Al2O3-SiC-C refractory castable product and preparation method thereof

Abstract

The invention belongs to the technical field of novel refractory materials, and particularly relates to an Al2O3-SiC-C refractory castable product and a preparation method thereof. The Al2O3-SiC-C refractory castable is prepared from the following raw materials in percentage by mass: 50%-85% of aggregate, 6%-35% of a matrix, 1%-10% of a binding agent, 1%-5% of an antioxidant, 0.2%-2% of an additive and an additive accounting for 0.1%-1% of the total mass of the raw materials, the binding agent is light calcined magnesia powder. The Al2O3-SiC-C refractory castable product disclosed by the invention is high in strength and good in slag corrosion resistance and permeability, and also has the advantages of convenience in construction, long construction time during pouring, low production energy consumption and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of new refractory materials, and specifically relates to an Al2O3-SiC-C refractory castable product and a preparation method thereof. Background Art

[0002] Al2O3-SiC-C refractory castables are mainly used in blast furnace tapping channels, which are passages for high-temperature molten iron and slag. Tapping channels are a type of amorphous refractory material that meets tapping requirements. With the development of large-scale and long-life modern blast furnaces, the amount of tapping iron in blast furnace tapping channels has increased dramatically, which has put forward more stringent requirements on the refractory materials used in tapping channels. No introduction of impurities, strong anti-oxidation and anti-corrosion properties, and long service life have become the main development direction of tapping channels refractory materials.

[0003] Regarding the performance of Tiegou refractory materials, the type of binder has a great influence on the performance of Tiegou materials. This type of refractory castable needs to have good high-temperature mechanical properties, slag erosion resistance, oxidation resistance and thermal shock stability. At present, the binder used in Tiegou refractory materials is mainly calcium aluminate cement. The use of calcium aluminate cement as a binder to prepare refractory castables has high strength and is easy to form, but calcium aluminate cement will introduce CaO and generate low-melting products under high temperature conditions, which directly affects the high-temperature performance and slag erosion resistance of the refractory materials. In addition, the use of calcium aluminate cement will increase the water demand, resulting in an increase in hydration products. The hydration products will dehydrate and decompose during the heating process, causing micropores inside the structure and destroying the hydration network.

[0004] Antioxidants also have a great impact on the refractory castable. At present, silicon powder and boron carbide are commonly used as antioxidants in refractory castables of this system. Boron carbide will generate boron oxide liquid phase under high temperature conditions, reducing high temperature corrosion resistance. Silicon powder will generate silicon dioxide distributed on the surface of the castable at high temperature, making the internal silicon powder lose its antioxidant effect, resulting in poor oxidation resistance of silicon powder. Summary of the invention

[0005] In view of the problems and shortcomings in the prior art, the object of the present invention is to provide an Al2O3-SiC-C refractory castable product and a preparation method thereof.

[0006] To achieve the purpose of the invention, the technical solution adopted by the present invention is as follows:

[0007] The first aspect of the present invention provides an Al2O3-SiC-C refractory castable product. The raw material composition of the Al2O3-SiC-C refractory castable is, by weight percentage, 50% to 85% aggregate, 6% to 35% matrix, 1% to 10% binder, 1% to 5% antioxidant, 0.2% to 2% additive, and an admixture accounting for 0.1% to 1% of the total weight of the above raw materials; the binder is lightly burned magnesium oxide powder.

[0008] According to the above-mentioned Al2O3-SiC-C refractory castable product, preferably, the antioxidant is passivated metal aluminum powder.

[0009] According to the above-mentioned Al2O3-SiC-C refractory castable product, preferably, the preparation method of the passivated metal aluminum powder is: calcining the metal aluminum powder at 500-620°C for 1-20 hours, and obtaining the passivated metal aluminum powder after cooling. More preferably, the preparation method of the passivated metal aluminum powder is: calcining the metal aluminum powder at 500-620°C for 5-20 hours, and obtaining the passivated metal aluminum powder after cooling. Most preferably, the preparation method of the passivated metal aluminum powder is: calcining the metal aluminum powder at 580°C for 15 hours, and obtaining the passivated metal aluminum powder after cooling.

[0010] According to the above Al2O3-SiC-C refractory castable product, preferably, the aggregate is at least one of corundum particles and silicon carbide particles. More preferably, the aggregate is corundum particles and silicon carbide particles.

[0011] According to the above Al2O3-SiC-C refractory castable product, preferably, the matrix is ​​at least one of corundum fine powder, silicon carbide fine powder, activated alumina fine powder, and carbon material. More preferably, the matrix is ​​at least one of corundum fine powder, silicon carbide fine powder, activated alumina fine powder, and carbon material.

[0012] According to the above-mentioned Al2O3-SiC-C refractory castable product, preferably, the additive is lactate; more preferably, the lactate is at least one of aluminum lactate, magnesium lactate, zinc lactate, and nickel lactate; most preferably, the lactate is aluminum lactate.

[0013] According to the above Al2O3-SiC-C refractory castable product, preferably, the particle size of the carbon material is 1-2 mm, and the carbon material is asphalt, graphite or carbon black. More preferably, the carbon material is carbon black.

[0014] According to the above Al2O3-SiC-C refractory castable product, preferably, the admixture is a water reducer; the water reducer is a polycarboxylic acid water reducer or a naphthalene water reducer. More preferably, the water reducer is a polycarboxylic acid water reducer.

[0015] According to the above-mentioned Al2O3-SiC-C refractory castable product, preferably, the raw material composition of the Al2O3-SiC-C refractory castable is, by mass percentage: 50% to 70% corundum particles, 1% to 15% silicon carbide particles, 1% to 10% corundum fine powder, 1% to 10% silicon carbide fine powder, 3% to 5% activated alumina fine powder, 1% to 10% carbon material, 1% to 10% binder, 1% to 5% antioxidant, 0.2% to 2% additives, plus 0.1% to 1% of the total mass of the above-mentioned raw materials. The binder is lightly burned magnesium oxide powder.

[0016] According to the above-mentioned Al2O3-SiC-C refractory castable product, preferably, the raw material composition of the Al2O3-SiC-C refractory castable is, by mass percentage: 50% to 70% corundum particles, 1% to 15% silicon carbide particles, 1% to 10% corundum fine powder, 1% to 10% silicon carbide fine powder, 3% to 5% activated alumina fine powder, 1% to 5% carbon material, 1% to 7% binder, 2% to 5% antioxidant, 0.2% to 2% additives, plus an admixture accounting for 0.1% to 1% of the total mass of the above-mentioned raw materials; the binder is lightly burned magnesium oxide powder.

[0017] According to the above-mentioned Al2O3-SiC-C refractory castable product, preferably, the raw material composition of the Al2O3-SiC-C refractory castable is, by mass percentage: 64.5% corundum particles, 8% silicon carbide particles, 4.4% corundum fine powder, 8% silicon carbide fine powder, 5% activated alumina fine powder, 3% carbon material, 3% binder, 3.5% antioxidant, 0.6% additives, plus an admixture accounting for 0.15% of the total mass of the above-mentioned raw materials; the binder is lightly burned magnesium oxide powder.

