A device for sorting and grading lunar soil ilmenite under a lunar environment

Abstract

The application discloses a lunar soil ilmenite sorting and particle size grading device under the lunar surface environment, a net conveying belt passes through a parallel electric field formed by a first positive plate and a first negative plate; the first negative plate is provided with a hole for receiving the mineral material charged by a self-friction charging unit; the first negative plate covers an upper belt of the net conveying belt, and another part of the upper belt is located at a feeding port of a particle size grading unit; a part of the first positive plate forms an electric field with the first negative plate, and the other part extends to the feeding port of the particle size grading unit; the particle size grading unit comprises a second negative plate and a second positive plate fixed on opposite sides of a grading bin. The electric field formed by the two parallel electrodes realizes ilmenite sorting. Especially, the length of the first negative plate is controlled to be out of the coverage range of the particle size grading unit, the electric field force is formed by the longer first positive plate and the second positive plate and the second negative plate, the particle size grading is realized, the structure of the screening device can be simplified, the device volume and weight are reduced, and the transportation cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of deep space resource development technology, specifically to a device for sorting and grading lunar soil ilmenite in a lunar environment. Background Technology

[0002] Helium-3 is mainly enriched on the surface of lunar regolith particles, existing as helium bubbles or in mineral lattice defects. Ilmenite is the most helium-3 enriched mineral in lunar regolith. Therefore, refining ilmenite can effectively improve the efficiency of helium-3 capture. Ilmenite is also a raw material for water production and infrastructure construction on the lunar surface. In order to achieve more efficient comprehensive utilization and development of lunar regolith, research on lunar regolith ilmenite enrichment technology has been carried out globally, resulting in some research results, but all of them have varying degrees of shortcomings, as described in the following published patents:

[0003] The publication number is CN115501945A, and the title is "A Lunar Reef Ilmenite Separation Device". This device mainly designs an electrostatic separation device based on a rotating structure. It has a simple structure but a high center of gravity, a single function, and a small screening capacity.

[0004] Currently, the most mature beneficiation technologies for ilmenite on the ground mainly utilize the different properties of ilmenite, such as density, surface properties, and electromagnetic properties. The main methods for separating ilmenite include gravity separation, flotation, and electrostatic separation. However, because the moon's gravity is only 1 / 6 that of Earth, its vacuum degree is 1.333 × 10⁻⁶. -8 ~1.333×10 -12 The mbar makes gravity separation inefficient. Commonly used mineral processing media on Earth, such as water, air, and chemical reagents, are hard to obtain and need to be replenished. The cost of transporting process fluids to the moon is very high. Therefore, mineral processing equipment with a low center of gravity, high efficiency, and mobility needs to be redesigned for lunar soil mineral processing technology.

[0005] Analysis using the Lunar Mineral Spectrometer (LMS) revealed that the main minerals and their contents in the lunar regolith sampled from the area were ilmenite (16.11%), olivine (1.86%), plagioclase (18.58%), pyroxene (14.08%), and cement and glass (49.36%). Among these, only ilmenite is a conductor, while the other minerals are non-conductive. During the friction process, ilmenite particles easily lose electrons and become positively charged, while other mineral particles easily gain electrons and become negatively charged. This results in ilmenite in the lunar regolith having opposite charge properties to other gangue minerals. Furthermore, in the extreme environment of the lunar surface, the electrical conductivity and dielectric loss of the lunar regolith are very low. In addition, the lunar environment lacks moisture and air flow interference to prevent particles from sticking together, making it suitable for ideal triboelectric charging and electrostatic separation. Therefore, electrostatic separation is a relatively ideal method for beneficiating ilmenite from lunar regolith.

[0006] 95% of the lunar soil particles in the lunar soil samples were concentrated in the range of 1.40–9.35 μm, indicating that the lunar soil is subject to relatively low gravity and is extremely easy to float. In addition, the smaller the ilmenite particles, the larger the specific surface area and the higher the helium-3 content. Therefore, for the mining of helium-3 resources in lunar soil, it is necessary to perform particle size classification while separating ilmenite, that is, to design a lunar soil ilmenite separation and particle size classification device in the in-situ environment on the lunar surface. Summary of the Invention

[0007] The technical problem to be solved by this invention is to overcome the shortcomings of existing ground mineral processing technology that is not suitable for the lunar environment, and to propose a lunar soil ilmenite sorting and particle size classification device for the lunar environment.

