Thermal insulation mortar with cement modified by aerogel particles and preparation method of thermal insulation mortar

Abstract

The invention belongs to the technical field of thermal insulation materials, and particularly relates to thermal insulation mortar with cement modified by aerogel particles and a preparation method of the thermal insulation mortar. Comprising 400-650 parts of cement, 88-117 parts of mineral powder, 4-6 parts of cellulose ether, 10 parts of a silane coupling agent, 4-6 parts of redispersible latex powder, 133.3-390 parts of glass beads, 250-266.7 parts of aerogel lightweight aggregate, 50 parts of a compound ternary dispersant, 9 parts of PVA fibers, 4-6 parts of a water reducing agent and 440-680 parts of water. The compound ternary dispersant is obtained by ultrasonically dispersing aerogel for modification in a compound additive, and the aerogel for modification is prepared by dispersing and ball-milling aerogel particles. The mechanical property of the composite mortar is optimized, and meanwhile, the heat conductivity coefficient of the composite mortar is further remarkably reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of thermal insulation materials, and particularly relates to a thermal insulation mortar of aerogel particle modified cement and a preparation method thereof. BACKGROUND

[0002] Under the background of global sustainable development, energy saving and environmental protection has become an unavoidable topic in today's environmental protection development. Traditional thermal insulation materials can be divided into organic thermal insulation materials and inorganic thermal insulation materials. Although the organic thermal insulation materials such as polystyrene and polyurethane foam have low thermal conductivity and good thermal insulation effect, they are flammable and easy to deform, and the combustion produces volatile toxic gases. And the inorganic thermal insulation materials such as rock wool and glass wool are difficult to achieve the desired thermal insulation effect. In this case, thermal insulation mortar emerges as the times require. This cement-based composite material has the characteristics of low thermal conductivity, excellent fireproof performance, strong adhesion, and green environmental protection, and has received widespread attention from the market.

[0003] However, the existing market thermal insulation mortar still has some problems, one of which is low strength, the second of which is that the thermal conductivity still has room for further optimization, and the third of which is the shrinkage problem of cement-based materials. Therefore, the present application aims at the above problems existing in the market thermal insulation mortar, introduces aerogel material into the cement-based system, so as to further reduce the thermal conductivity to improve the thermal insulation effect, uses part of mineral admixtures and organic fibers to alleviate the possible shrinkage and cracking problem of thermal insulation mortar, and further improves the compressive strength and tensile bonding strength.

[0004] However, the existing market aerogel thermal insulation mortar product shows that although the aerogel particles have the advantages of low thermal conductivity and low density, the interfacial bonding performance of the aerogel particles with the cement matrix is usually poor. This leads to the difficulty of further improving the thermal insulation performance of the thermal insulation mortar while maintaining sufficient mechanical strength. SUMMARY

[0005] The purpose of the present application is to provide a thermal insulation mortar of aerogel particle modified cement, which solves the technical problems of insufficient thermal insulation performance and material strength of the existing technology by using aerogel to strengthen the thermal insulation performance of refractory materials.

[0006] The thermal insulation mortar of aerogel particle modified cement, by weight, comprises: cement 400-650 parts, mineral powder 88-117 parts, cellulose ether 4-6 parts, silane coupling agent 10 parts, redispersible latex powder 4-6 parts, vitrified microbead 133.3-390 parts, aerogel lightweight aggregate 250-266.7 parts, compound ternary dispersant 50 parts, PVA fiber 9 parts, water reducing agent 4-6 parts and water 440-680 parts; the compound ternary dispersant is obtained by ultrasonic dispersion of modified aerogel in a compound admixture, and the modified aerogel is prepared by dispersing ball milling of aerogel particles.

[0007] Preferably, the components in the compound additive, by weight, include: 4-8 parts sodium dodecyl sulfate, 1-4 parts sodium hexametaphosphate, 1-6 parts silane coupling agent, and 39 parts deionized water, and the aerogel for modification, by weight, is 20-30 parts.

[0008] Preferably, after the aerogel particles are dispersed and ball-milled, aerogel powder with a D50 of 50μm, a specific surface area of ​​400-500m2 / g, and a water contact angle >145° is selected as the aerogel for modification. The cement is finely ground so that the aerogel powder and cement have the same particle size.

