Fly ash high-temperature thermal insulation material and preparation method thereof

Abstract

The invention discloses a fly ash high-temperature thermal insulation material and a preparation method thereof, and relates to the technical field of thermal insulation materials, the fly ash high-temperature thermal insulation material comprises the following raw materials: 40-50 parts of fly ash floating beads, 20-28 parts of vermiculite, 15-21 parts of mineral cotton, 17-25 parts of borax, 0.17-0.26 part of alumina, and 15-20 parts of water glass; the mass ratio of the borax to the aluminum oxide is 1: (0.01-0.015); the preparation method comprises the following steps: uniformly mixing borax and aluminum oxide, adding vermiculite and mineral cotton, and uniformly mixing and stirring to obtain a mixture A; mixing fly ash floating beads with water glass to obtain a mixture B; uniformly mixing the mixture A and the mixture B, and calcining to obtain a fly ash high-temperature heat insulation blank; acidizing the blank, and modifying with polyaniline; and then the surface of the fly ash is coated with a YSZ / La2O3 composite coating, and the fly ash high-temperature thermal insulation material is obtained. The high-temperature-resistant heat-insulating material has excellent high-temperature-resistant heat-insulating effect and compression strength.

Description

Technical Field

[0001] The present application relates to the field of thermal insulation material technology, and in particular to a fly ash high-temperature thermal insulation material and a preparation method thereof. Background Art

[0002] Industrial solid waste primarily refers to solid waste generated or left over from industrial production processes, such as mining tailings, smelting slag, coal gangue from the coal-fired power industry, and fly ash. Statistics show that with the development of industries such as chemical, steel, coal-fired power, and non-ferrous metals, industrial solid waste emissions exceed 4 billion tons annually. If not properly handled, the long-term accumulation of industrial solid waste not only occupies significant land, increases economic costs, but also seriously harms the ecological environment. Fly ash is the solid waste emitted after coal combustion in thermal power plants. Fly ash beads are hollow microspheres that float on water, obtained by removing the iron-rich ash from fly ash through sorting and electrostatic separation. The hollow, thin-walled structure of fly ash beads can be used to create thermal insulation materials after mixing with aluminum-silicon raw materials and calcining at high temperatures. They are widely used in construction, petrochemicals, metallurgy, and machinery.

[0003] However, due to the hollow thin-walled structure of fly ash beads, their strength is relatively low. In some application scenarios that need to withstand high mechanical stress or pressure, such as the load-bearing parts of building structures, fly ash bead insulation materials may not meet the requirements and are prone to damage, thus limiting their scope of use. Summary of the Invention

[0004] In order to solve the problems in the prior art, the present application provides a fly ash high-temperature thermal insulation material and a preparation method thereof.

[0005] This application provides a fly ash high-temperature thermal insulation material, which adopts the following technical solution:

[0006] A fly ash high-temperature thermal insulation material comprises, by weight, 40-50 parts of fly ash floating beads, 20-28 parts of vermiculite, 15-21 parts of slag wool, 17-25 parts of borax, 0.17-0.26 parts of aluminum oxide, and 15-20 parts of water glass; the mass ratio of the borax to the aluminum oxide is 1:0.01-0.015.

[0007] Preferably, the particle size of the fly ash floating beads is 150-850 μm.

[0008] This application also provides a method for preparing fly ash high-temperature thermal insulation material, which adopts the following technical solution:

[0009] A method for preparing a fly ash high-temperature thermal insulation material comprises the following steps:

[0010] S1. After mixing 17-25 parts of borax and 0.17-0.25 parts of alumina by weight, add 20-28 parts of vermiculite, 15-21 parts of slag wool, mix and stir to obtain a mixture A; 40-50 parts of fly ash beads and 15-20 parts of water glass are mixed to obtain a mixture B;

[0011] S2. The mixture A and the mixture B were mixed and stirred for 20-30min, followed by pre-baking at 110-130 ℃ for 10-16h; and then calcined at 800-1000 ℃ for 3-6h to obtain a fly ash high-temperature insulation billet;

[0012] S3. After the fly ash high temperature insulation billet is acidified, the fly ash high temperature insulation billet is obtained by acidification; the fly ash high temperature insulation billet is modified by polyaniline to obtain a polyaniline-modified fly ash high temperature insulation billet;

[0013] S4. A YSZ / La2O3 composite coating was applied to the surface of a polyaniline-modified fly ash high-temperature insulation blank by electrophoretic deposition. The fly ash high-temperature insulation material was obtained by sintering the blank at 800-1000°C for 4-6 hours in an argon atmosphere.

