Method of preparing high-similarity simulated lunar soil containing glassy cemented agglomerate

Abstract

The application discloses a method for preparing simulated lunar soil, comprising: crushing and screening a mineral raw material to obtain mineral screening materials in multiple particle size intervals; calculating volume ratios corresponding to the multiple particle size intervals in a simulated lunar soil primary product; mixing the simulated lunar soil primary product with a glass material and performing sintering treatment to obtain a glassy cemented agglomerate rock aggregate; and mixing the simulated lunar soil primary product with the glassy cemented agglomerate rock aggregate to obtain the simulated lunar soil. Thus, the simulated lunar soil containing the glassy cemented agglomerate rock can be obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of space exploration, in particular, to a method for preparing high-similarity simulated lunar soil containing glassy agglutinate. BACKGROUND

[0002] With the development of space technology in recent years, the value of lunar exploration in economy, military and scientific research is increasingly prominent. In the process of promoting lunar exploration, the physical and mechanical properties of lunar soil need to be understood. For example, the influence of rocket plume on landing safety when the lunar explorer lands, the interaction between lunar soil and airflow needs to be considered; the path planning problem of lunar rover needs to consider the wheel-soil interaction problem, and the lunar construction problem is closely related to the physical and mechanical properties of lunar soil. Glassy agglutinate is a unique substance in the soil of celestial bodies without atmospheric surrounding, and has only been found on the moon so far. Glassy agglutinate has a great influence on the physical and mechanical properties of lunar soil, such as particle morphology, internal pore, shear strength and compressibility. Under low confining pressure on the lunar surface, highly irregular glassy agglutinate particles often produce interlocking effect and produce abnormally high shear strength. Due to the crushing of viscous particles under load, lunar soil has higher compressibility than terrestrial soil, and stress path and stress history have a great influence on its deformation characteristics.

[0003] Due to the scarcity of real lunar soil, the current research mainly uses simulated lunar soil, such as TJ-1 developed by Tongji University, CUG-1A developed by China University of Geosciences, JLU developed by Jilin University, etc. The simulated lunar soil is similar to the real lunar soil in terms of particle morphology and particle size distribution. Although there are a large number of research results, the mechanical and engineering properties of simulated lunar soil still have many problems that have not been effectively solved, especially it is difficult to simulate the glassy agglutinate contained in the lunar soil. Therefore, the method for preparing simulated lunar soil still needs to be improved. SUMMARY

[0004] In the first aspect of the present application, a method for preparing simulated lunar soil is provided, comprising: crushing and screening a mineral raw material to obtain a plurality of particle size intervals of mineral screening material, wherein the plurality of particle size intervals comprises: a first particle size interval, the particle size of the first particle size interval is 0-0.01mm; a second particle size interval, the particle size of the second particle size interval is 0.01mm-0.025mm; a third particle size interval, the particle size of the third particle size interval is 0.025mm-0.05mm; a fourth particle size interval, the particle size of the fourth particle size interval is 0.05mm-0.075mm; a fifth particle size interval, the particle size of the fifth particle size interval is 0.075mm-0.1mm; a sixth particle size interval, the particle size of the sixth particle size interval is 0.1mm-1mm; and the particle size of the sixth particle size interval is obtained according to the formula d k ∑i=∑i×d ik, i = a, b, c, d, e, f, the volume ratio corresponding to multiple particle size intervals in the simulated lunar soil primary product is calculated, wherein d k is the cumulative volume fraction of particles of a specific particle size in the real lunar soil, a is the volume ratio of particles in the first particle size interval, b is the volume ratio of particles in the second particle size interval, c is the volume ratio of particles in the third particle size interval, d is the volume ratio of particles in the fourth particle size interval, e is the volume ratio of particles in the fifth particle size interval, and f is the volume ratio of particles in the sixth particle size interval. ik is the cumulative volume fraction of particles in the i-th particle size interval in the simulated lunar soil d k at d The simulated lunar soil primary product is mixed with a glass material, and sintering treatment is performed to obtain a glassy cemented agglomerate rock aggregate; the simulated lunar soil primary product is mixed with the glassy cemented agglomerate rock aggregate to obtain a simulated lunar soil. In this way, a high-similarity simulated lunar soil containing glassy cemented agglomerate rock can be obtained.

[0005] In some embodiments, the mineral raw material includes 2.5-3.5 parts by weight of basalt, 6-8 parts by weight of plagioclase, 0.8-1.1 parts by weight of ilmenite, 0.7-0.9 parts by weight of olivine, and 8.3-8.6 parts by weight of pyroxene. In this way, the mineral composition of the simulated lunar soil is closer to Chang'e-5 lunar soil.

