A high-temperature composite material liner and its preparation method

Abstract

This invention discloses a high-temperature composite material lining, comprising: 50-70 parts of mullite ceramsite aggregate, 5-35 parts of high-alumina fly ash, 5-25 parts of additives, and 1-6 parts of binder. The above raw materials are mixed in a wet mill, then processed and shaped to obtain the high-temperature resistant material lining; the high-temperature resistant material lining is dried, then coated on the working surface and dried again to obtain a high-temperature resistant material precursor; the high-temperature resistant material precursor is fired in a kiln to obtain the final product. The high-temperature resistant material provided by this invention allows for the utilization of some industrial solid waste in the region, and enables the prepared coated lining to possess suitable strength, matching high-temperature expansion and contraction, and good thermal insulation performance, thereby achieving good application and economic value.

Description

Technical Field

[0001] This invention belongs to the field of waste incineration environmental protection technology, specifically relating to a high-temperature composite material liner and its preparation method. Background Technology

[0002] Waste incineration produces a large amount of low-melting-point salts containing Ka and Na. As the furnace temperature fluctuates, these substances deposit on the surface of the refractory materials, forming nodules and bulges. This affects equipment operating efficiency, damages the furnace body, and reduces the furnace's service life. The temperature fluctuations in the incinerator are mainly due to the unstable calorific value of the waste combustion products, requiring constant replenishment of the heat source. Although some furnaces have adopted intelligent control measures, which have improved the situation to some extent, frequent adjustments are still necessary.

[0003] Currently, the furnace body material is mainly silicon carbide castable to reduce adhesion and crust formation, but this does not help improve the temperature fluctuation of the furnace body. Strengthening the furnace body temperature insulation usually involves adding a layer of calcium silicate board insulation or lightweight castable between the refractory material and the iron furnace shell near the furnace shell to reduce the loss of furnace temperature, which has achieved certain results.

[0004] Given the above shortcomings, how to retain the advantages of the former while attaching a high-temperature composite material lining to the working layer inside the furnace to both insulate the working layer and improve temperature fluctuations is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] To address the shortcomings and deficiencies of existing technologies, this invention enhances kiln insulation, thereby improving kiln thermal stability, reducing the frequency of temperature adjustments, and lowering the risk of kiln damage. This invention is achieved through the following technical means:

[0006] This invention discloses a high-temperature composite material liner, comprising:

[0007] 50-70 parts of mullite ceramsite aggregate, 5-35 parts of high-alumina fly ash, 5-25 parts of additives, and 1-6 parts of binder.

[0008] Furthermore, the particle size of the mullite ceramsite aggregate is <5mm.

[0009] Furthermore, the mullite ceramsite aggregate is refractory spherical ceramsite with an alumina content of 42-55%.

[0010] Furthermore, in the high-alumina fly ash, more than 80% of the particles have a particle size of <0.074mm.

[0011] Furthermore, the high-alumina fly ash is fly ash with an alumina content of ≥40% produced by circulating fluidized bed coal combustion in thermal power plants.

[0012] Furthermore, the additives include: Baotou rare earth tailings powder, Zhungeer Banner quartz tailings powder, and Hangjin clay.

[0013] Furthermore, in the additive, more than 90% of the particles have a particle size <0.044 mm.

[0014] Furthermore, the mass ratio of the Baotou rare earth tailings, Zhunqi quartz tailings and Hangjin clay is (1-5):(1-5):(3-15).

[0015] Furthermore, the binder is a liquid with a specific gravity ≥ 1.12.

[0016] Furthermore, the binder includes: a concrete-forming agent and pulp.

[0017] In this invention, the high-temperature resistant material made from this (high-temperature coating) liner has high strength, matching high-temperature expansion and contraction, and good thermal insulation performance.

[0018] The present invention also discloses a high-temperature resistant material, which is prepared from the above-mentioned high-temperature composite material liner.

[0019] Furthermore, the working surface of the high-temperature resistant material is coated with a low-shrinkage heat-insulating coating based on the CaO-Al2O3-SiO2 system.

[0020] Furthermore, the maximum operating temperature of the high-temperature resistant material is 1450°C.

[0021] This invention also discloses a method for preparing a high-temperature resistant material, comprising:

[0022] (1) Ingredients: Weigh out mullite ceramsite, high-alumina fly ash, additives and binders in proportion;

[0023] (2) Molding: The raw materials are mixed in a wet mill, then processed into shape and dried to obtain a high-temperature resistant material liner;

[0024] (3) Coating: Dry the high-temperature resistant material liner, dry the liner obtained by molding, coat it on its working surface, and dry it to obtain the high-temperature resistant material precursor.

[0025] (4) Firing: The high-temperature resistant material precursor is fired in a kiln to obtain the product.

[0026] Furthermore, the processing and molding described in step (2) is machine pressing, and the density after pressing is 2.0-1.6 g / cm³. 3 .

[0027] Furthermore, the drying conditions described in step (2) are: heat preservation at 110℃ for 1-12 hours.

[0028] Furthermore, the drying conditions described in step (3) are: heat preservation at 110℃ for 1-12 hours.

