Lunar soil fiber aerogel composite thermal insulation material as well as preparation method and application thereof

Abstract

The invention discloses a lunar soil fiber aerogel composite thermal insulation material as well as a preparation method and application thereof. The lunar soil fiber aerogel composite thermal insulation material is prepared by the following steps: mixing lunar soil fibers and silica gel, gelatinizing, drying to obtain an aerogel matrix, coating a silicon-based binder on the surface of the aerogel matrix, and curing, so as to obtain the lunar soil fiber aerogel composite thermal insulation material. Wherein the aerogel matrix is prepared from the following components in parts by weight: 15 to 30 parts of lunar soil fiber and 65 to 85 parts of silica sol; the lunar soil fibers are continuous fibers prepared by taking lunar soil as a raw material, and the silica sol is prepared from a lunar soil silicon source. The material is low in heat conductivity coefficient, high in compressive strength, small in heat conductivity change rate after extreme temperature difference circulation and high in radiation shielding efficiency. According to the method, efficient conversion of lunar in-situ resources is achieved, earth-moon transportation cost is reduced, and the method is suitable for lunar base building heat insulation structures and has important aerospace application value.

Description

Technical Field

[0001] This application relates to the field of new materials, and in particular to a lunar soil fiber aerogel thermal insulation material, its preparation method, and its application. Background Technology

[0002] With the advancement of deep space exploration, the construction of lunar bases has become a core objective of human deep space habitation. Self-sufficiency in materials for extreme environments and high-performance protection are crucial for the long-term operation of lunar bases. The lunar surface presents harsh conditions such as diurnal temperature variations exceeding 300°C (-173°C to 127°C), intense cosmic radiation, and micrometeorite impacts, placing stringent demands on the thermal insulation, mechanical strength, and environmental adaptability of building materials.

[0003] Aerogels, with their extremely low thermal conductivity (≤0.025 W / (m·K)), high porosity (≥99%), and lightweight properties, have become a core candidate for thermal insulation materials in lunar construction. However, existing aerogel preparation technologies have significant limitations: on the one hand, traditional aerogels rely on terrestrial precursors such as tetraethyl orthosilicate, resulting in extremely high transportation costs between Earth and the Moon (over US$100,000 per kilogram), and pure aerogels have weak mechanical properties (compressive strength typically <0.5 MPa), making them susceptible to damage from micrometeorite impacts or thermal stress; on the other hand, aerogel drying processes are complex. While supercritical drying is mature, it requires sophisticated equipment and is expensive, while atmospheric pressure drying results in insufficient product quality stability, and freeze-drying makes it difficult to prepare blocky, intact structures, all of which are unsuitable for large-scale in-situ production on the Moon.

[0004] Lunar soil, as the richest in-situ resource on the Moon, is rich in oxides such as SiO2 and Al2O3, and has the potential to be transformed into reinforcing fibers. Among the existing technologies for utilizing lunar soil, lunar soil brick making mostly adopts processes such as sintering and 3D printing, but it suffers from problems such as poor heating uniformity, high energy consumption, and reliance on Earth-derived binders; while aerogel reinforcement mostly uses heterogeneous materials such as glass fiber and carbon fiber, which are prone to interfacial cracking due to the large difference in thermal expansion coefficients with aerogel, and further increase the burden of Earth-Moon transportation.

[0005] Therefore, how to utilize lunar soil to prepare high-performance fibers in situ and form a highly compatible composite structure with aerogel, while optimizing the preparation process to adapt to the extreme lunar environment and in-situ production constraints, has become an urgent need to overcome the technological bottleneck of thermal insulation materials for lunar bases. Developing lunar soil fiber-aerogel composite thermal insulation materials can achieve the efficient conversion of "in-situ resources into functional materials," balancing low thermal conductivity and high mechanical strength, which is of great significance for reducing the construction cost of lunar bases and improving the environmental adaptability of materials. Summary of the Invention

[0006] The purpose of this application is to provide a lunar soil fiber aerogel composite thermal insulation material that combines low thermal conductivity and high mechanical strength and is suitable for the extreme lunar environment, using lunar soil to prepare lunar soil fiber reinforcement, lunar soil silicon source to prepare aerogel matrix and in-situ binder, and its application in the thermal insulation structure of lunar base buildings.

