Simulated lunar soil preparation method based on nonferrous metal tailings

Abstract

The invention relates to the technical field of lunar soil preparation, in particular to a simulated lunar soil preparation method based on nonferrous metal tailings. Comprising the following steps: grinding and screening nonferrous metal tailing powder; mixing the non-ferrous metal tailing powder with the plagioclase powder, the pyroxene powder, the olivine powder and the hematite powder in proportion, and grinding; uniformly mixing the mixed powder with graphite powder to obtain composite powder containing elemental iron, and uniformly mixing ilmenite powder with carbon black powder to obtain composite powder containing coexisting elemental iron and ilmenite; and uniformly mixing the two kinds of powder, performing low-intensity magnetic separation, ball-milling and screening, and mixing according to a specified particle size distribution ratio to obtain the lunar soil simulant. Not only is efficient resource utilization of the nonferrous metal tailings realized, but also simulated lunar soil with matched components and stable performance can be prepared.

Description

Technical Field

[0001] This invention relates to the field of lunar soil preparation technology, and in particular to a method for preparing simulated lunar soil based on non-ferrous metal tailings. Background Technology

[0002] Simulated lunar soil is a crucial basic material for conducting ground tests in lunar exploration missions, spacecraft performance testing, and research on lunar surface resource utilization. Its physicochemical properties must closely match those of real lunar soil to ensure the accuracy and reliability of experimental data. However, due to the extreme scarcity of real lunar soil samples and the highly complex mineral composition, particle morphology, and elemental distribution, how to prepare highly realistic simulated lunar soil at low cost and high efficiency has become a key technological challenge in the aerospace field.

[0003] Currently, the preparation of simulated lunar soil both domestically and internationally is mainly based on natural rock materials, such as basalt and volcanic ash, using mechanical crushing, sieving, and mixing to simulate the physical properties of lunar soil. However, this method has significant limitations: the chemical composition of whole-rock materials such as basalt differs considerably from that of real lunar soil, especially the occurrence state of key elements such as iron and titanium, which is difficult to precisely control. Furthermore, the use of single-rock raw materials results in a relatively simple mineral composition in the simulated material, failing to reflect the complex multi-mineral system found in real lunar soil. This leads to deviations between simulated lunar soil and real lunar soil in terms of mineral composition, spectral characteristics, and mechanical properties.

[0004] On the other hand, my country generates a large amount of non-ferrous metal tailings waste every year, such as copper tailings, lead-zinc tailings, and molybdenum tailings. These tailings are generally characterized by complex composition, uneven particle size distribution, and diverse associated minerals, which limits traditional resource utilization methods. In building materials applications, some active ingredients are insufficient, resulting in unsatisfactory cementing performance; in ceramic raw material applications, the large fluctuations in chemical composition affect the stability of product quality. Currently, the overall comprehensive utilization rate of non-ferrous metal tailings in my country is low, and a large amount of tailings can only be stockpiled for a long time, which not only occupies land resources but also may pose potential environmental risks due to the heavy metal elements they contain. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned defects in the existing technology and to propose a method for preparing simulated lunar soil based on non-ferrous metal tailings. This method not only realizes the efficient resource utilization of non-ferrous metal tailings, but also prepares simulated lunar soil with matching composition and stable performance.

[0006] The technical solution of this invention is: a method for preparing simulated lunar soil based on non-ferrous metal tailings, comprising the following steps:

[0007] S1. Grind and sieve the non-ferrous metal tailings powder to make the particle size reach the micron level.

[0008] S2. The non-ferrous metal tailings powder obtained in step S1 is mixed and ground with plagioclase powder, common pyroxene powder, olivine powder and hematite powder in a certain proportion. The proportion of non-ferrous metal tailings powder is not less than 50 wt%, the proportion of plagioclase powder is 10-20 wt%, the proportion of pyroxene powder is 15-25 wt%, the proportion of olivine powder is 5-15 wt%, and the proportion of hematite powder is 5-15 wt%.

[0009] S3. The mixed powder obtained in step S2 is uniformly mixed with graphite powder and subjected to high-temperature reduction sintering. After sintering, it is naturally cooled to obtain a composite powder containing elemental iron.

[0010] S4. Mix ilmenite powder and carbon black powder evenly, and then perform high-temperature reduction sintering. After sintering, cool naturally to obtain a composite powder containing elemental iron and ilmenite.

[0011] S5. Mix the powders obtained in steps S3 and S4 evenly.

[0012] S6. Perform weak magnetic separation on the powder obtained after mixing in step S5.

[0013] S7. The powder processed in step S6 is ball-milled and sieved, and then mixed according to the specified particle size distribution ratio to obtain lunar soil simulant.

[0014] In this invention, the specific implementation steps of step S1 include: finely grinding the non-ferrous metal tailings powder to pass through a 200-mesh standard sieve, so that the particle size of the non-ferrous metal tailings powder obtained after grinding is no greater than 72μm, thereby obtaining tailings powder with a particle size reaching the micron level.

[0015] In step S2, the non-ferrous metal powder after grinding and sieving is mixed with plagioclase powder, common pyroxene powder, olivine powder and hematite powder in a certain proportion, and then placed in the grinding jar of a planetary ball mill for mixing. Stainless steel grinding balls are added, and the ball-to-powder ratio is (5~10):1.

[0016] The planetary ball mill is used to mix at 500-600 rpm for 20-40 minutes. The planetary ball mill is run intermittently to control the temperature of the ball mill to not exceed 70℃.

[0017] The mixed powder obtained in step S2 is mixed with graphite powder at a mass ratio of (8-12):1, loaded into an alumina crucible, and placed in a high-temperature tube furnace for reduction sintering.

