Aluminum-zirconium-carbon refractory brick, its preparation method and application

Abstract

The present application relates to a kind of aluminum zirconium carbon refractory bricks and its preparation method and application.The existing blast furnace iron notch skimmer part usually uses Al2O3-SiC-C castable, there are high porosity, low high-temperature strength, insufficient problems such as erosion resistance and thermal shock stability, the present application is mainly corundum aggregate, zirconia corundum is fine aggregate, with zirconia corundum fine powder, alumina powder, silicon carbide fine powder, graphite fine powder, antioxidant as matrix, and introduce nano oxide additive, with phenolic resin, resin powder as binder, compacted into high density, low porosity aluminum zirconium carbon refractory brick.Zirconia corundum aggregate and fine powder improve the resistance of material to slag erosion;Nano oxide further reduces porosity, refines pore size and improves material density, thereby enhancing its high-temperature strength and erosion resistance performance.At the same time, the fine pore structure is beneficial to improve the local CO and SiO gas concentration and partial pressure, promote in-situ SiC whisker generation, form reinforced toughened structure, further improve the thermal shock resistance and erosion resistance.

Description

Technical Field

[0001] This invention relates to the field of refractory materials technology, specifically to an aluminum zirconium carbon refractory brick, its preparation method, and its application. Background Technology

[0002] The slag skimmer in the blast furnace tapping trough is a key functional component of the blast furnace ironmaking system. It is typically located between the main tapping trough and the branch and slag troughs, primarily used to effectively separate molten iron from slag and ensure the smooth flow of molten iron into subsequent channels. During operation, the skimmer is exposed to temperatures exceeding 1500℃, enduring repeated scouring and impact from the high-temperature molten iron, as well as chemical corrosion from the slag; its operating conditions are extremely harsh. Therefore, the performance of the refractory material used in the skimmer directly affects the operational stability of the tapping trough system and the continuous production efficiency of the blast furnace.

[0003] Currently, the working layer of the slag skimmer in the blast furnace tapping trough mainly uses Al2O3-SiC-C castable. While this type of castable, typically using aluminate cement as a binder, offers advantages such as convenient construction and good overall integrity, it still has significant shortcomings during long-term high-temperature service. On one hand, the castable has high porosity and strong pore connectivity, allowing slag and oxidizing components such as FeO and MnO to easily penetrate into the material's interior along the pores, reacting with the carbon phase and SiC, resulting in a loose material structure and reduced strength. On the other hand, the aluminate cement binder contains CaO, which readily reacts with slag under high-temperature molten slag conditions, generating low-melting-point phases or promoting slag penetration, further reducing the material's erosion resistance. Furthermore, the skimmer area is subjected to repeated scouring by molten iron and slag over a long period, making the interface between the castable aggregate and matrix prone to cracking and spalling, accelerating localized damage and limiting its service life.

[0004] Meanwhile, traditional castable refractory materials typically require on-site mixing, pouring, curing, and baking during construction, resulting in a long construction cycle and high requirements for on-site operating conditions. When local damage occurs to the skimmer, large-scale dismantling and repair are often necessary, making the maintenance process complex and affecting the continuous and stable operation of the blast furnace. With the increasing demands for larger, longer-lasting, and more efficient blast furnaces, existing Al2O3-SiC-C castable refractory materials are no longer sufficient to meet the requirements for erosion resistance, corrosion resistance, and thermal shock stability of the skimmer components. Therefore, developing a refractory material suitable for the skimmer operation in the blast furnace taphole and capable of replacing traditional Al2O3-SiC-C castable refractory materials is of significant engineering importance for improving the service life of the skimmer, shortening the maintenance cycle, reducing maintenance costs, and ensuring the safe, stable, and efficient operation of the blast furnace. Summary of the Invention

[0005] To address the problems of high porosity, low high-temperature strength, poor erosion and erosion resistance, insufficient thermal shock stability, long construction period, and difficult local maintenance associated with existing Al2O3-SiC-C castables used in blast furnace tapping trough skimmers, this invention aims to provide an alumina-zirconium-carbon refractory brick, its preparation method, and its application. This refractory brick features high density, low porosity, good erosion resistance, strong slag erosion resistance, and excellent thermal shock stability, effectively reducing refractory material consumption, extending the service life of the skimmer, and improving the blast furnace's iron-passing capacity.

