of 5 to 3 mm; the medium aggregate includes 25 to 30% plate-shaped corundum with a particle size of 3 to 1 mm, 20 to 25% plate-shaped corundum with a particle size of 1 to 0 mm, and 10 to 15% plate-shaped corundum fine powder with a particle size of 1 to 0.088 mm; the fine aggregate includes plate-shaped corundum micropowder with a particle size of less than 0.088 mm.

[0015] A method for preparing high-purity corundum bricks with high thermal shock resistance comprises the following steps: mixing a formulated amount of plate-shaped corundum particles, plate-shaped corundum fine powder, modified fused zirconium corundum particles, nano-alumina powder, and ρ-alumina powder with water, introducing hydrogen chloride gas into the water and continuously stirring for 10 to 20 minutes, then filtering and drying to obtain substance A; mixing substance A, a toughening agent, and a binder; then adding 3 to 7% water by weight of the total raw material mass, stirring evenly, then placing the brick in a mold and pressing to expel bubbles to form an embryonic body; and sintering the embryonic body to obtain the brick.

[0016] Furthermore, the firing steps are: first heating the temperature to 200-400°C at a heating rate of 60-80°C / h, keeping warm for 1-3 hours, then heating the temperature to 900-1000°C at a heating rate of 150-180°C / h, keeping warm for 2-4 hours, and finally heating the temperature to 1600-1650°C at a heating rate of 30-60°C / h, keeping warm for 8-12 hours.

[0017] Beneficial effects of the present invention:

[0018] The toughening agent of the present invention increases the fracture toughness of the high-thermal-shock-resistant high-purity corundum brick by causing multiple strengthening mechanisms such as crack deflection, crack branching, and microcracks, thereby endowing the high-thermal-shock-resistant high-purity corundum brick of the present invention with high thermal-shock-resistant and mechanical properties. At the same time, the present invention modifies the fused zirconium corundum to have a short fiber structure. The fibers can hinder the linear expansion of the main crack, forcing the crack to deflect and form crack branches, further enhancing the thermal-shock-resistant and mechanical properties of the high-thermal-shock-resistant high-purity corundum brick. The ρ-alumina added in the present invention can be converted into α-alumina when calcined at high temperatures. α-alumina can significantly increase the thermal-shock-resistant and mechanical strength of the high-thermal-shock-resistant high-purity corundum brick of the present invention.

[0019] The impurity Fe2O3 in high-purity corundum bricks will be reduced to Fe3O4, FeO and Fe in a C and CO reducing atmosphere, causing cracks in the refractory bricks, loss of structural strength and spalling. The high-purity corundum bricks with high thermal shock resistance of the present invention are introduced with hydrogen chloride gas during preparation. The hydrogen chloride gas reacts with Fe2O3 to generate FeCl3 soluble in water, thereby avoiding the Fe2O3 in the high-purity corundum bricks being reduced in a reducing atmosphere and causing cracks in the refractory bricks. The raw materials used in the present invention do not contain silicon dioxide components, preventing the silicon dioxide in the high-purity corundum bricks with high thermal shock resistance of the present invention from being corroded by HF gas or reduced in a strong reducing atmosphere, thereby causing structural damage to the refractory bricks. DETAILED DESCRIPTION

[0020] The present invention will be further described below with reference to the embodiments of the present invention.

[0021] The Al2O3 content of the plate-shaped corundum particles is ≥99.2%, Fe2O3 ≤0.2%, and SiO2 ≤0.2%. The particle size of the nano-alumina powder is 50-100nm. The particle size of the plate-shaped corundum fine powder is ≤0.074mm. The particle size of the ρ-alumina powder is ≤0.1μm.

[0022] Example 1

[0023] The high-purity, thermal-shock-resistant corundum bricks of Example 1 include the following raw materials: 55 kg of tabular corundum, 23 kg of tabular corundum fine powder, 9 kg of modified fused zirconium corundum particles, 5 kg of nano-alumina powder, 2 kg of ρ-alumina powder, 0.3 kg of toughening agent, and 0.3 kg of sol. The toughening agent has a particle size of 30 μm. The tabular corundum comprises coarse aggregate, medium aggregate, and the remainder of fine aggregate. The coarse aggregate comprises 25% tabular corundum with a particle size of 5 to 3 mm; the medium aggregate comprises 28% tabular corundum with a particle size of 3 to 1 mm, 22% tabular corundum with a particle size of 1 to 0 mm, and 15% tabular corundum fine powder with a particle size of 1 to 0.088 mm; the fine aggregate comprises tabular corundum micropowder with a particle size of less than 0.088 mm.