[0009] The present invention also provides a method for preparing the above-mentioned aerogel particle-modified cement thermal insulation mortar, comprising the following steps:

[0010] Step 1: Weigh 4-8 parts sodium dodecyl sulfate, 1-4 parts sodium hexametaphosphate, 1-6 parts silane coupling agent and 39 parts deionized water to prepare a compound additive;

[0011] Step 2: Grind 20-30 parts of aerogel particles to obtain the desired modified aerogel;

[0012] Step 3: Quickly pour the modified aerogel into the compound additive and ultrasonically disperse for 15 minutes to obtain the compound ternary dispersant;

[0013] Step 4: Add cement to a planetary ball mill and grind it to obtain fine cement for later use;

[0014] Step 5: Mix the compounded ternary dispersant with the finely ground cement until the slurry is in a viscous flow state, thus obtaining the aerogel modified cement slurry.

[0015] Step 6: Add mineral powder, pre-wetted vitrified microspheres, aerogel lightweight aggregate, cellulose ether, and redispersible latex powder to the aerogel-modified cement slurry in sequence, and continue stirring until the slurry is evenly mixed.

[0016] Step 7: Add the dispersed PVA fibers, water for mixing, water-reducing agent and the remaining silane coupling agent, and stir until the fibers are evenly distributed and do not agglomerate into large clumps. This will produce the thermal insulation mortar with aerogel particles modified cement.

[0017] Preferably, in step 2, the grinding is carried out using a planetary ball mill at a speed of 300-600 rpm for 2-4 hours, with a 5-minute stop after every 1 hour of grinding, and 3-5 mm agate balls are used as the grinding media.

[0018] Preferably, in step 4, the cement is added to a planetary ball mill and milled at 200 rpm for 30 minutes.

[0019] Preferably, in step 5, a portion of silane coupling agent is added to the compound ternary dispersant, and the amount of silane coupling agent added is 0 to 8 parts by weight.

[0020] Preferably, in step 6, the pre-wetting method for lightweight aggregate is as follows: weigh a sufficient amount of vitrified microspheres and dry them in an environment of 60±5℃ for 24 hours; add pre-wetting water of the same mass fraction as the vitrified microspheres to the spraying device and spray it evenly onto the surface of the vitrified microspheres to ensure surface wetting; weigh a sufficient amount of aerogel particles, add 1% of the mass fraction of the aerogel particles in anhydrous ethanol to the spraying device and spray it evenly onto the aerogel particles to evenly wet the surface of the aerogel particles.

[0021] Preferably, in step 7, the water-reducing agent is first mixed evenly with water and then continuously stirred until a viscous flowable state is formed. Then, the uniformly dispersed PVA fibers are slowly added in batches. After all the PVA fibers are added, the mixture is stirred for a certain period until the PVA fibers are coated with the slurry. The remaining mixing water and silane coupling agent are then added and stirred until the slurry is uniformly mixed. This invention has the following advantages:

[0022] 1. Based on existing technologies, this invention innovatively uses aerogel powder to functionalize cement, significantly improving the dispersibility and interfacial compatibility of aerogel materials in cement paste, thereby optimizing the mechanical properties of the composite material. Simultaneously, the inherent high porosity and nanoporous structure of aerogel are more effectively utilized, further significantly reducing the thermal conductivity of the composite mortar.

[0023] This invention utilizes an optimized ball milling process to prepare aerogel powder with the same particle size as cement, and employs a compound dispersant and surfactant to extend the lifetime of its surface hydroxyl active sites. When this active powder is blended with finely ground cement, the ≡Si-OH on the aerogel surface ionizes in the alkaline environment of the cement to form ≡Si-O-, which binds to and induces the directional adsorption of Ca2+ in the cement through ion-dipole interactions, thereby causing CSH gel to nucleate at the aerogel interface. This interaction directly forms a "core-shell" structure with the aerogel as the core and a dense CSH shell covering it. This structure effectively strengthens the interfacial bonding while also allowing multiple nanoscale pores to remain inside the cement paste, resulting in a significantly lower thermal conductivity compared to cement-based systems composed of dense hydration products (CSH).

[0024] 2. By using high-quality cement and mineral admixtures, the common problem of shrinkage cracking in premixed mortar is effectively alleviated. High-quality cement ensures the stability of material properties, while reducing cement usage reduces the intrinsic properties of cement, namely drying shrinkage and chemical shrinkage, and also reduces carbon emissions. Furthermore, organic fibers are used to bridge microcracks, suppressing cracking caused by shrinkage and enhancing bond strength.