[0006] The present invention provides an alumina-zirconium-carbon refractory brick, comprising aggregate, matrix, and additives. The aggregate includes corundum aggregate and zirconium-corundum aggregate. The matrix includes fine zirconium-corundum powder, alumina micro powder, silicon carbide fine powder, graphite fine powder, and antioxidant. The additives include nano-oxides.

[0007] Furthermore, by mass percentage, corundum aggregate accounts for 55-65%, zirconium corundum aggregate accounts for 10-20%, zirconium corundum fine powder accounts for 5-10%, alumina micro powder accounts for 4-10%, silicon carbide fine powder accounts for 2-5%, graphite fine powder accounts for 1-5%, antioxidant accounts for 3-6%, and nano oxides account for 0.5-3%.

[0008] Furthermore, the corundum aggregate is selected from one or more of fused alumina, sintered alumina, tabular alumina, or brown alumina, and adopts multi-level particle size distribution, with the following particle size distributions: 8-5mm corundum aggregate accounts for 35-45% of the total mass of corundum aggregate, 5-3mm corundum aggregate accounts for 35-45% of the total mass of corundum aggregate, 3-1mm corundum aggregate accounts for 5-15% of the total mass of corundum aggregate, and 1-0mm corundum aggregate accounts for 5-15% of the total mass of corundum aggregate.

[0009] Furthermore, in the zirconium corundum aggregate, the percentage of zirconium corundum aggregate with a particle size of 3-1 mm is 50-60% of the total mass of zirconium corundum aggregate, and the percentage of zirconium corundum aggregate with a particle size of 1-0 mm is 40-50% of the total mass of zirconium corundum aggregate.

[0010] Furthermore, the composition of the zirconium corundum aggregate and the zirconium corundum fine powder is: Al2O3 accounts for 67wt% and ZrO2 accounts for 33wt%.

[0011] Furthermore, the particle size of the zirconium corundum fine powder is ≤74μm, the particle size of the graphite fine powder is ≤200μm, the particle size of the alumina micro powder is ≤10μm, and the particle size of the silicon carbide fine powder is ≤200μm.

[0012] Furthermore, the antioxidant is one or more of aluminum powder, silicon powder, and boron carbide powder, wherein the particle size of aluminum powder is ≤74μm, the particle size of silicon powder is ≤100μm, and the particle size of boron carbide powder is ≤74μm.

[0013] Furthermore, the nano-oxide is one or more of nano-alumina, nano-zirconia, and nano-titanium oxide, wherein the nano-alumina particle size is ≤50nm, the nano-zirconia particle size is ≤60nm, and the nano-titanium oxide particle size is ≤60nm.

[0014] The present invention also provides a method for preparing the above-mentioned alumina-zirconium-carbon refractory brick, specifically including the following steps: (1) Add the binder to anhydrous ethanol and mix and stir until homogeneous. Then add the nano oxide and mix until homogeneous to obtain a binder solution containing nano oxide. (2) Weigh out corundum aggregate and zirconium corundum aggregate according to the proportion, add 30-40wt% of the binder solution obtained in step (1) (i.e., add 30-40wt% of the binder solution), mix for 10-15 min to obtain premixed aggregate; weigh out each matrix fine powder according to the proportion, mix for 15-20 min to obtain premixed matrix material; then add the above premixed aggregate to the premixed matrix material, add the remaining binder solution, continue mixing for 20-30 min to obtain a uniform mixture; (3) The mixture is pressed into a blank by liquid molding or isostatic pressing; (4) The formed blank is heat-treated in stages for drying and curing.

[0015] Furthermore, in step (1), the mass ratio of the binder to anhydrous ethanol is 1:1.

[0016] Furthermore, the binder mentioned in step (1) is one or more of phenolic resin and resin powder, and the amount of binder added is 3-5 wt% (that is, the percentage of the amount of binder added to the total mass of the raw materials is 3-5%).

[0017] Furthermore, the molding pressure in step (3) is 100-200 MPa.