[0018] According to the above-mentioned Al2O3-SiC-C refractory castable product, preferably, the corundum particles are mixed by corundum particles with a particle size of 5-8 mm, corundum particles with a particle size of 3-5 mm, corundum particles with a particle size of 1-3 mm, and corundum particles with a particle size of 0.1-1 mm in a mass ratio of 5:5:5:2.

[0019] According to the above-mentioned Al2O3-SiC-C refractory castable product, preferably, the particle size of the silicon carbide particles is 0.1-1 mm.

[0020] According to the above-mentioned Al2O3-SiC-C refractory castable product, preferably, the particle size of the corundum fine powder is ≤0.045mm; the particle size of the silicon carbide fine powder is ≤0.075mm; the particle size of the activated alumina fine powder is 2-4μm; the particle size of the binder is 4-5μm; the particle size of the passivation metal aluminum powder is 0.048-0.11mm; the particle size of the additive is ≤0.075mm; and the particle size of the carbon material is 1-2mm.

[0021] According to the above Al2O3-SiC-C refractory castable product, preferably, the corundum is one of brown corundum (Al2O3≥95.7% in brown corundum), white corundum (Al2O3≥97.5% in white corundum), and plate-like corundum (Al2O3≥99% in plate-like corundum). More preferably, the corundum is brown corundum.

[0022] According to the above-mentioned Al2O3-SiC-C refractory castable product, preferably, the purity of the silicon carbide is ≥98.5%.

[0023] The second aspect of the present invention provides a method for preparing the Al2O3-SiC-C refractory castable product according to the first aspect, comprising the following steps:

[0024] (1) mixing aggregate, matrix, binder, antioxidant, additive and admixture uniformly to obtain a mixture;

[0025] (2) adding water to the mixture prepared in step (1), stirring and mixing uniformly to obtain a wet mixture;

[0026] (3) The wet mixed material is cast, cured and dried to obtain a blank; the blank is calcined at 1150° C. to 1450° C. for 1 to 10 hours in a carbon-buried atmosphere to obtain a refractory castable product.

[0027] Compared with the prior art, the present invention has the following positive and beneficial effects:

[0028] (1) Existing refractory castable products mostly use silicon powder, boron carbide, etc. as antioxidants. When silicon powder is used as an antioxidant, the addition of a high content of small-particle-size elemental silicon powder leads to an increase in the amount of low-melting-point composite silicate formed, thereby reducing the castable's ability to resist slag erosion and penetration. When boron carbide is used as an antioxidant, the addition of a high content of boron carbide leads to an increase in the amount of low-viscosity boron-containing liquid phase generated in the castable, which reduces the castable's ability to resist slag erosion and penetration. The Al2O3-SiC-C refractory castable product of the present invention uses passivated metal aluminum powder as an antioxidant. On the one hand, the passivation layer on the surface of the passivated metal aluminum powder can effectively prevent the metal aluminum powder from reacting with free water in the castable to produce gas. On the other hand, the metal aluminum powder and the hydration product of light-burned magnesium oxide produce a synergistic effect to generate dense magnesium-aluminum hydrotalcite, which further prevents the hydration of the aluminum powder, avoids the expansion of the green body, improves the density of the castable, and thus improves the performance of the castable.

[0029] (2) The present invention calcines metal aluminum powder at 500-620°C for 1-20 hours, oxidizing its surface to form a dense aluminum oxide layer, and obtaining a passivated metal aluminum powder after cooling. The passivated metal aluminum powder has a simple preparation process, a relatively uniform coating layer, and can be mass-produced. It can also avoid the problem that the passivated metal aluminum powder is easy to agglomerate when the passivated metal aluminum powder is prepared by aluminum sol coating, which makes it difficult to disperse evenly during mixing and reduces the performance of refractory products. It also avoids the problem that the passivated metal aluminum powder is easy to agglomerate when prepared by aluminum sol coating, and needs to be crushed when used. The crushing process easily causes the passivation layer to peel off, thereby affecting the passivation effect.

[0030] (3) The refractory product of the present invention contains an additive, and the additive is preferably lactate. Lactate can limit the formation of Mg(OH)2, help control the hydration reaction rate of light-burned magnesia in the initial processing stage of the refractory product, and extend the construction time of casting.

[0031] (4) The present invention uses lightly burned magnesium oxide powder as a binder to prepare refractory castable products. The lightly burned magnesium oxide powder can react with the active alumina powder in the matrix at high temperature to generate magnesium aluminum spinel in situ, which promotes the sintering and densification of the material and blocks the further infiltration of oxygen. At the same time, the magnesium aluminum spinel can also absorb FeO and Fe2O3 in the slag to form a dense layer, which prevents the continued occurrence of infiltration and greatly improves the ability of the refractory products to resist slag erosion and penetration. In addition, the use of lightly burned magnesium oxide powder as a binder can avoid the formation of CaO-Al2O3-SiO2 eutectic phase during the calcination process. At the same time, lightly burned magnesium oxide can produce MgO-Al2O3-SiO2 phase with a higher melting point and higher viscosity under high temperature conditions, so that the refractory castable has better oxidation resistance, corrosion resistance and permeability resistance, and greatly improves the service life of the refractory castable. Moreover, compared with calcium aluminate cement, a commonly used binder for castables, the lightly burned magnesium oxide powder used as a binder in the present invention can avoid the introduction of CaO into the castable, thereby solving the technical problem that when calcium aluminate cement is used as a binder, CaO will be introduced into the castable to reduce the slag erosion resistance and permeability of the refractory products.

[0032] (5) The Al2O3-SiC-C refractory castable product of the present invention contains a carbon material with a particle size of 1 to 2 mm. The carbon material has the characteristics of being not easily wetted by molten steel and slag, having a small thermal expansion coefficient and high thermal conductivity, and can significantly increase the thermal shock resistance and erosion resistance of the refractory product.

[0033] (6) The bulk density of the Al2O3-SiC-C refractory castable product of the present invention is 3.3 to 3.6 g / cm 3 The room temperature flexural strength reaches 3.1-26MPa, the room temperature compressive strength reaches 69.1-145.2MPa, the high temperature flexural strength reaches 1.1-12MPa, and the erosion index reaches 3-24.1%; therefore, the Al2O3-SiC-C refractory castable product of the present invention has high strength, good resistance to slag erosion and permeability, and also has the advantages of convenient construction, long construction time during pouring, and low production energy consumption. DETAILED DESCRIPTION

[0034] The following examples are only for further explanation of the present invention. It should be noted that all technical and scientific terms used in the present invention have the same meanings as in the technical field to which the present invention belongs unless otherwise specified. The experimental methods in the following examples without specifying specific conditions are all based on conventional techniques in the technical field, or according to the conditions recommended by the manufacturer; the reagents or instruments used without specifying the manufacturer are all conventional products that can be purchased commercially.