[0025] 3. This invention also achieves a certain degree of viscosity in the thermal insulation mortar by precisely adjusting the dosage of admixtures, ensuring both workability and viscosity. Cellulose ethers form polymer films through high-molecular cross-linking to improve water retention, and redispersible latex powder promotes improved matrix adhesion. However, the combined effect of these two factors significantly reduces the fluidity of the mortar. Therefore, this invention requires the formulation of high-performance polycarboxylate superplasticizers. Detailed Implementation

[0026] The following description of the embodiments will provide a more detailed explanation of the specific implementation of the present invention, in order to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention.

[0027] This invention provides a thermal insulation mortar with aerogel particles modified cement, comprising, by weight: 400-650 parts cement, 88-117 parts mineral powder, 4-6 parts cellulose ether, 10 parts silane coupling agent, 4-6 parts redispersible latex powder, 133.3-390 parts vitrified microspheres, 250-266.7 parts aerogel lightweight aggregate, 50 parts compound ternary dispersant, 9 parts PVA fiber, 4-6 parts water-reducing agent, and 440-680 parts water; the compound ternary dispersant is obtained by ultrasonically dispersing the modified aerogel in the compound admixture, and the modified aerogel is prepared by dispersing and ball milling aerogel particles.

[0028] After dispersion and ball milling, aerogel powder with a D50 of 50 μm, a specific surface area of ​​400-500 m2 / g, and a water contact angle of >145° was selected as the aerogel for modification.

[0029] The components of the compound additive, by weight, include: 4-8 parts sodium dodecyl sulfate, 1-4 parts sodium hexametaphosphate, 1-6 parts silane coupling agent, and 39 parts deionized water. The aerogel for modification, by weight, comprises 20-30 parts.

[0030] The cement used is P·II 52.5 cement; the mineral powder used is S95 grade mineral powder; the cellulose ether used as an admixture is hydroxypropyl methylcellulose ether with a viscosity of 50000 mPa·s; the redispersible latex powder used is ethylene-vinyl acetate copolymer (VAE) with an effective content of ≥95%; the water-reducing agent used is a polycarboxylate-based water-reducing agent with a water reduction rate of ≥35%; and the vitrified microspheres are lightweight aggregates, using 90-110 mesh with a bulk density of 80-150 kg / m³. 3 Vitrified microspheres; aerogel lightweight aggregate with a bulk density of 8-30 kg / m³ 3 SiO2 aerogel particles with a thermal conductivity of <0.03W / (m·K) are used as lightweight aggregate; PVA fibers with a length of 12mm are selected.

[0031] This invention also provides a method for preparing aerogel particle-modified cement insulating mortar, comprising the following steps:

[0032] Step 1: Weigh 4-8 parts sodium dodecyl sulfate, 1-4 parts sodium hexametaphosphate, 1-6 parts silane coupling agent and 39 parts deionized water to prepare a compound additive.

[0033] Step 2: Grind 20-30 portions of aerogel particles to obtain the desired modified aerogel. Grinding is performed using a planetary ball mill at 300-600 rpm for 2-4 hours, with a 5-minute pause after each hour of grinding. 3-5 mm agate balls are used as the grinding media.

[0034] Step 3: Quickly pour the modified aerogel into the compound additive and ultrasonically disperse for 15 minutes to obtain a dispersant solution.

[0035] The dispersant solution obtained in this step is a compound ternary dispersant, which contains well-dispersed finely ground aerogel powder.

[0036] Step 4: Add cement to a planetary ball mill and mill at 200 rpm for 30 minutes to obtain finely ground cement for later use. After grinding, the aerogel powder and cement have the same particle size.

[0037] Step 5: Mix the dispersant solution with a portion of the silane coupling agent and finely ground cement until the slurry reaches a viscous flow state, thus obtaining the aerogel-modified cement slurry. This step can also be performed without adding the silane coupling agent.

[0038] Step 6: Add mineral powder, pre-wetted vitrified microspheres, aerogel lightweight aggregate, cellulose ether, and redispersible latex powder to the aerogel-modified cement slurry in sequence, and continue stirring until the slurry is evenly mixed.

[0039] The pre-wetting method for lightweight aggregates is as follows: Weigh a sufficient amount of vitrified microspheres and dry them in an environment of 60±5℃ for 24 hours. Add pre-wetting water of the same mass fraction as the vitrified microspheres to a spraying device and spray it evenly onto the surface of the vitrified microspheres to ensure surface wetting. Weigh a sufficient amount of aerogel particles and add 1% anhydrous ethanol (by mass fraction of the aerogel particles) to a spraying device and spray it evenly onto the aerogel particles to ensure uniform wetting of the aerogel particle surface.