[0024] The preparation method of the toughening agent is as follows: 0.5 kg of YAlO3 powder, 10 kg of SiAlON powder, and 0.5 kg of Al2O3 powder are mixed to obtain a mixture, 3.5 kg of ethanol is added to the mixture to obtain a slurry, the slurry is ball-milled at a rotation speed of 350 rpm for 2 hours, and dried at 100°C to obtain a solid, the solid is heated to 1200°C in nitrogen at a heating rate of 120°C / h, kept warm for 2 hours, and then cooled at room temperature and crushed to obtain the product.

[0025] The modified fused zirconium corundum particles are prepared by uniformly mixing 20 kg of fused zirconium corundum, 0.05 kg of carboxymethyl cellulose, and 0.8 kg of water. The mixture is then extruded and granulated into columnar particles. Drying is performed continuously during the extrusion process to prevent the particles from sticking together. The columnar particles are then dried and sintered at 1200°C. The columnar particles have a diameter of 20 μm and a length of 50 μm.

[0026] The preparation method of high-purity corundum bricks with high thermal shock resistance is as follows: a formulated amount of plate-shaped corundum, plate-shaped corundum fine powder, modified fused zirconium corundum particles, nano-alumina powder, and rho-alumina powder are mixed with a small amount of water, HCl gas is introduced into the water and stirred continuously for 10 minutes, followed by filtration and drying to obtain substance A. Substance A, a toughening agent, a sol, and 4 kg of water are mixed and stirred uniformly to obtain a slurry, which is placed in a mold and pressed to expel bubbles to form an embryonic body, which is then fired to obtain the product.

[0027] The firing steps are as follows: heating to 200°C at a heating rate of 60°C / h, keeping warm for 2h, then heating to 900°C at a heating rate of 180°C / h, keeping warm for 2h, and finally heating to 1630°C at a heating rate of 30°C / h, keeping warm for 8h.

[0028] Example 2

[0029] The high-purity, thermal-shock-resistant corundum bricks of Example 2 include the following raw materials: 65 kg of tabular corundum, 25 kg of tabular corundum fine powder, 8 kg of modified fused zirconium corundum particles, 5 kg of nano-alumina powder, 3 kg of rho-alumina powder, 0.8 kg of toughening agent, and 1.2 kg of sol. The toughening agent has a particle size of 40 μm. The tabular corundum comprises coarse aggregate, medium aggregate, and the remainder of fine aggregate. The coarse aggregate comprises 27% tabular corundum with a particle size of 5 to 3 mm; the medium aggregate comprises 30% tabular corundum with a particle size of 3 to 1 mm, 20% tabular corundum with a particle size of 1 to 0 mm, and 10% tabular corundum fine powder with a particle size of 1 to 0.088 mm; the fine aggregate comprises tabular corundum micropowder with a particle size of less than 0.088 mm.

[0030] The preparation method of the toughening agent is as follows: 1 kg of YAlO3 powder, 15 kg of SiAlON powder, and 3 kg of Al2O3 powder are mixed to obtain a mixture, 6.5 kg of ethanol is added to the mixture to obtain a slurry, the slurry is ball-milled at a rotation speed of 500 rpm for 2 hours, and dried at 120°C to obtain a solid. The solid is heated to 1350°C in nitrogen at a heating rate of 100°C / h, kept warm for 2 hours, and then cooled at room temperature and crushed to obtain the product.

[0031] The modified fused zirconium corundum particles are prepared by uniformly mixing 20 kg of fused zirconium corundum, 0.1 kg of carboxymethyl cellulose, and 1 kg of water. The mixture is then extruded and granulated into columnar particles. Drying is performed continuously during the extrusion process to prevent the particles from sticking together. The columnar particles are then dried and sintered at 1400°C. The columnar particles have a diameter of 30 μm and a length of 40 μm.

