A high-temperature platen with heavy load capacity and its manufacturing method

Abstract

The present invention belongs to the field of preparation of advanced structural ceramics, and in particular relates to a heavy-load high-temperature table board and a manufacturing method thereof. The manufacturing method of the heavy-load high-temperature table board of the present invention comprises the following steps: (1) sequentially spreading an outer layer material, an inner layer material, and the outer layer material into a mold, and performing high-pressure molding to obtain a formed blank; (2) drying the formed blank to obtain a dry blank; (3) firing the dry blank at a temperature of 1550-1680 °C to obtain the table board. The manufacturing method of the present invention uses low-zircon corundum, white corundum, fused mullite, and andalusite as raw materials, introduces zircon, and tabular corundum fine powder, and respectively prepares the outer layer material and the inner layer material; through pressure molding and sintering, an interlaced structure in which zircon corundum crystals are filled in the gaps of the mullite network is formed, and a high-strength wear-resistant table board with a low-zircon corundum outer layer is obtained, which has good high-temperature strength and excellent thermal shock resistance, can withstand the impact of continuous changes in high and low temperatures in a pusher kiln, and has a long service life.

Description

Technical Field

[0001] The present invention belongs to the field of preparation of advanced structural ceramics, and particularly relates to a high-temperature platen with heavy load and a manufacturing method thereof. Background Art

[0002] The platen, also known as the pusher plate, is a key component in the pusher kiln for carrying products and pushing them forward. It not only needs to meet the high-temperature atmosphere conditions for sintering, but also requires the platen (usually with a thickness of only 30 mm) to withstand a pressure of 20 - 30 kg / plate, as well as the extrusion force for long-distance (about 30 m) pushing of the products being fired. It has to endure the continuous impact of high and low temperature changes caused by the long-term cycle from room temperature → high temperature → room temperature (the furnace cycles about once every 20 - 30 h). At the same time, it is required to have a long service life. During use, even if a small piece on the pusher plate breaks, chips off, creeps, adheres, or deforms, it will cause the entire pusher plate to be unable to continue pushing forward, resulting in a major accident where the kiln has to be stopped for roof turning treatment, causing significant economic losses to users. Therefore, the platen is required to have excellent high-temperature strength and wear resistance, good thermal shock stability and volume stability, and extremely high comprehensive performance requirements.

[0003] Currently, mullite-based platen is commonly used in the market. Other types of platen, such as cordierite and corundum-based platen, are not suitable because of their low refractoriness and large expansion. Silicon carbide platen is not suitable because it is not resistant to oxidation in an oxidizing atmosphere. For example: Chinese Patent CN1763465 discloses a pusher plate for soft magnetic ferrite sintering nitrogen kiln, with the weight percentage as follows: fused mullite 0.5 - 3 mm 40 - 45%, 0.06 - 0.5 mm 5 - 8%, <0.04 mm 18 - 22%, tabular corundum 0.5 - 3 mm 8 - 12%, fused white corundum 0.06 - 0.5 mm 1 - 3%, α-aluminum oxide <0.045 mm 10 - 14%, <4um 4 - 6%, silica powder 2 - 4%, and additionally 8 - 9% of silicon-aluminum gel. This pusher plate for soft magnetic ferrite sintering nitrogen kiln can only be used in nitrogen kilns below 1450°C.

[0004] Chinese Patent CN201410809937.3 discloses a high-performance modified mullite high-temperature table board and its preparation process. By weight percentage: fused mullite ≤3mm 40 - 50%, tabular corundum ≤3mm 20 - 35%, α-aluminum oxide ≤320 mesh 12 - 20%, spinel ≤200 mesh 3 - 5%, kaolin ≤200 mesh 7 - 10%, lanthanum oxide and yttrium oxide composite rare earth additive ≤1um 0.5 - 1%. In the lanthanum oxide and yttrium oxide composite rare earth additive, the mass ratio of yttrium oxide to lanthanum oxide is 1:0.05 - 0.3. This patent has good thermal shock resistance and high-temperature strength. However, after long-term use, due to insufficient high-temperature load-bearing capacity and strength, the pushing surface and loading surface of the pusher plate are prone to large changes, such as size increase, bending deformation, and even fracture under force extrusion, reducing the service life. Summary of the Invention

[0005] The present invention provides a heavy-duty high-temperature table board applicable to pusher kilns with temperatures of 1650°C and below. When in use, the table board can withstand a pressure of 40 - 60 kg / plate, with a significantly improved load capacity, stable volume, long service life, and reliable performance. Therefore, the table board of the present invention has higher compressive strength, stronger wear resistance, and better thermal shock stability.