[0018] Furthermore, the phased heat treatment in step (4) specifically involves first holding the temperature at 100-120℃ for 6-12 hours, and then holding it at 180-220℃ for 6-12 hours.

[0019] The aluminum zirconium carbon refractory brick of the present invention is used as the working layer material of the slag skimmer in the tapping trough of a blast furnace.

[0020] The introduction of zirconium corundum aggregate and fine powder improves the material's resistance to slag erosion; nano-oxide additives can further reduce porosity, refine pore size and improve material density, thereby enhancing its high-temperature strength and erosion resistance.

[0021] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention uses phenolic resin or resin powder as a binder to replace the aluminate cement binder in the traditional Al2O3-SiC-C castable, thus avoiding the problem that the CaO component in the cement binder reacts with the slag at high temperature to generate a low melting point phase and reduce the material’s resistance to erosion, thereby improving the slag erosion resistance of refractory bricks.

[0022] (2) The present invention adopts a pressing molding process and combines zirconium corundum aggregate, zirconium corundum fine powder and nano oxide additives to make the refractory bricks have high density and low porosity, which can effectively reduce the penetration of slag into the material and improve the high temperature strength, erosion resistance and corrosion resistance of the material.

[0023] (3) The present invention introduces zirconium corundum aggregate and zirconium corundum fine powder, which can improve the resistance of refractory bricks to multi-element slags such as CaO-SiO2-Al2O3-MgO-FeO, slow down slag erosion and material structure deterioration, thereby extending the service life of skimmer.

[0024] (4) The present invention introduces nano-oxide additives, which can fill the micropores in the matrix, promote the densification of the material and refine the pore size; at the same time, the refined pore structure is conducive to increasing the local CO and SiO gas concentration and partial pressure, promoting the in-situ generation of SiC whiskers, forming an interlaced reinforcement network, thereby improving the high temperature strength and thermal shock stability of the material.

[0025] (5) The refractory bricks of the present invention can be directly used for masonry without the need for complex processes such as on-site mixing, pouring, curing and baking of traditional castables, and the construction cycle is short; when local damage occurs, it is easy to quickly replace and maintain, which helps to reduce maintenance costs and ensure the continuous and stable operation of the blast furnace. Detailed Implementation

[0026] To better understand the content of this invention, specific embodiments will be used to further illustrate the invention below. The following embodiments are based on the technology of this invention and provide detailed implementation methods and operating steps; however, the scope of protection of this invention is not limited to the following embodiments.

[0027] The performance testing procedures in the following examples and comparative examples are consistent, and are all conducted in accordance with national standards GB / T 2997-2015, GB / T 3001-2007, GB / T 3002-2007 and GB / T 30873-2014, testing the bulk density, apparent porosity, room temperature flexural strength, high temperature flexural strength and thermal shock resistance of the samples. A rotary slag resistance test was used to evaluate the slag resistance of the samples, using blast furnace slag as the slag source, and the test conditions were erosion at 1500℃ for 3 hours.

[0028] In the following examples and comparative examples, the composition of the zirconium corundum aggregate and zirconium corundum fine powder is as follows: Al2O3 accounts for 67wt%, and ZrO2 accounts for 33wt%; the particle size of the zirconium corundum fine powder is ≤74μm, the particle size of the graphite fine powder is ≤200μm, the particle size of the alumina micro powder is ≤10μm, and the particle size of the silicon carbide fine powder is ≤200μm; in the antioxidant, the particle size of the aluminum powder is ≤74μm, the particle size of the silicon powder is ≤100μm, and the particle size of the boron carbide powder is ≤74μm; the particle size of the nano alumina is ≤50nm, and the particle size of the nano zirconium oxide is ≤60nm.