[0018] Nitrogen gas is introduced during sintering at a flow rate of 300–500 ml / min. During the sintering reduction process, the temperature is gradually increased to 900–1000 °C at a rate of 5–10 °C / min and held for 1–2 hours. The temperature is then naturally cooled to room temperature to obtain a composite powder containing elemental iron.

[0019] In step S4, the ilmenite powder comprises: 70.18 wt% titanium, 29.519 wt% iron, 0.19 wt% silicon, 0.10 wt% manganese, and 0.011 wt% sulfur;

[0020] The ilmenite powder and carbon black powder were uniformly mixed at a mass ratio of 18 to 25:1, loaded into an alumina crucible, and placed in a high-temperature tube furnace for reduction sintering.

[0021] During the reduction sintering process, nitrogen gas is introduced into the high-temperature tube furnace at a flow rate of 300-500 ml / min. The high-temperature tube furnace is gradually heated to 850-1000℃ at a heating rate of 5-10℃ / min, and sintered at this high temperature for 0.5-1 h.

[0022] The mixture was then allowed to cool naturally to room temperature to obtain a composite powder containing both elemental iron and ilmenite.

[0023] In step S5, the composite powder containing elemental iron obtained in step S3 and the composite powder containing elemental iron and ilmenite obtained in step S4 are placed in a planetary ball mill at a mass ratio of 8 to 10:1.

[0024] The above-mentioned mixed powder was mixed using stainless steel grinding balls in a planetary ball mill. The mass ratio of stainless steel grinding balls to mixed powder was (5-10):1. The planetary ball mill was used to mix the powder for 20-40 minutes at a speed of 500-600 rpm, and intermittent operation was adopted to control the working temperature to not exceed 70℃.

[0025] In step S6, the mixed powder obtained in step S5 is evenly spread on the feeding plate of the combined magnetic separator, with a spreading thickness of 1-5 mm.

[0026] A weak magnetic field module is used, with a magnetic field strength of 0.15–0.25 T;

[0027] Free iron particles are separated by the differential rotation of the double-layer sorting drums, with the outer drum rotating at 10–20 rpm and the inner drum rotating at 5–15 rpm.

[0028] The specific implementation steps of step S7 are as follows:

[0029] S7.1. Place the powder obtained after magnetic separation in step S6 into a planetary ball mill for classification, grinding, and sieving:

[0030] S7.1.1, Coarse grinding stage: Place the primary crushed product in a planetary ball mill and grind it at 550-650 rpm for 20 minutes. Immediately pass it through a 500μm standard sieve. The product on the sieve with a particle size greater than 500μm is collected by coarse grinding, while the powder under the sieve with a particle size less than 500μm enters the medium grinding stage.

[0031] S7.1.2, Medium grinding stage: The undersize powder obtained in the coarse grinding stage is ground at 650-750 rpm for 30 minutes and immediately passed through a 100μm standard sieve. The oversize product with a particle size range of 100-500μm is collected separately, and the undersize powder with a particle size of less than 100μm enters the fine grinding stage.

[0032] S7.1.3 Fine grinding stage: Grind the undersized powder obtained from the medium grinding stage at 750-850 rpm for 40 minutes, and pass it through 50μm and 20μm standard sieves in sequence to collect powders of 50-100μm, 20-50μm and less than 20μm in grade.

[0033] S7.2. Mix the products obtained from the above graded sieving according to the specified ratio to obtain lunar soil simulant.

[0034] In step S7.2, when mixing the products from the grading and sieving process,

[0035] Powder with a particle size greater than 500 μm, comprising 0.7% to 1.4% by mass;

[0036] Powder with a particle size of 100–500 micrometers, comprising 13–16% by mass;

[0037] Powder with a particle size of 50–100 micrometers, comprising 35–43% by mass;

[0038] Powder with a particle size of 20–50 micrometers, comprising 27–31% by mass;

[0039] Powder with a particle size of less than 20 micrometers, accounting for 7-12% by mass.

[0040] The beneficial effects of this invention are:

[0041] (1) This invention uses non-ferrous metal tailings as the main raw material to realize the efficient resource utilization of bulk industrial solid waste: Compared with traditional single rock raw materials, this invention not only alleviates the environmental and land occupation problems caused by long-term tailings storage, but also gives tailings higher added value, opening up a new way for the large-scale application of non-ferrous metal tailings.

[0042] (2) The present invention rationally sets the proportions of non-ferrous metal tailings powder, plagioclase powder, pyroxene powder, olivine powder, hematite powder and ilmenite powder, thereby achieving the preliminary control of the chemical and mineral composition of the final simulated lunar soil and ensuring a high degree of similarity to the real lunar soil.

[0043] (3) This application utilizes carbon black to reduce iron oxides in the mixed powder under an inert gas atmosphere, simulating the real lunar soil being subjected to H-rich conditions. +The solar wind reduction effect was used to generate elemental metallic iron particles, a key component required to simulate lunar soil, accurately simulating the occurrence state of iron on the moon; and the ilmenite powder was moderately reduced to avoid over-reduction and damage to the ilmenite structure.

[0044] (4) The simulated lunar soil prepared in this application provides a high-fidelity basic material for ground tests, spacecraft performance testing and in-situ utilization of lunar resources (ISRU) for lunar exploration missions.