[0014] Preferably, the acidification treatment of the fly ash high-temperature insulation blank in S3 comprises the following steps:

[0015] The fly ash high-temperature insulation blank is placed in dilute acid and mixed, and then heated at 75-85° C. for 7-9 hours. The product is filtered and washed with water until neutral, and vacuum dried to obtain the acidified fly ash high-temperature insulation blank.

[0016] Preferably, the dilute acid is a 1-3 mol / L HCl aqueous solution.

[0017] Preferably, the solid-liquid ratio of the fly ash high-temperature thermal insulation blank to the dilute acid is 1:10-12 g / mL.

[0018] Preferably, the polyaniline-modified fly ash high-temperature insulation blank in S3 comprises the following steps:

[0019] Weigh cetyltrimethylammonium bromide and stir it evenly with distilled water to obtain a cetyltrimethylammonium bromide solution; add distilled water to the acidified fly ash high-temperature insulation blank, stir it evenly, then add the cetyltrimethylammonium bromide solution, and react at 75-85° C. for 1-2 hours; filter the reactant under reduced pressure, wash, and dry to obtain a cetyltrimethylammonium bromide-modified fly ash high-temperature insulation blank;

[0020] Aniline, hexadecyltrimethylammonium bromide-modified fly ash high-temperature thermal insulation blank and dodecylbenzenesulfonic acid are added to distilled water and stirred at room temperature to form an emulsion. Ammonium persulfate is dissolved in water and added dropwise to the emulsion. The reaction is continuously carried out at 4-6°C for 12-14 hours. After the reaction is completed, the fly ash high-temperature thermal insulation blank is filtered under reduced pressure, washed and dried to obtain a polyaniline-modified fly ash high-temperature thermal insulation blank.

[0021] Preferably, the mass ratio of the acidified fly ash high-temperature insulation blank to polyaniline is 1:0.0075-0.01.

[0022] Preferably, the mass ratio of the hexadecyltrimethylammonium bromide modified fly ash high-temperature insulation blank, aniline, dodecylbenzenesulfonic acid, and ammonium persulfate is 1:0.7-0.9:0.8-0.9:1.5-2.5.

[0023] Preferably, the step of coating the YSZ / La2O3 composite coating on the surface of the polyaniline-modified fly ash high-temperature insulation blank by electrophoretic deposition in S4 comprises the following steps:

[0024] Yttria-stabilized zirconia powder and lanthanum oxide powder were dispersed in anhydrous ethanol and homogenized in an ultrasonic bath for 15-20 minutes. A dispersant was added and ultrasonic treatment was performed for 2-3 hours to prepare a YSZ / La2O3 suspension. A polyaniline-modified fly ash high-temperature insulation billet was used as the cathode and a graphite plate as the anode, and deposition was carried out at a voltage of 40-60V for 8-12 minutes.

[0025] Preferably, the dispersant is iodine; the mass ratio of the yttria-stabilized zirconia powder, lanthanum oxide powder, and iodine is 18-20:1:1.5-1.7.

[0026] In summary, this application includes at least one of the following beneficial technical effects:

[0027] 1. This application uses a mixture of alumina and borax to effectively improve the high-temperature stability of borax. The introduction of boron element through borax can promote the diffusion and rearrangement between mineral particles during the sintering process, making the sintering process more uniform and efficient, helping to form a dense material structure and improve the mechanical properties and stability of the material.

