Corundum-based refractory castable containing rare earth oxide and preparation method thereof

Abstract

The application belongs to the technical field of refractory materials, and relates to a corundum-based refractory castable containing rare earth oxides and a preparation method thereof. The application comprises the following components in percentage by weight: brown corundum granular material 35-50%, mullite granular material 20-40%, white corundum powder 5-12%, microsilica powder 2-5%, silica sol 5-10%, alpha-alumina powder 5-10%, water reducing agent 0.05-0.10%, and rare earth oxides 1-5%; the rare earth oxides are a mixture of Nd2O3, La2O3 and Pr6O 11 , and the mass ratio of Nd2O3, La2O3 and Pr6O 11 is 1:1:(0.3-0.6). The application controls the type and ratio of rare earth oxides and the specific type of water reducing agent, so that the prepared corundum-based refractory castable has good high-temperature bending strength, pressure resistance and low apparent porosity.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of refractory materials, and particularly relates to a corundum-based refractory castable containing rare earth oxides and a preparation method thereof. BACKGROUND

[0002] Refractory material refers to a kind of inorganic non-metallic material with a refractoriness of not less than 1580 DEG C. As a material for traditional industries, refractory material plays an irreplaceable role in the development of the entire high-temperature industry and is one of the basic materials for the metallurgical industry. As a high-temperature container for steelmaking, the primary function of refractory material is to withstand high temperature, and it is also required to have the function of safely and stably smelting molten steel in the face of temperature changes and slag erosion in steelmaking.

[0003] Refractory castable is a typical indefinite refractory material, which is a mixture of aggregate particles, fine powder, binder and additive. Refractory castable is usually in a dry state, and can be made into a slurry, paste or loose state by adding water or other liquids for casting construction. There are many types of aggregate in refractory castable, including clay aggregate, high alumina aggregate, alkaline aggregate, silica aggregate, mullite aggregate, corundum aggregate, and heat-insulating aggregate. Corundum-based refractory castable has good high-temperature wear resistance and excellent corrosion resistance to acid and alkaline slag (metallic glass solution), and is widely used in the fields of building materials, metallurgy and other high-temperature industries.

[0004] Chinese patent CN115893994A discloses a rare earth oxide modified corundum-mullite castable and its use method and application. In the castable, the components and their mass percentages include: dense corundum particles 35-45%, mullite particles 20-25%, white corundum 10-15%, silica powder 2-5%, active alumina powder 5-10%, composite additive 1-3%, external water-reducing agent 0.05-0.15%, rare earth oxide 2-5%, and silica sol 7-9%. The rare earth oxide is Y2O3 and CeO2 with a mass ratio of 1:(0.2-0.5). After modification of Y2O3 and CeO2 by reasonable proportioning and mixing, the low and medium temperature strength of the obtained castable is significantly improved, and its high temperature performance is also improved, while having the advantages of wear resistance, high temperature corrosion resistance, and strong thermal shock resistance.

[0005] Chinese patent CN 109650918A discloses a preparation method of an environmentally friendly chromium-containing refractory castable, comprising the following steps: 1) taking 1-14wt% of environmentally friendly chromium-containing solid solution fine powder, 2-8wt% of pure calcium aluminate cement fine powder, 6-15wt% of electrically fused white corundum fine powder and 5-10wt% of alpha-Al2O3 micro powder as the base material, adding 0.06-0.3wt% of polycarboxylic acid water reducing agent, and blending to prepare a mixed base material; 2) taking 65-75wt% of tabular corundum particles as the aggregate, adding the aggregate to the mixed base material obtained in step 1), mixing well, and then adding 3-6wt% of water, stirring, vibration casting, baking at 110℃ for 24h, demolding, and finally heating to 500-1500℃ and keeping for 6h to obtain the environmentally friendly chromium-containing refractory castable. The invention also provides the environmentally friendly chromium-containing refractory castable prepared by the above method, which has no hexavalent chromium formation, good slag resistance, high high-temperature strength, and meets the requirements of safe use of chromium-containing refractory materials.

[0006] In summary, the high-temperature bending strength and the apparent porosity of the existing corundum castable cannot better meet the requirements, and therefore it is necessary to develop a corundum refractory castable with good high-temperature bending strength and low apparent porosity. SUMMARY

[0007] In view of the deficiencies in the prior art, the present application aims to provide a corundum refractory castable containing rare earth oxides and a preparation method thereof, which has good high-temperature bending strength and low apparent porosity by controlling the types and proportions of rare earth oxides and the specific types of water reducing agents.

