Separating device for non-magnetic powder and application of separating device in metal powder processing

Abstract

The invention provides a non-magnetic powder separation device and application of the non-magnetic powder separation device in metal powder processing. The non-magnetic powder separation device comprises a first magnet, a second magnet, a magnetic fluid solution supply device, a separation container and a separation disc. The first magnet and the second magnet are coaxially arranged in the vertical direction, the same poles of the first magnet and the second magnet are opposite, the magnetic field diameter of the first magnet in the horizontal direction is 1.5-2 times that of the second magnet, and the height of the first magnet in the axial direction is adjustable; an outlet of the magnetofluid solution supply device is connected with a first inlet of the separation container and is used for providing a magnetofluid solution for the separation container; a second inlet of the separation container is positioned above the separation container and is used for adding non-magnetic powder to be separated and suspending the non-magnetic powder in the magnetic fluid solution; and the outlet of the separation container is connected with the inlet of the separation disc.

Description

Technical Field

[0001] This application belongs to the field of metal powder processing in B22F, and more specifically, relates to a separation device for non-magnetic powder and its application in metal powder processing. Background Art

[0002] As a key basic material in the modern industrial system, the application of metal powder has deeply penetrated into the high-end manufacturing field. For example, in the aerospace industry, ultra-fine titanium alloy powder is used in the manufacturing of aero-engine turbine blades through additive manufacturing technology; in the automotive industry, iron-based powder metallurgy technology realizes the near-net forming of complex-structured parts, significantly improving the lightweight level. With the continuous growth of the demand for metal powder in the above fields, its large-scale recycling, separation, and high-value utilization have become important strategic issues in building a resource recycling system.

[0003] Metal powders can be classified into magnetic and non-magnetic types according to their magnetic properties, and non-magnetic metal powders occupy the main market share. For magnetic metal powders, magnetic separation technology is commonly used, and the classification and separation of powders with different magnetic strengths can be achieved by adjusting the external magnetic field intensity. For non-magnetic metal powders, due to the complexity of components caused by the coupling of multiple phases, existing sorting devices generally face technical bottlenecks such as a decrease in separation efficiency and cross-contamination of products, severely restricting their high-value application.

[0004] The separated metal powder needs to be polished before application. For example, in additive manufacturing technology, a smooth surface can reduce the friction and electrostatic adsorption between powder particles, significantly improving fluidity. Poor fluidity of the powder will cause uneven powder spreading, affecting the quality of the printed parts. At the same time, polishing can eliminate surface microcracks and defects, reduce the porosity after powder pressing or sintering, and enhance the mechanical strength of the final product. However, most of the existing separation steps and polishing steps are carried out separately, and the steps are complex. It is impossible to polish the metal powder in-situ after separating the metal, resulting in a decrease in the overall processing efficiency.

[0005] Magnetic Archimedes suspension is a type of diamagnetic suspension. By introducing a paramagnetic medium solution, it brings buoyancy and enhances the magnetic force, greatly reducing the requirements for the magnetic field. Based on the density of substances, a series of separation studies have been carried out using the principle of magnetic Archimedes suspension, including the separation of polymer particles, simulating the separation and recycling of waste plastics by mixing various polymers. The separation of crystal polymorphs with a small density difference, and the continuous separation of polymer microparticles in fluids, etc. For example, patent document JPS51115361A discloses a method for sorting powdery powders using the density separation method of a magnetic fluid solution. This method generates suspension by overcoming the magnetic attraction of particles, applying a constant gradient field below the magnetic saturation level of the ferrofluid to form a density gradient column of the ferrofluid. In this device, the particles are suspended in the magnetic fluid and stratified according to density differences, but filtration or centrifugation and other methods still need to be used to recover the particles in each density layer. The further operation is complex, in-situ separation cannot be achieved, and there is also a risk of mixing different particles during the subsequent separation process. Summary of the Invention

[0006] Aiming at the defects that the prior art cannot perform in-situ separation of powdery powders and the processing after separation is inconvenient, the present application provides a separation device for non-magnetic powders and its application in the processing of metal powders, realizing the separation of non-magnetic powders with different densities and the processing of the separated metal powders through the synergistic effect of the magnetic field gradient and the magnetic fluid solution.