[0006] The purpose of the present invention is to provide a heavy-duty high-temperature table board.

[0007] The purpose of the present invention is to provide a preparation method for the above-mentioned heavy-duty high-temperature table board.

[0008] According to the preparation method of the heavy-duty high-temperature table board in the specific embodiment of the present invention, it includes the following steps:

[0009] (1) The outer layer material, inner layer material, and outer layer material are laid flat into the mold in sequence from bottom to top according to a mass ratio of 1 - 2:6 - 8:1 - 2, and high-pressure molding is carried out under a pressure of 200 - 250 MPa to obtain a formed blank; where

[0010] (2) The formed blank is dried until the moisture content is less than 1% to obtain a dry blank;

[0011] (3) The dry blank is fired at a temperature of 1550 - 1680°C to obtain the table board.

[0012] According to the preparation method of the heavy-duty high-temperature table board in the specific embodiment of the present invention, by weight, the raw materials of the outer layer material include: 4 - 5 parts of low-zircon corundum, 4 - 5.5 parts of tabular corundum, and 0.8 - 1.5 parts of zircon. Among them, the surfaces of the low-zircon corundum and the tabular corundum are coated with zircon.

[0013] The preparation method of the heavy-load type high-temperature table board according to the specific embodiment of the present invention, the particle size of low-zircon corundum is 3-1 mm; and / or,

[0014] The particle size of tabular corundum is 1-0.125 mm; and / or,

[0015] The particle size of zircon is ≤50 um.

[0016] The preparation method of the heavy-load type high-temperature table board according to the specific embodiment of the present invention, the steps of coating zircon on the surface of low-zircon corundum and the surface of tabular corundum are as follows:

[0017] Mix 4-5 parts of low-zircon corundum and 4-5.5 parts of tabular corundum to obtain a mixed dry material;

[0018] Prepare a mixed solution with a concentration of 70-85% of zircon;

[0019] Atomize and spray the mixed solution into the mixed dry material to obtain an outer layer material.

[0020] Preferably, through the PVA solution, a mixed solution with a concentration of 70-85% of zircon is prepared, and the concentration of the PVA solution is 1-1.5%.

[0021] The preparation method of the heavy-load type high-temperature table board according to the specific embodiment of the present invention, calculated by weight, the raw materials of the inner layer material include: 3-4 parts of white corundum, 0.8-1.5 parts of fused mullite, 0.8-1.5 parts of andalusite, 0.8-1.5 parts of zircon, and 1.3-2.5 parts of tabular corundum. Among them, the surfaces of white corundum, fused mullite, andalusite, and zircon are coated with tabular corundum.

[0022] The preparation method of the heavy-load type high-temperature table board according to the specific embodiment of the present invention, the particle size of white corundum is 2 mm-0.5 mm; and / or,

[0023] The particle size of fused mullite is 0.5-0.125 mm; and / or,

[0024] The particle size of andalusite is 2 mm-0.5 mm; and / or,

[0025] The particle size of zircon is 3 mm-0.5 mm; and / or,

[0026] The particle size of tabular corundum is ≤50 um.

[0027] The preparation method of the heavy-load type high-temperature table board according to the specific embodiment of the present invention, the inner layer material is prepared by the following steps:

[0028] Mix 3-4 parts of white corundum, 0.8-1.5 parts of fused mullite, 0.8-1.5 parts of andalusite, and 0.8-1.5 parts of zircon to obtain a mixed dry material;

[0029] Prepare a mixed solution with tabular corundum at a concentration of 45-60%.

[0030] Atomize and spray the mixed solution into the mixed dry materials to obtain the inner layer materials.

[0031] Preferably, prepare a mixed solution with tabular corundum at a concentration of 45-60% through a PVA solution, and the concentration of the PVA solution is 1-1.5%.

[0032] According to the preparation method of the heavy load type high-temperature table board according to the specific embodiment of the present invention, in step (3), fire the green body according to the following temperature program:

[0033]

[0034]

[0035] The present invention provides a heavy load type high-temperature table board prepared by the above method, which realizes controlling the decomposition ratio of large-grain raw materials of zircon andalusite and the distribution of the crystal phase intersection structure inside the table board, forms an interlaced structure with zircon corundum crystals filling the gaps in the mullite network, and obtains a high-strength and wear-resistant table board with a low zircon corundum outer layer.