[0008] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0009] A corundum refractory castable containing rare earth oxides, comprising the following components in terms of weight percentage: 35-50% of brown corundum particle material, 20-40% of mullite particle material, 5-12% of white corundum powder, 2-5% of microsilica powder, 5-10% of silica sol, 5-10% of alpha-alumina powder, 0.05-0.10% of water reducing agent, and 1-5% of rare earth oxides.

[0010] Preferably, the corundum refractory castable containing rare earth oxides comprises the following components in terms of weight percentage: 40-45% of brown corundum particle material, 25-35% of mullite particle material, 6-10% of white corundum powder, 3-4% of microsilica powder, 6-9% of silica sol, 6-9% of alpha-alumina powder, 0.06-0.09% of water reducing agent, and 2-4% of rare earth oxides.

[0011] Preferably, the corundum-based refractory castable containing rare earth oxide comprises the following components in percentage by weight: brown corundum granular material 42-45%, mullite granular material 25-30%, white corundum powder 6-8%, microsilica powder 3.5-4%, silica sol 7-8%, α-alumina powder 7-9%, water reducing agent 0.08-0.09% and rare earth oxide 3-5%.

[0012] Further preferably, the corundum-based refractory castable containing rare earth oxide comprises the following components in percentage by weight: brown corundum granular material 40%, mullite granular material 28%, white corundum powder 8%, microsilica powder 4.41%, silica sol 8%, α-alumina powder 9%, water reducing agent 0.09% and rare earth oxide 2.5%.

[0013] Preferably, the rare earth oxide is a mixture of Nd2O3, La2O3 and Pr6O 11 , and the mass ratio of Nd2O3, La2O3 and Pr6O 11 is 1:1:(0.3-0.6).

[0014] Preferably, the mass ratio of Nd2O3, La2O3 and Pr6O 11 is 1:1:(0.4-0.5).

[0015] Further preferably, the mass ratio of Nd2O3, La2O3 and Pr6O 11 is 1:1:0.5.

[0016] In some preferred embodiments, the particle size of the rare earth oxide is ≤3.5 μm.

[0017] In some other preferred embodiments, the brown corundum granular material is two kinds of granular materials with particle sizes of 5-3 mm and 1-0 mm, and the mass ratio is 1:2.8-3.2.

[0018] Preferably, the brown corundum granular material is two kinds of granular materials with particle sizes of 3-5 mm and 0-1 mm, and the mass ratio is 1:3.0-3.2.

[0019] Further preferably, the brown corundum granular material is two kinds of granular materials with particle sizes of 3-5 mm and 0-1 mm, and the mass ratio is 1:3.0.

[0020] The mullite granular material is two kinds of granular materials with particle sizes of 1-3 mm and 3-5 mm, and the mass ratio is 2-2.8:1.

[0021] Preferably, the mullite granular material is two kinds of granular materials with particle sizes of 1-3 mm and 3-5 mm, and the mass ratio is 2.2-2.5:1.

[0022] More preferably, the mullite granular material is two kinds of granular material with particle size of 1-3mm and 3-5mm, and the mass ratio is 2.5:1.

[0023] The Al2O3 content in the mullite granular material is ≥70%.

[0024] The Al2O3 content in the white corundum powder is ≥98%, and the particle size is ≤0.050mm.

[0025] The Al2O3 content in the α-alumina powder is ≥99%, and the particle size is ≤1.8μm.

[0026] Further, the water reducing agent is a mixture of sodium tripolyphosphate, sodium alginate and polystyrene; preferably, the mass ratio of the three is 3-5:1:1; preferably 4:1:1.

[0027] The mass fraction of SiO2 in the silica sol is 30-45%, and the particle size is 10-15nm.

[0028] The preparation method of the above-mentioned corundum-based refractory castable containing rare earth oxide is as follows: the raw materials are prepared according to the formula, the white corundum powder, the microsilica powder, the silica sol, the α-alumina powder, the water reducing agent and the rare earth oxide are mixed, then the corundum granular material and the mullite granular material are added, water is added and mixed, the water amount is controlled to be 3-5wt%, and then the mixture is poured into a mold and vibrated; after baking at 100-150℃ for 15-20h, the mold is demolded, and finally the temperature is increased to 800-1200℃, and the temperature is kept for 4-8h, to obtain the corundum-based refractory castable containing rare earth oxide.