[0006] In some embodiments, the mixing mass ratio of the simulated lunar soil primary product and the glass material is (2-5):1. In this way, a glassy cemented agglomerate rock particle aggregate with different silicate contents and different particle morphologies can be obtained.

[0007] In some embodiments, the glass material includes hollow glass beads, and the particle size difference between the hollow glass beads and the simulated lunar soil primary product is less than or equal to 15 μm. In this way, the yield of the glassy cemented agglomerate rock aggregate can be improved.

[0008] In some embodiments, the hollow glass beads satisfy at least one of the following conditions: the median particle size of the hollow glass beads is 5-25 μm; the compressive strength of the hollow glass beads is 30,000-50,000 psi; the glass wall thickness of the hollow glass beads is 0.7-1.5 μm; and the glass volume ratio of the hollow glass beads is 24%-50%. In this way, it is helpful to regulate the silicate content of the glassy cemented agglomerate rock aggregate.

[0009] In some embodiments, the sintering device includes a spark plasma sintering furnace; and / or, the vacuum degree of the spark plasma sintering furnace during the sintering process is less than or equal to 15 Pa; and / or, the pressure of the spark plasma sintering furnace during the sintering process is 1,000-2,000 N. In this way, it is helpful to reduce the breakage of the glassy cemented agglomerate rock aggregate during sintering.

[0010] In some embodiments, the sintering process has a heating rate of 90K / min-120K / min; and / or, the sintering process has a sintering temperature of 650℃-850℃; and / or, the sintering process has a sintering time of 20min-30min. Thereby, the softening bonding of the glass material is facilitated.

[0011] In some embodiments, the mixing process is further preceded by a sieving process to remove particles with a size larger than 50μm from the lunar soil simulant primary product. Thereby, the influence of large particles of the lunar soil simulant primary product on the sintering process is reduced, and the sieving of the glassy agglomerate rock particles with a size larger than 50μm after the sintering process is facilitated.

[0012] In some embodiments, the sintering process is further followed by a sieving process to remove particles with a size larger than 50μm from the glassy agglomerate rock assembly, and adding glass fragments with a size of 30μm-50μm. Thereby, the heterogeneous glass material in the real lunar soil is simulated.

[0013] In some embodiments, the mixing mass ratio of the lunar soil simulant primary product to the glassy agglomerate rock assembly is (70-75):(25-30). Thereby, lunar soil simulants with different degrees of maturity are obtained. BRIEF DESCRIPTION OF DRAWINGS

[0014] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description, taken in conjunction with the following drawings in which:

[0015] Figure 1 Flow chart of a method of preparing a lunar soil simulant according to one embodiment of the present application;

[0016] Figure 2 Grading curves of glassy agglomerate rock assemblies obtained using different sintering temperatures, and the initial mix grading curve, according to some embodiments of the present application;

[0017] Figure 3 Binary image of an image particle size analyzer scan before sintering process according to one embodiment of the present application;

[0018] Figure 4 Binary image of an image particle size analyzer scan after sintering process according to one embodiment of the present application;

[0019] Figure 5 Microscopic image of a glassy agglomerate rock assembly according to one embodiment of the present application;

[0020] Figure 6 Microscopic image of a glassy agglomerate rock assembly in real lunar soil;

[0021] Figure 7 The gradation curve of the mineral screening material in the different particle size intervals of some embodiments of the present application. DETAILED DESCRIPTION

[0022] Embodiments of the present application are described in detail below with reference to the attached drawing figures, but it is to be understood that the embodiments described are by way of illustration only and are not intended to limit the scope of the application. For example, specific details are set forth in connection with particular embodiments to provide a thorough understanding of the embodiments disclosed herein. It should be understood, however, that the embodiments described below are merely examples and are not intended to limit the scope of the application. Rather, the following description gives a general understanding of the application and the scope of its application. It will be apparent, however, to those skilled in the art that changes can be made and equivalents employed without departing from the scope of the application.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application. Unless otherwise specified, all parameters, values, and the like are to be determined using standard methods (for example, as described in the examples of the present application).

[0024] As used in the description of the application and the appended claims, the terms "including" and "having," along with their derivatives, are meant to be construed open-ended terms. That is, the terms "including" and "having" should be interpreted as specifying the presence of stated features or steps, but not excluding the presence of other steps.

[0025] In the description of the present application, all numbers disclosing herein are approximations. The numerical values of each maximum numerical limitation can have inherent variations causing minor variations. The terms "about" and "approximately" as used herein can mean ± 10%, ± 9%, ± 8%, ± 7%, ± 6%, ± 5%, ± 4%, ± 3%, ± 2%, ± 1%, or another suitable number whether explicit or implicit, to the exact value desired by the skilled artisan to achieve at least the purposes of the application.