[0035] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in conjunction with specific embodiments.

[0036] Example 1: Discussion of Antioxidant Types

[0037] In order to study the influence of the type of antioxidant in the refractory castable product on the performance of the prepared Al2O3-SiC-C refractory castable product, the present invention carried out Example 1-1, Comparative Example 1-1, and Comparative Example 1-2. The specific contents of Example 1-1, Comparative Example 1-1, and Comparative Example 1-1, and Comparative Example 1-2 are as follows:

[0038] Example 1-1:

[0039] The invention discloses an Al2O3-SiC-C refractory castable product. The raw materials of the Al2O3-SiC-C refractory castable are composed of the following components, calculated by mass percentage: 64.5% of corundum particles, 8% of silicon carbide particles with a particle size of 0-1 mm, 4.4% of corundum fine powder with a particle size of ≤0.074 mm, 8% of silicon carbide fine powder with a particle size of ≤0.045 mm, 5% of activated alumina fine powder with a particle size of ≤0.045 mm, 3% of carbon material with a particle size of 1-2 mm, 3% of a binder with a particle size of 4-5 μm, 3.5% of an antioxidant with a particle size of 0.048-0.11 mm, 0.6% of an additive, and an admixture accounting for 0.15% of the total mass of the above raw materials. Wherein, the corundum is brown corundum, the binder is light-burned magnesium oxide powder, the carbon material is carbon black, the additive is aluminum lactate, and the water reducer is a polycarboxylic acid water reducer; the antioxidant is passivated metal aluminum powder, and the preparation method of the passivated metal aluminum powder is: calcining the metal aluminum powder at 500-620°C for 1-20h, and obtaining the passivated metal aluminum powder after cooling; preferably, calcining the metal aluminum powder at 580°C for 15h, and obtaining the passivated metal aluminum powder after cooling.

[0040] The corundum particles are mixed with corundum particles with a particle size of 5 to 8 mm, corundum particles with a particle size of 3 to 5 mm, corundum particles with a particle size of 1 to 3 mm, and corundum particles with a particle size of 0.1 to 1 mm in a mass ratio of 5:5:5:2.

[0041] The preparation method of the above-mentioned Al2O3-SiC-C refractory castable product comprises the following specific steps:

[0042] (1) mixing corundum particles, silicon carbide particles, corundum fine powder, silicon carbide fine powder, activated alumina fine powder, carbon material, binder, antioxidant, additive and admixture to obtain a mixture;

[0043] (2) adding water to the mixture prepared in step (1), wherein the amount of water added is 4% of the total mass of the mixture, and stirring and mixing the mixture to obtain a wet mixture;

[0044] (3) The wet mixed material is poured, cured, and dried to obtain a blank, and the blank is calcined at 1350° C. for 3 h in a carbon-buried atmosphere to obtain a refractory castable product.

[0045] Comparative Example 1-1:

[0046] The content of Comparative Example 1-1 is substantially the same as that of Example 1-1, except that the antioxidant is metallic aluminum powder.

[0047] Comparative Example 1-2:

[0048] The content of Comparative Example 1-2 is substantially the same as that of Example 1-1, except that the antioxidant is silicon powder.

[0049] The mechanical properties of the refractory products prepared by calcining the blanks of Example 1-1, Comparative Example 1-1 and Comparative Example 1-2 were tested. The mechanical properties testing methods are as follows: the bulk density is tested according to GB / T 2999-2016; the room temperature flexural strength is tested according to GB / T 3001-2017; the high temperature flexural strength is tested according to GB / T 3002-2017; the room temperature pressure resistance is tested according to GB / T 5072-2008; the erosion rate is tested using the static crucible method. The mechanical properties test results are shown in Table 1.

[0050] Table 1 is the mechanical properties test results of refractory castable products prepared in Example 1-1, Comparative Example 1-1 and Comparative Example 1-2

[0051]

[0052] It can be seen from Table 1 that when unpassivated metal aluminum powder is used as an antioxidant, the prepared refractory product has a small volume density and poor mechanical properties. This is because the addition of metal aluminum powder will cause the blank to expand significantly during the curing process, reducing the density. Therefore, the prepared refractory product has poor mechanical properties and corrosion resistance. When silicon powder is used as an antioxidant, the presence of silicon powder leads to an increase in the formation of low-melting point composite silicates, thereby reducing the castable's resistance to slag corrosion and penetration. Therefore, the prepared refractory product has poor corrosion resistance and mechanical properties. The passivated metal aluminum powder of the present invention as an antioxidant for Al2O3-SiC-C refractory castable can effectively overcome the shortcomings of using unpassivated metal aluminum powder and silicon powder as antioxidants, and the prepared Al2O3-SiC-C refractory castable products have excellent corrosion resistance and mechanical properties.

[0053] Example 2: Discussion on the amount of passivated aluminum powder

[0054] In order to study the effect of the amount of passivation metal aluminum powder on the performance of the prepared Al2O3-SiC-C refractory castable products, the present invention carried out Examples 2-1 to 2-4 and Comparative Example 2-1. The specific contents of Examples 2-1 to 2-4 and Comparative Example 2-1 are as follows:

[0055] Example 2-1:

[0056] The invention discloses an Al2O3-SiC-C refractory castable product. The raw materials of the Al2O3-SiC-C refractory castable are composed of the following components, calculated by mass percentage: 64.5% of corundum particles, 8% of silicon carbide particles with a particle size of 0-1 mm, 6.9% of corundum fine powder with a particle size of ≤0.074 mm, 8% of silicon carbide fine powder with a particle size of ≤0.045 mm, 5% of activated alumina fine powder with a particle size of ≤0.045 mm, 3% of carbon material with a particle size of 1-2 mm, 3% of a binder with a particle size of 4-5 μm, 1% of an antioxidant with a particle size of 0.048-0.11 mm, 0.6% of an additive, and an admixture accounting for 0.15% of the total mass of the above raw materials. Wherein, the corundum is brown corundum, the binder is light-burned magnesium oxide powder, the carbon material is carbon black, the additive is aluminum lactate, and the water reducer is a polycarboxylic acid water reducer; the antioxidant is passivated metal aluminum powder, and the preparation method of the passivated metal aluminum powder is: calcining the metal aluminum powder at 500-620°C for 1-20h, and obtaining the passivated metal aluminum powder after cooling; preferably, calcining the metal aluminum powder at 580°C for 15h, and obtaining the passivated metal aluminum powder after cooling.

[0057] The corundum particles are mixed with corundum particles with a particle size of 5 to 8 mm, corundum particles with a particle size of 3 to 5 mm, corundum particles with a particle size of 1 to 3 mm, and corundum particles with a particle size of 0.1 to 1 mm in a mass ratio of 5:5:5:2.