[0029] Preferably, after baking at 120℃ for 18h, the mold is demolded, and finally the temperature is increased to 1000℃, and the temperature is kept for 6h.

[0030] Compared with the prior art, the present application has the following beneficial effects:

[0031] (1) By adding rare earth oxides Nd2O3, La2O3 and Pr6O 11 in the castable components and controlling the mass ratio of the three to be 1:1:(0.3-0.6), the powder and aggregate in the castable can be better combined through the silica sol, the microstructure is more compact, the pores are reduced, and the bending strength and compressive strength of the castable are significantly improved.

[0032] (2) By controlling the particle size of Nd2O3, La2O3 and Pr6O 11 , the rare earth oxides can be combined with the silica sol and fully filled into the pores of the aggregate and powder, thereby improving the density of the castable; and it is found in the implementation process that the mass ratio of Nd2O3, La2O3 and Pr6O 11 will affect the high temperature resistance of the castable.

[0033] (3) The present application uses a mixture of sodium tripolyphosphate, sodium alginate and polystyrene as water reducing agent, and controls the mass ratio of the three to be 3-5:1:1, which can significantly improve the mixing effect of the granular material and the powder, reduce the pore of the castable and significantly reduce the apparent porosity. DETAILED DESCRIPTION

[0034] The following non-limiting examples can make the ordinary skilled in the art more comprehensive understanding of the present application, but not in any way limit the present application. The following content is only an exemplary description of the scope of the present application, those skilled in the art can make various changes and modifications to the present application according to the disclosed content, and it should also belong to the scope of the present application claimed.

[0035] When the example gives a numerical range, it should be understood that, unless otherwise stated by the present application, each numerical range of two endpoints and any one numerical between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as generally understood by those skilled in the art to which the present application belongs.

[0036] The present application is further described below in the manner of specific examples. The various chemical reagents used in the examples of the present application are obtained by conventional commercial routes unless otherwise specified.

[0037] Example 1

[0038] The components include the following by weight percentage: brown corundum granular material 35%, mullite granular material 40%, white corundum powder 5%, microsilica powder 2%, silica sol 10%, α-alumina powder 5%, water reducing agent 0.05% and rare earth oxide 2.95%.

[0039] The rare earth oxide is a mixture of Nd2O3, La2O3 and Pr6O 11 in a mass ratio of 1:1:0.5;

[0040] The brown corundum granular material has two kinds of granular materials with particle size of 3-5mm and 0-1mm, and the mass ratio is 1:3.0;

[0041] The mullite granular material is two kinds of granular materials with particle size of 1-3mm and 3-5mm, and the mass ratio is 2.5:1.

[0042] The Al2O3 content of the mullite granular material is ≥70%.

[0043] The Al2O3 content of the white corundum powder is ≥98%, and the particle size is ≤0.050mm.

[0044] The Al2O3 content of the α-alumina powder is ≥99%, and the particle size is ≤1.8μm.

[0045] The water reducing agent is a mixture of sodium tripolyphosphate, sodium alginate and polystyrene; the mass ratio of the three is 3:1:1.

[0046] The mass fraction of SiO2 in the silica sol is 40%, and the particle size is 10-15 nm.

[0047] The preparation method is as follows: the raw materials are mixed according to the formula, the white corundum powder, microsilica powder, silica sol, alpha-alumina powder, water reducing agent and rare earth oxide are mixed, then corundum granules and mullite granules are added, water is added and mixed, the water amount is controlled at 3-5 wt%, and then the mixture is poured into a mold and vibrated; after baking at 120℃ for 18h, the mold is removed, and finally the temperature is raised to 1000℃ and kept for 6h, to obtain the corundum-based refractory castable containing rare earth oxide.

[0048] Example 2

[0049] The components include the following by weight percentage: brown corundum granules 40%, mullite granules 25%, white corundum powder 10%, microsilica powder 4%, silica sol 8%, alpha-alumina powder 9%, water reducing agent 0.09% and rare earth oxide 3.91%.