[0026] In the present application, the order of steps written does not mean the strict execution order and constitute any limitation to the implementation process. The specific execution order of each step should be determined by its function and possible inherent logic. If not specifically stated, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method comprises steps (a) and (b), which means that the method can comprise sequentially performed steps (a) and (b), or sequentially performed steps (b) and (a). For example, it is mentioned that the method can further comprise step (c), which means that step (c) can be added to the method in any order, for example, the method can comprise steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0027] It is generally believed that glassy agglutinate is formed by melting and mixing of lunar surface caused by micro-meteorite bombardment. Because micro-meteorite bombardment on the lunar surface will continuously produce glassy agglutinate, its abundance will increase over time and is proportional to the cumulative exposure time. As the main component of mature lunar soil, the volume fraction of glassy agglutinate in lunar soil can be as high as 60 vol%, and the average volume fraction of lunar soil is 25 vol% to 30 vol%. The preparation process of glassy agglutinate in the related art mainly simulates meteorite impact, which has the problems of high preparation cost and high process difficulty. The glassy agglutinate aggregate has a great influence on the engineering properties of lunar soil, and the related art cannot meet the research on the constitutive model and other geotechnical engineering properties of lunar soil.

[0028] In the first aspect of the present application, a method for preparing simulated lunar soil is provided, which has the characteristics of low cost and high preparation efficiency, and can prepare simulated lunar soil containing glassy agglutinate with high similarity, which can be used to simulate the physical and mechanical properties of real lunar soil, and can restore the particle size and shape of lunar soil to the greatest extent. It can effectively overcome the shortcomings of high cost and complex process of preparing glassy agglutinate aggregate in the related art, and can be popularized to the research and development of other extraterrestrial planetary simulated rock-soil bodies, such as simulated Martian soil development, etc., and has high universality. Specifically, referring to Figure 1 , the method for preparing simulated lunar soil comprises:

[0029] S100: crushing and screening the mineral raw material to obtain a plurality of mineral screening materials in different particle size intervals

[0030] In some embodiments, the mineral raw material is crushed and screened in this step to obtain a plurality of mineral screening materials in different particle size intervals. Based on the consideration of screening accuracy and cost, referring to Table 1, the particle size intervals can include: a first particle size interval, the particle size of the first particle size interval is 0-0.01mm; a second particle size interval, the particle size of the second particle size interval is 0.01mm-0.025mm; a third particle size interval, the particle size of the third particle size interval is 0.025mm-0.05mm; a fourth particle size interval, the particle size of the fourth particle size interval is 0.05mm-0.075mm; a fifth particle size interval, the particle size of the fifth particle size interval is 0.075mm-0.1mm; a sixth particle size interval, the particle size of the sixth particle size interval is 0.1mm-1mm.

[0031] Table 1

[0032]

[0033]

[0034] It can be understood that due to the problem of screening accuracy, the particle size range of the obtained particles cannot be accurately controlled within the predetermined range, so that the screened samples of different particle size ranges cannot be directly used, and the grading curve of the real lunar soil is referred to for configuration. Therefore, the volume ratio corresponding to the particle size of each particle size range in the simulated lunar soil primary product calculated by the formula in the present application is needed to obtain the best fitting effect of the simulated lunar soil primary product and the real lunar soil grading curve, so that the six components are mixed according to the calculated volume ratio to achieve the best mixing effect.

[0035] In some embodiments, the crushing method of the mineral raw material can be impact crushing, so that the mineral raw material can be quickly and efficiently crushed.

[0036] In some embodiments, basalt and anorthosite are used as the main mixed body of the mineral raw material, and after mixing, ilmenite, pyroxene and other mineral raw materials are supplemented according to the difference between the mineral composition of the mineral raw material and the mineral elements of the real lunar soil sample. For example, the mineral raw material includes 2.5-3.5 parts by weight of basalt, 6-8 parts by weight of anorthosite, 0.8-1.1 parts by weight of ilmenite, 0.7-0.9 parts by weight of olivine, and 8.3-8.6 parts by weight of pyroxene. In this way, the mineral composition of the simulated lunar soil is closer to that of the real lunar soil.

[0037] As an example, the mass ratio of each substance in the mineral raw material can be basalt:anorthosite:pyroxene:olivine:ilmenite=3:7:8.41:0.81:0.96.

[0038] S200: Calculate the volume ratio corresponding to each particle size range in the simulated lunar soil primary product according to the formula d k ∑i=∑i×d ik , i=a, b, c, d, e, f

[0039] In some embodiments, the formula is expanded as d k (a+b+c+d+e+f)=a×d ak +b×d bk +c×d ck +d×d dk +e×d ek +f×d fk . In this way, the particle size distribution in the simulated lunar soil primary product is closer to that in the real lunar soil.