[0040] Step 7: Add the dispersed PVA fibers, water for mixing, water-reducing agent and the remaining silane coupling agent, and stir until the fibers are evenly distributed and do not agglomerate into large clumps. This will produce the thermal insulation mortar with aerogel particles modified cement.

[0041] The first step involves mixing the water-reducing agent with water until a viscous flow is formed. Then, the PVA fibers, which have been uniformly dispersed, are slowly added in batches to ensure that the PVA fibers are evenly dispersed. After all the fibers are added, the mixture is stirred for a certain period of time until the PVA fibers are coated with the slurry. The remaining mixing water and silane coupling agent are then added and stirred until the slurry is uniformly mixed.

[0042] After using thermal insulation mortar to fill the mold, remove the mold after 24 hours and cure it in an environment with a temperature of 20±2℃ and a relative humidity of more than 95% to obtain the corresponding finished product.

[0043] In the aforementioned scheme, the microporous nature of aerogel particles results in extremely low thermal conductivity and density, effectively meeting the requirements for dry density and thermal conductivity in the current national standard for thermal insulation mortar. Therefore, some researchers have already considered incorporating it into the scope of lightweight aggregates. However, compared to vitrified microspheres, the interface defects between aerogel and cement paste are more pronounced, and the bonding is weaker. This is due to the multi-scale interfacial mismatch between the two materials, a phenomenon that severely restricts the synergistic optimization of the mechanical strength and thermal insulation performance of thermal insulation mortar.

[0044] This invention involves dispersing and ball milling silica aerogel. After appropriate grinding time and rate, the aerogel powder forms ≡Si-O· free radicals and exhibits good micro-nano-scale porosity. Cement, after grinding, more readily forms silicon free radicals during hydration: this is because the cement hydration reaction environment is alkaline, and the silicon-oxygen tetrahedra are attacked and broken into silicon and silicon-oxygen free radicals by hydroxyl groups. Grinding cement further enhances its bond-breaking efficiency (similar to how finely ground cement is more prone to hydration), thus forming more free radicals.

[0045] The silicon-oxygen radicals in the aerogel treated by dispersion ball milling are more active, and therefore more readily combine with silicon radicals in the hydration reaction environment to form stable Si-O-Si bonds, as expressed by:

[0046] ≡Si·+≡Si-O.→≡Si-O-Si≡.

[0047] Silicon radicals encapsulate the aerogel powder by binding to the abundant ≡Si-O· radical active sites within the aerogel. Subsequently, using this hydrophobic aerogel powder as nucleation sites, the silicon radicals combine with siloxane radicals, calcium ions, and other components in an alkaline environment to form CSH gel. This process ultimately constructs a composite structure with CSH gel as the "shell" and aerogel as the "core." This "shell-core" structure not only effectively protects the nanopores within the aerogel particles but also significantly enhances the interfacial bonding strength between the aerogel and the cement paste matrix through chemical bonding.

[0048] Specific embodiments of the present invention are as follows:

[0049] Example 1:

[0050] The thermal insulation mortar modified with aerogel particles, by weight, includes: 500 parts cement, 100 parts mineral powder, 5 parts cellulose ether, 10 parts silane coupling agent, 5 parts redispersible latex powder, 250 parts vitrified microspheres, 250 parts aerogel lightweight aggregate, 50 parts compound ternary dispersant, 6.4 parts PVA fiber, 5 parts water-reducing agent, and 560 parts water.

[0051] The compound additives, by weight, include: 5 parts sodium dodecyl sulfate, 2 parts silane coupling agent, 4 parts sodium hexametaphosphate, and 39 parts water.

[0052] The preparation method of this aerogel particle-modified cement insulation mortar includes the following steps:

[0053] Step 1: Weigh 5 parts sodium dodecyl sulfate, 4 parts sodium hexametaphosphate, 2 parts silane coupling agent and 39 parts deionized water to prepare a compound additive.

[0054] Step 2: Grind 20 portions of aerogel particles to obtain the desired modified aerogel. The grinding was carried out using a planetary ball mill at 400 rpm for 3 hours, with a 5-minute pause after each hour of grinding. 3-5 mm agate balls were used as the grinding media.

[0055] Step 3: Quickly pour the modified aerogel into the compound additive and ultrasonically disperse for 15 minutes to obtain a dispersant solution.