[0007] Another objective of this application is to provide a method for preparing a lunar soil fiber aerogel composite thermal insulation material.

[0008] This application is in the research, verification, and pilot-scale testing stage of the invention conducted in an Earth environment. Due to the extremely high cost and limited quantity of obtaining real lunar soil, this application uses simulated lunar soil (Lunar Regolith Simulant) to replace real lunar soil for material preparation and performance testing. The chemical composition, mineral phase structure, and physical properties (such as particle size distribution, specific surface area, and thermal stability) of the simulated lunar soil are all designed with reference to publicly available lunar samples to ensure that the experimental results have high reference value for applications with real lunar soil.

[0009] To achieve the above-mentioned objectives, this application adopts the following technical solution: A lunar soil fiber aerogel composite thermal insulation material is disclosed. The composite thermal insulation material is obtained by mixing and gelling lunar soil fibers with silica sol, drying the resulting aerogel matrix, coating the surface of the aerogel matrix with a silicone-based binder, and then curing it. The aerogel matrix comprises 15-30 parts by weight of lunar soil fibers and 65-85 parts by weight of silica sol. The lunar soil fibers are continuous fibers prepared from lunar soil, and the silica sol is silica sol prepared from lunar soil silica source.

[0010] Furthermore, the silicon-based binder includes siloxane binders or lunar soil in-situ extracted binders.

[0011] Furthermore, the surface of the lunar soil fiber is modified with a silane coupling agent, wherein the silane coupling agent is KH550.

[0012] Furthermore, the silicon-based binder is selected from at least one of the following: tetraethyl orthosilicate hydrolysate with a solid content of 10-15%, lunar soil sulfur-based binder, and lunar soil ceramicized binder layer; wherein the lunar soil sulfur-based binder is obtained by melting sulfur in lunar soil at 240°C; and the lunar soil ceramicized binder layer is obtained by extracting PO4 from lunar soil apatite. 3- It is produced by reacting with aluminum oxide.

[0013] This application also discloses a method for preparing a lunar soil fiber aerogel composite thermal insulation material, comprising the following steps: (1) Preparation of lunar soil fiber: After pretreatment of lunar soil, lunar soil fiber is obtained by melt spinning, and then the surface of lunar soil fiber is modified. (2) Preparation of aerogel matrix: Silica sol is prepared using lunar soil silica source, and the lunar soil fiber is mixed with silica sol and gelled, and then dried to obtain composite material preform; (3) Composite molding: A silicon-based binder is coated on the surface of the composite material blank, and then cured to obtain lunar soil fiber aerogel composite thermal insulation material.

[0014] Furthermore, the pretreatment described in step (1) includes: crushing lunar soil to a particle size ≤ 50 μm, controlling the uniform particle size distribution, and then calcining it in a vacuum furnace at 800°C for 2 hours.

[0015] Furthermore, the drying process described in step (2) adopts a combination of cryogenic-atmospheric pressure drying: first, it is cryogenically cured at -170℃ to -190℃, and then it is dried in a vacuum atmospheric pressure gradient of 50℃→120℃ under lunar daytime conditions, with a total drying cycle of ≤48 hours.

[0016] Furthermore, the preparation method of the silica sol in step (2) is as follows: extract the silica source from lunar soil, mix it with ethanol and deionized water in a volume ratio of 1:3:0.5, add hydrochloric acid to adjust the pH to 2~3, and stir at 50°C for 2 hours.

[0017] Furthermore, the acquisition of the lunar soil silicon source: the lunar soil raw material for lunar soil fiber is purified by a microwave-acid leaching combined process, specifically including: the lunar soil is activated by microwave at 800℃ for 10 min, and then leached with a gradient of 5%-20% hydrofluoric acid to obtain SiO2 with a purity ≥99.5%.

