Coke oven door lining brick and preparation method thereof

Abstract

The invention discloses a coke oven door lining brick and a preparation method thereof.The coke oven door lining brick comprises a multi-layer structure formed by a base body and a surface layer, the base body is coated with the surface layer, and the base body is prepared from, by weight, 30-50 parts of waste mullite heat insulation brick powder, 3-5 parts of zirconite, 10-15 parts of talcum powder and 20-30 parts of aluminum oxide micro powder; the surface layer is prepared from the following raw materials in parts by weight: 45 to 55 parts of ceramic roller waste powder, 3 to 5 parts of silicon micro powder, 35 to 45 parts of silicon carbide powder, 2 to 5 parts of aluminum oxide micro powder, 5 to 10 parts of kaolin and 5 to 8 parts of silica sol, and the surface layer is prepared from the following raw materials in parts by weight: 45 to 55 parts of ceramic roller waste powder, 3 to 5 parts of silicon micro powder, 35 to 45 parts of silicon carbide powder, 2 to 5 parts of aluminum oxide micro powder, 5 to 10 parts of kaolin and 5 to 8 parts of silica sol. The coke oven door lining brick provided by the invention can effectively reduce carbon deposition and permeation of harmful substances into the brick, and is relatively good in heat insulation effect and good in thermal shock resistance.

Description

Technical Field

[0001] The invention relates to the technical field of coke oven door lining bricks, and in particular to a coke oven door lining brick and a preparation method thereof. Background Art

[0002] During coke oven production, the oven door needs to be frequently opened and closed, and is subject to significant temperature fluctuations during loading and unloading. This makes it susceptible to thermal shock damage, cracking, and carbon deposition during use. Damaged oven doors must be regularly repaired. The short lifespan of doors made of ordinary clay bricks or clay-cordierite bricks has seriously impacted normal coke oven operation. In the coke oven's thermal balance, heat dissipation from the oven door accounts for 10.44% of the oven's overall heat loss. Therefore, effective door insulation is crucial for reducing heat loss. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a coke oven door lining brick, which can effectively reduce carbon deposition and penetration of harmful substances into the brick, and has good thermal insulation effect and good thermal shock resistance.

[0004] The technical problem to be solved by the present invention is to provide a method for preparing lining bricks for a coke oven door.

[0005] In order to solve the above technical problems, the present invention provides a coke oven door lining brick, which includes a multi-layer structure formed by a base and a surface layer, wherein the surface layer covers the base, and the raw materials of the base include, by weight: 30 to 50 parts of waste mullite insulation brick powder, 3 to 5 parts of zircon, 10 to 15 parts of talc, 20 to 30 parts of alumina powder, 20 to 30 parts of kaolin, and 8 to 12 parts of silica sol; the raw materials of the surface layer include, by weight: 45 to 55 parts of ceramic roller waste powder, 3 to 5 parts of silicon powder, 35 to 45 parts of silicon carbide powder, 2 to 5 parts of alumina powder, 5 to 10 parts of kaolin, and 5 to 8 parts of silica sol.

[0006] In some embodiments, the phase composition of the waste mullite insulation brick powder includes, by mass percentage, 83% to 85% of mullite phase, 8% to 10% of cordierite phase, 3% to 5% of spinel phase, and 1% to 3% of corundum phase.

[0007] In some embodiments, the phase composition of the ceramic roller waste powder includes, by mass percentage, 30% to 40% cordierite phase, 39% to 49% silicon carbide phase, and 1% to 2% spinel phase.

[0008] In some embodiments, the mass ratio of the cordierite phase of the matrix to the cordierite phase of the surface layer is 1:3-5; and / or

[0009] The mass ratio of the mullite phase of the matrix to the silicon carbide phase of the surface layer is 1 to 2:1.