[0056] The dispersant solution obtained in this step is a compound ternary dispersant, which contains well-dispersed finely ground aerogel powder.

[0057] Step 4: Add cement to a planetary ball mill and mill at 200 rpm for 30 minutes to obtain finely ground cement for later use. After grinding, the aerogel powder and cement have the same particle size.

[0058] Step 5: Mix the dispersant solution with the finely ground cement to make the slurry viscous and fluid, thus obtaining the aerogel-modified cement slurry.

[0059] Specifically, 500 parts of finely ground cement and 50 parts of compounded ternary dispersant are added to a mortar mixer and mechanically mixed for 120 seconds until the slurry is in a viscous flow state, thus obtaining aerogel-modified cement slurry.

[0060] Step 6: Add mineral powder, pre-wetted vitrified microspheres, aerogel lightweight aggregate, cellulose ether, and redispersible latex powder to the aerogel-modified cement slurry in sequence, and continue stirring until the slurry is evenly mixed.

[0061] The specific steps are as follows: Add the corresponding proportions of mineral powder, pre-wetted vitrified microspheres, aerogel particles, cellulose ether, and redispersible latex powder to the mortar mixer and mix for 120 seconds until the slurry is uniformly mixed.

[0062] The pre-wetting method for lightweight aggregates is as follows: Weigh 250 parts of vitrified microspheres and dry them in an environment of 60±5℃ for 24 hours. Add 250 parts of pre-wetting water to a spraying device and spray evenly onto the surface of the vitrified microspheres to ensure surface wetting. Weigh 250 parts of aerogel particles and add 2.5 parts of anhydrous ethanol to a spraying device and spray evenly onto the aerogel particles to wet their surface.

[0063] Step 7: Add the dispersed PVA fibers, water for mixing, water-reducing agent and the remaining silane coupling agent, and stir until the fibers are evenly distributed and do not agglomerate into large clumps. This will produce the thermal insulation mortar with aerogel particles modified cement.

[0064] The first step is to mix the water-reducing agent with 160 parts of water evenly and stir continuously for 120 seconds until a viscous flow state is formed. Then, the PVA fibers that have been uniformly dispersed are slowly sprinkled in batches to ensure that the PVA fibers are evenly dispersed. After all the fibers are added, stir for 60 seconds until the PVA fibers are coated with the slurry. Then, add the remaining mixing water and silane coupling agent and stir until the slurry is evenly mixed.

[0065] Example 2:

[0066] The thermal insulation mortar modified with aerogel particles, by weight, includes: 400 parts cement, 88 parts mineral powder, 4 parts cellulose ether, 10 parts silane coupling agent, 4 parts redispersible latex powder, 133.3 parts vitrified microspheres, 266.7 parts aerogel lightweight aggregate, 50 parts compound ternary dispersant, 6 parts PVA fiber, 4 parts water-reducing agent, and 440 parts water.

[0067] The compound additives, by weight, include: 8 parts sodium dodecyl sulfate, 1 part silane coupling agent, 2 parts sodium hexametaphosphate, and 39 parts water.

[0068] The preparation method of this aerogel particle-modified cement insulation mortar includes the following steps:

[0069] Step 1: Weigh 8 parts sodium dodecyl sulfate, 2 parts sodium hexametaphosphate, 1 part silane coupling agent and 39 parts deionized water to prepare a compound additive.

[0070] Step 2: Grind 30 portions of aerogel particles to obtain the desired modified aerogel. The grinding was carried out using a planetary ball mill at 600 rpm for 2 hours, with a 5-minute pause after each hour of grinding. 3-5 mm agate balls were used as the grinding media.

[0071] Step 3: Quickly pour the modified aerogel into the compound additive and ultrasonically disperse for 15 minutes to obtain a dispersant solution.

[0072] The dispersant solution obtained in this step is a compound ternary dispersant, which contains well-dispersed finely ground aerogel powder.

[0073] Step 4: Add cement to a planetary ball mill and mill at 200 rpm for 30 minutes to obtain finely ground cement for later use. After grinding, the aerogel powder and cement have the same particle size.

[0074] Step 5: Mix the dispersant solution, silane coupling agent and finely ground cement to make the slurry viscous and fluid, thus obtaining aerogel modified cement slurry.

[0075] Specifically, 400 parts of finely ground cement, 50 parts of compounded ternary dispersant and 4 parts of silane coupling agent are added to a mortar mixer and mechanically mixed for 120 seconds until the slurry is in a viscous flow state, thus obtaining aerogel modified cement slurry.