[0018] Furthermore, in step (3), the energy supply for the curing process is combined with an energy storage device. During the lunar day, solar energy is used for high-temperature curing, and during the lunar night, low power consumption and heat preservation are maintained. The curing conditions are 60°C for 2 hours in a vacuum environment.

[0019] Application of a lunar soil fiber aerogel composite insulation material in the thermal insulation structure of a lunar base building.

[0020] Compared with the prior art, the present invention has the following significant advantages: Efficient utilization of in-situ resources: The entire process relies on lunar soil to prepare fibers, silicon sources and binders, reducing the cost of Earth-Moon transportation, making full use of in-situ resources, and achieving "self-sufficiency" of materials for the lunar base.

[0021] Synergistic performance optimization: The lunar soil fiber and aerogel matrix have the same composition and excellent interfacial compatibility. The composite material has low thermal conductivity and high compressive strength, which meets the requirements of thermal insulation and structural support under the extreme temperature difference of the moon.

[0022] High process adaptability: The use of combined refrigeration-atmospheric pressure drying to replace supercritical drying shortens the drying cycle to 48 hours; combined with a solar-energy storage system, energy utilization efficiency is improved, adapting to the characteristics of lunar energy supply.

[0023] Excellent environmental stability: After 20 extreme temperature cycles, the thermal conductivity change rate is <5%, there is no obvious cracking, the radiation shielding efficiency is ≥99%, and it can adapt to the harsh environment of strong lunar radiation and micrometeorite impact for a long time.

[0024] This invention provides a high-performance, low-cost, and easy-to-implement thermal insulation material solution for lunar base construction through material design and process innovation, and has significant value for aerospace engineering applications. Detailed Implementation

[0025] The present application will be further illustrated by the following embodiments, but the scope of protection of the present application is not limited to the embodiments.

[0026] This application is in the research, verification, and pilot-scale testing stage of the invention conducted in an Earth environment. Due to the extremely high cost and limited quantity of obtaining real lunar soil, this application uses simulated lunar soil (Lunar Regolith Simulant) to replace real lunar soil for material preparation and performance testing. The chemical composition, mineral phase structure, and physical properties (such as particle size distribution, specific surface area, and thermal stability) of the simulated lunar soil are all designed with reference to publicly available lunar samples to ensure that the experimental results have high reference value for applications with real lunar soil.

[0027] The simulated lunar soil used in this application was prepared according to the following steps: Raw material ratio: Weigh the following high-purity oxides or mineral raw materials according to their mass percentage: Silicon dioxide (SiO2): 45–50% Aluminum oxide (Al2O3): 15–20% Ferrous oxide (FeO) or iron(III) oxide (Fe3O4): 10–18% Calcium oxide (CaO): 8–12% Magnesium oxide (MgO): 4–8% Titanium oxide (TiO2): 1–3% Apatite (Ca5(PO4)3(F,Cl,OH)): 2–3% (used to provide PO4) 3- ) Elemental sulfur (S): 0.1–0.2% The above proportions are based on the average chemical composition of lunar maria basalt-type regolith.

[0028] Preparation method 1. Mixing and ball milling: The above raw materials are placed in a high-energy planetary ball mill and mixed and milled for 4–6 hours under an inert atmosphere (such as argon) to homogenize the particle size and promote the initial solid-phase reaction, thereby obtaining a mixed powder.

[0029] 2. High-temperature melting and quenching: The mixed powder is placed in a corundum crucible and then placed in an electric arc furnace or induction furnace. It is melted at 1500–1600°C for 2 hours, followed by rapid quenching (such as water quenching or metal plate pressure quenching) to form an amorphous-microcrystalline mixed glassy block, which simulates the natural structure of lunar soil after being melted by micrometeorite impact and then rapidly cooled.