[0058] The preparation method of the above-mentioned Al2O3-SiC-C refractory castable product is the same as that of Example 1-1.

[0059] Example 2-2:

[0060] The invention discloses an Al2O3-SiC-C refractory castable product. The raw materials of the Al2O3-SiC-C refractory castable are composed of the following components, calculated by mass percentage: 64.5% of corundum particles, 8% of silicon carbide particles with a particle size of 0-1 mm, 5.9% of corundum fine powder with a particle size of ≤0.074 mm, 8% of silicon carbide fine powder with a particle size of ≤0.045 mm, 5% of activated alumina fine powder with a particle size of ≤0.045 mm, 3% of carbon material with a particle size of 1-2 mm, 3% of a binder with a particle size of 4-5 μm, 2% of an antioxidant with a particle size of 0.048-0.11 mm, 0.6% of an additive, and an admixture accounting for 0.15% of the total mass of the above raw materials. Wherein, the corundum is brown corundum, the binder is light-burned magnesium oxide powder, the carbon material is carbon black, the additive is aluminum lactate, and the water reducer is a polycarboxylic acid water reducer; the antioxidant is passivated metal aluminum powder, and the preparation method of the passivated metal aluminum powder is: calcining the metal aluminum powder at 500-620°C for 1-20h, and obtaining the passivated metal aluminum powder after cooling; preferably, calcining the metal aluminum powder at 580°C for 15h, and obtaining the passivated metal aluminum powder after cooling.

[0061] The corundum particles are mixed with corundum particles with a particle size of 5 to 8 mm, corundum particles with a particle size of 3 to 5 mm, corundum particles with a particle size of 1 to 3 mm, and corundum particles with a particle size of 0.1 to 1 mm in a mass ratio of 5:5:5:2.

[0062] The preparation method of the above-mentioned Al2O3-SiC-C refractory castable product is the same as that of Example 1-1.

[0063] Embodiment 2-3:

[0064] The invention discloses an Al2O3-SiC-C refractory castable product. The raw materials of the Al2O3-SiC-C refractory castable are composed of the following components, calculated by mass percentage: 64.5% of corundum particles, 8% of silicon carbide particles with a particle size of 0 to 1 mm, 3.9% of corundum fine powder with a particle size of ≤0.074 mm, 8% of silicon carbide fine powder with a particle size of ≤0.045 mm, 5% of activated alumina fine powder with a particle size of ≤0.045 mm, 3% of carbon material with a particle size of 1 to 2 mm, 3% of a binder with a particle size of 4 to 5 μm, 4% of an antioxidant with a particle size of 0.048 to 0.11 mm, 0.6% of an additive, and an admixture accounting for 0.15% of the total mass of the above raw materials. Wherein, the corundum is brown corundum, the binder is light-burned magnesium oxide powder, the carbon material is carbon black, the additive is aluminum lactate, and the water reducer is a polycarboxylic acid water reducer; the antioxidant is passivated metal aluminum powder, and the preparation method of the passivated metal aluminum powder is: calcining the metal aluminum powder at 500-620°C for 1-20h, and obtaining the passivated metal aluminum powder after cooling; preferably, calcining the metal aluminum powder at 580°C for 15h, and obtaining the passivated metal aluminum powder after cooling.

[0065] The corundum particles are mixed with corundum particles with a particle size of 5 to 8 mm, corundum particles with a particle size of 3 to 5 mm, corundum particles with a particle size of 1 to 3 mm, and corundum particles with a particle size of 0.1 to 1 mm in a mass ratio of 5:5:5:2.

[0066] The preparation method of the above-mentioned Al2O3-SiC-C refractory castable product is the same as that of Example 1-1.

[0067] Embodiment 2-4:

[0068] The invention discloses an Al2O3-SiC-C refractory castable product. The raw materials of the Al2O3-SiC-C refractory castable are composed of the following components, calculated by mass percentage: 64.5% of corundum particles, 8% of silicon carbide particles with a particle size of 1 to 0 mm, 2.9% of corundum fine powder with a particle size of ≤0.074 mm, 8% of silicon carbide fine powder with a particle size of ≤0.045 mm, 5% of activated alumina fine powder with a particle size of ≤0.045 mm, 3% of carbon material with a particle size of 1 to 2 mm, 3% of a binder with a particle size of 4 to 5 μm, 5% of an antioxidant with a particle size of 0.048 to 0.11 mm, 0.6% of an additive, and an admixture accounting for 0.15% of the total mass of the above raw materials. Wherein, the corundum is brown corundum, the binder is light-burned magnesium oxide powder, the carbon material is carbon black, the additive is aluminum lactate, and the water reducer is a polycarboxylic acid water reducer; the antioxidant is passivated metal aluminum powder, and the preparation method of the passivated metal aluminum powder is: calcining the metal aluminum powder at 500-620°C for 1-20h, and obtaining the passivated metal aluminum powder after cooling; preferably, calcining the metal aluminum powder at 580°C for 15h, and obtaining the passivated metal aluminum powder after cooling.

[0069] The corundum particles are mixed with corundum particles with a particle size of 5 to 8 mm, corundum particles with a particle size of 3 to 5 mm, corundum particles with a particle size of 1 to 3 mm, and corundum particles with a particle size of 0.1 to 1 mm in a mass ratio of 5:5:5:2.

[0070] The preparation method of the above-mentioned Al2O3-SiC-C refractory castable product is the same as that of Example 1-1.

[0071] Comparative Example 2-1:

[0072] The invention discloses an Al2O3-SiC-C refractory castable product. The raw materials of the Al2O3-SiC-C refractory castable are composed of the following components, calculated by mass percentage: 64.5% of corundum particles, 8% of silicon carbide particles with a particle size of 1 to 0 mm, 1.9% of corundum fine powder with a particle size of ≤0.074 mm, 8% of silicon carbide fine powder with a particle size of ≤0.045 mm, 5% of activated alumina fine powder with a particle size of ≤0.045 mm, 3% of carbon material with a particle size of 1 to 2 mm, 3% of a binder with a particle size of 4 to 5 μm, 6% of an antioxidant with a particle size of 0.048 to 0.11 mm, 0.6% of an additive, and an admixture accounting for 0.15% of the total mass of the above raw materials. Wherein, the corundum is brown corundum, the binder is light-burned magnesium oxide powder, the carbon material is carbon black, the additive is aluminum lactate, and the water reducer is a polycarboxylic acid water reducer; the antioxidant is passivated metal aluminum powder, and the preparation method of the passivated metal aluminum powder is: calcining the metal aluminum powder at 500-620°C for 1-20h, and obtaining the passivated metal aluminum powder after cooling; preferably, calcining the metal aluminum powder at 580°C for 15h, and obtaining the passivated metal aluminum powder after cooling.