[0076] Step 6: Add mineral powder, pre-wetted vitrified microspheres, aerogel lightweight aggregate, cellulose ether, and redispersible latex powder to the aerogel-modified cement slurry in sequence, and continue stirring until the slurry is evenly mixed.

[0077] The specific steps are as follows: Add the corresponding proportions of mineral powder, pre-wetted vitrified microspheres, aerogel particles, cellulose ether, and redispersible latex powder to the mortar mixer and mix for 120 seconds until the slurry is uniformly mixed.

[0078] The pre-wetting method for lightweight aggregates is as follows: Weigh 133.3 parts of vitrified microspheres and dry them in an environment of 60±5℃ for 24 hours. Add 133.3 parts of pre-wetting water to a spraying device and spray evenly onto the surface of the vitrified microspheres to ensure surface wetting. Weigh 266.7 parts of aerogel particles and add 2.7 parts of anhydrous ethanol to a spraying device and spray evenly onto the aerogel particles to wet their surface.

[0079] Step 7: Add the dispersed PVA fibers, water for mixing, water-reducing agent and the remaining silane coupling agent, and stir until the fibers are evenly distributed and do not agglomerate into large clumps. This will produce the thermal insulation mortar with aerogel particles modified cement.

[0080] The first step is to mix the water-reducing agent with 120 parts of water evenly and stir continuously for 120 seconds until a viscous flow state is formed. Then, the PVA fibers that have been uniformly dispersed are slowly sprinkled in batches to ensure that the PVA fibers are evenly dispersed. After all the fibers are added, stir for 60 seconds until the PVA fibers are coated with the slurry. Then, add the remaining mixing water and silane coupling agent and stir until the slurry is evenly mixed.

[0081] Example 3:

[0082] The thermal insulation mortar modified with aerogel particles comprises, by weight, 650 parts cement, 117 parts mineral powder, 6 parts cellulose ether, 10 parts silane coupling agent, 6 parts redispersible latex powder, 390 parts vitrified microspheres, 260 parts aerogel lightweight aggregate, 50 parts compound ternary dispersant, 9 parts PVA fiber, 6 parts water-reducing agent, and 680 parts water.

[0083] The compound additives, by weight, include: 4 parts sodium dodecyl sulfate, 6 parts silane coupling agent, 1 part sodium hexametaphosphate, and 39 parts water.

[0084] The preparation method of this aerogel particle-modified cement insulation mortar includes the following steps:

[0085] Step 1: Weigh 4 parts sodium dodecyl sulfate, 1 part sodium hexametaphosphate, 6 parts silane coupling agent and 39 parts deionized water to prepare a compound additive.

[0086] Step 2: Grind 25 portions of aerogel particles to obtain the desired modified aerogel. The grinding was carried out using a planetary ball mill at 300 rpm for 4 hours, with a 5-minute pause after each hour of grinding. 3-5 mm agate balls were used as the grinding media.

[0087] Step 3: Quickly pour the modified aerogel into the compound additive and ultrasonically disperse for 15 minutes to obtain a dispersant solution.

[0088] The dispersant solution obtained in this step is a compound ternary dispersant, which contains well-dispersed finely ground aerogel powder.

[0089] Step 4: Add cement to a planetary ball mill and mill at 200 rpm for 30 minutes to obtain finely ground cement for later use. After grinding, the aerogel powder and cement have the same particle size.

[0090] Step 5: Mix the dispersant solution, silane coupling agent and finely ground cement to make the slurry viscous and fluid, thus obtaining aerogel modified cement slurry.

[0091] Specifically, 650 parts of finely ground cement, 50 parts of compounded ternary dispersant and 8 parts of silane coupling agent are added to a mortar mixer and mechanically mixed for 120 seconds until the slurry is in a viscous flow state, thus obtaining aerogel modified cement slurry.

[0092] Step 6: Add mineral powder, pre-wetted vitrified microspheres, aerogel lightweight aggregate, cellulose ether, and redispersible latex powder to the aerogel-modified cement slurry in sequence, and continue stirring until the slurry is evenly mixed.

[0093] The specific steps are as follows: Add the corresponding proportions of mineral powder, pre-wetted vitrified microspheres, aerogel particles, cellulose ether, and redispersible latex powder to the mortar mixer and mix for 120 seconds until the slurry is uniformly mixed.