[0028] 2. This application first uses the cationic surfactant hexadecyltrimethylammonium bromide as a modifier, and adsorbs the hexadecyltrimethylammonium bromide on the surface of the fly ash high-temperature thermal insulation material through electrostatic adsorption; then uses the principle of similar compatibility to introduce aniline into the surface of the floating beads, and polymerizes the aniline through emulsion polymerization, thereby coating the hexadecyltrimethylammonium bromide-modified fly ash high-temperature thermal insulation blank to obtain a polyaniline-modified fly ash high-temperature thermal insulation blank. The polyaniline-modified fly ash high-temperature thermal insulation blank can significantly improve the thermal stability of the material, and at the same time can effectively improve the electrical conductivity, which is beneficial to the subsequent electrophoretic deposition coating.

[0029] 3. This application adopts the electrophoretic deposition method to coat the YSZ coating doped with rare earth La2O3 on the surface of the fly ash high-temperature resistant thermal insulation material, which can effectively enhance the high-temperature stability of the fly ash high-temperature resistant thermal insulation material; at the same time, the YSZ coating doped with rare earth La2O3 has high mechanical strength and good wear resistance, which helps to reduce the wear of the material during use, enhance its mechanical properties, and extend its service life. DETAILED DESCRIPTION

[0030] The present application is further described in detail below with reference to the embodiments.

[0031] The chemical reagents used in the examples and comparative examples provided by the present invention are all commercially available products.

[0032] Example 1

[0033] S1. After mixing 17g of borax and 0.17g of alumina (the mass ratio of borax to alumina was 1:0.01), 20g of vermiculite and 15g of slag wool were added and stirred to obtain a mixture A; 40g of fly ash beads having a particle size of 150-850μm was mixed with 15g of water glass to obtain a mixture B;

[0034] S2. The mixture A and mixture B were mixed and stirred for 20min to mix the clay evenly; after 12h of trapped material, the cylindrical specimens were pressed into φ50mm×50mm at a pressure of 5MPa, and then pre-baked at 110 ℃ for 10h; and then calcined at 800 ℃ for 6h to obtain fly ash high-temperature insulation billet;

[0035] S3. After the fly ash high temperature insulation billet is acidified, the acidified fly ash high temperature insulation billet is obtained. The specific operations are as follows:

[0036] 20 g of fly ash high-temperature insulation blank was placed in 200 mL of 1 mol / L HCl aqueous solution and mixed, followed by heating at 75°C for 7 h. The product was filtered and washed with water until neutral, and then vacuum-dried at 60°C to obtain an acidified fly ash high-temperature insulation blank.

[0037] The acidified fly ash high-temperature thermal insulation blank is modified with polyaniline to obtain the polyaniline-modified fly ash high-temperature thermal insulation blank. The specific operation is as follows:

[0038] Weigh 0.075 g of hexadecyltrimethylammonium bromide and stir evenly with 150 mL of distilled water to obtain a hexadecyltrimethylammonium bromide solution; add 200 mL of distilled water to 10 g of acidified fly ash high-temperature insulation billet (i.e., the mass ratio of the acidified fly ash high-temperature insulation billet to hexadecyltrimethylammonium bromide is 1:0.0075), stir evenly, then add the hexadecyltrimethylammonium bromide solution, and react at 75°C for 1 hour; the reactant is filtered under reduced pressure, washed with distilled water, and dried to obtain a hexadecyltrimethylammonium bromide-modified fly ash high-temperature insulation billet;

[0039] 7 g of aniline, 10 g of hexadecyltrimethylammonium bromide-modified fly ash high-temperature thermal insulation blank and 8 g of dodecylbenzenesulfonic acid were added to 200 g of distilled water and stirred at room temperature to form an emulsion. 15 g of ammonium persulfate (i.e., the mass ratio of hexadecyltrimethylammonium bromide-modified fly ash high-temperature thermal insulation blank, aniline, dodecylbenzenesulfonic acid, and ammonium persulfate was 1:0.7:0.8:1.5) was dissolved in 100 g of water and added dropwise to the emulsion. The reaction was continuously carried out at 4°C for 14 hours. After the reaction was completed, the mixture was filtered under reduced pressure, washed with acetone, and dried to obtain a polyaniline-modified fly ash high-temperature thermal insulation blank.