[0029] Furthermore, the firing temperature control method in step (4) is as follows:

[0030] The initial temperature is raised to 550℃, with the heating rate controlled at 10-60℃ / h; at 550℃, the temperature is held for 2-10 hours; from 550 to 900℃, the heating rate is controlled at 60-180℃ / h, and at 900℃, the temperature is held for 2-10 hours; from 900 to 1400℃, the heating rate is controlled at 60-180℃ / h, and at 1400℃, the temperature is held for 2-12 hours.

[0031] The present invention also discloses high-temperature resistant materials prepared by any of the above preparation methods.

[0032] The beneficial effects of this invention are as follows:

[0033] The high-temperature resistant material lining provided by this invention allows for the utilization of some industrial solid waste within the region. The resulting coated lining possesses suitable strength, matched high-temperature expansion and contraction, and excellent thermal insulation performance, thus achieving significant practical and economic value. This invention utilizes industrial solid waste and thermal insulation coating raw materials and technologies to produce a composite material that effectively solves the technical problem of frequent temperature fluctuations within the furnace, reduces costs, and achieves the technical effect of stabilizing the furnace and extending its lifespan by preventing bulging caused by temperature fluctuations. Testing of the material itself primarily reveals its thermal conductivity, strength, and bonding properties. Detailed Implementation

[0034] To further understand the technical content, features, and effects of this invention, the following description is provided in conjunction with the embodiments.

[0035] This does not constitute a limitation of the present invention. Detailed explanation follows:

[0036] Example 1:

[0037] A high-temperature composite material and its preparation method

[0038] (1) Ingredients: 68 parts of mullite ceramsite particles with a particle size ≤5mm, 15 parts of high-alumina fly ash, 5 parts of Baotou rare earth tailings powder, 5 parts of Zhunqi quartz tailings powder, 5 parts of Hangjin clay powder, and 2 parts of concrete-forming agent.

[0039] (2) Molding: The above raw materials are mixed in a wet mill and then placed in a 300t press for molding. The prepared mud is loaded into a steel mold and the molding load is 100MPa to obtain a high-temperature resistant material liner.

[0040] (3) Coating: The high-temperature resistant material liner is dried at 110°C for 24 hours, and then coated on its working surface and dried at 110°C for 4 hours to obtain the high-temperature resistant material precursor.

[0041] (4) Firing: The high-temperature resistant material precursor is fired in an air atmosphere in a kiln. The firing temperature is controlled as follows: the initial temperature is raised to 550℃, and the heating rate is controlled at 30℃ / h; when it reaches 550℃, it is held for 6h; from 550℃ to 900℃, the heating rate is controlled at 60℃ / h, and when it reaches 900℃, it is held for 4h; from 900℃ to 1400℃, the heating rate is controlled at 100℃ / h, and when it reaches 1400℃, it is held for 8h; finally, it is cooled to room temperature to obtain the product.

[0042] Performance indicators: thermal conductivity less than 0.1 W / mK at 900℃, compressive strength greater than 400 MPa, and good adhesion between coating and lining.

[0043] Example 2:

[0044] A high-temperature composite material and its preparation method

[0045] (1) Ingredients: 60 parts of mullite ceramsite particles with a particle size ≤3mm, 15 parts of high-alumina fly ash, 3 parts of Baotou rare earth tailings powder, 3 parts of Zhunqi quartz tailings powder, 14 parts of Hangjin clay powder, and 5 parts of pulp.

[0046] (2) Molding: The above raw materials are mixed in a wet mill and then placed in a 300t press for molding. The prepared mud is loaded into a steel mold and the molding load is 50MPa to obtain a high-temperature resistant material liner.

[0047] (3) Coating: The high-temperature resistant material liner is dried at 110°C for 24 hours, and then coated on its working surface and dried at 110°C for 4 hours to obtain the high-temperature resistant material precursor.

[0048] (4) Firing: The high-temperature resistant material precursor is fired in an air atmosphere in a kiln. The firing temperature is controlled as follows: the initial temperature is raised to 550℃, and the heating rate is controlled at 30℃ / h; when it reaches 550℃, it is held for 10h; from 550℃ to 900℃, the heating rate is controlled at 80℃ / h, and when it reaches 900℃, it is held for 4h; from 900℃ to 1400℃, the heating rate is controlled at 80℃ / h, and when it reaches 1400℃, it is held for 4h; finally, it is cooled to room temperature to obtain the product.

[0049] Performance indicators: thermal conductivity less than 0.1 W / mK at 900℃, compressive strength greater than 30 MPa, and good adhesion between coating and lining.

[0050] Example 3:

[0051] A high-temperature composite material and its preparation method

[0052] (1) Ingredients: 69 parts of mullite ceramsite particles with a particle size ≤5mm, 16 parts of high-alumina fly ash, 2 parts of Baotou rare earth tailings powder, 1 part of Zhunqi quartz tailings powder, 6 parts of Hangjin clay powder, and 4 parts of concrete-forming agent.

[0053] (2) Molding: The above raw materials are mixed in a wet mill and then placed in a 300t press for molding. The prepared mud is loaded into a steel mold and the molding load is 100MPa to obtain a high-temperature resistant material liner.