[0036] The beneficial effects of the present invention:

[0037] In the present invention, different formulations are used for the inner layer and the outer layer of the table board. The outer layer uses low zircon corundum and tabular corundum granular materials as raw materials, and zircon powder is added thereto in an atomized form; the inner layer uses white corundum, fused mullite, andalusite, and zircon granular materials as raw materials, and tabular corundum powder is introduced therein in an atomized form. Add and scrape the outer layer materials, inner layer materials, and outer layer materials in sequence, uniformly distribute the materials, then form by applying pressure. After the green body is dried, through the sintering process, finally form an interlaced structure with zircon corundum crystals filling the gaps in the mullite network. The bonding materials of the inner and outer layers react to form an integrated crystal phase intersection network, which not only strengthens the wear resistance of the outer layer of the table board but also enhances the structural strength of the inner layer, that is, the high-strength and wear-resistant table board with a low zircon corundum outer layer of the present invention.

[0038] The micro-powder atomization process is introduced during the raw material mixing to form droplets with a particle size of 50-100 μm. After sufficient mixing, the surface of the granular materials is evenly adsorbed with the micro-powder materials, with less agglomeration and good uniformity of the particle size distribution, which is convenient for the forming and pressing process and ensures the uniformity and reliability of the micro-structure inside the table board. Specific Embodiment

[0039] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other implementation manners obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope protected by the present invention.

[0040] The preparation method of the heavy-load high-temperature platen of the present invention includes the following steps:

[0041] (1) The outer layer material, inner layer material, and outer layer material are laid flat into the mold in sequence from bottom to top according to a mass ratio of 1-2:6-8:1-2, and are subjected to high-pressure molding under a pressure of 200-250 MPa to obtain a formed blank.

[0042] (2) The formed blank is dried until the moisture content is less than 1% to obtain a dry blank.

[0043] (3) The dry blank is fired at a temperature of 1550-1680 °C to obtain the platen.

[0044] Among them, the preparation method of the outer layer material is:

[0045] 4.0-5.0 parts by mass of low-zircon corundum with a particle size of 3-1 mm and 4.0-5.5 parts by mass of tabular corundum with a particle size of 1-0.125 mm are put into a mixer and dry-mixed for 0.5-1 hour.

[0046] 0.8-1.5 parts by mass of zircon with a particle size ≤50 um is added to 1-1.5% PVA to prepare a mixed solution with a concentration of 70-85%, stirred by a homogenizing pump for 20-30 minutes until evenly mixed, transported to an atomizing nozzle through a medium-low pressure diaphragm pump, atomized and sprayed into the mixed dry material, and then mixed for 0.5-1 hour to obtain a uniform mixed material. The moisture content of the mixed material is controlled at 3-8%, and it is stored after aging.

[0047] Preferably, the low-zircon corundum is 4.2-4.6 parts by weight; the tabular corundum is 4.4-5.2 parts by weight; the zircon is 1.0-1.3 parts by weight.

[0048] The outer layer material uses low-zircon corundum and tabular corundum as raw materials, and zircon is introduced in the form of micro-powder atomization. Compared with corundum or corundum-mullite, low-zircon corundum has better wear resistance, thermal shock resistance and high compressive strength, and can withstand high temperature and pressure, and thermal shock of rapid temperature change. Tabular corundum has strong chemical inertness, is produced by rapid cooling after high-temperature calcination, has tiny unevenness on the surface of crystal particles, and has uniformly distributed micro-pores inside the particle structure, and has strong activity. Zircon has high chemical stability and extremely strong corrosion resistance, small thermal expansion coefficient and good toughness. After high-temperature firing, most of the fine powder decomposes into t-ZrO2 and SiO2, and a small amount of mullite phase main crystal phase and SiO2 liquid phase appear. Zircon reacts with tabular corundum at high temperature to form an interlaced grid structure with modified zircon corundum mullite composite phase, which has good compressive strength and excellent thermal shock resistance. Zircon reacts and combines with low-zircon corundum particles, and the product has better high-temperature wear resistance. Therefore, compared with the table board of corundum-mullite phase, the load performance of the table board of the present invention is greatly improved and enhanced.

[0049] Preferably, the concentration of zircon in the mixed liquid is 75-82%.

[0050] Preferably, the moisture content of the mixed material is 3-6%.