[0045] In summary, this application innovatively proposes a method for preparing simulated lunar regolith using non-ferrous metal tailings as the main raw material. By grinding and sieving the tailings powder, rationally combining it with supplementary minerals such as plagioclase, pyroxene, olivine, hematite, and ilmenite, and combining reduction sintering and magnetic separation processes, elemental iron and coexisting iron-titanium components are successfully introduced into the powder system. After ball milling, classification, and proportioning, a simulated material with a particle size distribution highly consistent with Chang'E-5 lunar regolith is obtained. This method not only achieves efficient resource utilization of non-ferrous metal tailings but also prepares simulated lunar regolith with matching composition and stable performance. This method not only provides an economically feasible material solution for lunar exploration missions but also opens up new avenues for solving the environmental remediation challenges of tailings. Attached Figure Description

[0046] Figure 1 This is an X-ray diffraction pattern of the tungsten tailings raw material selected in the examples;

[0047] Figure 2 This is the final lunar soil simulation obtained;

[0048] Figure 3 This is the X-ray diffraction pattern of the final lunar soil simulation;

[0049] Figure 4 This is a scanning electron microscope image of the final lunar soil simulant;

[0050] Figure 5 This is a comparison chart of the particle size distribution test results of lunar soil simulant CSU-1C and Chang'E-5 lunar soil obtained in Example 1. Detailed Implementation

[0051] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0052] Specific details are set forth in the following description to provide a full understanding of the invention. However, the invention can be practiced in many ways other than those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0053] This application proposes a method for preparing simulated lunar soil based on non-ferrous metal tailings. In this embodiment, tungsten tailings are selected as the non-ferrous metal tailings, and the specific implementation steps are as follows.

[0054] The first step is to grind and sieve the non-ferrous metal tailings sample so that the particle size of the ground powder reaches the micron level.

[0055] In this embodiment, the non-ferrous metal tailings are finely ground to pass through a 200-mesh sieve, and the particle size of the non-ferrous metal tailings powder obtained after grinding is no greater than 72 μm.

[0056] The second step involves mixing the non-ferrous metal tailings powder obtained in the first step with plagioclase powder, common pyroxene powder, olivine powder, and hematite powder in a certain proportion, and then grinding them.

[0057] In this application, the proportion of non-ferrous metal tailings powder is not less than 50 wt%, the proportion of plagioclase powder is 10-20 wt%, the proportion of pyroxene powder is 15-25 wt%, the proportion of olivine powder is 5-15 wt%, and the proportion of hematite powder is 5-15 wt%.

[0058] The above-mentioned materials are placed in the grinding jar of a planetary ball mill and mixed, with stainless steel grinding balls added at a ball-to-powder ratio of (5-10):1. The planetary ball mill is run at 500-600 rpm for 20-40 minutes, while the mill is operated intermittently to control its temperature to not exceed 70°C. Argon gas can be introduced during the grinding process to prevent oxidation reactions during high-temperature grinding.

[0059] The third step involves uniformly mixing the mixed powder obtained in the second step with graphite powder, placing the mixture in an alumina crucible, and then performing reduction sintering in a tube furnace. After sintering, the mixture is naturally cooled to room temperature to obtain a composite powder containing elemental iron. The graphite powder has a particle size of 500-800 mesh.

[0060] The mixed powder obtained in the second step is uniformly mixed with graphite powder at a mass ratio of (8-12):1, placed in an alumina crucible, and then placed in a high-temperature tube furnace for reduction sintering. In this application, a high-temperature tube furnace of model RHTH-120-300 / 7 can be used.

[0061] Nitrogen gas is introduced during sintering at a flow rate controlled at 300–500 ml / min. The introduced nitrogen acts as a protective atmosphere, dispersing air and maintaining an inert environment for the reduction sintering process, preventing secondary oxidation. During the sintering reduction process, the temperature is gradually increased to 900–1000℃ at a rate of 5–10℃ / min and held for 1–2 hours. Subsequently, it is naturally cooled to room temperature to obtain a composite powder containing elemental iron.

[0062] The fourth step involves uniformly mixing ilmenite powder and carbon black powder together, loading the mixture into an alumina crucible, and placing it in a tube furnace for reduction sintering. After sintering, the mixture is naturally cooled to room temperature to obtain a composite powder containing both elemental iron and ilmenite.

[0063] In this embodiment, the ilmenite powder used is "Ilmenite 70" ilmenite powder sold by Kimpson Metal Materials Co., Ltd. The composition of this ilmenite powder includes: 70.18 wt% titanium, 29.519 wt% iron, 0.19 wt% silicon, 0.10 wt% manganese, and 0.011 wt% sulfur. This ilmenite powder is mixed with carbon black powder at a mass ratio of 18–25:1 and then placed in a tube furnace for reduction sintering.

[0064] The particle size of graphite powder is 500-800 mesh.

[0065] During the reduction sintering process, nitrogen gas is introduced into the tube furnace at a flow rate of 300-500 ml / min. The temperature inside the tube furnace is gradually increased to 850-1000℃ at a rate of 5-10℃ / min, and sintering is carried out at this high temperature for 0.5-1 h.

[0066] The fifth step involves mixing the composite powder containing elemental iron obtained in the third step with the composite powder containing elemental iron and ilmenite obtained in the fourth step in a certain proportion in the grinding jar of a planetary ball mill to ensure that the elemental iron and ilmenite are evenly dispersed.

[0067] In this embodiment, the composite powder containing elemental iron obtained in step three and the composite powder containing both elemental iron and ilmenite obtained in step four are placed in a planetary ball mill at a mass ratio of 8–10:1. The above-mentioned mixed powders are mixed using stainless steel grinding balls in the planetary ball mill, with a mass ratio of stainless steel grinding balls to mixed powder of (5–10):1. The planetary ball mill is operated at a speed of 500–600 rpm for 20–40 minutes, and intermittent operation is used to control its operating temperature to not exceed 70°C.

[0068] During the grinding process, argon gas is introduced into the grinding jar of the planetary ball mill to prevent oxidation reactions during the high-temperature grinding process.

[0069] The sixth step is to perform weak magnetic separation on the powder obtained in the previous step to remove free iron particles from the composite powder.