[0032] The preparation method of high-purity corundum bricks with high thermal shock resistance is as follows: a formulated amount of plate-shaped corundum, plate-shaped corundum fine powder, modified fused zirconium corundum particles, nano-alumina powder, and rho-alumina powder are mixed with a small amount of water, HCl gas is introduced into the water and stirred continuously for 20 minutes, followed by filtration and drying to obtain substance A. Substance A, a toughening agent, a sol, and 7 kg of water are mixed and stirred uniformly to obtain a slurry, which is placed in a mold and pressed to expel bubbles to form an embryonic body, which is then fired to obtain the product.

[0033] The firing steps are as follows: heating to 350°C at a heating rate of 80°C / h, keeping warm for 1 hour, then heating to 1000°C at a heating rate of 150°C / h, keeping warm for 2 hours, and finally heating to 1600°C at a heating rate of 50°C / h, keeping warm for 12 hours.

[0034] Example 3

[0035] The high-purity, thermal shock-resistant corundum bricks of Example 3 include the following raw materials: 60 kg of tabular corundum, 20 kg of tabular corundum fine powder, 12 kg of modified fused zirconium corundum particles, 8 kg of nano-alumina powder, 2.5 kg of rho-alumina powder, 1 kg of toughening agent, and 1.5 kg of sol. The toughening agent has a particle size of 25 μm. The tabular corundum comprises coarse aggregate, medium aggregate, and the remainder of fine aggregate. The coarse aggregate comprises 23% tabular corundum with a particle size of 5 to 3 mm; the medium aggregate comprises 25% tabular corundum with a particle size of 3 to 1 mm, 20% tabular corundum with a particle size of 1 to 0 mm, and 10% tabular corundum fine powder with a particle size of 1 to 0.088 mm; the fine aggregate comprises tabular corundum powder with a particle size of less than 0.088 mm.

[0036] The preparation method of the toughening agent is as follows: 1 kg of YAlO3 powder, 16 kg of SiAlON powder, and 5 kg of Al2O3 powder are mixed to obtain a mixture, 7 kg of ethanol is added to the mixture to obtain a slurry, the slurry is ball-milled at a rotation speed of 400 rpm for 4 hours, and dried at 100°C to obtain a solid, the solid is heated to 1500°C in nitrogen at a heating rate of 120°C / h, kept warm for 2 hours, and then cooled at room temperature and crushed to obtain the product.

[0037] The modified fused zirconium corundum particles are prepared by uniformly mixing 20 kg of fused zirconium corundum, 0.07 kg of carboxymethyl cellulose, and 0.9 kg of water. The mixture is then extruded and granulated into columnar particles. Drying is performed continuously during the extrusion process to prevent the particles from sticking together. The columnar particles are then dried and sintered at 1500°C. The columnar particles have a diameter of 20 μm and a length of 60 μm.

[0038] The preparation method of high-purity corundum bricks with high thermal shock resistance is as follows: a formulated amount of plate-shaped corundum, plate-shaped corundum fine powder, modified fused zirconium corundum particles, nano-alumina powder, and rho-alumina powder are mixed with a small amount of water, HCl gas is introduced into the water and stirred continuously for 10 minutes, followed by filtration and drying to obtain substance A. Substance A, a toughening agent, a sol, and 5 kg of water are mixed and stirred uniformly to obtain a slurry, which is placed in a mold and pressed to expel bubbles to form an embryonic body, which is then fired to obtain the product.

[0039] The firing steps are as follows: heating to 400°C at a heating rate of 70°C / h, keeping warm for 1 hour, then heating to 1000°C at a heating rate of 180°C / h, keeping warm for 2 hours, and finally heating to 1650°C at a heating rate of 60°C / h, keeping warm for 12 hours.

[0040] Comparative Example 1

[0041] The raw materials of the high-purity corundum bricks in Comparative Example 1 are the same as those in Example 1.

[0042] The preparation method of the high-purity corundum brick of Comparative Example 1 is: mix the formulated amount of plate-shaped corundum, plate-shaped corundum fine powder, modified fused zirconium corundum particles, nano-alumina powder, ρ-alumina powder, toughening agent, sol and 4 kg of water and stir them evenly to obtain a mud material, place the mud material in a mold and press to expel bubbles to form a embryo, and then burn the embryo to obtain it.