[0040] S4. Applying a YSZ / La2O3 composite coating to the surface of a polyaniline-modified fly ash high-temperature insulation blank by electrophoretic deposition, as follows:

[0041] 1.8 g of yttria-stabilized zirconia powder and 0.1 g of lanthanum oxide powder were dispersed in 300 mL of anhydrous ethanol and homogenized in an ultrasonic bath for 15 min. 0.15 g of iodine, a dispersant, was added (i.e., the mass ratio of yttria-stabilized zirconia powder, lanthanum oxide powder, and iodine was 18:1:1.5). After ultrasonic treatment for 2 h, a YSZ / La2O3 suspension was prepared. Polyaniline-modified fly ash high-temperature insulation blank was used as the cathode and a graphite plate was used as the anode, and deposition was carried out at a voltage of 40 V for 8 min.

[0042] Then, the fly ash high-temperature thermal insulation material was obtained after sintering at 800°C for 6 hours in an argon atmosphere.

[0043] Example 2

[0044] S1. After 21g of borax and 0.21g of alumina were mixed (the mass ratio of borax to alumina was 1:0.01), 24g of vermiculite and 18g of slag wool were added and mixed and stirred to obtain a mixture A; 45g of fly ash beads with a particle size of 150-850μm were mixed with 18.5g of water glass to obtain a mixture B;

[0045] S2. The mixture A and mixture B were mixed and stirred for 25min to mix the clay evenly; after 13h of trapped material, cylindrical specimens of φ50mm×50mm were pressed under a pressure of 5MPa and then pre-baked at 120°C for 13h; and then calcined at 900°C for 4.5h to obtain fly ash high-temperature insulation billet;

[0046] S3. After the fly ash high temperature insulation billet is acidified, the acidified fly ash high temperature insulation billet is obtained. The specific operations are as follows:

[0047] 20 g of fly ash high-temperature insulation blank was placed in 220 mL of 2 mol / L HCl aqueous solution and mixed, followed by heating at 80°C for 8 h. The product was filtered and washed with water until neutral, and then vacuum-dried at 65°C to obtain an acidified fly ash high-temperature insulation blank.

[0048] The acidified fly ash high-temperature thermal insulation blank is modified with polyaniline to obtain the polyaniline-modified fly ash high-temperature thermal insulation blank. The specific operation is as follows:

[0049] Weigh 0.075 g of hexadecyltrimethylammonium bromide and stir evenly with 175 mL of distilled water to obtain a hexadecyltrimethylammonium bromide solution; add 250 mL of distilled water to 10 g of acidified fly ash high-temperature insulation billet (i.e., the mass ratio of acidified fly ash high-temperature insulation billet to hexadecyltrimethylammonium bromide is 1:0.0075), stir evenly, then add the hexadecyltrimethylammonium bromide solution, and react at 80°C for 1.5 hours; the reactant is filtered under reduced pressure, washed with distilled water, and dried to obtain a hexadecyltrimethylammonium bromide-modified fly ash high-temperature insulation billet;

[0050] 7 g of aniline, 10 g of hexadecyltrimethylammonium bromide-modified fly ash high-temperature thermal insulation blank, and 8 g of dodecylbenzenesulfonic acid were added to 220 g of distilled water and stirred at room temperature to form an emulsion. 15 g of ammonium persulfate (i.e., the mass ratio of hexadecyltrimethylammonium bromide-modified fly ash high-temperature thermal insulation blank, aniline, dodecylbenzenesulfonic acid, and ammonium persulfate was 1:0.7:0.8:1.5) was dissolved in 120 g of water and added dropwise to the emulsion. The reaction was continuously carried out at 5° C. for 13 hours. After the reaction was completed, the mixture was filtered under reduced pressure, washed with acetone, and dried to obtain a polyaniline-modified fly ash high-temperature thermal insulation blank.