[0050] The rare earth oxide is a mixture of Nd2O3, La2O3 and Pr6O 11 The mass ratio of Nd2O3, La2O3 and Pr6O 11 is 1:1:0.3.

[0051] The brown corundum granules are two kinds of granules with particle sizes of 3-5mm and 0-1mm, and the mass ratio is 1:3.0.

[0052] The mullite granules are two kinds of granules with particle sizes of 1-3mm and 3-5mm, and the mass ratio is 2.5:1.

[0053] The Al2O3 content in the mullite granules is ≥70%.

[0054] The Al2O3 content in the white corundum powder is ≥98%, and the particle size is ≤0.050mm.

[0055] The Al2O3 content in the alpha-alumina powder is ≥99%, and the particle size is ≤1.8μm.

[0056] The water reducing agent is a mixture of sodium tripolyphosphate, sodium alginate and polystyrene; the mass ratio of the three is 3:1:1.

[0057] The mass fraction of SiO2 in the silica sol is 40%, and the particle size is 10-15 nm.

[0058] The preparation method comprises the following steps: preparing the raw materials according to the formula, mixing white corundum powder, microsilica powder, silica sol, α-alumina powder, a water reducer and rare earth oxides, adding corundum particles and mullite particles, adding water and mixing, wherein the amount of water is controlled at 3-5wt%, pouring into a mold, and vibrating the mold; baking at 120°C for 18 hours, demoulding the mold, and finally heating to 1000°C and keeping the temperature for 6 hours to obtain the corundum refractory castable containing rare earth oxides.

[0059] Example 3

[0060] The composition includes the following components by weight percentage: 45% of brown corundum particles, 28% of mullite particles, 6% of white corundum powder, 3.5% of microsilica powder, 7% of silica sol, 7% of α-alumina powder, 0.08% of water reducer and 3.42% of rare earth oxide.

[0061] The rare earth oxides are Nd2O3, La2O3 and Pr6O 11 mixture of Nd2O3, La2O3 and Pr6O 11 The mass ratio is 1:1:0.4;

[0062] The brown corundum particles have two sizes: 3-5 mm and 0-1 mm, with a mass ratio of 1:3.0.

[0063] The mullite particles are of two types, with particle sizes of 1-3 mm and 3-5 mm, and a mass ratio of 2.5:1.

[0064] The Al2O3 content in the mullite particles is ≥70%.

[0065] The Al2O3 content of the white corundum powder is ≥98%, and the particle size is ≤0.050mm.

[0066] The Al2O3 content of the α-alumina powder is ≥99%, and the particle size is ≤1.8 μm.

[0067] The water reducer is a mixture of sodium tripolyphosphate, sodium alginate and polystyrene; the mass ratio of the three is 3:1:1;

[0068] The mass fraction of SiO2 in the silica sol is 40%, and the particle size is 10-15 nm.

[0069] The preparation method comprises the following steps: preparing the raw materials according to the formula, mixing white corundum powder, microsilica powder, silica sol, α-alumina powder, a water reducer and rare earth oxides, adding corundum particles and mullite particles, adding water and mixing, wherein the amount of water is controlled at 3-5wt%, pouring into a mold, and vibrating the mold; baking at 120°C for 18 hours, demoulding the mold, and finally heating to 1000°C and keeping the temperature for 6 hours to obtain the corundum refractory castable containing rare earth oxides.

[0070] Example 4

[0071] comprising the following components by weight percentage: brown corundum granules 40%, mullite granules 28%, white corundum powder 8%, microsilica powder 4.41%, silica sol 8%, α-alumina powder 9%, water reducing agent 0.09% and rare earth oxide 2.5%.

[0072] The rare earth oxide is a mixture of Nd2O3, La2O3 and Pr6O 11 ; the mass ratio of Nd2O3, La2O3 and Pr6O 11 is 1:1:0.5.

[0073] The particle size of the rare earth oxide is ≤3.5 μm.

[0074] The brown corundum granules have two kinds of particle sizes of 3-5 mm and 0-1 mm, and the mass ratio is 1:3.0.

[0075] The mullite granules have two kinds of particle sizes of 1-3 mm and 3-5 mm, and the mass ratio is 2.5:1.

[0076] The Al2O3 content of the mullite granules is ≥70%.

[0077] The Al2O3 content of the white corundum powder is ≥98%, and the particle size is ≤0.050 mm.