[0043] The firing steps are as follows: heating to 200°C at a heating rate of 60°C / h, keeping warm for 2h, then heating to 900°C at a heating rate of 180°C / h, keeping warm for 2h, and finally heating to 1630°C at a heating rate of 30°C / h, keeping warm for 8h.

[0044] Comparative Example 2

[0045] The preparation method of the high-purity corundum bricks in Comparative Example 2 is substantially the same as that in Example 1. The difference between the preparation method of the high-purity corundum bricks in Comparative Example 2 and Example 1 is that no toughening agent is added in Comparative Example 2.

[0046] Comparative Example 3

[0047] The preparation method of the high-purity corundum bricks in Comparative Example 3 is substantially the same as that in Example 1. The difference between the preparation method of the high-purity corundum bricks in Comparative Example 3 and Example 1 is that in Comparative Example 3, the modified fused zirconium corundum particles in Example 1 are replaced with fused zirconium corundum particles of equal mass.

[0048] Test Example 1

[0049] Performance Testing

[0050] 1. Thermal shock resistance test: Place the sample in a resistance furnace, keep it at 1100℃ for 20 minutes, take it out and put it in cold water for 5 minutes, place it in air for 5 minutes, and then put it in the resistance furnace for 5 minutes, and repeat 10 times;

[0051] 2. Mechanical properties test;

[0052] 3. Iron oxide content test: Use sodium thiosulfate titration method to detect the content of Fe2O3 in high-purity corundum bricks;

[0053] 4. Silica content test;

[0054] 5. Porosity test;

[0055] 6. Bulk density test.

[0056] Table 1 Performance test results of high purity corundum bricks of Examples 1-3 and Comparative Examples 1-3

[0057]

[0058]

[0059] As can be seen from Table 1, the high-thermal-shock-resistant, high-purity corundum bricks prepared by the present invention have excellent thermal shock resistance and mechanical properties, and can be used under operating conditions with large temperature fluctuations. Furthermore, the high-thermal-shock-resistant, high-purity corundum bricks prepared by the present invention have a low iron oxide content, which prevents the high-thermal-shock-resistant, high-purity corundum bricks from being reduced in reducing atmospheres and affecting their structural strength. Furthermore, the high-thermal-shock-resistant, high-purity corundum bricks of the present invention have a very low silica content, which can prevent the silica in the product from being corroded by HF gas or reduced in a strong reducing atmosphere, thereby causing structural damage to the refractory bricks.

[0060] Test Example 2

[0061] The high-purity corundum bricks in Examples 1-3 and Comparative Examples 1-3 were placed in a high-temperature furnace at 1100°C and kept warm for 20 minutes. Reducing gases such as CO, H2, and water vapor were continuously introduced into the high-temperature furnace. At the same time, Al2O3 particles with a particle size of 50-100 μm were sprayed at high speed onto the surface of the high-purity corundum bricks in Example 1 and Comparative Example 1. After 20 minutes, the high-purity corundum bricks in Example 1 and Comparative Example 1 were taken out and placed in cold water for rapid cooling. They were placed in the air for 5 minutes and then placed in a high-temperature furnace for keeping warm for 5 minutes. CO, H2, water vapor reducing gases and Al2O3 particles were continuously introduced into the high-temperature furnace. This was repeated 50 times. After testing, the flexural strength of Examples 1-3 and Comparative Example 1-3 is shown in Table 2.

[0062] Table 2 Room temperature flexural strength of high purity corundum bricks of Examples 1-3 and Comparative Examples 1-3

[0063] sample Flexural strength at room temperature (Mpa) Flexural strength at room temperature after test (MPa) Example 1 28.7 18.3 Example 2 30.2 20.5 Example 3 29.5 19.7 Comparative Example 1 26.9 9.5 Comparative Example 2 25.7 9.8 Comparative Example 3 24.5 10.1

[0064] As can be seen from Table 2, the flexural strength of the high-purity corundum bricks in Examples 1-3 remains relatively high compared to the room-temperature flexural strength, while the flexural strength of the high-purity corundum bricks in Comparative Examples 1-3 decreases significantly. This is due to the high Fe₂O₃ content in the high-purity corundum brick in Reference 1, which is reduced by the reducing gas, affecting the structural strength of the high-purity corundum brick. References 2 and 3, which lack the addition of toughening agents and modified fused zirconium alumina particles, exhibit poor fracture toughness.