[0040] In some embodiments, the grading curve of the real lunar soil is used as the target grading curve in this step, and the particle volume fraction in each particle size range required in the simulated lunar soil is calculated according to the foregoing formula to obtain the simulated lunar soil primary product, wherein d kis the cumulative volume fraction of the particles in the real lunar soil with the specific particle size, a is the volume ratio of the particles in the first particle size interval in the simulated lunar soil, b is the volume ratio of the particles in the second particle size interval in the simulated lunar soil, c is the volume ratio of the particles in the third particle size interval in the simulated lunar soil, d is the volume ratio of the particles in the fourth particle size interval in the simulated lunar soil, e is the volume ratio of the particles in the fifth particle size interval in the simulated lunar soil, and f is the volume ratio of the particles in the sixth particle size interval in the simulated lunar soil. ik is the cumulative volume fraction of the particles in the i-th particle size interval in the simulated lunar soil at the particle size d k . Specifically, d ak is the cumulative volume fraction of the particles in the first particle size interval in the simulated lunar soil at the particle size d k . Specifically, d bk is the cumulative volume fraction of the particles in the second particle size interval in the simulated lunar soil at the particle size d k . Specifically, d ck is the cumulative volume fraction of the particles in the third particle size interval in the simulated lunar soil at the particle size d k . Specifically, d dk is the cumulative volume fraction of the particles in the fourth particle size interval in the simulated lunar soil at the particle size d k . Specifically, d ek is the cumulative volume fraction of the particles in the fifth particle size interval in the simulated lunar soil at the particle size d k . Specifically, d fk is the cumulative volume fraction of the particles in the sixth particle size interval in the simulated lunar soil at the particle size d k . Specifically, d

[0041] In some embodiments, due to the precision problem of sieving, the actual particle size interval of the particles obtained after crushing and sieving may deviate from the preset range, and therefore, the mixing ratio of the particles in different particle size intervals needs to be determined to achieve the best fitting effect with the real lunar soil grading curve. Specifically, referring to Figure 7 , the grading curves of the particles in the foregoing multiple particle size intervals can be measured by using a laser particle size analyzer, wherein the grading curves corresponding to 0-0.01 mm, 0.01 mm-0.025 mm, 0.025 mm-0.05 mm, 0.05 mm-0.075 mm, 0.075 mm-0.1 mm and 0.1 mm-1 mm are respectively Figure 7 , VI, V, IV, III, II, I in the foregoing formula, and thus, based on the calculation results of the foregoing formula, the six components can be mixed in a specific ratio to achieve the best mixing effect and prepare the simulated lunar soil primary product.

[0042] S300: mixing the simulated lunar soil primary product with a glass material and performing sintering treatment

[0043] In some embodiments, in this step, the simulated lunar soil primary product is mixed with glass material to obtain a mixture. After sintering the mixture, the particle size is significantly increased, forming a glassy bonded agglomerate aggregate.

[0044] In some embodiments, during the vacuum sintering process of the mixture, the glass material melts and binds adjacent simulated lunar soil particles together. After cooling and solidification, the adjacent simulated lunar soil primary sample particles are stably connected by glass, thereby obtaining a glass-bonded agglomerate aggregate.

[0045] In some embodiments, the mixing mass ratio of simulated lunar soil primary product to glass material is (2-5):1. This allows for the production of glassy agglomerate particles with varying silicate contents and particle morphologies.

[0046] By incorporating different proportions of hollow glass materials, the morphology of glassy aggregates in simulated lunar soil was altered, thereby changing the physical and mechanical properties of the simulated lunar soil.

[0047] As an example, the mass ratio of simulated lunar soil primary products to glass materials can be 2:1, 3:1, 4:1, or 5:1.

[0048] As an example, the simulated lunar soil primary product can be mixed with the product obtained from glass material at a mass ratio of 4.335:1 to obtain a glassy agglomerate with a silicate content of 25%.

[0049] As an example, the simulated lunar soil primary product can be mixed with the product obtained from glass material at a mass ratio of 2.747:1 to obtain a glassy agglomerate aggregate with a silicate content of 35%.

[0050] As an example, the simulated lunar soil primary product can be mixed with the product obtained from glass material at a mass ratio of 2.011:1 to obtain a glassy agglomerate with a silicate content of 45%.

[0051] In some embodiments, a quartering method can be used to mix the simulated lunar soil primary product with glass material to obtain a well-mixed mixture.

[0052] In some embodiments, the glass material comprises hollow glass beads, the size difference between the hollow glass beads and the simulated lunar soil primary product being less than or equal to 15 μm. This can improve the yield of glassy agglomerate aggregates.