[0051] The preparation method of the inner layer material is as follows:

[0052] Mix 3.0-4.0 parts by mass of white corundum with a particle size of 2 mm to 0.5 mm, 1.5-2.5 parts by mass of fused mullite with a particle size of 0.5-0.125 mm, 0.8-1.5 parts by mass of andalusite with a particle size of 2 mm to 0.5 mm, 0.8-1.5 parts by mass of zircon with a particle size of 3 mm to 0.5 mm dry for 0.5-1 hour;

[0053] Add 1.3-2.5 parts by mass of tabular corundum with a particle size ≤50um to 1-1.5% PVA to prepare a mixed liquid with a concentration of 45-60%, stir with a homogenizing pump for 20-30 minutes, stir evenly, transport it to an atomizing nozzle through a medium-low pressure diaphragm pump, atomize and spray it into the mixed dry material, and then mix for 0.5-1 hour to obtain a uniform mixed material. Control the moisture content of the mixed material at 3-8%, and store it for later use after aging.

[0054] Preferably, the white corundum is 3.3-3.8 parts; the fused mullite is 1.7-2.3 parts; the andalusite is 1.0-1.3 parts; the zircon is 1.0-1.3 parts; the tabular corundum is 1.6-2.2.

[0055] The inner layer material uses white corundum, fused mullite, andalusite, and zircon particles as raw materials, and tabular corundum is introduced in the form of micro-powder atomization.

[0056] Among them, white fused alumina has stable chemical properties, high purity, good high-temperature thermal stability, and is a high-quality refractory aggregate. Fused mullite has stable chemical properties, small linear expansion, and good thermal shock resistance. Andalusite fine powder can be completely transformed into irreversible mullite phase matrix and dissociate free SiO2 at high temperature. The free SiO2 can react with the introduced tabular corundum phase to generate secondary mullite reaction, increasing the content of mullite phase inside the product, reducing the entry of free SiO2 into the liquid phase, improving the microstructure of crystal phase, and enhancing the high-temperature performance and thermal shock resistance of the product. Zircon has good chemical inertness. The fine powder starts to decompose into t-ZrO2 and SiO2 at 1540 °C, with a small amount of mullite phase matrix and SiO2 liquid phase emerging.

[0057] Through high-temperature firing, the inner layer material forms a framework network with corundum and zirconia grains embedded in needle-like modified mullite crystal phase. A staggered structure with zircon corundum crystals filling the mullite network is formed, enhancing the high-temperature strength and thermal shock resistance of the product, and significantly improving the load capacity.

[0058] The present invention optimizes the particle ratio of the raw materials of the inner layer material. By controlling the particle composition and firing temperature curve, a small part of large andalusite particles and some large zircon particles do not complete decomposition, so that they can slowly decompose and react during the later use process, further transforming into mullite, monoclinic zirconia and glass phase SiO2. Part of the glass phase SiO2 promotes the combination of corundum and mullite, enhancing the strength of the composite staggered network structure. Another part undergoes secondary mullitization with tabular corundum fine powder, increasing the fracture energy of the platen, playing a role in modification and toughening, and enabling the platen to have a longer service life.

[0059] Preferably, the concentration of tabular corundum in the mixed liquid is 50-58%.

[0060] Preferably, the moisture content of the mixture is 3-6%.

[0061] In step (1), the inner and outer layer mixed materials that have been stored for 36-48 hours are weighed and distributed according to the mass ratio of the product, and are successively placed into the mold cavity. After scraping the material to be flat, a pressure of 200-250 MPa is applied by a molding hydraulic press for high-pressure molding. The pressure is applied slowly, and multiple re-pressures and pressure-holdings are carried out to remove the air in the green body, obtaining a dense and non-laminated green body.

[0062] In step (2), the green body is naturally stored for 24-36 hours, and after releasing the internal stress, it is placed in a drying oven for drying. After drying in two temperature regions of 60-100 °C and 100-150 °C, a dry green body with a moisture content of less than 1% is obtained and reserved for loading into the kiln.

[0063] In step (3), the high-temperature roasting system is as follows:

[0064]

[0065]

[0066] The qualified blanks are loaded into the kiln and fired at the highest firing temperature of 1680 °C by optimizing the firing curve, so as to control the decomposition and synthesis ratio of large-grained raw materials of zircon and andalusite and the distribution of the interlaced crystal structure inside the table board, forming an interlaced structure in which zircon corundum crystals are filled in the gaps of the mullite network, and having a high-strength wear-resistant table board with a low zircon corundum outer layer.