[0010] In some embodiments, the waste mullite insulation brick powder includes a first waste mullite insulation brick powder with an average particle size of 0.1 mm to 1 mm, a second waste mullite insulation brick powder with an average particle size of 1 mm to 3 mm, and a third waste mullite insulation brick powder with an average particle size of 3 mm to 5 mm, and the mass of the first waste mullite insulation brick powder: the mass of the second waste mullite insulation brick powder: the mass of the third waste mullite insulation brick powder is 1:1:2-3; and / or

[0011] The ceramic roller waste powder includes a first ceramic roller waste powder with an average particle size of 0.01mm to 0.2mm and a second ceramic roller waste powder with an average particle size of 0.2mm to 0.5mm. The mass ratio of the first ceramic roller waste powder to the second ceramic roller waste powder is 1:2 to 3.

[0012] In some embodiments, the zircon has a particle size of less than 1 μm; and / or

[0013] The particle size of the talc is less than 44 μm; and / or

[0014] The particle size of the alumina powder is less than 5 μm; and / or

[0015] The particle size of the kaolin is less than 1 μm; and / or

[0016] The particle size of SiO2 in the silica sol is less than 1 μm; and / or

[0017] The particle size of the silicon carbide powder is less than 88 μm; and / or

[0018] The particle size of the silicon micropowder is less than 1 μm.

[0019] In some embodiments, the zircon has a ZrSiO4 content of 63 wt% to 65 wt%; and / or

[0020] The MgO content of the talc is 30wt% to 35wt%; and / or

[0021] The Al2O3 content of the alumina powder is greater than 99.5wt%; and / or

[0022] The kaolin has an Al2O3 content greater than or equal to 35 wt% and an Fe2O3 content less than or equal to 1.5 wt%; and / or

[0023] The SiO2 content of the silica sol is 20wt% to 30wt%; and / or

[0024] The SiC content of the silicon carbide powder is greater than 98 wt%; and / or

[0025] The SiO2 content of the silicon micropowder is greater than or equal to 94wt%.

[0026] In some embodiments, the surface layer completely covers the substrate, and the thickness of the surface layer is 1 mm to 10 mm.

[0027] In order to solve the above problems, the present invention also provides a method for preparing coke oven door lining bricks, comprising the following steps:

[0028] Providing a mold, the mold comprising a base layer and a surface layer covering the base layer;

[0029] Pour matrix raw materials into the collective layer and distribute them evenly. The matrix raw materials include, by weight: 30 to 50 parts of waste mullite insulation brick powder, 3 to 5 parts of zircon, 10 to 15 parts of talc, 20 to 30 parts of alumina powder, 20 to 30 parts of kaolin, and 8 to 12 parts of silica sol.

[0030] Pour surface layer raw materials into the surface layer and distribute them evenly. The surface layer raw materials include, by weight: 45 to 55 parts of ceramic roller waste powder, 3 to 5 parts of silicon powder, 35 to 45 parts of silicon carbide powder, 2 to 5 parts of alumina powder, 5 to 10 parts of kaolin, and 5 to 8 parts of silica sol;

[0031] After pressurization and vibration, demoulding, drying and firing are carried out to obtain the finished product.

[0032] In some embodiments, firing is performed in a shuttle kiln, with a maximum firing temperature of 1380° C. to 1400° C. and a holding time of 6 to 8 hours.

[0033] The implementation of the present invention has the following beneficial effects:

[0034] The coke oven door lining brick provided by the present invention comprises a multi-layer structure formed by a base and a surface layer, wherein the surface layer covers the base. The base serves as an inner insulation layer, and the surface layer serves as an outer dense layer. This reduces the weight of the oven door, improves the thermal efficiency of the coke oven, lowers the surface temperature of the oven door, and reduces heat loss in the coke oven.