[0053] When the particle size of the simulated lunar soil primary product particles is similar to that of hollow glass beads, the bonding efficiency of hollow glass beads is higher. This can effectively improve the yield of glassy bonded agglomerate aggregates.

[0054] In some embodiments, the hollow glass beads satisfy at least one of the following conditions: the median particle size of the hollow glass beads is 5 μm-25 μm; the compressive strength of the hollow glass beads is 30000 psi-50000 psi; the glass wall thickness of the hollow glass beads is 0.7 μm-1.5 μm; and the glass volume ratio of the hollow glass beads is 24%-50%. In this way, the silicate content of the vitric agglomerate assembly can be regulated.

[0055] In some embodiments, the sintering device can be a spark plasma sintering furnace, so that a lunar surface oxygen-free high vacuum environment can be simulated during the sintering process to simulate the actual production environment of the vitric agglomerate assembly.

[0056] In some embodiments, the sintering device can be a muffle furnace.

[0057] In some embodiments, the vacuum degree of the spark plasma sintering furnace during the sintering process is less than or equal to 15 Pa. In this way, the vitric agglomerate assembly can be prevented from being broken during the sintering process, and the yield can be improved.

[0058] In some embodiments, the pressure of the spark plasma sintering furnace during the sintering process is 1000 N-2000 N. In this way, the vitric agglomerate assembly can be prevented from being broken during the sintering process, and the yield can be improved.

[0059] In some embodiments, the heating rate of the sintering process is 90 K / min-120 K / min; and / or, the sintering temperature of the sintering process is 650℃-850℃; and / or, the sintering time of the sintering process is 20 min-30 min. In this way, the mineral facies properties are relatively stable during the sintering process, and the hollow glass beads can be smoothly melted and softened to bond the simulated lunar soil primary product particles to form the vitric agglomerate assembly.

[0060] In some embodiments, the mixing process further comprises: removing particles with a particle size greater than 50 μm from the simulated lunar soil primary product through a screening process, so that the adverse effects of mixed large particles due to the screening accuracy on the sintering process can be effectively reduced.

[0061] In some embodiments, the sintering process further comprises: removing particles with a particle size greater than 50 μm from the vitric agglomerate assembly through a screening process, and adding glass fragments to the vitric agglomerate assembly, the particle size of the glass fragments being 30 μm-50 μm, the glass fragments can simulate the heterogeneous glass material in the real lunar soil, so that the similarity between the simulated lunar soil and the real lunar soil can be improved.

[0062] S400: mixing the simulated lunar soil primary product with the vitric agglomerate assembly

[0063] In some embodiments, the glassy cemented agglomerate assembly is mixed with the simulated lunar soil primary product in a certain volume percentage at this step to obtain a high-similarity simulated lunar soil containing the glassy cemented agglomerate assembly.

[0064] In some embodiments, the mixing mass ratio of the simulated lunar soil primary product and the glassy cemented agglomerate assembly is (70-75):(25-30). By changing the mixing ratio of the glassy cemented agglomerate assembly and the simulated lunar soil primary product, the maturity of the simulated lunar soil can be changed, and the similarity between the simulated lunar soil and the real lunar soil can be improved.

[0065] The scheme of the present application is described below through specific embodiments. It should be noted that the following embodiments are only used to illustrate the present application, and should not be regarded as limiting the scope of the present application. If the specific technology or condition is not specified in the embodiments, the technology or condition described in the literature in the art or according to the product instruction is used. If the reagent or instrument used is not specified by the manufacturer, it is a conventional product that can be obtained by purchase.

[0066] Example 1: Determination of the Proportion of Mineral Raw Materials

[0067] (1) The six mineral raw materials are as follows: basalt is from Liuhe, Nanjing, Jiangsu Province, anorthosite is from Daimiao Town, Chengde, Hebei Province, and feldspar, ilmenite, olivine and pyroxene are all selected from relatively pure ores.

[0068] (2) The mineral distribution proportion of basalt from Liuhe, Nanjing, Jiangsu Province is shown in Table 2:

[0069] Table 2

[0070] Feldspar Pyroxene Olivine Vitreous Other 60 wt% 15 wt% 15 wt% 5 wt% 15 wt%

[0071] (3) The mineral distribution proportion of anorthosite from Daimiao Town, Chengde, Hebei Province is shown in Table 3:

[0072] Table 3

[0073] Feldspar Vitreous Other 65％ 20 wt% 15 wt%

[0074] (4) The mineral distribution proportion of Chang'e-5 lunar soil is shown in Table 4:

[0075] Table 4

[0076] Feldspar Pyroxene Olivine Ilmenite Vitreous Other 30.1 wt% 42 wt% 5.7 wt% 4.5 wt% 17 wt% 0.7 wt%

[0077] (5) Select basalt and plagioclase mixed mass ratio = 3:7, get the first mixture, at this time the first mixture of mineral composition mass ratio is feldspar: pyroxene: olivine: glass = 63.5wt%:4.5wt%:4.5wt%:15.5wt%, compared with the mineral composition mass of Chang'e five lunar soil sample, olivine, ilmenite and pyroxene need to be supplemented, first supplement pyroxene, calculated to supplement 84.1wt% of the first mixture, at this time the mixing ratio is basalt: plagioclase: pyroxene = 3:7:8.41.