[0008] The present invention solves the above-mentioned technical problems through the following technical means:

[0009] A device for separating and classifying lunar regolith ilmenite in a lunar environment includes, in sequence, a ore feeder, a feed distributor, and a triboelectric charging unit; it also includes an electrostatic separation unit, a conveying unit, and a particle size classification unit. The electrostatic separation unit includes a first positive electrode plate and a first negative electrode plate, which are arranged in parallel. The conveying unit includes a mesh conveyor belt that passes through the parallel electric field formed by the first positive and first negative electrode plates. The first negative electrode plate has holes for receiving ore charged by the triboelectric charging unit. The first negative electrode plate covers part of the upper belt of the mesh conveyor belt, and another part of the upper belt is located at the inlet of the particle size classification unit. A part of the first positive electrode plate forms an electric field with the first negative electrode plate, and the other end extends to the inlet of the particle size classification unit.

[0010] The particle size classification unit includes a second negative electrode plate and a second positive electrode plate fixed on two opposite sides of the classification chamber; the classification chamber has multiple partitions fixed on the side wall of the second negative electrode plate.

[0011] Furthermore, the inner ring of the mesh conveyor belt is provided with carrying teeth.

[0012] Furthermore, the mesh conveyor belt is closely fitted with the first negative electrode plate and the first positive electrode plate.

[0013] Furthermore, the particle size classification unit is located above the mesh conveyor belt; the feed inlet of the particle size classification unit is located at the bottom; and multiple partitions are arranged at intervals along the height direction.

[0014] Furthermore, the partition is inclined and fixed to the side wall of the grading bin, and the side wall of the grading bin and the fixing point of the partition have a discharge port, and a collection trough is fixed outside the discharge port.

[0015] Furthermore, recycling bins are provided at both ends of the mesh conveyor belt, and the mesh conveyor belt corresponding to the recycling bins is located outside the parallel electric field.

[0016] Furthermore, the first positive electrode plate, the first negative electrode plate, the second negative electrode plate, and the second positive electrode plate are all coated with an insulating membrane.

[0017] Furthermore, the triboelectric charging unit includes a sleeve and a spiral structure; the two ends of the sleeve are an inlet and an outlet, respectively, and the spiral structure is made of aluminum and is fixed inside the sleeve.

[0018] Furthermore, the distributor is provided with at least two chutes, each chute conveying ore to a triboelectric charging unit.

[0019] Furthermore, it also includes a moving unit, on which the ore feeder, feed distributor, triboelectric charging unit, electrostatic separation unit, conveying unit, and particle size classification unit are all fixed.

[0020] The advantages of this invention are:

[0021] The electric field formed by the two parallel electrodes of this invention can attract mineral particles with different charges to the vicinity of opposite electrode plates. The insulating membrane prevents charge exchange, that is, positively charged ilmenite particles move towards the top negative electrode, and negatively charged gangue minerals move towards the bottom positive electrode. Then, the top and bottom minerals are swept up by a continuously moving mesh conveyor belt and transported in opposite directions to achieve the purpose of separating ilmenite from other gangue minerals.

[0022] Furthermore, the ilmenite particles in lunar soil are small in size, lightweight, and positively charged. Under the vacuum and microgravity environment, they are subjected to the electric fields of the first positive plate, the second positive plate, and the second negative plate. Due to their mass differences, they exhibit inconsistent upward parabolic trajectories, ultimately entering different classification bins. At the end of the sorting process, the ilmenite particles stored in each classification bin flow into the collection tank. This invention controls the length of the first negative plate to be outside the coverage area of ​​the particle size classification unit. By utilizing the relatively long first positive plate to form an electric field with the second positive plate and the second negative plate, the structure of the screening device can be simplified, the size and weight of the device can be reduced, and transportation costs can be lowered. Attached Figure Description

[0023] Figure 1 This is a cross-sectional view of the screening device in an embodiment of the present invention;

[0024] Figure 2 for Figure 1 Schematic diagram of the electrostatic separation unit;

[0025] Figure 3 for Figure 1 Schematic diagram of a medium-sized particle size classification unit;

[0026] Figure 4 for Figure 3 Schematic diagram of electric field distribution within a medium-sized particle size classification unit;