[0035] Furthermore, the use of zircon as a thermal barrier in the base layer further reduces the thermal conductivity of the furnace door lining brick matrix, or the inner insulation layer, thereby lowering the furnace door surface temperature. Secondly, the chemical stability of silicon carbide in the surface layer reduces surface carbon deposition, thereby reducing maintenance costs. Finally, the use of silica sol as a binder in both the base layer and the surface layer improves the sintering strength of the furnace door lining bricks and reduces mechanical impact damage during the furnace door opening and closing process.

[0036] Furthermore, the differences in thermal expansion coefficients between cordierite and mullite in the matrix and between cordierite and silicon carbide in the surface layer provided by the present invention produce microcracks of different specific shapes in the matrix and the surface layer, thereby achieving reinforcement and toughening of the furnace door lining bricks, improving the overall thermal shock stability of the furnace door lining bricks, and making the furnace door lining bricks more durable. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the embodiments.

[0038] In the present invention, the terms "preferred" and "better" are merely used to describe preferred implementation methods or examples and should be understood not to limit the scope of protection of the present invention. In the present invention, technical features described as open-ended include both closed-ended technical solutions consisting of the listed features and open-ended technical solutions containing the listed features. In the present invention, references to numerical ranges include both endpoints of the numerical range unless otherwise specified.

[0039] The present invention provides a coke oven door lining brick. The coke oven door lining brick comprises a multilayer structure formed by a base and a surface layer, wherein the surface layer covers the base. The raw materials of the base comprise, by weight, 30 to 50 parts of waste mullite insulation brick powder, 3 to 5 parts of zircon, 10 to 15 parts of talc, 20 to 30 parts of alumina fine powder, 20 to 30 parts of kaolin, and 8 to 12 parts of silica sol. The raw materials of the surface layer comprise, by weight, 45 to 55 parts of ceramic roller waste powder, 3 to 5 parts of silicon fine powder, 35 to 45 parts of silicon carbide powder, 2 to 5 parts of alumina fine powder, 5 to 10 parts of kaolin, and 5 to 8 parts of silica sol.

[0040] The coke oven door lining brick provided by the present invention comprises a multi-layer structure formed by a base and a surface layer, wherein the surface layer covers the base. The base serves as an inner insulation layer, and the surface layer serves as an outer dense layer. This reduces the weight of the oven door, improves the thermal efficiency of the coke oven, lowers the surface temperature of the oven door, and reduces heat loss in the coke oven.

[0041] Specifically, the constituent materials of the substrate will be described first.

[0042] Waste mullite insulation bricks mainly refer to mullite insulation bricks that have been eliminated or replaced in industrial production. Mullite insulation bricks are generally ceramic materials formed by high-temperature sintering of mullite and other auxiliary materials, such as bauxite, silica sand, etc. The exemplary addition amount of the waste mullite insulation bricks is 32 parts, 35 parts, 40 parts, 45 parts, and 48 parts, which are not limited to the above. In some embodiments, the phase composition of the waste mullite insulation brick powder includes, by mass percentage: 83% to 85% mullite phase, 8% to 10% cordierite phase, 3% to 5% spinel phase, and 1% to 3% corundum phase. The waste mullite insulation brick powder adopts a specific phase composition. On the one hand, the high mullite content is used to improve the high-temperature resistance. On the other hand, mullite has a high thermal expansion coefficient, cordierite has a low thermal contraction, and a specific content of cordierite is distributed around the mullite, so that dispersed closed microcracks are formed around the cordierite particles, which can absorb energy during thermal shock and prevent crack expansion. In addition, during the crack expansion process, a small amount of distributed spinel will prevent the crack from further expanding, thereby improving the thermal shock resistance.

[0043] In some embodiments, the waste mullite insulation brick powder includes a first waste mullite insulation brick powder having an average particle size of 0.1 mm to 1 mm, a second waste mullite insulation brick powder having an average particle size of 1 mm to 3 mm, and a third waste mullite insulation brick powder having an average particle size of 3 mm to 5 mm. The mass ratio of the first waste mullite insulation brick powder to the second waste mullite insulation brick powder to the third waste mullite insulation brick powder is 1:1:2-3. The waste mullite insulation brick powder is prepared in a three-grade powder format (coarse, medium, and fine), which helps improve the material's density, strength, thermal shock resistance, and microcrack toughening effect.