[0030] 3. Crushing and screening: The quenched blocks are coarsely crushed by a jaw crusher, then ground to a particle size of ≤50μm by a planetary ball mill, and then classified by a vibrating screen (such as a three-stage screen of 50μm, 30μm, and 20μm) to control the particle size distribution to conform to D50≈30μm, which is consistent with the characteristics of real lunar soil particles.

[0031] 4. Vacuum roasting for impurity removal: The sieved simulated lunar soil powder was placed in a vacuum furnace and calcined at 800℃ for 2 hours (vacuum degree ≤10). -2 (Pa) is used to remove adsorbed water, organic impurities and volatile components to obtain a dry and clean simulated lunar soil product.

[0032] The simulated lunar soil was characterized by X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Its chemical composition, mineral phases (mainly pyroxene, plagioclase, and olivine amorphous phases), and microstructure are highly similar to those of real lunar soil, making it suitable for the full-process verification of the preparation of lunar soil fibers, silica sol, and binders described in this invention.

[0033] Example 1: 1. Raw material preparation Lunar soil: The main components are SiO2 (48%), Al2O3 (18%), and FeO (15%), with a sulfur content of 0.12% and an apatite content of 2.5%. Auxiliary reagents: hydrochloric acid (analytical grade), hydrofluoric acid (5%-20% gradient concentration), silane coupling agent KH550 (analytical grade), ethanol (analytical grade), alumina powder (99% purity).

[0034] 2. Preparation of lunar soil fiber (1) Lunar soil pretreatment: The lunar soil was crushed to a particle size of ≤50μm using a planetary ball mill and then subjected to three-stage vibrating sieves with screen apertures of 50μm, 30μm and 20μm respectively to control the uniform particle size distribution. After crushing, the lunar soil was placed in a vacuum furnace and roasted at 800℃ for 2 hours to remove water, organic matter and other substances.

[0035] (2) Purification of lunar soil silicon source: Take 1000g of roasted lunar soil and perform microwave-acid leaching combined treatment: microwave activation at 800℃ for 10min, cool and add 5% hydrofluoric acid solution for leaching for 30min, filter and then leach again with 10% hydrofluoric acid for 20min, finally obtain SiO2 with a purity of 99.6%.

[0036] (3) Melt spinning: The purified lunar soil raw material is added to an electric arc furnace and heated to 1700℃ to melt. It is then extruded through a spinneret with a diameter of 0.2 mm and spun at a traction speed of 800 m / min to obtain continuous lunar soil fibers with a diameter of 10 μm and a length of 12 mm.

[0037] (4) Surface modification: Immerse the lunar soil fiber in a 1% KH550 ethanol solution, sonicate at 300W for 30 minutes, and then dry it in a vacuum drying oven at 80℃ for later use.

[0038] 3. Preparation of Aerogel Matrix (1) Preparation of silica sol: Take 50g of silicon source (SiO2 with a purity of 99.6%) extracted from lunar soil, mix it with 150mL of ethanol and 25mL of deionized water at a volume ratio of 1:3:0.5, adjust the pH to 2.5, and stir in a constant temperature water bath at 50℃ for 2 hours to form a uniform silica sol (viscosity 120mPa・s).

[0039] (2) Composite gelation: Take 20g of modified lunar soil fiber and 80g of silica sol. Add the modified lunar soil fiber to the silica sol and stir at 500r / min for 15 minutes until it is evenly dispersed. Pour it into a mold and let it stand at room temperature for 5 hours to complete the gelation.

[0040] (3) Freeze-atmospheric pressure combined drying: The wet gel was transferred to the lunar night simulation environment chamber and cryogenically cured at -180℃ for 8 hours; then it was transferred to the lunar day simulation environment and vacuum atmospheric pressure gradient drying was adopted: 50℃ drying for 12 hours → 80℃ drying for 12 hours → 120℃ drying for 24 hours, with a total drying cycle of 48 hours, to obtain the composite material blank.