[0027] In the diagram: 1. Mineral feeder, 2. Feed distributor, 3. Triboelectric charging unit, 4. Electrostatic separation unit, 5. Conveying unit, 6. Particle size classification unit, 7. Classification bin, 8. Mineral recovery bin, 9. Moving unit, 10. Feed inlet, 11. Support structure, 12. Top seat, 13. Base, 14. First negative electrode plate, 15. First positive electrode plate, 16. Mesh conveyor belt, 17. Conveyor motor, 18. Second positive electrode plate, 19. Second negative electrode plate, 20. Support frame, 21. Synchronous pulley, 22. Cover plate, 23. Wheel, 24. Partition plate, 25. Collection tank; Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] like Figure 1 As shown, Figure 1 The diagram shown is a cross-sectional view of the device in this embodiment, including:

[0030] 1. Mineral feeder; 2. Feed distributor; 3. Triboelectric charging unit; 4. Electrostatic separation unit; 5. Conveying unit; 6. Particle size classification unit; 7. Classification bin; 8. Mineral recovery bin; 9. Moving unit.

[0031] The ore feeder 1 is a hollow hopper with a funnel-shaped upper inlet 10 for easy feeding of topsoil mining equipment. A support structure 11 is installed at the lower end to improve the structural stability of the ore feeder 1. The support structure 11 can be directly fixed to the moving unit 9 or fixed to the top of the triboelectric charging unit 3 below it; the specific fixing structure is a conventional design and will not be detailed here. Below the feeder 1 is a feed distributor 2, which is generally a rectangular frame structure with two smooth chutes arranged in a V-shape. The starting ends of the two chutes are located at the center of the feeder 1's outlet, facilitating even distribution of the ore into the two chutes and preventing blockage caused by excessive soil particles. The ends of the chutes are the outlets, corresponding to the two triboelectric charging units 3 respectively. In this embodiment, the two chutes of the feed distributor 2 are enclosed by a rectangular frame to prevent ore spillage. Furthermore, the rectangular frame size is adapted to the two chutes, minimizing the overall volume of the equipment. The discharge port at the end of the chute and the inlet of the triboelectric charging unit 3 can be connected by a connecting cylinder, or they can be unconnected, allowing the ore to fall into the triboelectric charging unit 3 by its own weight. In this embodiment, the triboelectric charging unit 3 includes a sleeve and a spiral structure. The spiral structure is welded or fixed inside the sleeve by bolts. The spiral structure is made of aluminum and is placed vertically. The ore enters from the top of the sleeve and rotates downward along the spiral structure. During the rotation, the mineral particles tumble and rub against each other along the inclined surface. Since ilmenite in lunar soil has the best conductivity, it loses electrons and becomes positively charged after passing through the triboelectric charging unit, while other gangue minerals have poor conductivity and gain electrons and become negatively charged. The difference in charge carried by the minerals facilitates subsequent electrostatic separation. To improve the stability of the triboelectric charging unit 3, its top and bottom are fixed to the moving unit by a top seat 12 and a base 13, respectively. In this embodiment, the top seat 12 and the base 13 can be in the form of clamps. The two clamps are fixed as a whole by a vertical bracket and fixed to the moving unit.

[0032] Based on the above, implement electrostatic separation operation: such as Figure 2As shown, a first negative electrode plate 14 and a first positive electrode plate 15 are provided below the two triboelectric charging units 3. Each electrode plate is coated with an insulating diaphragm, with a gap in the middle to form a parallel electric field. The first negative electrode plate 14 has a discharge hole corresponding to the discharge port at the bottom of the triboelectric charging unit 3. The conveying unit 5 consists of a synchronous pulley 21, a mesh conveyor belt 16, and a conveyor motor 17. The conveyor motor 17 drives the mesh conveyor belt 16 to pass through the gap between the first negative electrode plate 14 and the first positive electrode plate 15, and the mesh conveyor belt 16 is in close contact with the first negative electrode plate 14 and the first positive electrode plate 15. The ore falls from the discharge port of the triboelectric charging unit 3 into the discharge hole of the first negative electrode plate 14, and enters the inner ring of the mesh conveyor belt 16 through the mesh. In this embodiment, the inner ring of the mesh conveyor belt 16 is also provided with carrying teeth. The carrying teeth can be raised steps provided on the inner ring of the mesh conveyor belt 16. The size of the steps does not affect the cooperation between the synchronous pulley and the mesh conveyor belt, but can carry the ore material located near the first negative electrode plate 14 or the first positive electrode plate 15 to the corresponding position.