[0044] In some embodiments, the zircon has a ZrSiO4 content of 63% to 65% by weight, and exemplary amounts of zircon are 3.2 parts, 3.5 parts, 4.0 parts, 4.5 parts, and 4.8 parts, without limitation. The zircon has a particle size of less than 1 μm. Using zircon as a thermal barrier can further reduce the thermal conductivity of the furnace door lining brick matrix or inner insulation layer, thereby lowering the furnace door surface temperature.

[0045] In some embodiments, the talc powder has a MgO content of 30 wt% to 35 wt%; exemplary amounts of the talc powder are 11 parts, 12 parts, 13 parts, 14 parts, and 15 parts, without limitation. The talc powder has a particle size of less than 44 μm. The addition of talc powder can optimize the sintering properties of the material and react with alumina and silica at high temperatures to form cordierite, thereby improving the material's thermal shock resistance.

[0046] In some embodiments, the aluminum oxide powder in the matrix layer has an Al2O3 content greater than 99.5 wt%. Exemplary addition amounts of the aluminum oxide powder are 22 parts, 24 parts, 26 parts, 28 parts, and 29 parts, respectively, and are not limited to the aforementioned. The aluminum oxide powder has a particle size of less than 5 μm. As a fine powder filler, the aluminum oxide powder can fill micropores in the material, increasing the density and strength of the brick while promoting the formation of mullite and cordierite to prevent crack propagation.

[0047] In some embodiments, in the matrix layer, the kaolin has an Al2O3 content greater than or equal to 35 wt% and an Fe2O3 content less than or equal to 1.5 wt%. Exemplary amounts of the kaolin are 22 parts, 24 parts, 26 parts, 28 parts, and 29 parts, but are not limited to the above. The kaolin has a particle size less than 1 μm. The acicular mullite crystals formed by the addition of kaolin can enhance toughness and reduce the rapid propagation of cracks, thereby improving thermal shock resistance.

[0048] In some embodiments, the silica sol in the base layer has a SiO2 content of 20 wt% to 30 wt%. Exemplary addition amounts of the silica sol are, but are not limited to, 8.5, 9, 9.5, 10, 10.5, and 11 parts. The SiO2 particles in the silica sol have a size of less than 1 μm. Using silica sol as a binder improves the sintering strength of the furnace door lining bricks and reduces mechanical damage during door opening and closing.

[0049] Next, the constituent materials of the surface layer will be described.

[0050] Ceramic roller scrap refers to powdered waste generated during the production, processing, or use of ceramic rollers. Exemplary addition amounts of this ceramic roller scrap powder are 48 parts, 50 parts, 51 parts, 52 parts, and 54 parts, but are not limited to the above. In some embodiments, the phase composition of this ceramic roller scrap powder, measured by mass percentage, includes: 30%-40% cordierite phase, 39%-49% silicon carbide phase, and 1%-2% spinel phase. This ceramic roller scrap powder contains a high cordierite content. When the material is subjected to temperature fluctuations, the different expansion behaviors of cordierite and silicon carbide lead to stress concentration between them, which promotes the formation of microcracks. The high cordierite content creates open microcracks in the surface layer, allowing stress release, reducing spalling, and improving thermal shock resistance. The network-like distribution of microcracks in the surface layer causes cracks to continuously deflect, branch, and bridge during propagation, enhancing thermal shock resistance.

[0051] In some embodiments, the ceramic roller waste powder includes a first ceramic roller waste powder having an average particle size of 0.01 mm to 0.2 mm and a second ceramic roller waste powder having an average particle size of 0.2 mm to 0.5 mm, with the mass ratio of the first ceramic roller waste powder to the second ceramic roller waste powder being 1:2-3. The smaller particle size of the surface layer material creates a dense outer protective layer, which helps prevent harmful substances from penetrating into the interior of the lining bricks.