[0078] (6) The mixture obtained in the second mixture of mineral composition mass ratio is feldspar: pyroxene: olivine: glass: other = 30.1:42.2:2.1:7.4:5.7, at this time the olivine needs to be supplemented, needs to supplement 0.04wt% of the second mixture, at this time the mixing ratio is basalt: plagioclase: pyroxene: olivine = 3:7:8.41:0.81.

[0079] (7) The mixture obtained in the third mixture of mineral composition mass ratio is feldspar: pyroxene: olivine: glass: other = 30.1:42.2:5.7:7.4:5.7, at this time the ilmenite needs to be supplemented, needs to supplement 0.05wt% of the third mixture, at this time the mixing ratio is basalt: plagioclase: pyroxene: olivine: ilmenite = 3:7:8.41:0.81:0.96.

[0080] (8) The mixture obtained in the fourth mixture of mineral composition mass ratio is feldspar: pyroxene: olivine: ilmenite: glass: other = 30.1:42.2:5.7:4.5:7.4:5.7. Similar to the main mineral composition of Chang'e five, therefore, the mineral mixing ratio is: basalt: plagioclase: pyroxene: olivine: ilmenite = 3:7:8.41:0.81:0.96.

[0081] Example 2: Determination of the proportion of different particle size samples

[0082] (1) Due to the problem of screening accuracy, the particle size cannot be accurately controlled within the predetermined range, so it is necessary to determine the mixing ratio of particles with different particle sizes to achieve the best fitting effect with the real lunar soil grading curve. The particle samples of different particle sizes are screened, and the grading curve is measured by using a laser particle size analyzer, wherein the grading curves corresponding to 0-0.01mm, 0.01-0.025mm, 0.025-0.05mm,

[0083] 0.05-0.075mm, 0.075-0.1mm and 0.1-1mm are respectively Ⅵ, V, IV, III, II, I. Figure 7

[0084] (2) The particle grading of Chang'e five lunar soil is as follows:

[0085] ​

[0086] (3) Based on the formula d k ∑i = ∑i x d ik , i = a, b, c, d, e, f, for simplicity of calculation, we have Figure 7 The lunar sample grading curve of CE-5 (i.e., Chang'e-5) in the middle is divided into three sections, which are 0-20 μm, 20-50 μm, and 50-100 μm, respectively. We observe that Figure 7 The VI component grading curve in the 0-20 μm section is closest to the real lunar soil grading curve, so we use the VI component to configure this section.

[0087] (4) For the real lunar soil, d 27 = 20 μm, and for the VI component, d 20 = 20 μm, so the VI component accounts for 27% of the total volume, i.e., 27% / 0.7 = 38.6 vol%.

[0088] (5) We configure the 20-50 μm section. Since the VI component contains the 20-50 μm component when configuring the 0-20 μm section in (4), we need to remove this part. We observe that Figure 7 The IV component grading curve in the 20-50 μm section is closest to the real lunar soil grading curve, so we use the IV component to configure this section.

[0089] (6) For the real lunar soil, d 46.2 = 50 μm, and for the IV component, d 14 = 50 μm, and this component contains almost no particles smaller than 20 μm, so we do not need to consider the impact on the 0-20 μm section configuration. For the real lunar soil, the volume ratio of the 20-50 μm component is 46.2% - 27% = 19.2%,

[0090] so the IV component accounts for (19.2% - 38.6% x (1 - 0.7)) / 0.74 = 10.3 vol% of the total.

[0091] (7) Finally, we configure the 50-100 μm section. Similarly, since the IV component includes the 50-100 μm component when configuring the 20-50 μm section in (6), we need to remove this part. We observe that Figure 7 The III component grading curve in the 50-100 μm section is closest to the real lunar soil grading curve, so we use the III component to configure this section.

[0092] (8) For the real lunar soil, d 74 = 100 μm, and for the III component, d 57= 100 pm, and the proportion of 20 pm-50 pm component particles in the component is 26%, and the subsequent step will consider the content of the 20 pm-50 pm component in (6), and then adjust the proportion of the IV component as appropriate. In the real lunar soil, the volume proportion of the 50 pm-100 pm component is 74%-46.2% = 27.8%, therefore, the total percentage of the III component is (27.8%-10.3% x 0.26) / 0.57 = 44.1%

[0093] (9) At this time, the proportion of 20 pm-50 pm component in the III component is: 44.1% x 0.26 = 11.5%, which is similar to the proportion of 20 pm-50 pm component in the real lunar soil: 38.6% x (1-0.7) = 19.2%. Therefore, the IV component does not need to be added.