[0033] Specifically, lunar soil particles fall through the discharge holes from the triboelectric charging unit 3 into the gap between the first negative electrode plate 14 and the first positive electrode plate 15. Since the ilmenite particles in the lunar soil are positively charged, they are attracted to the vicinity of the first negative electrode plate 14. The toothed structure of the mesh conveyor belt 16 sweeps up the ilmenite particles, which are then continuously conveyed by the mesh conveyor belt 16 towards the particle size classification unit. Similarly, since other gangue minerals in the lunar soil are positively charged, they are attracted to the vicinity of the first positive electrode plate 15. The carrying teeth sweep up the ilmenite particles, which are then continuously conveyed by the mesh conveyor belt 16 to the other side until they leave the parallel electric field and fall into the mineral recovery bin 8 under the influence of gravity. It should be noted that recovery bins 8 are provided at both ends of the mesh conveyor belt 16. The recovery bins 8 are located outside the parallel electric field. When the ore can be carried away from the parallel electric field, it passes through the mesh of the mesh conveyor belt 16 under its own weight and falls into the recovery bin 8.

[0034] Based on the above, particle size classification is performed, such as... Figure 3As shown, the particle size classification unit 6 includes a box with an open bottom and a closed top by a cover plate 22. A second positive electrode plate 18 and a second negative electrode plate 19 are fixed to two opposite side walls of the box along the conveying direction of the mesh conveyor belt, respectively. Each electrode plate is coated with an insulating diaphragm. Multiple partitions 24 are fixed from top to bottom on the inner wall where the second negative electrode plate 19 is located. Each partition 24 is inclined, and there is a gap between adjacent partitions 24. The multiple partitions 24 divide the inner cavity of the box into multiple classification chambers 7. A large distance exists between the partitions 24 and the second positive electrode plate 18 to facilitate the movement of mineral particles. Through holes are opened on the side walls of the box at the positions of the partitions 24, and a collection trough 25 is fixed outside the through holes. It should be noted that the first negative plate 14 is shorter than the first positive plate 15, so that the inlet of the box is outside the parallel electric field. However, the first positive plate 15 can form an electric field force with the second positive plate 18 and the second negative plate 19. Thus, when the mesh conveyor belt 16 carries ilmenite to the bottom of the box, it is freed from the constraint of the parallel electric field and moves inside the box under the action of the electric field force formed by the first positive plate 15, the second positive plate 18 and the second negative plate 19.

[0035] Specifically, the electric field distribution in particle size classification unit 6 is as follows: Figure 4 As shown, the electric field lines inside the box point from the first positive plate 15 and the second positive plate 18 to the second negative plate 19, indicating that the electric potential in the electric field decreases from high to low from the electrostatic separation unit 4 to the classification bin 7. When positively charged ilmenite particles are transported into the electric field, they are subjected to the electric field forces of the first positive plate 15, the second positive plate 18 and the second negative plate 19 under the vacuum microgravity environment. Due to the difference in mass, they form inconsistent upward parabolic motion trajectories and eventually enter different classification bins 7. When the separation is completed, the ilmenite particles stored in each classification bin flow into the collection tank 25.

[0036] In this embodiment, the location of the second positive plate 18 and the second negative plate 19 on the side of the housing can be set as needed. In order to facilitate the setting of the collection groove 25, in this embodiment, the second negative plate 19 is set on the side of the housing that is away from the friction charging unit 3.

[0037] Based on the above, a moving unit is provided, such as... Figure 1 As shown, the moving unit 9 includes a support frame 20 and wheels 23, serving as a support platform and a moving structure. All the aforementioned units and structures are fixed to the moving unit, facilitating overall movement.

[0038] In this embodiment, both the triboelectric charging unit 3 and the particle size classification unit 6 are located above the mesh conveyor belt 16. The charging process utilizes the weight of the mineral particles themselves to achieve a spiral descent, as well as the descent of particles of different masses during the classification process. Of course, since the moon's gravity is only 1 / 6 that of Earth, if the electric field force is sufficiently large, the triboelectric charging unit 3 and the particle size classification unit 6 can be arranged laterally, obliquely, or even below the mesh conveyor belt 16, depending on layout optimization requirements, as long as the needs of this embodiment are met.