[0052] In some embodiments, the silicon micropowder has a SiO2 content of greater than or equal to 94 wt %. Exemplary addition amounts of the silicon micropowder are 48 parts, 50 parts, 51 parts, 52 parts, and 54 parts, without limitation. The silicon micropowder has a particle size of less than 1 μm. Silicon micropowder has a large specific surface area, which effectively fills the gaps between particles, reducing porosity, thereby making the surface layer more compact and increasing its permeability and corrosion resistance.

[0053] In some embodiments, the SiC content of the silicon carbide powder is greater than 98 wt %, and exemplary amounts of the silicon micropowder are 48 parts, 50 parts, 51 parts, 52 parts, or 54 parts, without limitation. The silicon carbide powder has a particle size of less than 88 μm. The surface layer utilizes the chemical stability of silicon carbide to reduce surface carbon deposition, thereby reducing maintenance costs.

[0054] In some embodiments, the Al2O3 content of the alumina powder in the surface layer is greater than 99.5 wt%. Exemplary amounts of the alumina powder are 2.5 parts, 3 parts, 3.5 parts, 4 parts, and 4.5 parts, respectively. The alumina powder has a particle size of less than 5 μm. As a fine powder filler, the alumina powder can fill micropores in the material, increasing the density and strength of the brick while promoting the formation of cordierite.

[0055] In some embodiments, in the surface layer, the kaolin has an Al2O3 content of greater than or equal to 35 wt% and a Fe2O3 content of less than or equal to 1.5 wt%. Exemplary amounts of the kaolin added are 6 parts, 7 parts, 8 parts, or 9 parts, but are not limited to the above. The kaolin has a particle size of less than 1 μm. The addition of kaolin improves sintering performance and density, thereby increasing the strength and compactness of the material.

[0056] In some embodiments, the silica sol in the base layer has a SiO2 content of 20 wt% to 30 wt%. Exemplary addition amounts of the silica sol are 5.5 parts, 6 parts, 6.5 parts, 7.5 parts, and 8 parts, without limitation. The SiO2 particles in the silica sol have a size of less than 1 μm. Using the silica sol as a binder improves the sintering strength of the furnace door lining bricks and reduces mechanical damage during door opening and closing.

[0057] Furthermore, the present invention provides that the differences in thermal expansion coefficients between cordierite and mullite in the matrix and between cordierite and silicon carbide in the surface layer produce microcracks of varying specific morphologies in the matrix and surface layer, thereby strengthening and toughening the furnace door lining bricks, improving the overall thermal shock resistance of the furnace door lining bricks, and making them more durable. In some embodiments, the ratio of the cordierite phase in the matrix to the cordierite phase in the surface layer is 1:3-5, and / or the ratio of the mullite phase in the matrix to the silicon carbide phase in the surface layer is 1-2:1. Under these ratios, the cordierite content in the matrix is ​​less than the cordierite content in the surface layer, and the mullite content in the matrix is ​​greater than the silicon carbide content in the surface layer. The closed microcracks formed in the matrix confine thermal stresses to a smaller area, preventing the expansion of larger cracks and thus enhancing the toughness. Open microcracks are formed on the surface, which can effectively disperse the stress caused by thermal expansion during high-temperature thermal shock, contribute to the self-repair of the material, and enhance the toughness of the surface.

[0058] In some embodiments, the surface layer completely covers the substrate, and the thickness of the surface layer is 1 mm to 10 mm. By completely covering the surface layer, the thermal stress can be more evenly distributed to the surface with open cracks rather than local areas, thereby reducing large cracks caused by stress concentration. Exemplary thicknesses of the surface layer are 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, and 9 mm, but are not limited to the above. The appropriate surface layer thickness provides a temperature difference buffering function, and through effective heat transfer during thermal cycles, the surface layer can adapt to larger temperature differences when the temperature changes, without being prone to local rupture.