[0029] Example 1: A type of alumina-zirconium-carbon refractory brick for a blast furnace tapping trough skimmer has the following raw material composition (by mass percentage): 55% tabular corundum aggregate (of which 8-5mm tabular corundum aggregate accounts for 40% of the total mass of tabular corundum aggregate, 5-3mm tabular corundum aggregate accounts for 40% of the total mass of tabular corundum aggregate, 3-1mm tabular corundum aggregate accounts for 10% of the total mass of tabular corundum aggregate, and 1-0mm tabular corundum aggregate accounts for 10% of the total mass of tabular corundum aggregate). The composition includes: 10% tabular corundum aggregate (10% of the total mass of tabular corundum aggregate), 20% zirconium corundum aggregate (3-1mm particle size zirconium corundum aggregate accounts for 50% of the total mass of zirconium corundum aggregate, and 1-0mm particle size zirconium corundum aggregate accounts for 50% of the total mass of zirconium corundum aggregate), 8% zirconium corundum fine powder, 5% alumina micro powder, 3% SiC fine powder, 3% flake graphite, 3% aluminum powder, 1% silicon powder, 1% boron carbide powder, and 1% nano-zirconia powder. Phenolic resin liquid and phenolic resin powder are added as binders, with the phenolic resin liquid added at 1.5% (i.e., the mass of the phenolic resin liquid accounts for 1.5% of the total mass of the above raw materials), and the phenolic resin powder added at 2% (i.e., the mass of the phenolic resin powder accounts for 2% of the total mass of the above raw materials).

[0030] The preparation method is as follows: (1) Mix the binder (i.e., phenolic resin liquid and resin powder) with anhydrous ethanol at a mass ratio of 1:1 and stir for 10 min. Then add nano-zirconia powder and mix and stir for 10 min to obtain a binder solution containing nano-zirconia. (2) Mix the tabular corundum aggregate, zirconium corundum aggregate and 30wt% binder solution obtained in step (1) for 10 min to form a premixed aggregate; mix the zirconium corundum fine powder, alumina micro powder, SiC fine powder, flake graphite, aluminum powder, silicon powder and boron carbide powder for 15 min to form a premixed matrix material; then add the above premixed aggregate to the premixed matrix material, and add the remaining 70wt% binder solution and continue mixing for 20 min to obtain a uniform mixture. (3) The mixture is pressed into shape at 120 MPa using isostatic pressing. (4) The shaped brick blanks are first dried at 120℃ for 6 hours and then dried at 200℃ for 12 hours.

[0031] The resulting alumina-zirconium-carbon refractory bricks were heat-treated at 1500℃ for 3 hours under carbon-embedded conditions, and their performance was tested according to national standards. Their key properties are as follows: apparent porosity 7.5%, bulk density 3.23 g / cm³. 3 The flexural strength at room temperature is 49.7 MPa, and the flexural strength at high temperature is 42.6 MPa. After three water-cooled thermal shock cycles at 1100℃, the flexural strength retention rate is 88.2%, and the eroded layer thickness is 1.1 mm. (The last sentence appears to be incomplete and possibly refers to a 1200m...) 3 Application verification of blast furnace tapping trough skimmer shows that, compared with the traditional Al2O3-SiC-C castable, material consumption is reduced by 82% and iron throughput is increased by 69%.

[0032] Example 2: A type of alumina-zirconium-carbon refractory brick for a blast furnace tapping trough skimmer has the following raw material composition (by mass percentage): 60% tabular corundum aggregate (of which 8-5mm size tabular corundum aggregate accounts for 35% of the total mass of tabular corundum aggregate, 5-3mm size tabular corundum aggregate accounts for 35% of the total mass of tabular corundum aggregate, 3-1mm size tabular corundum aggregate accounts for 15% of the total mass of tabular corundum aggregate, and 1-0mm size tabular corundum aggregate... The composition includes: 15% of tabular corundum aggregate, 15% zirconium corundum aggregate (3-1mm particle size zirconium corundum aggregate accounts for 60% of the total zirconium corundum aggregate mass, and 1-0mm particle size zirconium corundum aggregate accounts for 40% of the total zirconium corundum aggregate mass), 6% zirconium corundum fine powder, 5% alumina micro powder, 3% SiC fine powder, 3% flake graphite, 3% aluminum powder, 2% silicon powder, 1% boron carbide powder, 1% nano-zirconia powder, and 1% nano-alumina powder. Phenolic resin liquid and phenolic resin powder are added as binders, with the amount of phenolic resin liquid added being 1.5% and the amount of phenolic resin powder added being 2%.