[0039] The working principle of the device in this embodiment is as follows:

[0040] The mining equipment feeds lunar soil into the feeder through inlet 10. The lunar soil passes through distributor 2 and falls evenly into two triboelectric charging units 3. During the spiral descent, ilmenite particles carry a positive charge, while other minerals carry a negative charge. They fall through the through-holes of the first negative electrode plate 14 into the inner ring of the mesh conveyor belt 16. Under the parallel electric field formed by the first negative electrode plate 14 and the first positive electrode plate 15, the ilmenite particles separate from the other mineral particles and are carried to their respective positions by the carrying teeth of the mesh conveyor belt. When the other mineral particles leave the parallel electric field, they fall freely into the recovery bin 8. The ilmenite particles are carried to the bottom of the bin. Under the electric force formed by the first positive electrode plate 15, the second positive electrode plate 18, and the second negative electrode plate 19, the ilmenite particles, due to their mass differences, form inconsistent upward parabolic trajectories, ultimately entering different grading bins 7. At the end of the sorting process, the ilmenite particles stored in each grading bin flow into the collection tank 25.

[0041] The device in this embodiment achieves screening and grading of ilmenite through two electric fields. The entire screening and grading process is smooth and can be completed with just one mesh conveyor belt, which greatly reduces the size and weight of the device and lowers transportation costs.

[0042] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for separating and classifying lunar regolith ilmenite in a lunar environment, comprising, in the order of feeding, a ore feeder, a feed distributor, and a triboelectric charging unit; characterized in that, It also includes an electrostatic separation unit, a conveying unit, and a particle size classification unit; the electrostatic separation unit includes a first positive electrode plate and a first negative electrode plate; the first positive electrode plate and the first negative electrode plate are arranged in parallel; the conveying unit includes a mesh conveyor belt; the mesh conveyor belt passes through the parallel electric field formed by the first positive electrode plate and the first negative electrode plate; the first negative electrode plate has holes for receiving the mineral material charged by the self-friction charging unit; the first negative electrode plate covers part of the upper belt of the mesh conveyor belt, and another part of the upper belt is located at the feed inlet of the particle size classification unit; a part of the first positive electrode plate forms an electric field with the first negative electrode plate, and the other end extends to the feed inlet of the particle size classification unit; The particle size classification unit includes a second negative electrode plate and a second positive electrode plate fixed on two opposite sides of the classification chamber; multiple partitions are fixed to the side wall of the classification chamber located on the second negative electrode plate; the particle size classification unit is located above the mesh conveyor belt; the inlet of the particle size classification unit is located at the bottom; the multiple partitions are arranged at intervals along the height direction.

2. The device for separating and classifying lunar regolith ilmenite in a lunar environment according to claim 1, characterized in that, The inner ring of the mesh conveyor belt is equipped with carrying teeth.

3. The device for separating and classifying lunar regolith ilmenite in a lunar environment according to claim 1, characterized in that, The mesh conveyor belt is closely attached to the first negative electrode plate and the first positive electrode plate.

4. The device for separating and classifying lunar regolith ilmenite in a lunar environment according to claim 3, characterized in that, The partition is fixed at an incline to the side wall of the grading bin, and the side wall of the grading bin and the fixing point of the partition have a discharge port, and a collection trough is fixed outside the discharge port.

5. A device for separating and classifying lunar regolith ilmenite in a lunar environment according to any one of claims 1 to 4, characterized in that, A recycling bin is provided at both ends of the mesh conveyor belt, and the mesh conveyor belt corresponding to the recycling bin is located outside the parallel electric field.

6. A device for separating and classifying lunar regolith ilmenite in a lunar environment according to any one of claims 1 to 4, characterized in that, The first positive electrode plate, the first negative electrode plate, the second negative electrode plate, and the second positive electrode plate are all coated with an insulating membrane.

7. A device for separating and classifying lunar regolith ilmenite in a lunar environment according to any one of claims 1 to 4, characterized in that, The triboelectric charging unit includes a sleeve and a spiral structure; the two ends of the sleeve are a feed inlet and a discharge outlet, respectively, and the spiral structure is made of aluminum and is fixed inside the sleeve.

8. A device for separating and classifying lunar regolith ilmenite in a lunar environment according to any one of claims 1 to 4, characterized in that, The distributor has at least two chutes, each chute conveying ore to a triboelectric charging unit.

9. A device for separating and classifying lunar regolith ilmenite in a lunar environment according to any one of claims 1 to 4, characterized in that, It also includes a moving unit, on which the ore feeder, feed distributor, triboelectric charging unit, electrostatic separation unit, conveying unit, and particle size classification unit are all fixed.

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