[0059] Accordingly, the present invention also provides a method for preparing a coke oven door lining brick, comprising the following steps:

[0060] Providing a mold, the mold comprising a base layer and a surface layer covering the base layer;

[0061] Pour matrix raw materials into the collective layer and distribute them evenly. The matrix raw materials include, by weight: 30 to 50 parts of waste mullite insulation brick powder, 3 to 5 parts of zircon, 10 to 15 parts of talc, 20 to 30 parts of alumina powder, 20 to 30 parts of kaolin, and 8 to 12 parts of silica sol.

[0062] Pour surface layer raw materials into the surface layer and distribute them evenly. The surface layer raw materials include, by weight: 45 to 55 parts of ceramic roller waste powder, 3 to 5 parts of silicon powder, 35 to 45 parts of silicon carbide powder, 2 to 5 parts of alumina powder, 5 to 10 parts of kaolin, and 5 to 8 parts of silica sol;

[0063] After pressurization and vibration, demoulding, drying and firing are carried out to obtain the finished product.

[0064] In some embodiments, a vibration press is used, and after pressurizing and vibrating for 2 to 5 minutes, demolding is performed by vibration molding. The base and the surface layer are molded into a whole at one time, thereby improving the integrity of the furnace door lining bricks and avoiding separation of the base and the surface layer at the contact interface of the two layers during use.

[0065] In some embodiments, firing is performed in a shuttle kiln at a maximum firing temperature of 1380°C to 1400°C and a holding time of 6 to 8 hours. This firing schedule is conducive to the formation of a surface layer and matrix with a specific crystalline structure, promoting the formation of a phase structure in which the cordierite content in the matrix is ​​less than the cordierite content in the surface layer, and the mullite content in the matrix is ​​greater than the silicon carbide content in the surface layer. This also increases sintered density and optimizes the microstructure, thereby enhancing thermal shock stability, high temperature resistance, and thermal shock resistance.

[0066] The present invention is further described below with specific examples:

[0067] Example 1

[0068] This embodiment provides a coke oven door lining brick, including a multi-layer structure formed by a base and a surface layer, wherein the surface layer covers the base. The raw materials of the base include, by weight: 30 parts of waste mullite insulation brick powder, 5 parts of zircon, 15 parts of talc, 30 parts of alumina powder, 20 parts of kaolin, and 10 parts of silica sol. The raw materials of the surface layer include, by weight: 50 parts of ceramic roller waste powder, 3 parts of silicon powder, 35 parts of silicon carbide powder, 4 parts of alumina powder, 8 parts of kaolin, and 5 parts of silica sol.

[0069] The phase composition of the waste mullite insulation brick powder, calculated by mass percentage, includes: 85% mullite phase, 9% cordierite phase, 5% spinel phase, and 1% corundum phase. The phase composition of the waste ceramic roller powder, calculated by mass percentage, includes: 35% cordierite phase, 45% silicon carbide phase, and 1% spinel phase.

[0070] Example 2

[0071] This embodiment provides a coke oven door lining brick, including a multi-layer structure formed by a base and a surface layer, wherein the surface layer covers the base. The raw materials of the base include, by weight: 40 parts of waste mullite insulation brick powder, 3 parts of zircon, 12 parts of talc, 30 parts of alumina powder, 20 parts of kaolin, and 12 parts of silica sol. The raw materials of the surface layer include, by weight: 45 parts of ceramic roller waste powder, 5 parts of silicon powder, 40 parts of silicon carbide powder, 5 parts of alumina powder, 5 parts of kaolin, and 7 parts of silica sol.

[0072] The phase composition of the waste mullite insulation brick powder, calculated by mass percentage, includes: 84% mullite phase, 10% cordierite phase, 4% spinel phase, and 2% corundum phase. The phase composition of the waste ceramic roller powder, calculated by mass percentage, includes: 40% cordierite phase, 46% silicon carbide phase, and 2% spinel phase.