[0078] The Al2O3 content of the α-alumina powder is ≥99%, and the particle size is ≤1.8 μm.

[0079] Further, the water reducing agent is a mixture of sodium tripolyphosphate, sodium alginate and polystyrene; the mass ratio of the three is 4:1:1.

[0080] The mass fraction of SiO2 in the silica sol is 40%, and the particle size is 10-15 nm.

[0081] Comparative Example 1

[0082] The difference from Example 4 is that the component Pr6O 11 is omitted, i.e. the rare earth oxide is Nd2O3 and La2O3 with a mass ratio of 1:1, and the contents and proportions of other components are the same as in Example 4.

[0083] Comparative Example 2

[0084] The difference from Example 4 is that the rare earth oxide is replaced by Y2O3 and CeO2 with a mass ratio of 1:0.25, and the contents and proportions of other components are the same as in Example 4.

[0085] Comparative Example 3

[0086] The difference from Example 4 is that Nd2O3, La2O3 and Pr6O 11 The mass ratio of is 1:1:2, and the contents and proportions of other components are the same as those in Example 4.

[0087] Comparative Example 4

[0088] The difference from Example 4 is that the water reducer component is replaced by sodium hexametaphosphate, and the contents and proportions of other components are the same as those in Example 4.

[0089] Comparative Example 5

[0090] The difference from Example 4 is that the mass ratio of sodium tripolyphosphate, sodium alginate and polystyrene is 7:1:1, and the contents and proportions of other components are the same as those in Example 4.

[0091] Comparative Example 6

[0092] The difference from Example 4 is that the component sodium alginate is omitted, that is, the mass ratio of sodium tripolyphosphate to polystyrene is 4:1, and the contents and proportions of other components are the same as those in Example 4.

[0093] Effect experiment

[0094] 1. Flexural strength and compressive strength test

[0095] 1) High-temperature compressive strength: The test was conducted in accordance with GB / T 34218-2017 "Test method for high-temperature compressive strength of refractory materials", where the test temperature was 1400°C, the holding time was 3h, the heating rate was 10°C / min, and the loading rate was 1.0MPa / s;

[0096] 2) High-temperature flexural strength: The test was conducted in accordance with GB / T 3002-2017 "Test method for high-temperature flexural strength of refractory materials", with a test temperature of 1400°C, a holding time of 3 hours, a heating rate of 5°C / min, and a loading rate of 0.15 MPa / s;

[0097] The flexural strength and compressive strength of the rare earth oxide-containing corundum refractory castables prepared in Examples 1-4 and Comparative Examples 1-6 after firing were tested. The results are shown in Table 1 below.

[0098] Table 1 Flexural strength and compressive strength test results

[0099] Group High temperature compressive strength (Mpa) High temperature flexural strength (Mpa) Example 1 136.8 35.5 Example 2 137.6 34.9 Example 3 136.4 35.2 Example 4 140.7 36.8 Comparative Example 1 125.4 30.2 Comparative Example 2 121.3 26.4 Comparative Example 3 132.4 32.1 Comparative Example 4 125.8 29.4 Comparative Example 5 129.6 33.0 Comparative Example 6 128.1 31.8

[0100] As shown in Table 1, the flexural strength and compressive strength of the corundum refractory castables containing rare earth oxides prepared in Examples 1-4 of the present invention after firing are significantly higher than those in Comparative Examples 1-6.11 The kind or mass ratio of the water reducing agent will affect the combination of the powder and the aggregate in the castable through the silica sol, affect the microstructure, and further affect the modulus of rupture and the crushing strength of the castable; the kind or mass ratio of the water reducing agent in the comparative examples 4-6 will affect the mixing effect of the granular material and the powder, and further affect the modulus of rupture and the crushing strength of the corundum-based refractory castable containing rare earth oxide after firing.

[0101] 2. Apparent porosity detection

[0102] The apparent porosity of the corundum-based refractory castable containing rare earth oxide prepared in the examples 1-4 and the comparative examples 1-6 after firing was tested according to the standard GB / T2997-2015, and the results are shown in Table 2 below.