[0041] 4. Composite molding and curing (1) Preparation of silicon-based binder: Take lunar soil sulfur-based binder (sulfur extracted from lunar soil and heated to 240℃ to melt) and lunar soil ceramicized binder layer (PO4 extracted from lunar soil apatite) 3- (It is produced by reacting with alumina at a mass ratio of 3:1) and then mixed at a mass ratio of 1:1.

[0042] (2) Coating and curing: Take 3g of adhesive and spray it evenly on the surface of the composite material blank. The coating thickness is 8μm. The solar-energy storage combined power supply is used. During the lunar daytime, it is cured at 60℃ for 2 hours in a vacuum environment. During the lunar nighttime, it is kept at 20℃ for low power consumption to obtain lunar soil fiber aerogel composite thermal insulation material. Example 2

[0043] The difference between this embodiment and Embodiment 1 is that: the amount of lunar soil fiber is adjusted to 15g, the melt spinning temperature is 1600℃, the traction speed is 500m / min, and the silicone-based binder is tetraethyl orthosilicate hydrolysate (solid content 12%).

[0044] The remaining preparation methods are the same as in Example 1.

[0045] Key steps adjusted: Lunar soil fiber preparation: melt spinning temperature 1600℃, traction speed 500m / min, to obtain lunar soil fibers with a diameter of 15μm and a length of 8mm; Composite gelation: Mix 15g of lunar soil fiber with 85g of silica sol by weight; Composite molding: Spray with tetraethyl orthosilicate hydrolysate to a thickness of 6μm; cure under vacuum at 60℃ for 2 hours. Example 3

[0046] The difference between this embodiment and Embodiment 1 is that the lunar soil fiber is adjusted to 30g, the melt spinning temperature is 1800℃, the traction speed is 1000m / min, and the lunar day gradient drying process is 50℃→100℃→120℃ (16 hours each).

[0047] The remaining preparation methods are the same as in Example 1.

[0048] Key steps adjustment Lunar soil fiber preparation: melt spinning temperature 1800℃, traction speed 1000m / min, to obtain lunar soil fibers with a diameter of 8μm and a length of 15mm; Composite gelation: Mix 30g of lunar soil fiber with 70g of silica sol; Drying process: Total drying cycle 48 hours (50℃ 16h → 100℃ 16h → 120℃ 16h).

[0049] Comparative Example 1 (Pure Aerogel Control Group) No lunar soil fiber was added; the rest of the process was the same as in Example 1. After direct gelation of silica sol, it is dried by a combination of freeze-drying and atmospheric pressure, and then the surface is sprayed with tetraethyl orthosilicate hydrolysate for curing. Comparative Example 2 (Traditional Glass Fiber Reinforced Control Group) Replacing lunar soil fibers with glass fibers (10 μm in diameter) at a rate of 20%, with the remaining processes the same as in Example 1: Experiment: Comparative Test of Performance of Lunar Soil Fiber Aerogel Composite Thermal Insulation Material To verify the performance advantages of the lunar soil fiber aerogel composite thermal insulation material of this application, uniform performance tests were conducted on Examples 1-3 and Comparative Examples 1-2. The specific experimental design and results are as follows: I. Test Conditions and Detection Indicators 1. Simulation Environment and Testing Standards Extreme temperature difference cycle test: alternating between -173℃ (lunar night simulation) and 127℃ (lunar day simulation) 20 times, with each cycle holding the temperature for 8 hours to simulate the lunar day and night temperature difference environment; Thermal conductivity test: The protective hot plate method was used, and the test temperature was 25℃. Compressive strength test: using a universal testing machine, loading rate 1mm / min; Radiation shielding test: A 137Cs gamma-ray source (energy 0.662MeV) was used to test the radiation attenuation rate; Structural integrity assessment: Scanning electron microscopy (SEM) was used to observe the cracks in the material cross-section after temperature cycling.

[0050] 2. Core detection indicators Basic properties: thermal conductivity (W / (m・K)), compressive strength (MPa); Environmental stability: thermal conductivity change rate (%) and crack formation after 20 temperature cycles; Functional characteristics: Radiation shielding efficiency (%).