[0073] The corundum particles are mixed with corundum particles with a particle size of 5 to 8 mm, corundum particles with a particle size of 3 to 5 mm, corundum particles with a particle size of 1 to 3 mm, and corundum particles with a particle size of 0.1 to 1 mm in a mass ratio of 5:5:5:2.

[0074] The preparation method of the above-mentioned Al2O3-SiC-C refractory castable product is the same as that of Example 1-1.

[0075] The mechanical properties of the refractory products prepared after calcining the blanks of Examples 2-1 to 2-4 and Comparative Example 2-1 were tested (the testing method was the same as that of Example 1). The test results are shown in Table 2.

[0076] Table 2 shows the mechanical properties test results of refractory castable products prepared in Examples 2-1 to 2-4 and Comparative Example 2-1

[0077]

[0078] As shown in Table 2, with the increase of the amount of antioxidant passivated aluminum powder, the erosion rate of the refractory castable product shows a trend of first decreasing and then increasing. When the content of antioxidant passivated aluminum powder reaches 3.5%, the erosion rate of the prepared refractory product reaches the lowest and the mechanical properties reach the best value; when the amount of antioxidant passivated aluminum powder is further increased, the excessive antioxidant will increase the expansion degree of the material, the erosion rate of the refractory product increases, and the mechanical properties begin to decrease. Therefore, the content of antioxidant passivated aluminum powder is preferably 1%-5%; more preferably 2%-5%, and most preferably 3.5%.

[0079] Example 3: Discussion of binder types

[0080] In order to study the effect of binder type on the performance of prepared Al2O3-SiC-C refractory castable products, the present invention carried out comparative example 3-1.

[0081] Comparative Example 3-1:

[0082] The content of Comparative Example 3-1 is the same as that of Example 1-1, except that the binder is calcium aluminate cement.

[0083] The preparation method of the above-mentioned Al2O3-SiC-C refractory castable product is the same as that of Example 1-1.

[0084] The mechanical properties of the refractory product blanks prepared in Example 1-1 and Comparative Example 3-1 after calcination were tested, and the test results are shown in Table 3.

[0085] Table 3 is the mechanical properties test results of refractory castable products prepared in Example 1-1 and Comparative Example 3-1

[0086]

[0087] As shown in Table 3, although calcium aluminate cement is used as a binder to make the castable have higher mechanical properties, calcium aluminate will introduce CaO, and during the calcination process, a CaO-Al2O3-SiO2 eutectic phase will be generated, affecting its corrosion resistance. On the contrary, lightly burned magnesium oxide as a binder can produce MgO-Al2O3-SiO2 phase with a higher melting point and higher viscosity under high temperature conditions, making the refractory castable have better oxidation resistance, corrosion resistance and permeability resistance, greatly improving the service life of the refractory castable.

[0088] Example 4: Discussion on the dosage of binder

[0089] In order to study the effect of the amount of binder on the performance of the prepared Al2O3-SiC-C refractory castable products, the present invention carried out Examples 4-1 to 4-4 and Comparative Example 4-1. The specific contents of Examples 4-1 to 4-4 and Comparative Example 4-1 are as follows:

[0090] Example 4-1:

[0091] The invention discloses an Al2O3-SiC-C refractory castable product. The raw materials of the Al2O3-SiC-C refractory castable are composed of the following components, calculated by mass percentage: 64.5% of corundum particles, 8% of silicon carbide particles with a particle size of 0-1 mm, 6.4% of corundum fine powder with a particle size of ≤0.074 mm, 8% of silicon carbide fine powder with a particle size of ≤0.045 mm, 5% of activated alumina fine powder with a particle size of ≤0.045 mm, 3% of carbon material with a particle size of 1-2 mm, 1% of a binder with a particle size of 4-5 μm, 3.5% of an antioxidant with a particle size of 0.048-0.11 mm, 0.6% of an additive, and an admixture accounting for 0.15% of the total mass of the above raw materials. Wherein, the corundum is brown corundum, the binder is light-burned magnesium oxide powder, the carbon material is carbon black, the additive is aluminum lactate, and the water reducer is a polycarboxylic acid water reducer; the antioxidant is passivated metal aluminum powder, and the preparation method of the passivated metal aluminum powder is: calcining the metal aluminum powder at 500-620°C for 1-20h, and obtaining the passivated metal aluminum powder after cooling; preferably, calcining the metal aluminum powder at 580°C for 15h, and obtaining the passivated metal aluminum powder after cooling.

[0092] The corundum particles are mixed with corundum particles with a particle size of 5 to 8 mm, corundum particles with a particle size of 3 to 5 mm, corundum particles with a particle size of 1 to 3 mm, and corundum particles with a particle size of 0.1 to 1 mm in a mass ratio of 5:5:5:2.

[0093] The preparation method of the above-mentioned Al2O3-SiC-C refractory castable product is the same as that of Example 1-1.

[0094] Example 4-2:

[0095] The invention discloses an Al2O3-SiC-C refractory castable product. The raw materials of the Al2O3-SiC-C refractory castable are composed of the following components, calculated by mass percentage: 64.5% of corundum particles, 8% of silicon carbide particles with a particle size of 0-1 mm, 2.4% of corundum fine powder with a particle size of ≤0.074 mm, 8% of silicon carbide fine powder with a particle size of ≤0.045 mm, 5% of activated alumina fine powder with a particle size of ≤0.045 mm, 3% of carbon material with a particle size of 1-2 mm, 5% of a binder with a particle size of 4-5 μm, 3.5% of an antioxidant with a particle size of 0.048-0.11 mm, 0.6% of an additive, and an admixture accounting for 0.15% of the total mass of the above raw materials. Wherein, the corundum is brown corundum, the binder is light-burned magnesium oxide powder, the carbon material is carbon black, the additive is aluminum lactate, and the water reducer is a polycarboxylic acid water reducer; the antioxidant is passivated metal aluminum powder, and the preparation method of the passivated metal aluminum powder is: calcining the metal aluminum powder at 500-620°C for 1-20h, and obtaining the passivated metal aluminum powder after cooling; preferably, calcining the metal aluminum powder at 580°C for 15h, and obtaining the passivated metal aluminum powder after cooling.

[0096] The corundum particles are mixed with corundum particles with a particle size of 5 to 8 mm, corundum particles with a particle size of 3 to 5 mm, corundum particles with a particle size of 1 to 3 mm, and corundum particles with a particle size of 0.1 to 1 mm in a mass ratio of 5:5:5:2.

[0097] The preparation method of the above-mentioned Al2O3-SiC-C refractory castable product is the same as that of Example 1-1.