[0067] Example 1

[0068] The preparation method of the heavy-load high-temperature table board of the present invention includes the following steps:

[0069] 1. Raw material preparation:

[0070] (1) Outer layer material: 45 parts by mass of low zircon corundum with a particle size of 3 - 1 mm and 46 parts by mass of tabular corundum with a particle size of 1 - 0.125 mm are put into a mixer and dry-mixed for 1 hour to obtain a mixed dry material.

[0071] 9 parts by mass of zircon with a particle size ≤ 50 um is added to 1.5% PVA to prepare a mixed solution with a concentration of 76%, and homogenized by a pump and stirred for 20 - 30 minutes until evenly mixed to obtain a mixed solution.

[0072] The mixed solution is transported to an atomizing nozzle through a medium and low pressure diaphragm pump, atomized and sprayed into the mixed dry material, and then mixed for 0.5 - 1 hour to obtain a uniform mixed material. The moisture content of the mixed material is controlled at 3.5%, and the material is stored for later use after being left to stand;

[0073] (2) Inner layer material: 38 parts by mass of white corundum with a particle size of 2 mm - 0.5 mm, 22 parts by mass of fused mullite with a particle size of 0.5 - 0.125 mm, 11 parts by mass of andalusite with a particle size of 2 mm - 0.5 mm, and 12 parts by mass of zircon with a particle size of 3 mm - 0.5 mm are dry-mixed for 0.5 - 1 hour to obtain a mixed dry material.

[0074] 17 parts by mass of tabular corundum with a particle size ≤ 50 um is added to 1% PVA to prepare a mixed solution with a concentration of 52%, and homogenized by a pump and stirred for 20 - 30 minutes until evenly mixed to obtain a mixed solution.

[0075] The mixed solution is transported to an atomizing nozzle through a medium and low pressure diaphragm pump, atomized and sprayed into the mixed dry material, and then mixed for 0.5 hour to obtain a uniform mixed material. The moisture content of the mixed material is controlled at 3%, and the material is stored for later use after being left to stand;

[0076] 2. Pressing and drying of forming:

[0077] Mix the inner and outer layer mixtures for 36 - 48 hours, then weigh and distribute the outer layer material, inner layer material, and outer layer material according to a mass ratio of 1:6:1. Sequentially place them into the mold cavity in the order of outer layer material, inner layer material, and outer layer material. After scraping the material to make it flat, apply a pressure of 200 - 250 MPa through a molding hydraulic press for high-pressure molding. Apply pressure slowly, perform multiple re-pressing and pressure holding to remove the air in the green body and obtain a dense and non-laminated green body.

[0078] Let the green body be stored naturally for 30 hours, then put it into a drying oven to dry after releasing the internal stress. After drying in two temperature zones of 80°C and 120°C, obtain a dry green body with a moisture content of less than 1% for standby before loading into the kiln.

[0079] 3. High-temperature roasting:

[0080] Load the qualified green body into the kiln and fire it according to the high-temperature roasting preparation:

[0081]

[0082] Example 2

[0083] The preparation method of the heavy-load high-temperature table board of the present invention includes the following steps:

[0084] 1. Raw material preparation:

[0085] (1) Outer layer material: Put 40 parts by mass of low-zircon corundum with a particle size of 3 - 1 mm and 40 parts by mass of tabular corundum with a particle size of 1 - 0.125 mm into a mixer and dry mix for 0.5 hour to obtain a mixed dry material.

[0086] Add 8 parts by mass of zircon with a particle size ≤ 50 um to 1% PVA to prepare a mixed solution with a concentration of 70%, and stir with a homogenizing pump for 20 minutes until evenly mixed to obtain a mixed solution.

[0087] Transport the mixed solution to the atomizing nozzle through a medium and low-pressure diaphragm pump, atomize and spray it into the mixed dry material, then remix for 1 hour to obtain a uniform mixed material. Control the moisture content of the mixed material at 3% and let it stand by after aging;

[0088] (2) Inner layer material: Put 30 parts by mass of white corundum with a particle size of 2 - 0.5 mm, 15 parts by mass of fused mullite with a particle size of 0.5 - 0.125 mm, 8 parts by mass of andalusite with a particle size of 2 - 0.5 mm, and 8 parts by mass of zircon with a particle size of 3 - 0.5 mm into a mixer and dry mix for 0.5 hour to obtain a mixed dry material.