[0054] (3) Coating: The high-temperature resistant material liner is dried at 110°C for 24 hours, and then coated on its working surface and dried at 110°C for 4 hours to obtain the high-temperature resistant material precursor.

[0055] (4) Firing: The high-temperature resistant material precursor is fired in an air atmosphere in a kiln. The firing temperature is controlled as follows: the initial temperature is raised to 550℃, and the heating rate is controlled at 60℃ / h; when it reaches 550℃, it is held for 8h; from 550℃ to 900℃, the heating rate is controlled at 120℃ / h, and it is held for 8h at 900℃; from 900℃ to 1400℃, the heating rate is controlled at 120℃ / h, and it is held for 8h at 1400℃; finally, it is cooled to room temperature to obtain the product.

[0056] Performance indicators: thermal conductivity less than 0.1 W / mK at 900℃, compressive strength greater than 50 MPa, and good adhesion between coating and lining.

[0057] Example 4:

[0058] A high-temperature composite material and its preparation method

[0059] (1) Ingredients: 65 parts of mullite ceramsite particles with a particle size ≤2mm, 17 parts of high-alumina fly ash, 3 parts of Baotou rare earth tailings powder, 3 parts of Zhunqi quartz tailings powder, 10 parts of Hangjin clay powder, and 2 parts of pulp.

[0060] (2) Molding: The above raw materials are mixed in a wet mill and then placed in a 300t press for molding. The prepared mud is loaded into a steel mold and the molding load is 120MPa to obtain a high-temperature resistant material liner.

[0061] (3) Coating: The high-temperature resistant material liner is dried at 110°C for 24 hours, and then coated on its working surface and dried at 110°C for 4 hours to obtain the high-temperature resistant material precursor.

[0062] (4) Firing: The high-temperature resistant material precursor is fired in an air atmosphere in a kiln. The firing temperature is controlled as follows: the initial temperature is raised to 550℃, and the heating rate is controlled at 10℃ / h; when it reaches 550℃, it is held for 6 hours; from 550℃ to 900℃, the heating rate is controlled at 180℃ / h, and when it reaches 900℃, it is held for 4 hours; from 900℃ to 1400℃, the heating rate is controlled at 150℃ / h, and when it reaches 1400℃, it is held for 4 hours; finally, it is cooled to room temperature to obtain the product.

[0063] Performance indicators: thermal conductivity less than 0.1 W / mK at 900℃, compressive strength greater than 40 MPa, and good adhesion between coating and lining.

[0064] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the claims. Furthermore, the above description should be understood and implemented by those skilled in the art; therefore, any modifications made based on the disclosure of this invention should be included within the scope of these claims.

Claims

1. A method for preparing a high-temperature resistant material, comprising: (1) Ingredients: Weigh out 50-70 parts of mullite ceramsite aggregate, 5-35 parts of high-alumina fly ash, 5-25 parts of additives, and 1-6 parts of binder according to the proportion. (2) Molding: The raw materials are mixed in a wet mill, then processed into shape and dried to obtain a high-temperature resistant material liner; (3) Coating: Dry the high-temperature resistant material liner, and after drying the liner obtained by molding, apply a CaO-Al2O3-SiO2 low-shrinkage heat insulation coating to its working surface, and dry it to obtain the high-temperature resistant material precursor. (4) Firing: The high-temperature resistant material precursor is fired in a kiln, with the initial temperature increased to 550℃, and the heating rate controlled at 10-60℃ / h; at 550℃, it is held for 2-10h; from 550-900℃, the heating rate is controlled at 60-180℃ / h, and at 900℃, it is held for 2-10h; from 900-1400℃, the heating rate is controlled at 60-180℃ / h, and at 1400℃, it is held for 2-12h, thus obtaining the high-temperature resistant material. The maximum service temperature of this high-temperature resistant material is 1450℃; where: The particle size of the mullite ceramsite aggregate is <5mm. The mullite ceramsite aggregate is refractory spherical ceramsite with an alumina content of 42-55%. In high-alumina fly ash, more than 80% of the particles have a particle size of <0.074mm; high-alumina fly ash is fly ash with an alumina content of ≥40% produced by circulating fluidized bed coal combustion in thermal power plants. The additives include: Baotou rare earth tailings powder, Zhunqi quartz tailings powder and Hangjin clay, with the mass ratio of Baotou rare earth tailings, Zhunqi quartz tailings and Hangjin clay being (1-5):(1-5):(3-15); in the additives, more than 90% of the particles have a particle size <0.044mm. The binder is a liquid with a specific gravity ≥ 1.12, and the binder is pulp.

2. The preparation method according to claim 1, wherein: The processing and molding described in step (2) is machine pressing, and the density after pressing is 2.0-1.6 g / cm³. 3 ; The drying conditions are: heat preservation at 110℃ for 1-12 hours.

3. The preparation method according to claim 1, wherein: The drying conditions described in step (3) are: heat preservation at 110℃ for 1-12 hours.

4. A high-temperature resistant material prepared by any one of the preparation methods according to claims 1-3.