[0098] Example 4-3:

[0099] The invention discloses an Al2O3-SiC-C refractory castable product. The raw materials of the Al2O3-SiC-C refractory castable are composed of the following components, calculated by mass percentage: 64.5% of corundum particles, 8% of silicon carbide particles with a particle size of 0-1 mm, 0.4% of corundum fine powder with a particle size of ≤0.074 mm, 8% of silicon carbide fine powder with a particle size of ≤0.045 mm, 5% of activated alumina fine powder with a particle size of ≤0.045 mm, 3% of carbon material with a particle size of 1-2 mm, 7% of a binder with a particle size of 4-5 μm, 3.5% of an antioxidant with a particle size of 0.048-0.11 mm, 0.6% of an additive, and an admixture accounting for 0.15% of the total mass of the above raw materials. Wherein, the corundum is brown corundum, the binder is light-burned magnesium oxide powder, the carbon material is carbon black, the additive is aluminum lactate, and the water reducer is a polycarboxylic acid water reducer; the antioxidant is passivated metal aluminum powder, and the preparation method of the passivated metal aluminum powder is: calcining the metal aluminum powder at 500-620°C for 1-20h, and obtaining the passivated metal aluminum powder after cooling; preferably, calcining the metal aluminum powder at 580°C for 15h, and obtaining the passivated metal aluminum powder after cooling.

[0100] The corundum particles are mixed with corundum particles with a particle size of 5 to 8 mm, corundum particles with a particle size of 3 to 5 mm, corundum particles with a particle size of 1 to 3 mm, and corundum particles with a particle size of 0.1 to 1 mm in a mass ratio of 5:5:5:2.

[0101] The preparation method of the above-mentioned Al2O3-SiC-C refractory castable product is the same as that of Example 1-1.

[0102] Example 4-4:

[0103] An Al2O3-SiC-C refractory castable product, wherein the raw materials of the Al2O3-SiC-C refractory castable are composed of 64.5% corundum particles, 8% silicon carbide particles with a particle size of 0 to 1 mm, 8% silicon carbide fine powder with a particle size of ≤0.045 mm, 2.4% activated alumina fine powder with a particle size of ≤0.045 mm, 3% carbon material with a particle size of 1 to 2 mm, 10% binder with a particle size of 4 to 5 μm, and 0.048 to 0.11

[0104] mm antioxidant 3.5%, additive 0.6%, plus additives accounting for 0.15% of the total mass of the above raw materials. Among them, the corundum is brown corundum, the binder is light-burned magnesium oxide powder, the carbon material is carbon black, the additive is aluminum lactate, and the water reducer is a polycarboxylic acid water reducer; the antioxidant is passivated metal aluminum powder, and the preparation method of the passivated metal aluminum powder is: calcining the metal aluminum powder at 500-620°C for 1-20h, and obtaining the passivated metal aluminum powder after cooling; preferably, calcining the metal aluminum powder at 580°C for 15h, and obtaining the passivated metal aluminum powder after cooling.

[0105] The corundum particles are mixed with corundum particles with a particle size of 5 to 8 mm, corundum particles with a particle size of 3 to 5 mm, corundum particles with a particle size of 1 to 3 mm, and corundum particles with a particle size of 0.1 to 1 mm in a mass ratio of 5:5:5:2.

[0106] The preparation method of the above-mentioned Al2O3-SiC-C refractory castable product is the same as that of Example 1-1.

[0107] Comparative Example 4-1:

[0108] The invention discloses an Al2O3-SiC-C refractory castable product. The raw materials of the Al2O3-SiC-C refractory castable are composed of the following components, calculated by mass percentage: 64.5% of corundum particles, 8% of silicon carbide particles with a particle size of 0 to 1 mm, 8% of silicon carbide fine powder with a particle size of ≤0.045 mm, 0.4% of activated alumina fine powder with a particle size of ≤0.045 mm, 3% of carbon material with a particle size of 1 to 2 mm, 12% of a binder with a particle size of 4 to 5 μm, 3.5% of an antioxidant with a particle size of 0.048 to 0.11 mm, 0.6% of an additive, and an admixture accounting for 0.15% of the total mass of the above raw materials. Wherein, the corundum is brown corundum, the binder is light-burned magnesium oxide powder, the carbon material is carbon black, the additive is aluminum lactate, and the water reducer is a polycarboxylic acid water reducer; the antioxidant is passivated metal aluminum powder, and the preparation method of the passivated metal aluminum powder is: calcining the metal aluminum powder at 500-620°C for 1-20h, and obtaining the passivated metal aluminum powder after cooling; preferably, calcining the metal aluminum powder at 580°C for 15h, and obtaining the passivated metal aluminum powder after cooling.

[0109] The preparation method of the above-mentioned Al2O3-SiC-C refractory castable product is the same as that of Example 1-1.

[0110] The mechanical properties of the refractory products prepared after calcining the blanks of Example 4-1 to Example 4-4 and Comparative Example 4-1 were tested, and the test results are shown in Table 4.

[0111] Table 4 shows the mechanical properties test results of refractory castable products prepared in Examples 4-1 to 4-4 and Comparative Example 4-1

[0112]

[0113] As can be seen from Table 4, with the increase of the amount of binder light-burned magnesium oxide powder, its anti-corrosion ability first increases and then decreases, because the addition of excessive light-burned magnesium oxide powder will cause the volume of the castable to expand significantly, reducing the density of the castable, thereby affecting its anti-corrosion performance. Therefore, the addition amount of binder light-burned magnesium oxide powder is preferably 1%-10%, more preferably 1%-7%, and most preferably 3%.

[0114] Example 5: Discussion on the amount of carbon material used

[0115] In order to study the effect of the amount of carbon material in refractory products on the performance of the prepared Al2O3-SiC-C refractory castable products, the present invention carried out Examples 5-1 to 5-4 and Comparative Example 5-1. The specific contents of Examples 5-1 to 5-4 and Comparative Example 5-1 are as follows:

[0116] Example 5-1:

[0117] The invention discloses an Al2O3-SiC-C refractory castable product. The raw materials of the Al2O3-SiC-C refractory castable are composed of the following components by weight percentage: 64.5% of corundum particles, 8% of silicon carbide particles with a particle size of 0 to 1 mm, 6.4% of corundum fine powder with a particle size of ≤0.074 mm, 8% of silicon carbide fine powder with a particle size of ≤0.045 mm, 5% of activated alumina fine powder with a particle size of ≤0.045 mm, 1% of carbon material with a particle size of 1 to 2 mm, 3% of a binder with a particle size of 4 to 5 μm, 3.5% of an antioxidant with a particle size of 0.048 to 0.11 mm, 0.6% of an additive, and an admixture accounting for 0.15% of the total weight of the above raw materials. Wherein, the corundum is brown corundum, the binder is light-burned magnesium oxide powder, the carbon material is carbon black, the additive is aluminum lactate, and the water reducer is a polycarboxylic acid water reducer; the antioxidant is passivated metal aluminum powder, and the preparation method of the passivated metal aluminum powder is: calcining the metal aluminum powder at 500-620°C for 1-20h, and obtaining the passivated metal aluminum powder after cooling; preferably, calcining the metal aluminum powder at 580°C for 15h, and obtaining the passivated metal aluminum powder after cooling.