[0073] Example 3

[0074] This embodiment provides a coke oven door lining brick, including a multi-layer structure formed by a base and a surface layer, wherein the surface layer covers the base. The raw materials of the base include, by weight: 47 parts of waste mullite insulation brick powder, 3 parts of zircon, 10 parts of talc, 20 parts of alumina powder, 20 parts of kaolin, and 13 parts of silica sol. The raw materials of the surface layer include, by weight: 55 parts of ceramic roller waste powder, 3 parts of silicon powder, 38 parts of silicon carbide powder, 2 parts of alumina powder, 5 parts of kaolin, and 8 parts of silica sol.

[0075] The mass ratio of the cordierite phase of the matrix to the cordierite phase of the surface layer is 1:1.2, and the mass ratio of the mullite phase of the matrix to the silicon carbide phase of the surface layer is 1.6:1.

[0076] Comparative Example 1

[0077] This comparative example provides a coke oven door lining brick, comprising a multilayer structure formed by a base and a surface layer, wherein the surface layer covers the base, and the raw materials of the base include, by weight: 25 parts of waste mullite insulation brick powder, 20 parts of talc powder, 35 parts of alumina powder, 35 parts of kaolin, and 13 parts of silica sol; the raw materials of the surface layer include, by weight: 30 parts of ceramic roller waste powder, 2 parts of silicon powder, 50 parts of silicon carbide powder, 2 parts of alumina powder, 5 parts of kaolin, and 8 parts of silica sol.

[0078] Coke oven door lining bricks produced in Examples 1 to 3 and Comparative Example 1 were tested for thermal shock stability and thermal insulation performance. The thermal shock stability test method involved subjecting the samples to a thermal cycle with a temperature gradient of 1100°C, 30°C, and 700°C. After 30 cycles, the surface condition of the samples and the presence of cracks were observed. Specific test results are shown in Table 1.

[0079] Table 1 shows the test results of thermal shock stability and thermal insulation performance of coke oven door lining bricks prepared in Examples 1 to 3 and Comparative Example 1.

[0080]

[0081] According to the above data, the coke oven door lining bricks provided by the present invention control the differences in thermal expansion coefficients between cordierite and mullite, and between cordierite and silicon carbide in the surface layer and the matrix, thereby generating microcracks of different specific forms in the matrix and the surface layer, thereby achieving reinforcement and toughening of the furnace door lining bricks, improving the overall thermal shock stability of the furnace door lining bricks, and making the furnace door lining bricks more durable.

[0082] Throughout this specification, reference to terms such as "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with an embodiment or example is included in at least one embodiment or example of the present application. In this specification, the illustrative use of the above terms does not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0083] The above is a preferred embodiment of the invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A coke oven door lining brick, characterized in that: The coke oven door lining brick comprises a multi-layer structure formed by a base and a surface layer, wherein the surface layer covers the base. The raw materials of the base include, by weight, 30 to 50 parts of waste mullite insulation brick powder, 3 to 5 parts of zircon, 10 to 15 parts of talc, 20 to 30 parts of alumina fine powder, 20 to 30 parts of kaolin, and 8 to 12 parts of silica sol. The raw materials of the surface layer include, by weight, 45 to 55 parts of ceramic roller waste powder, 3 to 5 parts of silicon fine powder, 35 to 45 parts of silicon carbide powder, 2 to 5 parts of alumina fine powder, 5 to 10 parts of kaolin, and 5 to 8 parts of silica sol.

2. The coke oven door lining brick according to claim 1, characterized in that: Calculated by mass percentage, the phase composition of the waste mullite insulation brick powder includes: 83% to 85% of mullite phase, 8% to 10% of cordierite phase, 3% to 5% of spinel phase, and 1% to 3% of corundum phase.