[0051] III. Test Results Group Thermal conductivity (W / (m・K)) Compressive strength (MPa) Change in thermal conductivity (%) after 20 temperature cycles Radiation shielding efficiency (%) Structural integrity after temperature cycling Example 1 0.018 1.8 3.2 99.2 No cracks, tight interface bonding Example 2 0.017 1.5 4.5 99.0 No cracks, good interface bonding Example 3 0.020 2.2 2.8 99.3 No cracks, stable fiber skeleton support Comparative Example 1 0.016 0.4 12.0 97.5 Multiple through cracks, loose structure Comparative Example 2 0.019 1.2 8.0 98.5 Microcracks at the fiber-aerogel interface IV. Analysis of Experimental Results 1. Synergistic optimization of thermal insulation and mechanical properties: The thermal conductivity of Examples 1-3 was controlled at 0.017~0.020 W / (m・K), maintaining the inherent low thermal conductivity of aerogel materials and meeting the thermal insulation requirements of lunar bases; at the same time, its compressive strength reached 1.5~2.2 MPa, which is 3~5 times higher than that of pure aerogel (Comparative Example 1, 0.4 MPa) and 25%~83% higher than that of traditional glass fiber reinforced aerogel (Comparative Example 2, 1.2 MPa).

[0052] Reasons for performance differences: The example uses lunar soil fiber (15%~30%) as the reinforcing phase, and the fiber surface is modified by KH550. It is tightly bonded to the SiO2 aerogel matrix (composite in composition), which not only gives full play to the mechanical support of the fiber, but also avoids the stress concentration problem at the interface of heterogeneous materials (comparative example 2 has limited mechanical reinforcement effect due to the large difference in thermal expansion coefficient between glass fiber and aerogel).

[0053] 2. Performance reliability under extreme temperature differences: After 20 cycles of temperature difference between -173℃ and 127℃, the thermal conductivity of Examples 1-3 changed by only 2.8% to 4.5%, and scanning electron microscopy showed no cracks and excellent structural integrity. In contrast, the thermal conductivity of Comparative Example 1 (pure aerogel) changed by 12%, with multiple through cracks. The thermal conductivity of Comparative Example 2 (glass fiber reinforced) changed by 8%, with microcracks appearing at the fiber-aerogel interface.

[0054] Reasons for performance differences: The example adopts the "freezing-atmospheric pressure combined drying" process, which utilizes the lunar day-night temperature difference to achieve low-stress drying of aerogel, reducing internal pore defects caused by traditional drying processes; at the same time, the lunar soil fiber and aerogel matrix are homologous, with a high degree of matching in thermal expansion coefficients, resulting in low interfacial stress during temperature difference cycling, effectively suppressing crack formation.

[0055] 3. Enhanced radiation shielding capability: The radiation shielding efficiency of Examples 1-3 reached 99.0%~99.3%, which is higher than that of pure aerogel (Comparative Example 1, 97.5%) and glass fiber reinforced aerogel (Comparative Example 2, 98.5%).

[0056] Reasons for performance differences: The mineral components naturally contained in lunar soil fibers have a natural shielding effect on gamma rays, and the embodiment further enhances the overall radiation attenuation capability of the material through the uniform dispersion of lunar soil fibers; Comparative Example 1 has no fiber reinforcement, so the radiation shielding relies on the aerogel itself, which has a lower efficiency; Comparative Example 2's glass fiber does not contain radiation shielding components, and the reinforcement does not increase the radiation shielding.

[0057] The experimental results show that the lunar soil fiber aerogel composite thermal insulation material of this application, through "lunar soil fiber reinforcement, homogeneous interface design, and preparation process adapted to the lunar environment," significantly outperforms the comparative schemes in terms of thermal insulation, mechanical strength, extreme environment stability, and radiation shielding capability. Moreover, the entire process relies on lunar soil to prepare fibers, silicon sources, and binders, reducing Earth-Moon transportation costs, making full use of in-situ resources, and achieving "self-sufficiency" of materials for the lunar base.