[0118] The corundum particles are mixed with corundum particles with a particle size of 5 to 8 mm, corundum particles with a particle size of 3 to 5 mm, corundum particles with a particle size of 1 to 3 mm, and corundum particles with a particle size of 0.1 to 1 mm in a mass ratio of 5:5:5:2.

[0119] The preparation method of the above-mentioned Al2O3-SiC-C refractory castable product is the same as that of Example 1-1.

[0120] Example 5-2:

[0121] The invention discloses an Al2O3-SiC-C refractory castable product. The raw materials of the Al2O3-SiC-C refractory castable are composed of the following components, calculated by mass percentage: 64.5% of corundum particles, 8% of silicon carbide particles with a particle size of 0-1 mm, 2.4% of corundum fine powder with a particle size of ≤0.074 mm, 8% of silicon carbide fine powder with a particle size of ≤0.045 mm, 5% of activated alumina fine powder with a particle size of ≤0.045 mm, 5% of carbon material with a particle size of 1-2 mm, 3% of a binder with a particle size of 4-5 μm, 3.5% of an antioxidant with a particle size of 0.048-0.11 mm, 0.6% of an additive, and an admixture accounting for 0.15% of the total mass of the above raw materials. Wherein, the corundum is brown corundum, the binder is light-burned magnesium oxide powder, the carbon material is carbon black, the additive is aluminum lactate, and the water reducer is a polycarboxylic acid water reducer; the antioxidant is passivated metal aluminum powder, and the preparation method of the passivated metal aluminum powder is: calcining the metal aluminum powder at 500-620°C for 1-20h, and obtaining the passivated metal aluminum powder after cooling; preferably, calcining the metal aluminum powder at 580°C for 15h, and obtaining the passivated metal aluminum powder after cooling.

[0122] The corundum particles are mixed with corundum particles with a particle size of 5 to 8 mm, corundum particles with a particle size of 3 to 5 mm, corundum particles with a particle size of 1 to 3 mm, and corundum particles with a particle size of 0.1 to 1 mm in a mass ratio of 5:5:5:2.

[0123] The preparation method of the above-mentioned Al2O3-SiC-C refractory castable product is the same as that of Example 1-1.

[0124] Example 5-3:

[0125] The invention discloses an Al2O3-SiC-C refractory castable product. The raw materials of the Al2O3-SiC-C refractory castable are composed of the following components, calculated by mass percentage: 64.5% of corundum particles, 8% of silicon carbide particles with a particle size of 0-1 mm, 0.4% of corundum fine powder with a particle size of ≤0.074 mm, 8% of silicon carbide fine powder with a particle size of ≤0.045 mm, 5% of activated alumina fine powder with a particle size of ≤0.045 mm, 7% of carbon material with a particle size of 1-2 mm, 3% of a binder with a particle size of 4-5 μm, 3.5% of an antioxidant with a particle size of 0.048-0.11 mm, 0.6% of an additive, and an admixture accounting for 0.15% of the total mass of the above raw materials. Wherein, the corundum is brown corundum, the binder is light-burned magnesium oxide powder, the carbon material is carbon black, the additive is aluminum lactate, and the water reducer is a polycarboxylic acid water reducer; the antioxidant is passivated metal aluminum powder, and the preparation method of the passivated metal aluminum powder is: calcining the metal aluminum powder at 500-620°C for 1-20h, and obtaining the passivated metal aluminum powder after cooling; preferably, calcining the metal aluminum powder at 580°C for 15h, and obtaining the passivated metal aluminum powder after cooling.

[0126] The corundum particles are mixed with corundum particles with a particle size of 5 to 8 mm, corundum particles with a particle size of 3 to 5 mm, corundum particles with a particle size of 1 to 3 mm, and corundum particles with a particle size of 0.1 to 1 mm in a mass ratio of 5:5:5:2.

[0127] The preparation method of the above-mentioned Al2O3-SiC-C refractory castable product is the same as that of Example 1-1.

[0128] Example 5-4:

[0129] The invention discloses an Al2O3-SiC-C refractory castable product. The raw materials of the Al2O3-SiC-C refractory castable are composed of the following components, calculated by mass percentage: 64.5% of corundum particles, 8% of silicon carbide particles with a particle size of 0 to 1 mm, 8% of silicon carbide fine powder with a particle size of ≤0.045 mm, 2.4% of activated alumina fine powder with a particle size of ≤0.045 mm, 10% of carbon material with a particle size of 1 to 2 mm, 3% of a binder with a particle size of 4 to 5 μm, 3.5% of an antioxidant with a particle size of 0.048 to 0.11 mm, 0.6% of an additive, and an admixture accounting for 0.15% of the total mass of the above raw materials. Wherein, the corundum is brown corundum, the binder is light-burned magnesium oxide powder, the carbon material is carbon black, the additive is aluminum lactate, and the water reducer is a polycarboxylic acid water reducer; the antioxidant is passivated metal aluminum powder, and the preparation method of the passivated metal aluminum powder is: calcining the metal aluminum powder at 500-620°C for 1-20h, and obtaining the passivated metal aluminum powder after cooling; preferably, calcining the metal aluminum powder at 580°C for 15h, and obtaining the passivated metal aluminum powder after cooling.

[0130] The corundum particles are mixed with corundum particles with a particle size of 5 to 8 mm, corundum particles with a particle size of 3 to 5 mm, corundum particles with a particle size of 1 to 3 mm, and corundum particles with a particle size of 0.1 to 1 mm in a mass ratio of 5:5:5:2.

[0131] The preparation method of the above-mentioned Al2O3-SiC-C refractory castable product is the same as that of Example 1-1.

[0132] Comparative Example 5-1:

[0133] The invention discloses an Al2O3-SiC-C refractory castable product. The raw materials of the Al2O3-SiC-C refractory castable are composed of the following components, calculated by mass percentage: 64.5% of corundum particles, 8% of silicon carbide particles with a particle size of 0-1 mm, 7.4% of corundum fine powder with a particle size of ≤0.074 mm, 8% of silicon carbide fine powder with a particle size of ≤0.045 mm, 5% of activated alumina fine powder with a particle size of ≤0.045 mm, 0% of carbon material with a particle size of 1-2 mm, 3% of a binder with a particle size of 4-5 μm, 3.5% of an antioxidant with a particle size of 0.048-0.11 mm, 0.6% of an additive, and an admixture accounting for 0.15% of the total mass of the above raw materials.

[0134] Wherein, the corundum is brown corundum, the binder is light-burned magnesium oxide powder, the carbon material is carbon black, the additive is aluminum lactate, and the water reducer is a polycarboxylic acid water reducer; the antioxidant is passivated metal aluminum powder, and the preparation method of the passivated metal aluminum powder is: calcining the metal aluminum powder at 500-620°C for 1-20h, and obtaining the passivated metal aluminum powder after cooling; preferably, calcining the metal aluminum powder at 580°C for 15h, and obtaining the passivated metal aluminum powder after cooling.