3. The coke oven door lining brick according to claim 1, characterized in that: Calculated by mass percentage, the phase composition of the ceramic roller waste powder includes: 30% to 40% cordierite phase, 39% to 49% silicon carbide phase, and 1% to 2% spinel phase.

4. The coke oven door lining brick according to claim 1, characterized in that: The mass ratio of the cordierite phase of the matrix to the cordierite phase of the surface layer is 1:3-5; and / or The mass ratio of the mullite phase of the matrix to the silicon carbide phase of the surface layer is 1 to 2:

1.

5. The coke oven door lining brick according to claim 1, characterized in that: The waste mullite insulation brick powder comprises a first waste mullite insulation brick powder having an average particle size of 0.1 mm to 1 mm, a second waste mullite insulation brick powder having an average particle size of 1 mm to 3 mm, and a third waste mullite insulation brick powder having an average particle size of 3 mm to 5 mm, wherein the mass of the first waste mullite insulation brick powder: the mass of the second waste mullite insulation brick powder: the mass of the third waste mullite insulation brick powder is 1:1:2-3; and / or The ceramic roller waste powder includes a first ceramic roller waste powder with an average particle size of 0.01mm to 0.2mm and a second ceramic roller waste powder with an average particle size of 0.2mm to 0.5mm. The mass ratio of the first ceramic roller waste powder to the second ceramic roller waste powder is 1:2 to 3.

6. The coke oven door lining brick according to claim 1, characterized in that: The particle size of the zircon is less than 1 μm; and / or The particle size of the talc is less than 44 μm; and / or The particle size of the alumina powder is less than 5 μm; and / or The particle size of the kaolin is less than 1 μm; and / or The particle size of SiO2 in the silica sol is less than 1 μm; and / or The particle size of the silicon carbide powder is less than 88 μm; and / or The particle size of the silicon micropowder is less than 1 μm.

7. The coke oven door lining brick according to claim 1, characterized in that: The ZrSiO4 content of the zircon is 63wt% to 65wt%; and / or The MgO content of the talc is 30wt% to 35wt%; and / or The Al2O3 content of the alumina powder is greater than 99.5wt%; and / or The kaolin has an Al2O3 content greater than or equal to 35 wt% and an Fe2O3 content less than or equal to 1.5 wt%; and / or The SiO2 content of the silica sol is 20wt% to 30wt%; and / or The SiC content of the silicon carbide powder is greater than 98 wt%; and / or The SiO2 content of the silicon micropowder is greater than or equal to 94wt%.

8. The coke oven door lining brick according to claim 1, characterized in that: The surface layer completely covers the substrate, and the thickness of the surface layer is 1 mm to 10 mm.

9. A method for preparing a coke oven door lining brick according to any one of claims 1 to 9, characterized in that: The following steps are involved: Providing a mold, the mold comprising a base layer and a surface layer covering the base layer; Pour matrix raw materials into the collective layer and distribute them evenly. The matrix raw materials include, by weight: 30 to 50 parts of waste mullite insulation brick powder, 3 to 5 parts of zircon, 10 to 15 parts of talc, 20 to 30 parts of alumina powder, 20 to 30 parts of kaolin, and 8 to 12 parts of silica sol. Pour surface layer raw materials into the surface layer and distribute them evenly. The surface layer raw materials include, by weight: 45 to 55 parts of ceramic roller waste powder, 3 to 5 parts of silicon powder, 35 to 45 parts of silicon carbide powder, 2 to 5 parts of alumina powder, 5 to 10 parts of kaolin, and 5 to 8 parts of silica sol; After pressurization and vibration, demoulding, drying and firing are carried out to obtain the finished product.

10. The method for preparing coke oven door lining bricks according to claim 9, characterized in that: The firing is completed in a shuttle kiln with a maximum firing temperature of 1380℃~1400℃ and a holding time of 6 hours to 8 hours.

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