[0070] The powder is evenly spread on the feed plate of the combined magnetic separator, with a thickness of 1–5 mm. A weak magnetic module is used, with a magnetic field strength of 0.15–0.25 T. Free iron particles are separated by the differential rotation of the double-layer sorting drums, with the outer drum rotating at 10–20 rpm and the inner drum rotating at 5–15 rpm.

[0071] In this embodiment, a combined magnetic separator of model ZH560 can be selected for weak magnetic separation.

[0072] Step 7: The powder that has undergone weak magnetic separation is placed in a planetary ball mill for graded grinding and sieving, and then mixed according to the particle size distribution ratio of Chang'E-5 lunar soil to obtain lunar soil simulant.

[0073] During the grading, grinding, and sieving process, the powder after weak magnetic separation is placed in a planetary ball mill using stainless steel grinding balls at a mass ratio of 5:1 to powder. Grading and sieving are performed at 550–850 rpm, employing a graded grinding process of coarse grinding > sieving > medium grinding > sieving > fine grinding > sieving to prevent the powder from becoming too fine. During the grinding process, argon gas is introduced into the ball mill's spherical jar as a protective gas. The specific process of grading, grinding, and sieving in this embodiment is described below.

[0074] The first stage is coarse grinding. The powder after weak magnetic separation is placed in a planetary ball mill and ground at 550-650 rpm for 20 minutes. It is then immediately passed through a 500μm standard sieve. The product on the sieve with a particle size greater than 500μm is collected for coarse grinding, while the powder under the sieve with a particle size less than 500μm enters the next stage of medium grinding.

[0075] The second stage is the intermediate grinding stage. The powder that passes through the sieve in the coarse grinding stage is ground at 650-750 rpm for 30 minutes and immediately passed through a 100μm standard sieve. The product on the sieve with a particle size range of 100-500μm is collected separately, and the powder that passes through the sieve with a particle size smaller than 100μm enters the next stage of fine grinding.

[0076] The third stage is the fine grinding stage. The powder that passes through the sieve obtained in the medium grinding stage is ground at 750-850 rpm for 40 minutes, and then passed through 50μm and 20μm standard sieves in sequence to collect powders of 50-100μm, 20-50μm and <20μm.

[0077] Finally, the sieved products from each stage are mixed in a specified ratio to obtain lunar soil simulants.

[0078] When mixing the products from the grading and sieving process, the following percentages are used: powder with a particle size greater than 500 μm: 0.7–1.4% by mass; powder with a particle size of 100–500 μm: 13–16% by mass; powder with a particle size of 50–100 μm: 35–43% by mass; powder with a particle size of 20–50 μm: 27–31% by mass; and powder with a particle size less than 20 μm: 7–12% by mass.

[0079] Example 1

[0080] In this embodiment, the non-ferrous metal tailings used in the simulated lunar soil preparation method based on non-ferrous metal tailings are tungsten tailings, and the method includes the following steps.

[0081] In the first step, this embodiment selects a tungsten tailings sample from a mining company in Hunan Province. The main chemical components and their contents in this sample are as follows: SiO2 content is 42.0 wt%, Al2O3 content is 11.40 wt%, CaO content is 23.37 wt%, and FeO content is... T The content of MgO is 5.978 wt%, MgO is 2.056 wt%, Na2O is 0.937 wt%, TiO2 is 0.121 wt%, K2O is 2.637 wt%, P2O5 is 0.026 wt%, MnO is 0.521 wt%, and F is 4.482 wt%.

[0082] The above tungsten tailings sample was ground into tungsten tailings powder using a planetary ball mill and passed through a 200-mesh standard sieve. At this time, the particle size of the tungsten tailings powder was no greater than 74 μm.

[0083] The X-ray diffraction pattern of the tungsten tailings raw material used in this implementation is as follows: Figure 1 As shown.

[0084] The second step involves mixing the tungsten tailings powder obtained in the first step with plagioclase powder, common pyroxene powder, olivine powder, and hematite powder in the following proportions:

[0085] The content of tungsten tailings powder is 59 wt%, plagioclase powder is 13 wt%, common pyroxene powder is 16 wt%, olivine powder is 5 wt%, and hematite powder is 7 wt%.

[0086] The above-mentioned materials were placed in the grinding jar of a planetary ball mill and mixed. Stainless steel grinding balls were added, with a ball-to-powder ratio of 8:1. The planetary ball mill was used to mix the materials in the jar at 550 rpm for 30 minutes. During the mixing process, the mill was operated intermittently to control the temperature to ≤70℃, and argon gas was introduced to prevent oxidation reactions at high temperatures.

[0087] The third step involves mixing the powder obtained in the second step with graphite powder at a mass ratio of 10:1, loading it into an alumina crucible, and placing it in a high-temperature tube furnace of model RHTH-120-300 / 7 for high-temperature reduction sintering.

[0088] During the sintering process, nitrogen gas was introduced at a flow rate of 400 ml / min, and the temperature in the high-temperature tube furnace was gradually increased to 950°C at a rate of 10°C / min, and held at 950°C for 1.5 hours. Subsequently, it was naturally cooled to room temperature to obtain a composite powder containing elemental iron.

[0089] The fourth step involves uniformly mixing ilmenite powder (model "Iron 70") sold by Jinpusen Metal Materials Co., Ltd. with carbon black powder at a mass ratio of 20:1, loading the mixture into an alumina crucible, and placing it in a high-temperature tube furnace (model RHTH-120-300 / 7) for high-temperature reduction sintering.

[0090] During the sintering process, nitrogen gas was introduced at a flow rate of 400 ml / min, and the temperature in the high-temperature tube furnace was gradually increased to 850°C at a rate of 10°C / min, and held at 850°C for 0.5 hours. Subsequently, it was naturally cooled to room temperature to obtain a composite powder containing both elemental iron and ilmenite.