[0135] The corundum particles are mixed with corundum particles with a particle size of 5 to 8 mm, corundum particles with a particle size of 3 to 5 mm, corundum particles with a particle size of 1 to 3 mm, and corundum particles with a particle size of 0.1 to 1 mm in a mass ratio of 5:5:5:2.

[0136] The preparation method of the above-mentioned Al2O3-SiC-C refractory castable product is the same as that of Example 1-1.

[0137] The mechanical properties of the refractory product blanks prepared in Examples 5-1 to 5-4 and Comparative Example 5-1 after calcination were tested, and the test results are shown in Table 5.

[0138] Table 5 shows the mechanical properties test results of refractory castable products prepared in Examples 5-1 to 5-4 and Comparative Example 5-1

[0139]

[0140] As shown in Table 5, adding carbon material can improve the room temperature and high temperature mechanical properties and slag erosion resistance of the castable. With the increase of the amount of carbon material added, the room temperature and high temperature mechanical properties and slag erosion resistance of the castable first increase and then decrease. Due to the poor wettability of carbon material itself, adding excessive carbon material will make it difficult to form the castable and affect its operating performance; in addition, during use, carbon will penetrate into the molten iron and reduce the purity of the iron. Therefore, the optimal addition amount of carbon material is preferably 3%.

[0141] Example 6: Discussion of Calcination Gas Atmosphere

[0142] In order to study the influence of the calcining gas atmosphere of refractory products on the performance of the prepared Al2O3-SiC-C refractory castable products, the present invention carried out Comparative Example 6-1 and Comparative Example 6-2.

[0143] Comparative Example 6-1:

[0144] The content of Comparative Example 6-1 is substantially the same as that of Example 1-1, except that the preparation method of the silicon carbide-magnesium aluminum spinel refractory product is different.

[0145] The preparation method of the Al2O3-SiC-C refractory castable product in this embodiment comprises the following specific steps:

[0146] (1) mixing corundum particles, silicon carbide particles, corundum fine powder, silicon carbide fine powder, activated alumina fine powder, carbonaceous fine powder, a binder, an antioxidant, an additive and an admixture to obtain a mixture;

[0147] (2) adding water to the mixture prepared in step (1), wherein the amount of water added is 4% of the total mass of the mixture, and stirring and mixing the mixture to obtain a wet mixture;

[0148] (3) The wet mixed material is poured, cured, and dried to obtain a blank, and the blank is calcined at 1350° C. in an air atmosphere for 3 hours to obtain a refractory castable product.

[0149] The mechanical properties of the refractory product blank prepared in Comparative Example 6-1 after calcination were tested, and the test results are shown in Table 6.

[0150] Table 6 is the mechanical properties test results of refractory castable products prepared in Example 1-1 and Comparative Example 6-1

[0151]

[0152] It can be seen from Table 6 that the samples fired in a carbon-buried atmosphere have better physical properties and slag erosion resistance than those fired in an air atmosphere. This is because in an air atmosphere, the carbon material undergoes an oxidation reaction to produce gas and form pores, which increases the apparent porosity of the material, thereby reducing the physical properties of the castable. At the same time, slag is more likely to enter the interior of the material, causing the castable to peel off during use, seriously affecting its service life. In a carbon-buried atmosphere, the carbon powder covering the surface of the material is preferentially oxidized, effectively reducing the oxidation of the antioxidant in the material during the sintering process, thereby increasing the service life of the castable.

[0153] Finally, it should be noted that the above embodiments are only preferred embodiments of the present invention, and are not intended to limit the present invention in other forms. Any technician familiar with the profession may use the above technical content as inspiration to make changes or modifications. This is an equivalent embodiment of equivalent changes. However, any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the technical concept of the present invention still fall within the scope of protection of the claims of the present invention.

Claims

1. An Al2O3-SiC-C refractory castable product, characterized in that: Calculated by weight percentage, the raw material composition of the Al2O3-SiC-C refractory castable is: 50% to 85% aggregate, 6% to 35% matrix, 1% to 10% binder, 1% to 5% antioxidant, 0.2% to 2% additive, plus 0.1% to 1% of the total weight of the above raw materials; the binder is lightly burned magnesium oxide powder.

2. The Al2O3-SiC-C refractory castable product according to claim 1, characterized in that: The antioxidant is passivated metal aluminum powder.

3. The Al2O3-SiC-C refractory castable product according to claim 2, characterized in that: The preparation method of the passivated metal aluminum powder is as follows: calcining the metal aluminum powder at 500-620° C. for 1-20 hours, and obtaining the passivated metal aluminum powder after cooling.

4. The Al2O3-SiC-C refractory castable product according to any one of claims 1 to 3, characterized in that: The aggregate is at least one of corundum particles and silicon carbide particles, and the matrix is ​​at least one of corundum fine powder, silicon carbide fine powder, activated alumina powder, and carbon material.

5. The Al2O3-SiC-C refractory castable product according to claim 4, characterized in that: The additive is lactate; the carbon material is asphalt, graphite or carbon black; and the admixture is a water reducing agent.

6. The Al2O3-SiC-C refractory castable product according to claim 5, characterized in that: The lactate is at least one of aluminum lactate, magnesium lactate, zinc lactate and nickel lactate; the particle size of the carbon material is 1 to 2 mm; and the water reducer is a polycarboxylic acid water reducer or a naphthalene-based water reducer.

7. The Al2O3-SiC-C refractory castable product according to claim 6, characterized in that: Calculated by weight percentage, the raw material composition of the Al2O3-SiC-C refractory castable is: 50% to 70% corundum particles, 1% to 15% silicon carbide particles, 1% to 10% corundum fine powder, 1% to 10% silicon carbide fine powder, 3% to 5% activated alumina powder, 1% to 10% carbon material, 1% to 10% binder, 1% to 5% antioxidant, 0.2% to 2% additives, plus 0.1% to 1% of the total weight of the above raw materials; the binder is lightly burned magnesium oxide powder.

8. The Al2O3-SiC-C refractory castable product according to claim 7, characterized in that: The corundum particles are mixed with corundum particles with a particle size of 5 to 8 mm, corundum particles with a particle size of 3 to 5 mm, corundum particles with a particle size of 1 to 3 mm, and corundum particles with a particle size of 0.1 to 1 mm in a mass ratio of 5:5:5:

2.

9. A method for preparing the Al2O3-SiC-C refractory castable product according to any one of claims 1 to 8, characterized in that: The following steps are involved: (1) Aggregates, matrix, binder, antioxidant, additives and admixtures are uniformly mixed to obtain a mixture; (2) adding water to the mixture prepared in step (1), stirring and mixing uniformly to obtain a wet mixture; (3) Casting, curing and drying the wet mixed material to obtain a blank; calcining the blank at 1150° C. to 1450° C. for 1 to 10 hours in a carbon-buried atmosphere to obtain a refractory castable product.

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