[0089] Add 13 parts by mass of tabular corundum with a particle size ≤ 50 um to 1% PVA to prepare a mixed solution with a concentration of 45%, and stir with a homogenizing pump for 20 - 30 minutes until evenly mixed to obtain a mixed solution.

[0090] The mixed liquid is transported to the atomizing nozzle by a medium and low pressure diaphragm pump, atomized and sprayed into the mixed dry material, and then mixed for 0.5 hours to obtain a uniform mixed material. The moisture content of the mixed material is controlled at 3%, and the material is stored for later use after being left to stand;

[0091] 2. Pressing and drying of forming:

[0092] For the inner and outer layer mixed materials that have been stored for 36 hours, the outer layer material, inner layer material, and outer layer material are weighed and distributed according to a mass ratio of 1.5:7:1.5. They are sequentially distributed into the mold cavity of the mold in the order of the outer layer material, inner layer material, and outer layer material. After scraping the material to be flat, a pressure of 200 - 250 MPa is applied by a forming hydraulic press for high-pressure forming. The pressure is applied slowly, and multiple re-pressures and pressure-holdings are carried out to remove the air in the green body, obtaining a green body with a dense and non-laminated shape.

[0093] The green body is stored naturally for 24 hours. After releasing the internal stress, it is placed in a drying oven for drying. After drying in two temperature zones of 60°C and 100°C, a dry green body with a moisture content of less than 1% is obtained and reserved for loading into the kiln.

[0094] 3. High-temperature roasting:

[0095] The qualified green body is loaded into the kiln and fired according to the preparation of high-temperature roasting:

[0096]

[0097]

[0098] Example 3

[0099] The preparation method of the heavy load type high-temperature table board of the present invention includes the following steps:

[0100] 1. Raw material preparation:

[0101] (1) Outer layer material: 50 parts by mass of low zirconia corundum with a particle size of 3 - 1 mm and 55 parts by mass of tabular corundum with a particle size of 1 - 0.125 mm are put into a mixer and dry-mixed for 1 hour to obtain a mixed dry material.

[0102] 15 parts by mass of zirconia with a particle size ≤ 50um is added to 1.5% PVA to prepare a mixed liquid with a concentration of 85%. It is stirred by a homogenizing pump for 30 minutes until evenly stirred to obtain a mixed liquid.

[0103] The mixed liquid is transported to the atomizing nozzle by a medium and low pressure diaphragm pump, atomized and sprayed into the mixed dry material, and then mixed for 1 hour to obtain a uniform mixed material. The moisture content of the mixed material is controlled at 5%, and the material is stored for later use after being left to stand;

[0104] (2) Inner layer material: Mix 40 parts by mass of white fused alumina with a particle size of 2 mm to 0.5 mm, 25 parts by mass of electrofused mullite with a particle size of 0.5 to 0.125 mm, 15 parts by mass of andalusite with a particle size of 2 mm to 0.5 mm, and 15 parts by mass of zircon with a particle size of 3 mm to 0.5 mm dry for 1 hour to obtain a mixed dry material.

[0105] Add 25 parts by mass of tabular corundum with a particle size ≤ 50um to a 1.5% PVA solution to prepare a 60% concentration mixed solution, and stir it with a homogenizing pump for 30 minutes until evenly mixed to obtain a mixed solution.

[0106] Transport the mixed solution to an atomizing nozzle through a medium and low pressure diaphragm pump, atomize and spray it into the mixed dry material, and then mix for 1 hour to obtain a uniform mixed material. Control the moisture content of the mixed material at 6%, and store it for later use after aging;

[0107] 2. Compression and drying of forming:

[0108] For the inner and outer layer mixed materials that have been aged for 48 hours, the outer layer material, inner layer material, and outer layer material are weighed and distributed according to a mass ratio of 2:8:2, and are sequentially distributed into the mold cavity of the mold in the order of outer layer material, inner layer material, and outer layer material. After scraping the material flat, apply a pressure of 200 - 250 MPa through a forming hydraulic press for high-pressure forming, apply pressure slowly, and perform multiple re-pressures and pressure holding to remove the air in the green body and obtain a dense and non-laminated green body.

[0109] Let the green body be stored naturally for 36 hours, release the internal stress, and then put it into a drying oven for drying. After drying in two temperature zones of 100°C and 150°C, obtain a dry green body with a moisture content less than 1% for standby to be loaded into the kiln.

[0110] 3. High-temperature roasting:

[0111] Load the qualified green body into the kiln and fire it according to the high-temperature roasting preparation:

[0112]

[0113]

[0114] Comparative Example 1

[0115] The difference from Example 1 is that in the outer layer material, zircon is directly added in powder form to low-zircon corundum and tabular corundum for mixing, and other steps are the same as in Example 1.