[0058] Those skilled in the art can implement this invention directly under real lunar soil conditions based on the disclosure of this invention, without any creative effort.

[0059] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A lunar soil fiber aerogel composite thermal insulation material, characterized in that, The composite thermal insulation material is obtained by mixing and gelling lunar soil fibers and silica sol, drying the resulting aerogel matrix, coating the surface of the aerogel matrix with a silicone-based binder, and then curing it. The aerogel matrix comprises 15-30 parts by weight of lunar soil fibers and 65-85 parts by weight of silica sol. The lunar soil fibers are continuous fibers prepared from lunar soil, and the silica sol is silica sol prepared from lunar soil silica source.

2. The lunar soil fiber aerogel thermal insulation composite material according to claim 1, characterized in that... The silicon-based binder includes siloxane binders or lunar soil in-situ extracted binders.

3. The lunar soil fiber aerogel composite thermal insulation material according to claim 1, characterized in that, The surface of the lunar soil fiber is modified with a silane coupling agent, namely KH550.

4. The lunar soil fiber aerogel composite thermal insulation material according to claim 2, characterized in that, The silicon-based binder is selected from at least one of the following: tetraethyl orthosilicate hydrolysate with a solid content of 10-15%, lunar soil sulfur-based binder, and lunar soil ceramicized binder layer; wherein the lunar soil sulfur-based binder is obtained by melting sulfur in lunar soil at 240°C; and the lunar soil ceramicized binder layer is obtained by extracting PO4 from lunar soil apatite. 3- It is produced by reacting with aluminum oxide.

5. A method for preparing a lunar soil fiber aerogel composite thermal insulation material according to any one of claims 1-4, characterized in that, Includes the following steps: (1) Preparation of lunar soil fiber: After pretreatment of lunar soil, lunar soil fiber is obtained by melt spinning, and then the surface of lunar soil fiber is modified. (2) Preparation of aerogel matrix: Silica sol is prepared using lunar soil silica source, and the lunar soil fiber is mixed with silica sol and gelled, and then dried to obtain composite material preform; (3) Composite molding: A silicon-based binder is coated on the surface of the composite material blank, and then cured to obtain lunar soil fiber aerogel composite thermal insulation material.

6. The preparation method of the lunar soil fiber aerogel composite thermal insulation material according to claim 5, characterized in that, The pretreatment described in step (1) includes: crushing lunar soil to a particle size ≤50μm, controlling the uniform particle size distribution, and then calcining it in a vacuum furnace at 800℃ for 2 hours.

7. The method for preparing a lunar soil fiber aerogel composite thermal insulation material according to claim 5, characterized in that, The drying process described in step (2) adopts a combination of cryogenic-atmospheric pressure drying: first, it is cryogenically cured at -170℃ to -190℃, and then dried in a vacuum atmospheric pressure gradient at 50℃→120℃ under lunar daytime conditions, with a total drying cycle of ≤48 hours.

8. The method for preparing a lunar soil fiber aerogel composite thermal insulation material according to claim 5, characterized in that, The preparation method of the silica sol in step (2) is as follows: extract the silica source from lunar soil, mix it with ethanol and deionized water at a volume ratio of 1:3:0.5, adjust the pH to 2~3, and stir at 50°C for 2 hours.

9. The method for preparing a lunar soil fiber aerogel composite thermal insulation material according to claim 8, characterized in that, The acquisition of the lunar soil silicon source: The lunar soil, the raw material for lunar soil fiber, is purified by a microwave-acid leaching combined process, specifically including: after the lunar soil is activated by microwave at 800℃ for 10 minutes, it is leached with a gradient of 5%-20% hydrofluoric acid to obtain SiO2 with a purity ≥99.5%.

10. The application of the lunar soil fiber aerogel composite insulation material according to any one of claims 1 to 4 in the thermal insulation structure of a lunar base building.