[0051] S4. Applying a YSZ / La2O3 composite coating to the surface of a polyaniline-modified fly ash high-temperature insulation blank by electrophoretic deposition, as follows:

[0052] 1.8 g of yttria-stabilized zirconia powder and 0.1 g of lanthanum oxide powder were dispersed in 350 mL of anhydrous ethanol and homogenized in an ultrasonic bath for 18 min. 0.15 g of iodine, a dispersant, was added (i.e., the mass ratio of yttria-stabilized zirconia powder, lanthanum oxide powder, and iodine was 18:1:1.5). The suspension was ultrasonically treated for 2.5 h to prepare a YSZ / La2O3 suspension. The polyaniline-modified fly ash high-temperature insulation blank was used as the cathode and a graphite plate as the anode, and deposition was carried out at a voltage of 50 V for 10 min.

[0053] Then, the fly ash high-temperature thermal insulation material was obtained after sintering at 900°C for 5 hours in an argon atmosphere.

[0054] Example 3

[0055] S1. After 25g of borax and 0.25g of alumina were mixed (the mass ratio of borax to alumina was 1:0.01), 28g of vermiculite and 21g of slag wool were added and mixed and stirred to obtain a mixture A; 50g of fly ash beads with a particle size of 150-850μm were mixed with 20g of water glass to obtain a mixture B;

[0056] S2. The mixture A and mixture B were mixed and stirred for 30min to mix the clay evenly; after 14h of trapped material, the cylindrical specimens were pressed into φ50mm×50mm at a pressure of 5MPa, and then pre-baked at 130 ℃ for 16h; and then calcined at 1000 ℃ for 3h to obtain fly ash high-temperature insulation billet;

[0057] S3. After the fly ash high temperature insulation billet is acidified, the acidified fly ash high temperature insulation billet is obtained. The specific operations are as follows:

[0058] 20 g of fly ash high-temperature insulation blank was placed in 240 mL of 3 mol / L HCl aqueous solution and mixed, followed by heating at 85°C for 9 h. The product was filtered and washed with water until neutral, and then vacuum-dried at 70°C to obtain an acidified fly ash high-temperature insulation blank.

[0059] The acidified fly ash high-temperature thermal insulation blank is modified with polyaniline to obtain the polyaniline-modified fly ash high-temperature thermal insulation blank. The specific operation is as follows:

[0060] Weigh 0.075 g of hexadecyltrimethylammonium bromide and stir evenly with 200 mL of distilled water to obtain a hexadecyltrimethylammonium bromide solution; add 300 mL of distilled water to 10 g of acidified fly ash high-temperature insulation billet (i.e., the mass ratio of the acidified fly ash high-temperature insulation billet to hexadecyltrimethylammonium bromide is 1:0.0075), stir evenly, then add the hexadecyltrimethylammonium bromide solution, and react at 85°C for 2 h; the reactant is filtered under reduced pressure, washed with distilled water, and dried to obtain a hexadecyltrimethylammonium bromide-modified fly ash high-temperature insulation billet;

[0061] 7 g of aniline, 10 g of hexadecyltrimethylammonium bromide-modified fly ash high-temperature thermal insulation blank, and 8 g of dodecylbenzenesulfonic acid were added to 250 g of distilled water and stirred at room temperature to form an emulsion. 15 g of ammonium persulfate (i.e., the mass ratio of hexadecyltrimethylammonium bromide-modified fly ash high-temperature thermal insulation blank, aniline, dodecylbenzenesulfonic acid, and ammonium persulfate was 1:0.7:0.8:1.5) was dissolved in 150 g of water and added dropwise to the emulsion. The reaction was continuously carried out at 6° C. for 12 hours. After the reaction was completed, the mixture was filtered under reduced pressure, washed with acetone, and dried to obtain a polyaniline-modified fly ash high-temperature thermal insulation blank.

[0062] S4. Applying a YSZ / La2O3 composite coating to the surface of a polyaniline-modified fly ash high-temperature insulation blank by electrophoretic deposition, as follows:

[0063] 1.8 g of yttria-stabilized zirconia powder and 0.1 g of lanthanum oxide powder were dispersed in 400 mL of anhydrous ethanol and homogenized in an ultrasonic bath for 20 min. 0.15 g of iodine, a dispersant, was added (i.e., the mass ratio of yttria-stabilized zirconia powder, lanthanum oxide powder, and iodine was 18:1:1.5). After ultrasonic treatment for 3 h, a YSZ / La2O3 suspension was prepared. Polyaniline-modified fly ash high-temperature insulation blank was used as the cathode and a graphite plate as the anode, and deposition was carried out at a voltage of 60 V for 12 min.