[0116] Comparative Example 2

[0117] The difference from Example 1 is that in the inner layer material, tabular corundum is directly added in powder form to white fused alumina, electrofused mullite, andalusite, and zircon for mixing, and other steps are the same as in Example 1.

[0118] Comparative Example 3

[0119] The difference from Example 1 lies in the firing regime. After the firing temperature reaches 1680 °C, the heat preservation time is only 0.5 hours, and other steps are the same as those in Example 1.

[0120] Comparative Example 4

[0121] The difference from Example 1 lies in the firing regime. After the firing temperature reaches 1650 °C, heat preservation is carried out for 1 - 2 hours, and then cooling is carried out, and other steps are the same as those in Example 1.

[0122] Comparative Example 5

[0123] The difference from Example 1 is that andalusite and zircon in the inner layer material are replaced with fine powder. Among them, the andalusite particles are 0.05 - 0.125 mm, and the zircon particles are 0.05 - 0.125 mm, and other steps are the same as those in Example 1.

[0124] The table boards obtained from Examples 1 - 3 and Comparative Examples 1 - 5 were taken respectively, and the compressive strength and thermal shock resistance of the table boards were detected.

[0125] Testing method for the compressive strength of the table board: Test method for the normal temperature compressive strength of refractories GB / T5072 - 2008. Testing method for the thermal shock resistance of the table board: Test method for the thermal shock resistance of refractory products (water quenching method) YB / T376.1 - 1995.

[0126] The experimental results are as follows:

[0127] Table 1 Performance detection data of the table board

[0128] Compressive strength (MPa) Number of thermal shock cycles (times) Example 1 132 63 Example 2 135 65 Example 3 124 55 Comparative Example 1 106 35 Comparative Example 2 116 37 Comparative Example 3 110 48 Comparative Example 4 115 26 Comparative Example 5 112 42

[0129] As can be seen from Table 1, for the table board of Example 3, due to the relatively large mass fraction of andalusite and zircon, after high - temperature sintering and dissociation, more SiO2 liquid phase is formed, resulting in a decrease in the high - temperature creep softening of the formed material, thereby reducing the high - temperature strength of the material. The compressive strength and thermal shock resistance of the obtained table board are lower than those of the table boards of Examples 1 and 2. At the same time, the compressive strength and thermal shock resistance of the table boards described in Examples 1 - 3 are significantly better than those of Comparative Examples 1 - 5.

[0130] For Comparative Example 1, zircon in the outer layer material was directly added in powder form to low - zircon corundum and tabular corundum for mixing. Since the zircon fine powder cannot uniformly wrap the surface of other granular materials, after high - temperature sintering and dissociation of zircon, zircon - containing corundum mullite formed locally with tabular corundum, resulting in an incomplete crystal network structure, thereby affecting the high - temperature strength and wear resistance of the material. The compressive strength and thermal shock resistance of the obtained table board are greatly reduced.

[0131] Comparative Example 2: In the inner layer material, tabular corundum was directly added in powder form to white corundum, fused mullite, andalusite, and zircon, and then mixed. Since the tabular corundum fine powder could not evenly coat the surfaces of other granular materials, after dissociation of zircon and andalusite during high-temperature sintering, the reaction with tabular corundum was incomplete, and there was an excessive amount of SiO2 liquid phase locally, resulting in the formation of a zircon-corundum mullite network structure locally, thus reducing the high-temperature load softening and strength of the material. The compressive strength and thermal shock resistance of the obtained table board were significantly reduced.

[0132] Comparative Example 3: The difference from Example 1 lies in the firing regime. When the firing temperature reached 1680 °C, the holding time was only 0.5 hours. The amount of SiO2 phase generated after dissociation in the andalusite and zircon granular materials in the inner layer material was less, and the amount of zircon-corundum mullite phase formed by reacting with tabular corundum was insufficient, resulting in the formation of a zircon-corundum mullite network structure only locally, thus reducing the high-temperature load softening and strength of the material. The compressive strength and thermal shock resistance of the obtained table board were significantly reduced.