[0091] The fifth step involves ball milling the mixed powder obtained in the third step with the mixed powder obtained in the fourth step at a mass ratio of 9:1 to ensure uniform dispersion of elemental iron and ilmenite.

[0092] The mixed powders obtained in steps three and four were placed in the grinding jar of a planetary ball mill according to a specified ratio. Stainless steel grinding balls were added, with a ball-to-powder ratio of 8:1. The planetary ball mill was used to mix the material in the jar at 550 rpm for 30 minutes. During the mixing process, the mill was operated intermittently to control the temperature to ≤70℃, and argon gas was introduced to prevent oxidation reactions at high temperatures.

[0093] Step 6: The mixed powder obtained in step 5 is subjected to weak magnetic separation using a ZH560 combined magnetic separator.

[0094] The mixed powder obtained in step 5 is spread on the feeding plate of the magnetic separator with a thickness of 3mm. A weak magnetic field with a magnetic field strength of 0.2T is used, and a differential drum with an outer drum speed of 15rpm and an inner drum speed of 10rpm is used to separate the free iron particles in the mixed powder.

[0095] The seventh step involves ball milling and sieving the powder obtained through weak magnetic separation. A segmented control process is adopted: coarse grinding > sieving > medium grinding > sieving > fine grinding > sieving, collecting powders of different particle sizes. In this embodiment, a planetary ball mill is used for grinding, and standard sieves of different apertures are used for sieving. During the grinding process, argon gas is introduced into the grinding jar as a protective gas to prevent oxidation reactions during high-temperature grinding.

[0096] First, the primary crushed product is coarsely ground. The primary crushed product is placed in a planetary ball mill and ground at 600 rpm for 20 minutes, then immediately passed through a 500 μm standard sieve. Powder with a particle size greater than 500 μm remains on the upper surface of the standard sieve and is collected separately; powder with a particle size no greater than 500 μm proceeds to the intermediate grinding stage.

[0097] Next, powder with a particle size no larger than 500 μm is placed in a planetary ball mill and ground at 700 rpm for 30 minutes, then immediately passed through a 100 μm standard sieve. Powder with a particle size larger than 100 μm remains on the upper surface of the standard sieve and is collected separately; powder with a particle size no larger than 100 μm proceeds to the fine grinding stage.

[0098] Then, the powder with a particle size of no more than 100 μm was placed in a planetary ball mill and ground at 800 rpm for 40 minutes. It was then passed through 50 μm and 20 μm standard sieves in sequence, and the powders of 50-100 μm, 20-50 μm and <20 μm were collected in stages.

[0099] The products obtained from each stage of grinding and sieving are mixed in the following proportions to obtain the following result: Figure 2 The lunar soil model shown is CSU-1C (Central South University-type 1 for construction).

[0100] Powder with a particle size greater than 500 micrometers accounts for 1.2% by mass; powder with a particle size of 100 to 500 micrometers accounts for 15.7% by mass; powder with a particle size of 50 to 100 micrometers accounts for 42.3% by mass; powder with a particle size of 20 to 50 micrometers accounts for 30.8% by mass; and powder with a particle size less than 20 micrometers accounts for 10% by mass.

[0101] The mineral composition of the simulants prepared in Example 1 was analyzed using a fully automated X-ray diffractometer D / max2500 (scanning range 10° - 90°, scan rate 8° / min) from Rigaku Corporation, Japan, as shown in Table 1.

[0102] Table 1. Main chemical composition (wt%) of each material

[0103]

[0104] As can be seen from Table 1, the lunar soil simulant prepared in this embodiment has a high degree of matching in Fe, Si and Ti elements, and successfully simulates the characteristics of Chang'E-5 lunar soil "titanium in the lunar maria" in terms of key components.

[0105] The surface features of the final simulant in Example 1 were characterized using a Czech TESCAN MIRA LMS scanning electron microscope (SEM). Figure 3 It can be confirmed that elemental iron appeared in the simulated material after reduction sintering.

[0106] The chemical composition of each material was analyzed using a Shimadzu XRF-1800 scanning X-ray fluorescence spectrometer. Figure 4The simulation particles exhibit distinct angular features, which is related to the mechanical grinding effect during the ball milling process. The particles form sharp edges under the high-energy impact of the grinding balls.

[0107] The particle size distribution test results of soil simulants CSU-1C and Chang'E-5 monthly soil are compared, for example... Figure 5 As shown.

[0108] Example 2

[0109] Unlike Example 1, the simulated lunar soil preparation method based on tungsten tailings in this example includes the following steps.

[0110] The first step is to use a planetary ball mill to grind the tungsten tailings sample into tungsten tailings powder and pass it through a 200-mesh standard sieve. At this point, the particle size of the tungsten tailings powder is no greater than 74μm.

[0111] The second step involves mixing the tungsten tailings powder obtained from the first step with plagioclase powder, common pyroxene powder, olivine powder, and hematite powder in the following proportions:

[0112] The content of tungsten tailings powder is 50 wt%, plagioclase powder is 10 wt%, common pyroxene powder is 25 wt%, olivine powder is 5 wt%, and hematite powder is 10 wt%.

[0113] The above-mentioned materials were placed in the grinding jar of a planetary ball mill and mixed. Stainless steel grinding balls were added, with a ball-to-powder ratio of 5:1. The planetary ball mill was used to mix the materials in the jar at 500 rpm for 40 minutes. During the mixing process, the mill was operated intermittently to control the temperature to ≤70℃, and argon gas was introduced to prevent oxidation reactions at high temperatures.