[0064] Then, the fly ash high-temperature thermal insulation material was obtained after sintering at 1000°C for 4 hours in an argon atmosphere.

[0065] Example 4

[0066] The difference between Example 4 and Example 1 is that the borax used in Example 4 is 17 g and the aluminum oxide is 0.221 g, that is, the mass ratio of borax to aluminum oxide is 1:0.013.

[0067] Example 5

[0068] The difference between Example 5 and Example 1 is that the borax used in Example 5 is 17 g and the aluminum oxide is 0.255 g, that is, the mass ratio of borax to aluminum oxide is 1:0.015.

[0069] Example 6

[0070] The difference between Example 6 and Example 1 is that in Example 6, the acidified fly ash high-temperature insulation blank used in S3 is 10g, and the hexadecyltrimethylammonium bromide is 0.085g, that is, the mass ratio of the fly ash high-temperature insulation blank to the hexadecyltrimethylammonium bromide is 1:0.0085.

[0071] Example 7

[0072] The difference between Example 7 and Example 1 is that in Example 7, the acidified fly ash high-temperature insulation blank used in S3 is 10g, and the hexadecyltrimethylammonium bromide is 0.1g, that is, the mass ratio of the fly ash high-temperature insulation blank to the hexadecyltrimethylammonium bromide is 1:0.01.

[0073] Example 8

[0074] The difference between Example 8 and Example 1 is that in Example 8, the acidified fly ash high-temperature insulation blank used in S3 is 10g, and the hexadecyltrimethylammonium bromide is 0.06g, that is, the mass ratio of the fly ash high-temperature insulation blank to the hexadecyltrimethylammonium bromide is 1:0.006.

[0075] Example 9

[0076] The difference between Example 9 and Example 1 is that in Example 9, the acidified fly ash high-temperature insulation blank used in S3 is 10g, and the hexadecyltrimethylammonium bromide is 0.115g, that is, the mass ratio of the fly ash high-temperature insulation blank to the hexadecyltrimethylammonium bromide is 1:0.0115.

[0077] Example 10

[0078] The difference between Example 10 and Example 1 is that in Example 10, the yttria-stabilized zirconia powder used in S4 is 1.9 g, the lanthanum oxide powder is 0.1 g, and the iodine is 0.16 g, that is, the mass ratio of yttria-stabilized zirconia powder, lanthanum oxide powder, and iodine is 19:1:1.6.

[0079] Example 11

[0080] The difference between Example 11 and Example 1 is that in Example 10, the yttria-stabilized zirconia powder used in S4 is 2 g, the lanthanum oxide powder is 0.1 g, and the iodine is 0.17 g, that is, the mass ratio of yttria-stabilized zirconia powder, lanthanum oxide powder, and iodine is 20:1:1.7.

[0081] Example 12

[0082] The difference between Example 12 and Example 1 is that in Example 12, the yttria-stabilized zirconia powder used in S4 is 1.7 g, the lanthanum oxide powder is 0.1 g, and the iodine is 0.14 g, that is, the mass ratio of yttria-stabilized zirconia powder, lanthanum oxide powder, and iodine is 17:1:1.4.

[0083] Example 13

[0084] The difference between Example 13 and Example 1 is that in Example 13, the yttria-stabilized zirconia powder used in S4 is 2.1 g, the lanthanum oxide powder is 0.1 g, and the iodine is 0.18 g, that is, the mass ratio of yttria-stabilized zirconia powder, lanthanum oxide powder, and iodine is 21:1:1.8.