[0133] Comparative Example 4: The difference from Example 1 lies in the firing regime. When the firing temperature reached 1650 °C, the holding time was only 1 - 2 hours. The dissociation of zircon granular material in the inner layer material was insufficient, and the amount of generated SiO2 phase was even less. Only a small part reacted with tabular corundum to form corundum mullite phase locally, resulting in the formation of a mullite network structure only in a small part, thus significantly reducing the high-temperature load softening and strength of the material. The compressive strength and thermal shock resistance of the obtained table board were significantly reduced.

[0134] Comparative Example 5: The difference from Example 1 is that the andalusite and zircon in the inner layer material were replaced with fine powders. The fine powders required a lower dissociation temperature. After high-temperature sintering, andalusite and zircon were completely dissociated, forming an excessive amount of SiO2 liquid phase, resulting in a decrease in the high-temperature load softening of the material, thus reducing the high-temperature strength of the material. The compressive strength and thermal shock resistance of the obtained table board were somewhat reduced.

[0135] As described above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claimed rights.

Claims

1. A method for preparing a heavy-duty high-temperature platen, characterized in that: The preparation method comprises the following steps: (1) The outer layer material, the inner layer material, and the outer layer material are laid flatly into the mold from bottom to top in a mass ratio of 1-2:6-8:1-2, and high-pressure molding is performed at a pressure of 200-250 MPa to obtain a molded blank; (2) Drying the formed blank until the moisture content is less than 1% to obtain a dry blank; (3) firing the dry blank at a temperature of 1680° C. and keeping the temperature for 2 to 4 hours to obtain the table plate; The raw materials of the outer layer material include, by weight: 4-5 parts of low-zirconium corundum, 4-5.5 parts of plate-shaped corundum and 0.8-1.5 parts of zircon, wherein the surface of the low-zirconium corundum and the surface of the plate-shaped corundum are coated with zircon; The raw materials of the inner layer material include: 3-4 parts of white corundum, 0.8-1.5 parts of fused mullite, 0.8-1.5 parts of andalusite, 0.8-1.5 parts of zircon and 1.3-2.5 parts of plate-like corundum, wherein the surfaces of white corundum, fused mullite, andalusite and zircon are coated with plate-like corundum.

2. The method for preparing a heavy-duty high-temperature platen according to claim 1, characterized in that: The particle size of low zirconium corundum is 3 to 1 mm; and / or, The particle size of the plate-like corundum is 1 to 0.125 mm; and / or, The particle size of zircon is ≤50um.

3. The method for preparing a heavy-duty high-temperature platen according to claim 1 or 2, characterized in that: The steps of coating the surface of low-zirconium corundum and plate-shaped corundum with zircon are as follows: Mix 4-5 parts of low-zirconium corundum and 4-5.5 parts of plate-shaped corundum to obtain a mixed dry material; Zircon is prepared into a mixed solution with a concentration of 70-85%; The mixed liquid is atomized and sprayed into the mixed dry material to obtain the outer layer material.

4. The method for preparing a heavy-duty high-temperature platen according to claim 1, characterized in that: The particle size of white corundum is 2 mm to 0.5 mm; and / or, The particle size of the fused mullite is 0.5 to 0.125 mm; and / or, The particle size of andalusite is 2 mm to 0.5 mm; and / or, The particle size of zircon is 3 mm to 0.5 mm; and / or, The particle size of plate-shaped corundum is ≤50um.

5. The method for preparing a heavy-duty high-temperature platen according to claim 1, characterized in that: Mix 3-4 parts of white corundum, 0.8-1.5 parts of fused mullite, 0.8-1.5 parts of andalusite, and 0.8-1.5 parts of zircon to obtain a mixed dry material; Prepare the plate-shaped corundum into a mixed solution with a concentration of 45-60%; The mixed liquid is atomized and sprayed into the mixed dry material to obtain the inner layer material.

6. The method for preparing a heavy-duty high-temperature platen according to claim 1, characterized in that: In step (3), the dry blank is fired according to the following temperature program: Firing temperature Firing curve Normal temperature~150℃40~50℃ / h 150~150℃ for 1h 150～300℃10～25℃ / h 300~300℃ insulation for 0.5h 300～600℃15～20℃ / h 600~600℃ insulation for 0.5h 600～1350℃40～50℃ / h 1350～1450℃20～25℃ / h 1450～1650℃40～50℃ / h 1650~1650℃ insulation for 1~2h 1650～1680℃30～40℃ / h 1680~1680℃ insulation for 2~4h 1680～1000℃150～200℃ / h 1000~normal temperature 60~100℃ / h.

7. A heavy-duty high-temperature platen obtained by the preparation method according to any one of claims 1 to 6.

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