[0094] The pre-wetting method for lightweight aggregates is as follows: Weigh 390 parts of vitrified microspheres and dry them in an environment of 60±5℃ for 24 hours. Add 390 parts of pre-wetting water to a spraying device and spray evenly onto the surface of the vitrified microspheres to ensure surface wetting. Weigh 260 parts of aerogel particles and add 2.6 parts of anhydrous ethanol to a spraying device and spray evenly onto the aerogel particles to wet their surface.

[0095] Step 7: Add the dispersed PVA fibers, water for mixing, water-reducing agent and the remaining silane coupling agent, and stir until the fibers are evenly distributed and do not agglomerate into large clumps. This will produce the thermal insulation mortar with aerogel particles modified cement.

[0096] The first step is to mix the water-reducing agent with 120 parts of water evenly and stir continuously for 120 seconds until a viscous flow state is formed. Then, the PVA fibers that have been uniformly dispersed are slowly sprinkled in batches to ensure that the PVA fibers are evenly dispersed. After all the fibers are added, stir for 60 seconds until the PVA fibers are coated with the slurry. Then, add the remaining mixing water and silane coupling agent and stir until the slurry is evenly mixed.

[0097] Comparative example:

[0098] The thermal insulation mortar with aerogel particles modified cement, by weight, includes: 700 parts cement, 140 parts mineral powder, 7 parts cellulose ether, 4 parts silane coupling agent, 7 parts redispersible latex powder, 350 parts vitrified microspheres, 350 parts aerogel lightweight aggregate, 9 parts PVA fiber, 7 parts water-reducing agent, and 840 parts water.

[0099] The preparation method of this aerogel particle-modified cement insulation mortar includes the following steps:

[0100] Step 1: Mix cement, mineral powder, pre-wetted vitrified microspheres, aerogel lightweight aggregate, cellulose ether, and redispersible latex powder, and continue stirring until the dry powder is evenly mixed.

[0101] The specific steps are as follows: Cement, mineral powder, pre-wetted vitrified microspheres, aerogel particles, cellulose ether, and redispersible latex powder are loaded into a mortar mixer and run for 120 seconds until the dry powder is evenly mixed.

[0102] The pre-wetting method for lightweight aggregates is as follows: Weigh 350 parts of vitrified microspheres and dry them in an environment of 60±5℃ for 24 hours. Add 350 parts of pre-wetting water to a spraying device and spray evenly onto the surface of the vitrified microspheres to ensure surface wetting. Weigh 350 parts of aerogel particles and add 3.5 parts of anhydrous ethanol to a spraying device and spray evenly onto the aerogel particles to wet their surface.

[0103] Step 2: Add the dispersed PVA fibers, water for mixing, water-reducing agent and the remaining silane coupling agent, and stir until the fibers are evenly distributed and do not agglomerate into large clumps, thus making the thermal insulation mortar with aerogel particles modified cement.

[0104] The first step is to mix the water-reducing agent with 210 parts of water evenly and stir continuously for 120 seconds until a viscous flow state is formed. Then, the PVA fibers that have been uniformly dispersed are slowly sprinkled in batches to ensure that the PVA fibers are evenly dispersed. After all the fibers are added, stir for 60 seconds until the PVA fibers are coated with the slurry. Then, add the remaining mixing water and silane coupling agent and stir until the slurry is evenly mixed.

[0105] The performance of various aspects was tested through experimental examples 1-3 and comparative examples. The test results are shown in Table 1.

[0106] Table 1: Modified material mix proportions for aerogel thermal insulation mortar products in Examples 1-3 and the comparative example

[0107]

[0108] The performance of various aspects was tested through experimental examples 1-3 and comparative examples. The test results are shown in Table 2.

[0109] Table 2: Performance Indicators of Examples 1-3 and Comparative Examples of the Invention

[0110]

[0111] As can be seen from the table above, the aerogel-modified silica-mullite bricks generated in the examples exhibit less strength loss compared to ordinary refractory bricks, and the strength loss is far greater than the national standard critical value. The thermal conductivity is significantly reduced by >30%, and the actual temperature measurement shows significant insulation performance with a temperature drop >40℃. Therefore, these aerogel-modified silica-mullite bricks possess both mechanical properties and thermal insulation effects, making them highly valuable for applications in industrial kilns.