[0085] Example 14

[0086] The difference between Example 14 and Example 1 is that in Example 14, the hexadecyltrimethylammonium bromide-modified fly ash high-temperature thermal insulation blank used in S3 is 10 g, aniline is 8 g, dodecylbenzenesulfonic acid is 8.5 g, and ammonium persulfate is 20 g, that is, the mass ratio of the hexadecyltrimethylammonium bromide-modified fly ash high-temperature thermal insulation blank, aniline, dodecylbenzenesulfonic acid, and ammonium persulfate is 1:0.8:0.85:2.

[0087] Example 15

[0088] The difference between Example 15 and Example 1 is that in Example 15, the hexadecyltrimethylammonium bromide-modified fly ash high-temperature thermal insulation blank used in S3 is 10 g, aniline is 9 g, dodecylbenzenesulfonic acid is 9 g, and ammonium persulfate is 25 g, that is, the mass ratio of the hexadecyltrimethylammonium bromide-modified fly ash high-temperature thermal insulation blank, aniline, dodecylbenzenesulfonic acid, and ammonium persulfate is 1:0.9:0.9:2.5.

[0089] Comparative Example 1

[0090] The difference between Comparative Example 1 and Example 1 is that no aluminum oxide is added in Comparative Example 1.

[0091] Comparative Example 2

[0092] The difference between Comparative Example 2 and Example 1 is that the borax used in Comparative Example 2 is 17 g and the aluminum oxide is 0.085 g, that is, the mass ratio of borax to aluminum oxide is 1:0.005.

[0093] Comparative Example 3

[0094] The difference between Comparative Example 3 and Example 1 is that the borax used in Comparative Example 3 is 17 g and the aluminum oxide is 0.34 g, that is, the mass ratio of borax to aluminum oxide is 1:0.02.

[0095] Comparative Example 4

[0096] The difference between Comparative Example 4 and Example 1 is that no slag wool is added in Comparative Example 4.

[0097] Comparative Example 5

[0098] The difference between Comparative Example 5 and Example 1 is that the YSZ / La2O3 composite coating is not performed in Comparative Example 5.

[0099] Comparative Example 6

[0100] The difference between Comparative Example 6 and Example 1 is that no polyaniline modification is performed in Comparative Example 6.

[0101] Performance testing

[0102] 1. Based on GB / T 5072-2008, the room temperature compressive strength of the fired samples was measured using a YAW-1000D microcomputer-controlled pressure testing machine. The results are shown in Table 1.

[0103] 2. According to YB / T 4130-2005, the thermal conductivity of the sample after sintering at 300°C was measured using a flat-plate thermal conductivity meter. The results are shown in Table 1.

[0104] The specific test results are as follows:

[0105] Table 1 Performance test results

[0106]

[0107]

[0108] It can be seen from the test results in Table 1 that the fly ash high-temperature thermal insulation material and the preparation method thereof provided in this application have high room temperature compressive strength of the fly ash high-temperature thermal insulation material obtained, which indicates that the fly ash high-temperature thermal insulation material provided in this application has strong mechanical properties; the thermal conductivity is relatively low, indicating that it has excellent thermal insulation ability.

[0109] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A fly ash high-temperature thermal insulation material, characterized by: The raw materials include 40-50 parts of fly ash floating beads, 20-28 parts of vermiculite, 15-21 parts of slag wool, 17-25 parts of borax, 0.17-0.26 parts of aluminum oxide, and 15-20 parts of water glass in parts by weight; the mass ratio of the borax to the aluminum oxide is 1:0.01-0.

015.

2. The fly ash high-temperature thermal insulation material according to claim 1, characterized in that: The particle size of the fly ash floating beads is 150-850 μm.