[0094] (10) Since there is a component above 100 pm in the real lunar soil, this component is configured with the II component, and the volume ratio is estimated to be 100%-38.6%-44.1% = 17.3 vol%.

[0095] (11) At this time, the volume ratio of I, II, III, IV, V, and VI components should be 0:17.3:44.1:0:0:38.6.

[0096] (12) When the relative density of the six components is 70%, the density ratio of I, II, III, IV, V, and VI components is 1.99:1.79:1.71:1.6:1.34:1.29.

[0097] (13) At this time, the configuration mass ratio of I, II, III, IV, V, and VI components is 0:31.0:48.9:0:0:32.3, and the mass fraction of each component is calculated as follows: II component: 27.6 wt%; III component: 43.6 wt%; VI component: 28.8 wt%.

[0098] (14) The primary simulated lunar soil sample is configured according to (13), and the grading curve of the primary simulated lunar soil sample obtained by configuration is shown in Figure 7 , which is highly similar to the CE-5 lunar sample grading curve, and the configuration effect is the best.

[0099] Example 3: Determination of the ratio of hollow glass beads to simulated lunar soil

[0100] (1) As known from Example 1, the glass content in the mineral raw material is about 7.7 wt%, and the glass content in the hollow glass beads is about 100 wt%, and the glass content gradient of the sintered sample is set to be 25 wt%, 35 wt%, and 45 wt%, respectively.

[0101] (2) To mix the sample with a glass content of 25 wt%, let the primary simulated lunar soil sample be ag, and the hollow glass beads be bg,

[0102] (7.7% x a + 100% x b) / (a + b) = 25%, calculated a: b = 75: 17.3, so the mixing ratio is lunar soil primary sample: hollow glass beads = 4.335: 1

[0103] (3) To prepare a mixture with 35wt% glass content, by the same reasoning, the mixing ratio is lunar soil primary sample: hollow glass beads = 2.747: 1.

[0104] (4) To prepare a mixture with 45wt% glass content, by the same reasoning, the mixing ratio is lunar soil primary sample: hollow glass beads = 2.011: 1.

[0105] Example 4: Sintering of glass-cemented conglomeration rock aggregate

[0106] (1) Weigh 417g of Group I simulated lunar soil, 417g of Group II simulated lunar soil, and 166g of hollow glass beads on an electronic balance to prepare a mixture with 45wt% glass content, and then sieve out particles larger than 50 microns using a 50-micron sieve.

[0107] (2) Pour the samples weighed in step (1) onto a smooth and flat table top or glass plate, and mix them using the quartering method. Specifically, mix the samples thoroughly using a sample divider, spread them into a square of uniform thickness, draw two diagonal lines on the sample using the sample divider to divide it into two triangular shapes with opposite corners, and randomly select two of the triangular shapes as samples. Mix the remaining samples again, and repeat the above process until the two triangular samples with opposite corners are close to the desired sample weight.

[0108] (3) Use a sample spoon to dig the mixture in step (2) into a thick-walled cylindrical graphite mold with an outer diameter of 7 cm, an inner diameter of 3 cm, and a height of 6 cm, and weigh the mass of the mixture loaded using an electronic balance.

[0109] (4) Place the graphite mold in step (3) along with the mixture inside it into a spark plasma sintering furnace, vacuumize for 5 minutes to achieve an essentially oxygen-free environment, apply a pressure of 2000N to fully consolidate the sample, rapidly increase the temperature to 120°C at a rate of 100°C / min, maintain the temperature for 10 minutes to evaporate the trace amount of water inside the sample, and then increase the temperature to different temperatures at the same rate, dividing it into 5 temperature experimental groups, which are 650°C, 700°C, 750°C, 800°C, and 850°C. The holding time is 20 minutes. Then, naturally cool the sample until the temperature is lower than 100°C, and remove the sample using heat-resistant gloves. Sieve out the components with a particle size greater than 50 microns from the cooled sample using a sieve machine, and obtain the glass-cemented conglomeration rock aggregate.

[0110] (5) Cool the glassy agglomerate to room temperature, then dry and seal it for storage.

[0111] Result characterization:

[0112] The gradation curves of glassy bonded agglomerates sintered at different temperatures before sieving, measured using a laser particle size analyzer, are shown in the attached figure. Figure 2 As shown, the particle size increases significantly after high-temperature sintering, and the higher the sintering temperature, the more significant the increase in particle size.