[0114] The third step involves mixing the powder obtained in the second step with graphite powder at a mass ratio of 8:1, loading it into an alumina crucible, and placing it in a high-temperature tube furnace of model RHTH-120-300 / 7 for high-temperature reduction sintering.

[0115] During the sintering process, nitrogen gas was introduced at a flow rate of 300 ml / min, and the temperature in the high-temperature tube furnace was gradually increased to 1000℃ at a rate of 5℃ / min, and held at 1000℃ for 1 hour. Subsequently, it was naturally cooled to room temperature to obtain a composite powder containing elemental iron.

[0116] The fourth step involves uniformly mixing ilmenite powder (model "Iron 70") sold by Jinpusen Metal Materials Company with carbon black powder at a mass ratio of 25:1, loading the mixture into an alumina crucible, and placing it in a high-temperature tube furnace (model RHTH-120-300 / 7) for high-temperature reduction sintering.

[0117] During the sintering process, nitrogen gas was introduced at a flow rate of 300 ml / min, and the temperature in the high-temperature tube furnace was gradually increased to 1000℃ at a rate of 10℃ / min, and held at 850℃ for 1 hour. Subsequently, it was naturally cooled to room temperature to obtain a composite powder containing both elemental iron and ilmenite.

[0118] The fifth step involves ball milling the mixed powder obtained in the third step with the mixed powder obtained in the fourth step at a mass ratio of 8:1 to ensure uniform dispersion of elemental iron and ilmenite.

[0119] The mixed powders obtained in steps three and four were placed in the grinding jar of a planetary ball mill according to a specified ratio. Stainless steel grinding balls were added, with a ball-to-powder ratio of 5:1. The planetary ball mill was used to mix the material in the jar at 500 rpm for 40 minutes. During the process, the mill was run intermittently to control the temperature to ≤70℃, and argon gas was introduced to prevent oxidation reactions at high temperatures.

[0120] Step 6: The mixed powder obtained in step 5 is subjected to weak magnetic separation using a ZH560 combined magnetic separator.

[0121] The mixed powder obtained in step 5 is spread on the feeding plate of the magnetic separator with a thickness of 5mm. A weak magnetic field with a magnetic field strength of 0.25T is used, and a differential speed drum with an outer cylinder speed of 10rpm and an inner cylinder speed of 5rpm is used to separate the free iron particles in the mixed powder.

[0122] The seventh step is to ball mill and classify the powder that has undergone weak magnetic separation.

[0123] Everything else is the same as in Example 1.

[0124] Example 3

[0125] Unlike Example 1, the simulated lunar soil preparation method based on tungsten tailings in this example includes the following steps.

[0126] The first step is to use a planetary ball mill to grind the tungsten tailings sample into tungsten tailings powder and pass it through a 200-mesh standard sieve. At this point, the particle size of the tungsten tailings powder is no greater than 74μm.

[0127] The second step involves mixing the tungsten tailings powder obtained in the first step with plagioclase powder, common pyroxene powder, olivine powder, and hematite powder in the following proportions:

[0128] The content of tungsten tailings powder is 50 wt%, plagioclase powder is 20 wt%, common pyroxene powder is 20 wt%, olivine powder is 5 wt%, and hematite powder is 5 wt%.

[0129] The above-mentioned materials were placed in the grinding jar of a planetary ball mill and mixed. Stainless steel grinding balls were added, with a ball-to-powder ratio of 10:1. The planetary ball mill was used to mix the materials in the jar at 600 rpm for 20 minutes. During the mixing process, the mill was operated intermittently to control the temperature to ≤70℃, and argon gas was introduced to prevent oxidation reactions at high temperatures.

[0130] The third step involves mixing the powder obtained in the second step with graphite powder at a mass ratio of 12:1, loading it into an alumina crucible, and placing it in a high-temperature tube furnace of model RHTH-120-300 / 7 for high-temperature reduction sintering.

[0131] During the sintering process, nitrogen gas was introduced at a flow rate of 500 ml / min, and the temperature in the high-temperature tube furnace was gradually increased to 900°C at a rate of 7°C / min, and then held at 1000°C for 2 hours. Subsequently, it was naturally cooled to room temperature to obtain a composite powder containing elemental iron.

[0132] The fourth step involves uniformly mixing ilmenite powder and carbon black powder at a mass ratio of 18:1, loading the mixture into an alumina crucible, and placing it in a high-temperature tube furnace (model RHTH-120-300 / 7) for high-temperature reduction sintering.

[0133] During the sintering process, nitrogen gas was introduced at a flow rate of 500 ml / min, and the temperature in the high-temperature tube furnace was gradually increased to 950°C at a rate of 5°C / min, and held at 950°C for 0.8 hours. Subsequently, it was naturally cooled to room temperature to obtain a composite powder containing both elemental iron and ilmenite.

[0134] The fifth step involves ball milling the mixed powder obtained in the third step with the mixed powder obtained in the fourth step at a mass ratio of 10:1 to ensure uniform dispersion of elemental iron and ilmenite.

[0135] The mixed powders obtained in steps four and five were placed in the grinding jar of a planetary ball mill according to a specified ratio. Stainless steel grinding balls were added, with a ball-to-powder ratio of 10:1. The planetary ball mill was used to mix the material in the jar at 600 rpm for 20 minutes. During the mixing process, the mill was operated intermittently to control the temperature to ≤70℃, and argon gas was introduced to prevent oxidation reactions at high temperatures.

[0136] Step 6: The mixed powder obtained in step 5 is subjected to weak magnetic separation using a ZH560 combined magnetic separator.

[0137] The mixed powder obtained in step 5 is spread on the feeding plate of the magnetic separator with a thickness of 1 mm. A weak magnetic field with a magnetic field strength of 0.15T is used, and a differential drum with an outer drum speed of 12 rpm and an inner drum speed of 5 rpm is used to separate the free iron particles in the mixed powder.