[0033] The preparation method is as follows: (1) Mix the binder (i.e., phenolic resin liquid and resin powder) with anhydrous ethanol at a mass ratio of 1:1 and stir for 10 min. Then add nano zirconium oxide powder and nano alumina powder and mix and stir for 10 min to obtain a binder solution containing nano zirconium oxide and nano alumina. (2) Mix the tabular corundum aggregate, zirconium corundum aggregate and 30wt% of the binder solution obtained in step (1) for 15 min to form a premixed aggregate; mix the zirconium corundum fine powder, alumina micro powder, silicon carbide fine powder, flake graphite, aluminum powder, silicon powder and boron carbide powder for 15 min to form a premixed matrix material; then add the above premixed aggregate to the premixed matrix material, and add the remaining 70wt% binder solution and continue mixing for 30 min to obtain a uniform mixture. (3) The mixture is pressed into shape at 150 MPa using isostatic pressing. (4) Dry the shaped brick blanks at 120℃ for 12 hours and then at 200℃ for 12 hours.

[0034] The resulting alumina-zirconium-carbon refractory bricks were heat-treated at 1500℃ for 3 hours under carbon-embedded conditions, and their performance was tested according to national standards. Their key properties are as follows: apparent porosity 7.1%, bulk density 3.28 g / cm³. 3 The flexural strength at room temperature is 53.7 MPa, and the flexural strength at high temperature is 44.1 MPa. After three water-cooled thermal shock cycles at 1100℃, the flexural strength retention rate is 86.4%, and the eroded layer thickness is 0.9 mm. (This is followed by a seemingly unrelated sentence about a 2000m...) 3 Application verification of blast furnace tapping trough skimmer shows that, compared with the traditional Al2O3-SiC-C castable, material consumption is reduced by 90% and iron throughput is increased by 75%.

[0035] Example 3: A type of alumina-zirconium-carbon refractory brick for a blast furnace tapping trough skimmer has the following raw material composition (by mass percentage): 65% tabular corundum aggregate (of which 8-5mm tabular corundum aggregate accounts for 35% of the total mass of tabular corundum aggregate, 5-3mm tabular corundum aggregate accounts for 35% of the total mass of tabular corundum aggregate, 3-1mm tabular corundum aggregate accounts for 15% of the total mass of tabular corundum aggregate, and 1-0mm tabular corundum aggregate accounts for 15% of the total mass of tabular corundum aggregate). The composition comprises 15% alumina aggregate, 10% zirconium corundum aggregate (3-1mm particle size zirconium corundum aggregate accounts for 50% of the total zirconium corundum aggregate mass, and 1-0mm particle size zirconium corundum aggregate accounts for 50% of the total zirconium corundum aggregate mass), 10% zirconium corundum fine powder, 4% alumina micro powder, 2% SiC fine powder, 3% flake graphite, 2.5% aluminum powder, 1.5% silicon powder, 0.5% boron carbide powder, 1% nano-zirconia powder, and 0.5% nano-alumina powder. Phenolic resin liquid and resin powder are added as binders, with 1.5% phenolic resin liquid and 2% resin powder added.

[0036] The preparation method is as follows: (1) Mix the binder (i.e., phenolic resin liquid and resin powder) with anhydrous ethanol at a mass ratio of 1:1 and stir for 10 min. Then add nano zirconium oxide powder and nano alumina powder and mix and stir for 10 min to obtain a binder solution containing nano zirconium oxide and nano alumina. (2) Mix the tabular corundum aggregate, zirconium corundum aggregate and 30wt% of the binder solution obtained in step (1) for 15 min to form a premixed aggregate; mix the zirconium corundum fine powder, alumina micro powder, SiC fine powder, flake graphite, aluminum powder, silicon powder and boron carbide powder for 25 min to form a premixed matrix material; then add the above premixed aggregate to the premixed matrix material, and add the remaining 70wt% binder solution and continue mixing for 30 min to obtain a uniform mixture. (3) The mixture is pressed into shape at 180 MPa using isostatic pressing. (4) Dry the shaped brick blanks at 120℃ for 12 hours and then at 220℃ for 12 hours.