[0103] Table 2: Apparent porosity test results

[0104]

[0105]

[0106] As shown in Table 2, the apparent porosity of the corundum-based refractory castable containing rare earth oxide prepared in the examples 1-4 after firing is significantly lower than that of the comparative examples 1-6, and the kind or mass ratio of the rare earth oxide Nd2O3, La2O3 and Pr6O 11 The kind or mass ratio of the water reducing agent will affect the combination of the powder and the aggregate in the castable through the silica sol, affect the microstructure, and further affect the modulus of rupture and the crushing strength of the castable; the kind or mass ratio of the water reducing agent in the comparative examples 4-6 will affect the mixing effect of the granular material and the powder, and further affect the modulus of rupture and the crushing strength of the corundum-based refractory castable containing rare earth oxide after firing.

[0107] Finally, it should be noted that the above content is only used to illustrate the technical solutions of the present application, and is not a limitation on the protection scope of the present application. Simple modifications or equivalent replacements of the technical solutions of the present application made by those skilled in the art do not deviate from the essence and scope of the technical solutions of the present application.

Claims

1. A corundum-based refractory castable containing rare earth oxide, characterized by: The composition comprises the following components by weight percentage: brown corundum granules 35-50%, mullite granules 20-40%, white corundum powder 5-12%, microsilica powder 2-5%, silica sol 5-10%, α-alumina powder 5-10%, water reducing agent 0.05-0.10% and rare earth oxide 1-5%; the rare earth oxide is a mixture of Nd2O3, La2O3 and Pr6O 11 , the mass ratio of Nd2O3, La2O3 and Pr6O 11 is 1:1:(0.3-0.6). The water reducing agent is a mixture of sodium tripolyphosphate, sodium alginate and polystyrene, and the mass ratio of the three is 3-5:1:

1.

2. The rare earth oxide-containing corundum-based refractory castable according to claim 1, characterized in that: The components include, by weight percentage, brown corundum granules 40-45%, mullite granules 25-35%, white corundum powder 6-10%, microsilica powder 3-4%, silica sol 6-9%, alpha-alumina powder 6-9%, water reducing agent 0.06-0.09% and rare earth oxide 2-4%.

3. The rare earth oxide-containing corundum-based refractory castable according to claim 1, characterized in that: The components include, by weight percentage, brown corundum granules 40%, mullite granules 28%, white corundum powder 8%, microsilica powder 4.41%, silica sol 8%, alpha-alumina powder 9%, water reducing agent 0.09% and rare earth oxide 2.5%.

4. The rare earth oxide-containing corundum-based refractory castable according to claim 1, characterized in that: The mass ratio of Nd2O3, La2O3and Pr6O 11 is 1:1:0.

5.

5. The rare earth oxide-containing corundum-based refractory castable according to claim 1, characterized in that: The particle size of the rare earth oxide is less than or equal to 3.5 microns.

6. The rare earth oxide-containing corundum-based refractory castable according to claim 1, characterized in that: The brown corundum granules are two kinds of granules with particle sizes of 5-3 mm and 1-0 mm, and the mass ratio is 1:2.8-3.2; the mullite granules are two kinds of granules with particle sizes of 1-3 mm and 3-5 mm, and the mass ratio is 2-2.8:

1.

7. The rare earth oxide-containing corundum-based refractory castable according to claim 6, characterized in that: The brown corundum granules are two kinds of granules with particle sizes of 3-5 mm and 0-1 mm, and the mass ratio is 1:3.0; the mullite granules are two kinds of granules with particle sizes of 1-3 mm and 3-5 mm, and the mass ratio is 2.5:

1.

8. The rare earth oxide-containing corundum-based refractory castable according to claim 1, characterized in that: The water reducing agent is a mixture of sodium tripolyphosphate, sodium alginate and polystyrene, and the mass ratio of the three is 4:1:

1.

9. Process for the production of a rare earth oxide-containing corundum-based refractory castable according to any one of claims 1 to 8, characterized in that: The raw materials are prepared according to the formula, the white corundum powder, the microsilica powder, the silica sol, the alpha-alumina powder, the water reducing agent and the rare earth oxide are mixed, then the corundum granules and the mullite granules are added and mixed with water, the water content is controlled to be 3-5 wt%, and then the mixture is poured into a mold and vibrated; after baking at 100-150 DEG C for 15-20 h, the mixture is demolded, and finally the temperature is increased to 800-1200 DEG C, and the mixture is kept at this temperature for 4-8 h, to obtain the corundum-based refractory castable containing rare earth oxide.

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