[0138] The seventh step is to ball mill and classify the powder that has undergone weak magnetic separation.

[0139] Everything else is the same as in Example 1.

[0140] Example 4

[0141] Unlike Example 1, the simulated lunar soil preparation method based on tungsten tailings in this example includes the following steps.

[0142] The first step is to use a planetary ball mill to grind the tungsten tailings sample into tungsten tailings powder and pass it through a 200-mesh standard sieve. At this point, the particle size of the tungsten tailings powder is no greater than 74μm.

[0143] The second step involves mixing the tungsten tailings powder obtained in the first step with plagioclase powder, common pyroxene powder, olivine powder, and hematite powder in the following proportions:

[0144] The content of tungsten tailings powder is 55 wt%, plagioclase powder is 10 wt%, common pyroxene powder is 15 wt%, olivine powder is 15 wt%, and hematite powder is 5 wt%.

[0145] The above-mentioned materials were placed in the grinding jar of a planetary ball mill and mixed. Stainless steel grinding balls were added, with a ball-to-powder ratio of 8:1. The planetary ball mill was used to mix the materials in the jar at a speed of 580 rpm for 35 minutes. During the mixing process, the mill was operated intermittently to control the temperature to ≤70℃, and argon gas was introduced to prevent oxidation reactions at high temperatures.

[0146] The third step involves mixing the powder obtained in the second step with graphite powder at a mass ratio of 9:1, loading it into an alumina crucible, and placing it in a high-temperature tube furnace of model RHTH-120-300 / 7 for high-temperature reduction sintering.

[0147] During the sintering process, nitrogen gas was introduced at a flow rate of 350 ml / min, and the temperature in the high-temperature tube furnace was gradually increased to 1050 °C at a rate of 5 °C / min, and held at 1050 °C for 1.2 hours. Subsequently, it was naturally cooled to room temperature to obtain a composite powder containing elemental iron.

[0148] The fourth step involves uniformly mixing ilmenite powder and carbon black powder at a mass ratio of 22:1, loading the mixture into an alumina crucible, and placing it in a high-temperature tube furnace (model RHTH-120-300 / 7) for high-temperature reduction sintering.

[0149] During the sintering process, nitrogen gas was introduced at a flow rate of 450 ml / min, and the temperature in the high-temperature tube furnace was gradually increased to 1000℃ at a rate of 8℃ / min, and held at 1000℃ for 0.5 hours. Subsequently, it was naturally cooled to room temperature to obtain a composite powder containing both elemental iron and ilmenite.

[0150] The fifth step involves ball milling the mixed powder obtained in the third step with the mixed powder obtained in the fourth step at a mass ratio of 10:1 to ensure uniform dispersion of elemental iron and ilmenite.

[0151] The mixed powders obtained in steps three and four were placed in the grinding jar of a planetary ball mill according to a specified ratio. Stainless steel grinding balls were added, with a ball-to-powder ratio of 10:1. The planetary ball mill was used to mix the material in the jar at 600 rpm for 30 minutes. During the mixing process, the mill was operated intermittently to control the temperature to ≤70℃, and argon gas was introduced to prevent oxidation reactions at high temperatures.

[0152] The sixth step is to perform weak magnetic separation on the mixed powder obtained in the fifth step using a ZH560 combined magnetic separator.

[0153] The mixed powder obtained in step 5 is spread on the feeding plate of the magnetic separator with a thickness of 4mm. A weak magnetic field with a magnetic field strength of 0.25T is used, and a differential drum with an outer drum speed of 20rpm and an inner drum speed of 15rpm is used to separate the free iron particles in the mixed powder.

[0154] The seventh step is to ball mill and classify the powder that has undergone weak magnetic separation.

[0155] Everything else is the same as in Example 1.

[0156] Example 5

[0157] Unlike Example 1, in the second step of the simulated lunar soil preparation method based on tungsten tailings in this example, the tungsten tailings powder obtained in the first step is mixed with plagioclase powder, common pyroxene powder, olivine powder, and hematite powder in the following proportions:

[0158] The content of tungsten tailings powder is 53 wt%, plagioclase powder is 10 wt%, common pyroxene powder is 15 wt%, olivine powder is 7 wt%, and hematite powder is 15 wt%.

[0159] Everything else is the same as in Example 1.

[0160] The method for preparing simulated lunar soil based on tungsten tailings provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from the principles of this invention, and these improvements and modifications also fall within the protection scope of the claims of this invention. The above description of the disclosed embodiments enables those skilled in the art to implement or use this invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this invention. Therefore, this invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing simulated lunar soil based on non-ferrous metal tailings, characterized in that, Includes the following steps: S1. Grind and sieve the non-ferrous metal tailings sample to make the particle size of the powder reach the micron level. S2. The non-ferrous metal tailings powder obtained in step S1 is mixed and ground with plagioclase powder, common pyroxene powder, olivine powder and hematite powder, wherein the proportion of non-ferrous metal tailings powder is not less than 50 wt%, the proportion of plagioclase powder is 10-20 wt%, the proportion of pyroxene powder is 15-25 wt%, the proportion of olivine powder is 5-15 wt%, and the proportion of hematite powder is 5-15 wt%. S3. The mixed powder obtained in step S2 is uniformly mixed with carbon black powder and subjected to high-temperature reduction sintering. After sintering, it is naturally cooled to obtain a composite powder containing elemental iron. S4. Mix ilmenite powder and carbon black powder evenly, and then perform high-temperature reduction sintering. After sintering, cool naturally to obtain a composite powder containing elemental iron and ilmenite. S5. Mix the powders obtained in steps S3 and S4 evenly. S6. Perform weak magnetic separation on the powder obtained after mixing in step S5. S7. The powder processed in step S6 is graded, ground, and sieved, and then mixed according to the specified particle size ratio to obtain lunar soil simulant.