[0037] The resulting alumina-zirconium-carbon refractory bricks were heat-treated at 1500℃ for 3 hours under carbon-embedded conditions, and their performance was tested according to national standards. Their key properties are as follows: apparent porosity 6.5%, bulk density 3.32 g / cm³. 3 The flexural strength at room temperature is 58.4 MPa, and the flexural strength at high temperature is 47.3 MPa. After three water-cooled thermal shock cycles at 1100℃, the flexural strength retention rate is 85.1%, and the eroded layer thickness is 0.7 mm. (The last sentence appears to be incomplete and possibly refers to a 2000m...) 3 Application verification of blast furnace tapping trough skimmer shows that, compared with the traditional Al2O3-SiC-C castable, material consumption is reduced by 95% and iron throughput is increased by 82%.

[0038] Comparative Example 1: To compare the performance of the aluminum zirconium carbon refractory brick of the present invention, the Al2O3-SiC-C castable currently used in the blast furnace tapping trough skimmer was selected as the material for this comparative example. By mass percentage, the main raw materials of this Al2O3-SiC-C castable include 60% brown fused alumina aggregate (of which, brown fused alumina particles with a diameter of 8-5 mm account for 35% of the mass of brown fused alumina aggregate, brown fused alumina particles with a diameter of 5-3 mm account for 35% of the mass of brown fused alumina aggregate, brown fused alumina particles with a diameter of 3-1 mm account for 20% of the mass of brown fused alumina aggregate, and brown fused alumina particles with a diameter of less than 1 mm account for 10% of the mass of brown fused alumina aggregate), 6% fine brown fused alumina powder (particle size ≤74 μm), 10% SiC aggregate (of which, SiC particles with a diameter of 3-1 mm and SiC particles with a diameter of less than 1 mm each account for 50% of the mass of SiC aggregate), 6% fine SiC powder (particle size ≤100 μm), and 5% alumina micro powder (particle size ≤100 μm). The mixture comprises: 3% silica powder (particle size ≤ 1 μm), 2.5% graphite (particle size ≤ 200 μm), 1% spherical asphalt (particle size 0.2-1 mm), 3% silica powder (particle size ≤ 74 μm), 0.5% aluminum powder (particle size ≤ 100 μm), and 3% aluminate cement binder. Water is added and stirred, with the water amounting to 5% of the total mass of the raw materials. After mixing, the mixture is vibrated and cast into molds, naturally cured for 24 hours, and then dried at 110℃ for 24 hours.

[0039] The obtained Al2O3-SiC-C castable was heat-treated at 1500℃ for 3 hours under carbon embedding conditions, and its performance was tested according to national standards. Its key properties are as follows: bulk density is 2.61 g / cm³. 3 The apparent porosity is 15.3%, the flexural strength at room temperature is 14.3 MPa, the flexural strength at high temperature is 9.6 MPa, and after three water-cooled thermal shocks at 1100℃, the flexural strength retention rate is 36.3%, and the thickness of the eroded layer is 5.4 mm.

[0040] As can be seen from the above embodiments and comparative examples, compared with existing Al2O3-SiC-C castables, the alumina-zirconium-carbon refractory bricks for the blast furnace tapping trough skimmer of the present invention have advantages such as high density, low porosity, high high-temperature strength, and good thermal shock stability. Under the same slag composition and heat treatment conditions, the refractory bricks of the present invention have a smaller erosion depth and are less prone to slag erosion, structural spalling, and local damage during service. This can effectively reduce the consumption of refractory materials in the blast furnace tapping trough skimmer section, extend the service life of the skimmer, and increase the blast furnace iron throughput.

[0041] The above description is merely an embodiment of the present invention and is not intended to limit the present invention in any way. The present invention can also have other embodiments based on the above structure and function, which will not be listed hereafter. Therefore, any simple modifications, equivalent changes, and alterations made by those skilled in the art to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. An alumina-zirconium-carbon refractory brick, characterized in that, It includes aggregates, matrix, and additives. The aggregates include corundum aggregates and zirconium corundum aggregates. The matrix includes zirconium corundum fine powder, alumina micro powder, silicon carbide fine powder, graphite fine powder, and antioxidants. The additives include nano-oxides.