[0113] The mixture in step (2) and the glassy agglomerate aggregate obtained by sintering at 850℃ in step (4) were scanned using an image particle size analyzer to obtain binarized images. Figure 3 and Figure 4 As shown, the particle morphology after sintering is significantly different from that before sintering. After sintering, the particles have more angular features and the degree of irregularity is increased, indicating the formation of glassy bonded agglomerate aggregates. Moreover, the sintered products can simulate the pore structure of real lunar soil particles.

[0114] Glassy, ​​cohesive agglomerate grains observed using a stereomicroscope at 80x magnification. See [reference needed]. Figure 5 The microscopic images clearly show the irregular morphology and the presence of pores. These pores are present in almost all sintered bonded agglomerates, and are related to... Figure 6 A comparison with NASA's lunar regolith glassy agglomerate aggregate sample 10084 reveals a high degree of similarity in grain morphology and pore structure. Furthermore, the processed agglomerate simulant exhibits a highly irregular morphology and significant cementing characteristics, which is consistent with... Figure 6 The structure of the aggregate rock in the real lunar soil shown is very similar.

[0115] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A method for preparing simulated lunar soil, characterized in that: The mineral raw materials are crushed and screened to obtain mineral screening materials with multiple particle size ranges, including: a first particle size range with a particle size of 0-0.01 mm; a second particle size range with a particle size of 0.01 mm-0.025 mm; a third particle size range with a particle size of 0.025 mm-0.05 mm; a fourth particle size range with a particle size of 0.05 mm-0.075 mm; a fifth particle size range with a particle size of 0.075 mm-0.1 mm; and a sixth particle size range with a particle size of 0.1 mm-1 mm. According to formula d k ∑i=∑i×d ik Let i = a, b, c, d, e, f. The volume ratios corresponding to multiple particle size ranges in the simulated primary lunar soil product are calculated. Where, d k The values ​​represent the cumulative volume fraction of particles of a specific size in real lunar soil. 'a' represents the volume ratio of particles in the first size range in the simulated lunar soil, 'b' represents the volume ratio of particles in the second size range, 'c' represents the volume ratio of particles in the third size range, 'd' represents the volume ratio of particles in the fourth size range, 'e' represents the volume ratio of particles in the fifth size range, and 'f' represents the volume ratio of particles in the sixth size range. ik To simulate the particle size range i in lunar soil at d k Cumulative volume fraction at particle size; Simulated lunar soil primary products are mixed with glass materials and then sintered to obtain glassy bonded agglomerate aggregates. Simulated lunar soil primary products are mixed with glassy bonded agglomerate aggregates to obtain simulated lunar soil.

2. The method according to claim 1, characterized in that, The mineral raw materials include 2.5-3.5 parts by weight of basalt, 6-8 parts by weight of anorthosite, 0.8-1.1 parts by weight of ilmenite, 0.7-0.9 parts by weight of olivine, and 8.3-8.6 parts by weight of pyroxene.

3. The method according to claim 1, characterized in that, The mass ratio of simulated lunar soil primary products to glass materials is (2-5):

1.

4. The method according to any one of claims 1-3, characterized in that, The glass material includes hollow glass beads, and the particle size difference between the hollow glass beads and the simulated lunar soil primary product is less than or equal to 15 μm.

5. The method according to claim 4, characterized in that, Hollow glass beads satisfy at least one of the following conditions: The median particle size of hollow glass beads is 5μm-25μm; The compressive strength of hollow glass beads is 30,000 psi-50,000 psi; The glass wall thickness of hollow glass beads is 0.7μm-1.5μm; The glass volume ratio of hollow glass beads is 24%-50%.

6. The method according to any one of claims 1-3, characterized in that, The equipment for sintering includes a spark plasma sintering furnace; and / or, the vacuum degree of the spark plasma sintering furnace during the sintering process is less than or equal to 15 Pa; and / or, the pressure of the spark plasma sintering furnace during the sintering process is 1000 N-2000 N.

7. The method according to claim 6, characterized in that, The heating rate of the sintering treatment is 90K / min-120K / min; and / or, the sintering temperature of the sintering treatment is 650℃-850℃; and / or, the sintering time of the sintering treatment is 20min-30min.

8. The method according to any one of claims 1-3, characterized in that, Prior to the mixing process, the process further includes removing particles larger than 50 μm from the simulated lunar soil primary product by sieving.

9. The method according to claim 8, characterized in that, The sintering process further includes: removing particles larger than 50 μm from the glassy agglomerate aggregate by sieving, and adding glass fragments with a particle size of 30 μm-50 μm.

10. The method according to claim 1, characterized in that, The mass ratio of the simulated primary lunar soil product to the glassy aggregate was (70-75):(25-30).

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