[0112] The present invention has been described above by way of example. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made by adopting the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A thermal insulation mortar with aerogel particles modified cement, characterized in that: By weight, it includes: 400-650 parts cement, 88-117 parts mineral powder, 4-6 parts cellulose ether, 10 parts silane coupling agent, 4-6 parts redispersible latex powder, 133.3-390 parts vitrified microspheres, 250-266.7 parts aerogel lightweight aggregate, 50 parts compound ternary dispersant, 9 parts PVA fiber, 4-6 parts water-reducing agent, and 440-680 parts water; the compound ternary dispersant is obtained by ultrasonic dispersion of the modifying aerogel in the compound additives, and the modifying aerogel is obtained by dispersing and ball milling aerogel particles.

2. The thermal insulation mortar with aerogel particles modified cement according to claim 1, characterized in that: The components of the compound additive, by weight, include: 4-8 parts sodium dodecyl sulfate, 1-4 parts sodium hexametaphosphate, 1-6 parts silane coupling agent, and 39 parts deionized water; and 20-30 parts aerogel for modification, by weight.

3. The thermal insulation mortar with aerogel particles modified cement according to claim 1, characterized in that: After the aerogel particles are dispersed and ball-milled, aerogel powder with a D50 of 50μm, a specific surface area of ​​400-500m2 / g, and a water contact angle of >145° is selected as the aerogel for modification. The cement is finely ground so that the aerogel powder and cement have the same particle size.

4. A method for preparing aerogel particle-modified cement insulating mortar according to any one of claims 1-3, characterized in that: Includes the following steps: Step 1: Weigh 4-8 parts sodium dodecyl sulfate, 1-4 parts sodium hexametaphosphate, 1-6 parts silane coupling agent and 39 parts deionized water to prepare a compound additive; Step 2: Grind 20-30 parts of aerogel particles to obtain the desired modified aerogel; Step 3: Quickly pour the modified aerogel into the compound additive and ultrasonically disperse for 15 minutes to obtain the compound ternary dispersant; Step 4: Add cement to a planetary ball mill and grind it to obtain fine cement for later use; Step 5: Mix the compounded ternary dispersant with the finely ground cement until the slurry is in a viscous flow state, thus obtaining the aerogel modified cement slurry. Step 6: Add mineral powder, pre-wetted vitrified microspheres, aerogel lightweight aggregate, cellulose ether, and redispersible latex powder to the aerogel-modified cement slurry in sequence, and continue stirring until the slurry is evenly mixed. Step 7: Add the dispersed PVA fibers, water for mixing, water-reducing agent and the remaining silane coupling agent, and stir until the fibers are evenly distributed and do not agglomerate into large clumps. This will produce the thermal insulation mortar with aerogel particles modified cement.

5. The method for preparing aerogel particle-modified cement insulating mortar according to claim 4, characterized in that: In step 2, the grinding is carried out using a planetary ball mill at a speed of 300-600 rpm for 2-4 hours, with a 5-minute stop after every 1 hour of grinding. The grinding media are 3-5 mm agate balls.

6. The method for preparing aerogel particle-modified cement insulating mortar according to claim 4, characterized in that: In step 4, the cement is added to a planetary ball mill and milled at 200 rpm for 30 minutes.

7. The method for preparing aerogel particle-modified cement insulating mortar according to claim 4, characterized in that: In step 5, a portion of silane coupling agent is added to the compound ternary dispersant. The amount of silane coupling agent added is 0 to 8 parts by weight.

8. The method for preparing a thermal insulation mortar with aerogel particles modified cement according to claim 4, characterized in that: In step 6, the pre-wetting method for lightweight aggregate is as follows: Weigh a sufficient amount of vitrified microspheres and dry them in an environment of 60±5℃ for 24 hours. Add pre-wetting water of the same mass fraction as the vitrified microspheres to the spraying device and spray it evenly onto the surface of the vitrified microspheres to ensure surface wetting. Weigh a sufficient amount of aerogel particles and add 1% of the mass fraction of the aerogel particles in anhydrous ethanol to the spraying device and spray it evenly onto the aerogel particles to wet the surface of the aerogel particles.

9. The method for preparing a thermal insulation mortar with aerogel particles modified cement according to claim 4, characterized in that: In step 7, the water-reducing agent is first mixed with water until it forms a viscous flow state. Then, the PVA fibers that have been uniformly dispersed are slowly sprinkled in batches. After all the PVA fibers are added, the mixture is stirred for a certain period of time until the PVA fibers are coated with the slurry. The remaining mixing water and silane coupling agent are then added and stirred until the slurry is uniformly mixed.

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