Claims

1. A high purity corundum brick with high thermal shock resistance, characterized in that: The raw materials include the following by mass: 55-65 parts of plate-like corundum particles, 20-25 parts of plate-like corundum fine powder, 8-12 parts of modified fused zirconium corundum particles, 5-8 parts of nano-alumina powder, 2-3 parts of ρ-alumina powder, 0.3-1 parts of toughening agent, and 0.3-1.5 parts of binder.

2. The high purity corundum brick with high thermal shock resistance according to claim 1, characterized in that: The preparation method of the toughening agent comprises the following steps: mixing YAlO3, SiAlON and Al2O3 to obtain a mixture, mixing the mixture with a solvent to obtain a slurry, and ball milling, drying, calcining and crushing the slurry to obtain the toughening agent.

3. The high purity corundum brick with high thermal shock resistance according to claim 2, characterized in that: The mass ratio of YAlO3 to SiAlON is 1:15-20; the mass ratio of YAlO3 to Al2O3 is 1:1-5; the added amount of the solvent accounts for 30-35% of the total mass of the mixture; and the solvent is ethanol.

4. The high purity corundum brick with high thermal shock resistance according to claim 2, characterized in that: The calcining step comprises: heating the temperature to 1200-1500° C. at a heating rate of 100-120° C. / h under an inert gas atmosphere, and keeping the temperature for 2-3 hours.

5. The high purity corundum brick with high thermal shock resistance according to claim 2, characterized in that: The rotation speed of the ball mill is 350-500 r / min, the ball milling time is 2-4 hours, and the drying temperature is 80-120°C.

6. The high purity corundum brick with high thermal shock resistance according to claim 1, characterized in that: The modified fused zirconium corundum particles are prepared by uniformly mixing fused zirconium corundum, a binder, and water, extruding and granulating the mixture into columnar particles, and sintering the columnar particles at 1200-1500° C. The columnar particles have a diameter of 20-30 μm and a length of 40-60 μm.

7. The high purity corundum brick with high thermal shock resistance according to claim 6, characterized in that: The mass ratio of the fused zirconium corundum to the binder is 20:0.05-0.1, and the mass ratio of the fused zirconium corundum to water is 20:0.8-1; the binder is carboxymethyl cellulose.

8. The high purity corundum brick with high thermal shock resistance according to claim 1, characterized in that: The particle size of the toughening agent is 25 to 40 μm; the binder is a sol; the plate-shaped corundum particles include 23 to 27% coarse aggregate, 55 to 70% medium aggregate and the remainder fine aggregate; the coarse aggregate includes plate-shaped corundum with a particle size of 5 to 3 mm; the medium aggregate includes 25 to 30% plate-shaped corundum with a particle size of 3 to 1 mm, 20 to 25% plate-shaped corundum with a particle size of 1 to 0 mm and 10 to 15% plate-shaped corundum fine powder with a particle size of 1 to 0.088 mm; and the fine aggregate includes plate-shaped corundum micropowder with a particle size of less than 0.088 mm.

9. A method for preparing high-purity corundum bricks with high thermal shock resistance as claimed in claim 1, characterized in that: The following steps are involved: The plate-like corundum particles, plate-like corundum fine powder, modified fused zirconium corundum particles, nano-alumina powder, and ρ-alumina powder are mixed with water in a formulated amount, hydrogen chloride gas is introduced into the water and stirred continuously for 10 to 20 minutes, followed by filtration and drying to obtain substance A, substance A, a toughening agent, and a binder are mixed, and then 3 to 7% of the total mass of the raw materials is added with water, stirred evenly, and then placed in a mold and pressed to expel bubbles to form an embryo body, which is then sintered into a shape.

10. The method for preparing high-purity corundum bricks with high thermal shock resistance according to claim 9, characterized in that: The firing steps are: first heating the temperature to 200-400°C at a heating rate of 60-80°C / h, keeping the temperature for 1-3 hours, then heating the temperature to 900-1000°C at a heating rate of 150-180°C / h, keeping the temperature for 2-4 hours, and finally heating the temperature to 1600-1650°C at a heating rate of 30-60°C / h, keeping the temperature for 8-12 hours.

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