2. The method for preparing simulated lunar soil based on non-ferrous metal tailings according to claim 1, characterized in that, The specific implementation steps of step S1 include: The non-ferrous metal tailings are finely ground to pass through a 200-mesh sieve so that the particle size of the non-ferrous metal tailings powder obtained after grinding is no greater than 72 μm.

3. The method for preparing simulated lunar soil based on non-ferrous metal tailings according to claim 1, characterized in that, In step S2, the non-ferrous metal powder tailings powder after grinding and sieving is mixed with plagioclase powder, common pyroxene powder, olivine powder and hematite powder in a certain proportion, and then placed in the grinding jar of a planetary ball mill for mixing. Stainless steel grinding balls are added, and the ball-to-powder ratio is (5~10):

1. The planetary ball mill is used to mix at 500-600 rpm for 20-40 minutes. The planetary ball mill is run intermittently to control the temperature of the ball mill to not exceed 70℃.

4. The method for preparing simulated lunar soil based on non-ferrous metal tailings according to claim 1, characterized in that, The mixed powder obtained in step S2 is mixed with carbon black powder at a mass ratio of (8-12):1, loaded into an alumina crucible, and placed in a high-temperature tube furnace for reduction sintering. Nitrogen gas is introduced during sintering at a flow rate of 300–500 ml / min. During the sintering reduction process, the temperature is gradually increased to 900–1000 °C at a rate of 5–10 °C / min and held for 1–2 hours. The temperature is then naturally cooled to room temperature to obtain a composite powder containing elemental iron.

5. The method for preparing simulated lunar soil based on non-ferrous metal tailings according to claim 1, characterized in that, In step S4, the ilmenite powder comprises: 70.18 wt% titanium, 29.519 wt% iron, 0.19 wt% silicon, 0.10 wt% manganese, and 0.011 wt% sulfur; The ilmenite powder and carbon black powder were uniformly mixed at a mass ratio of 18 to 25:1, loaded into an alumina crucible, and placed in a high-temperature tube furnace for reduction sintering. During the reduction sintering process, nitrogen gas is introduced into the high-temperature tube furnace at a flow rate of 300-500 ml / min. The high-temperature tube furnace is gradually heated to 850-1000℃ at a heating rate of 5-10℃ / min, and sintered at this high temperature for 0.5-1 h. The mixture was then allowed to cool naturally to room temperature to obtain a composite powder containing both elemental iron and ilmenite.

6. The method for preparing simulated lunar soil based on non-ferrous metal tailings according to claim 1, characterized in that, In step S5, the composite powder containing elemental iron obtained in step S3 and the composite powder containing elemental iron and ilmenite obtained in step S4 are placed in a planetary ball mill at a mass ratio of 8 to 10:

1. The above-mentioned mixed powder was mixed using stainless steel grinding balls in a planetary ball mill. The mass ratio of stainless steel grinding balls to mixed powder was (5-10):

1. The planetary ball mill was used to mix the powder for 20-40 minutes at a speed of 500-600 rpm, and intermittent operation was adopted to control the working temperature to not exceed 70℃.

7. The method for preparing simulated lunar soil based on non-ferrous metal tailings according to claim 1, characterized in that, In step S6, the mixed powder obtained in step S5 is evenly spread on the feeding plate of the combined magnetic separator, with a spreading thickness of 1-5 mm. A weak magnetic field module is used, with a magnetic field strength of 0.15–0.25 T; Free iron particles are separated by the differential rotation of the double-layer sorting drums, with the outer drum rotating at 10–20 rpm and the inner drum rotating at 5–15 rpm.

8. The method for preparing simulated lunar soil based on non-ferrous metal tailings according to claim 1, characterized in that, The specific implementation steps of step S7 are as follows: S7.

1. Place the powder obtained after magnetic separation in step S6 into a planetary ball mill for classification, grinding, and sieving: S7.1.1, Coarse grinding stage: Place the primary crushed product in a planetary ball mill and grind it at 550-650 rpm for 20 minutes. Immediately pass it through a 500μm standard sieve. The product on the sieve with a particle size greater than 500μm is collected by coarse grinding, while the powder under the sieve with a particle size less than 500μm enters the medium grinding stage. S7.1.2, Medium grinding stage: The undersize powder obtained in the coarse grinding stage is ground at 650-750 rpm for 30 minutes and immediately passed through a 100μm standard sieve. The oversize product with a particle size range of 100-500μm is collected separately, and the undersize powder with a particle size of less than 100μm enters the fine grinding stage. S7.1.3 Fine grinding stage: Grind the undersized powder obtained from the medium grinding stage at 750-850 rpm for 40 minutes, and pass it through 50μm and 20μm standard sieves in sequence to collect powders of 50-100μm, 20-50μm and less than 20μm in grade. S7.

2. Mix the products obtained from the above graded sieving according to the specified ratio to obtain lunar soil simulant.

9. The method for preparing simulated lunar soil based on non-ferrous metal tailings according to claim 8, characterized in that, In step S7.2, when mixing the products from the grading and sieving process, Powder with a particle size greater than 500 μm, comprising 0.7% to 1.4% by mass; Powder with a particle size of 100–500 micrometers, comprising 13–16% by mass; Powder with a particle size of 50–100 micrometers, comprising 35–43% by mass; Powder with a particle size of 20–50 micrometers, comprising 27–31% by mass; Powder with a particle size of less than 20 micrometers, accounting for 7-12% by mass.

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