2. The alumina-zirconium-carbon refractory brick as described in claim 1, characterized in that, By weight percentage, corundum aggregate accounts for 55-65%, zirconium corundum aggregate accounts for 10-20%, zirconium corundum fine powder accounts for 5-10%, alumina micro powder accounts for 4-10%, silicon carbide fine powder accounts for 2-5%, graphite fine powder accounts for 1-5%, antioxidant accounts for 3-6%, and nano oxides account for 0.5-3%.

3. The alumina-zirconium-carbon refractory brick as described in claim 1, characterized in that, The corundum aggregate is selected from one or more of fused alumina, sintered alumina, tabular alumina, or brown alumina, and adopts multi-stage particle size distribution. The percentage of corundum aggregate with a particle size distribution of 8-5mm is 35-45% of the total mass of corundum aggregate, 5-3mm corundum aggregate is 35-45% of the total mass of corundum aggregate, 3-1mm corundum aggregate is 5-15% of the total mass of corundum aggregate, and 1-0mm corundum aggregate is 5-15% of the total mass of corundum aggregate.

4. The alumina-zirconium-carbon refractory brick as described in claim 1, characterized in that, In the zirconium-alumina aggregate, zirconium-alumina aggregate with a particle size of 3-1 mm accounts for 50-60% of the total mass of zirconium-alumina aggregate, and zirconium-alumina aggregate with a particle size of 1-0 mm accounts for 40-50% of the total mass of zirconium-alumina aggregate; the particle size of the zirconium-alumina fine powder is ≤74μm, the particle size of the graphite fine powder is ≤200μm, the particle size of the alumina micro powder is ≤10μm, and the particle size of the silicon carbide fine powder is ≤200μm; the composition of both the zirconium-alumina aggregate and the zirconium-alumina fine powder is: Al2O3 67wt% and ZrO2 33wt%.

5. The alumina-zirconium-carbon refractory brick as described in claim 1, characterized in that, The antioxidant is one or more of aluminum powder, silicon powder, and boron carbide powder, wherein the particle size of aluminum powder is ≤74μm, the particle size of silicon powder is ≤100μm, and the particle size of boron carbide powder is ≤74μm.

6. The alumina-zirconium-carbon refractory brick as described in claim 1, characterized in that, The nano-oxide is one or more of nano-alumina, nano-zirconia, and nano-titanium oxide, wherein the nano-alumina particle size is ≤50nm, the nano-zirconia particle size is ≤60nm, and the nano-titanium oxide particle size is ≤60nm.

7. A method for preparing alumina-zirconium-carbon refractory brick as described in any one of claims 1-6, characterized in that, Specifically, the following steps are included: (1) Add the binder to anhydrous ethanol and mix and stir until homogeneous. Then add the nano oxide and mix until homogeneous to obtain a binder solution containing nano oxide. (2) Weigh out corundum aggregate and zirconium corundum aggregate according to the proportion, add 30-40wt% of the binder solution obtained in step (1), mix for 10-15 min to obtain premixed aggregate; weigh out each matrix fine powder according to the proportion, mix for 15-20 min to obtain premixed matrix material; then add the above premixed aggregate to the premixed matrix material, add the remaining binder solution, continue mixing for 20-30 min to obtain a uniform mixture; (3) The mixture is pressed into a blank by liquid molding or isostatic pressing; (4) The formed blank is heat-treated in stages for drying and curing.

8. The method for preparing alumina-zirconium-carbon refractory bricks as described in claim 7, characterized in that, In step (1), the mass ratio of binder to anhydrous ethanol is 1:1; the binder is one or more of phenolic resin and resin powder, and the amount added is 3-5 wt%.

9. The method for preparing alumina-zirconium-carbon refractory bricks as described in claim 7, characterized in that, In step (3), the molding pressure is 100-200 MPa; in step (4), the staged heat treatment is to first keep it at 100-120℃ for 6-12 hours, and then keep it at 180-220℃ for 6-12 hours.

10. The alumina-zirconium-carbon refractory brick as described in any one of claims 1-6 is used as the working layer material of the blast furnace tapping trough skimmer.