3. A method for preparing fly ash high-temperature thermal insulation material, characterized by: The following steps are involved: S1. After mixing 17-25 parts of borax and 0.17-0.25 parts of alumina by weight, add 20-28 parts of vermiculite, 15-21 parts of slag wool, mix and stir to obtain a mixture A; 40-50 parts of fly ash beads and 15-20 parts of water glass are mixed to obtain a mixture B; S2. The mixture A and the mixture B were mixed and stirred for 20-30min, followed by pre-baking at 110-130 ℃ for 10-16h; and then calcined at 800-1000 ℃ for 3-6h to obtain a fly ash high-temperature insulation billet; S3. After the fly ash high temperature insulation billet is acidified, the fly ash high temperature insulation billet is obtained by acidification; the fly ash high temperature insulation billet is modified by polyaniline to obtain a polyaniline-modified fly ash high temperature insulation billet; S4. A YSZ / La2O3 composite coating was applied to the surface of a polyaniline-modified fly ash high-temperature insulation blank by electrophoretic deposition. The fly ash high-temperature insulation material was obtained by sintering the blank at 800-1000°C for 4-6 hours in an argon atmosphere.

4. The method for preparing a fly ash high-temperature thermal insulation material according to claim 3, characterized in that: The acidification treatment of the fly ash high-temperature insulation blank in S3 comprises the following steps: The fly ash high-temperature insulation blank is placed in dilute acid and mixed, and then heated at 75-85° C. for 7-9 hours. The product is filtered and washed with water until neutral, and vacuum dried to obtain the acidified fly ash high-temperature insulation blank.

5. The method for preparing a fly ash high-temperature thermal insulation material according to claim 4, characterized in that: The dilute acid is a 1-3 mol / L HCl aqueous solution; the solid-liquid ratio of the fly ash high-temperature thermal insulation blank to the dilute acid is 1:10-12 g / mL.

6. The method for preparing a fly ash high-temperature thermal insulation material according to claim 3, characterized in that: The polyaniline-modified fly ash high-temperature insulation blank in S3 comprises the following steps: Weigh cetyltrimethylammonium bromide and stir it evenly with distilled water to obtain a cetyltrimethylammonium bromide solution; add distilled water to the acidified fly ash high-temperature insulation blank, stir it evenly, then add the cetyltrimethylammonium bromide solution, and react at 75-85° C. for 1-2 hours; filter the reactant under reduced pressure, wash, and dry to obtain a cetyltrimethylammonium bromide-modified fly ash high-temperature insulation blank; Aniline, hexadecyltrimethylammonium bromide-modified fly ash high-temperature thermal insulation blank and dodecylbenzenesulfonic acid are added to distilled water and stirred at room temperature to form an emulsion. Ammonium persulfate is dissolved in water and added dropwise to the emulsion. The reaction is continuously carried out at 4-6°C for 12-14 hours. After the reaction is completed, the fly ash high-temperature thermal insulation blank is filtered under reduced pressure, washed and dried to obtain a polyaniline-modified fly ash high-temperature thermal insulation blank.

7. The method for preparing a fly ash high-temperature thermal insulation material according to claim 6, characterized in that: The mass ratio of the acidified fly ash high-temperature insulation blank to hexadecyltrimethylammonium bromide is 1:0.0075-0.

01.

8. The method for preparing a fly ash high-temperature thermal insulation material according to claim 6, characterized in that: The mass ratio of the hexadecyltrimethylammonium bromide modified fly ash high-temperature thermal insulation blank, aniline, dodecylbenzenesulfonic acid, and ammonium persulfate is 1:0.7-0.9:0.8-0.9:1.5-2.

5.

9. The method for preparing a fly ash high-temperature thermal insulation material according to claim 3, characterized in that: The method of coating a YSZ / La2O3 composite coating on the surface of a polyaniline-modified fly ash high-temperature insulation blank by an electrophoretic deposition method in S4 comprises the following steps: Yttria-stabilized zirconia powder and lanthanum oxide powder were dispersed in anhydrous ethanol and homogenized in an ultrasonic bath for 15-20 minutes. A dispersant was added and ultrasonic treatment was performed for 2-3 hours to prepare a YSZ / La2O3 suspension. A polyaniline-modified fly ash high-temperature insulation billet was used as the cathode and a graphite plate as the anode, and deposition was carried out at a voltage of 40-60V for 8-12 minutes.

10. The method for preparing a fly ash high-temperature thermal insulation material according to claim 9, characterized in that: The dispersant is iodine; the mass ratio of the yttria-stabilized zirconia powder, the lanthanum oxide powder, and the iodine is 18-20:1:1.5-1.7.

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