[0007] To achieve the above object, the present application provides a separation device for non-magnetic powders, which includes a first magnet, a second magnet, a magnetic fluid solution supply device, a separation container, and a separation disk; The first magnet and the second magnet are coaxially arranged in the vertical direction and have the same poles facing each other. The magnetic field diameter of the first magnet in the horizontal direction is 1.5 to 2 times that of the second magnet, and it is adjustable in height in the axial direction; The outlet of the magnetic fluid solution supply device is connected to the first inlet of the separation container for supplying the magnetic fluid solution to the separation container; The second inlet of the separation container is located above the separation container for adding the non-magnetic powder to be separated and suspending it in the magnetic fluid solution; the outlet of the separation container is connected to the inlet of the separation disk; As the first magnet is adjusted in height, among the non-magnetic powders to be separated in the separation container, only the target powder is subjected to a magnetic force radially outward in the horizontal direction and enters the separation disk under the action of the magnetic fluid solution continuously supplied from the first inlet.

[0008] Preferably, the outlet of the separation container is connected to the inlet of the separation disk through a pipeline, so that the separation disk is away from the magnetic field formed by the first magnet and the second magnet.

[0009] As a further preference, there is a bar magnet horizontally arranged below the separation disc, and the bar magnet can rotate horizontally under the action of a rotating motor, so that the target powder and the non-magnetic polishing agent continuously move away from the magnetic field center and rub against each other to generate shear stress, enabling the target powder to be polished.

[0010] Preferably, the first magnet and the second magnet are neodymium iron boron cylindrical magnets.

[0011] Preferably, the density of the ferrofluid solution is 1.0 g / cm 3 ~3.0 g / cm 3 .

[0012] Preferably, the density of the target powder is greater than or equal to 5 g / cm 3 , the first magnet is located above the second magnet, and the outlet of the separation container is located below the separation container.

[0013] Preferably, the density of the target powder is less than 5 g / cm 3 , the first magnet is located below the second magnet, and the outlet of the separation container is located above the separation container.

[0014] Preferably, it further includes a separation bracket for fixing the first magnet and the second magnet. Between the separation container and the ferrofluid solution supply device, there is also a pump for continuously supplying the ferrofluid solution in the ferrofluid solution supply device to the separation container.

[0015] Another object of the present application is to provide the application of the above separation device in metal powder processing, and the target powder is a metal powder.

[0016] Preferably, the application includes the following steps: S1. Adjust the relative height of the first magnet and the second magnet so that the radial magnetic field forces between the first magnet and the second magnet are all inward; S2. Add the metal powder to be separated into the separation container, and supply the ferrofluid solution to the separation container through the ferrofluid solution supply device, so that the metal powder to be separated reaches a stable equilibrium state under the action of gravity, buoyancy, and axial magnetic field force; S3. Move the first magnet vertically away from the second magnet until only the target powder among the non-magnetic powders to be separated in the separation container is subjected to a radially outward magnetic field force in the horizontal direction; continuously supply the ferrofluid solution to the separation container by using the ferrofluid solution supply device, so that the target powder enters the separation disc under the action of the ferrofluid solution; S4. Add a polishing agent to the separation disk. Under the action of the rotating motor, the bar magnet rotates horizontally, causing the target powder and the non-magnetic polishing agent to continuously move away from the magnetic field center. During the movement, they rub against each other to generate shear stress, so that the target powder is polished.

[0017] As a further preference, after step S4, the following steps are further included: S5. Adjust the relative height of the first magnet and the second magnet so that the radial magnetic field forces between the first magnet and the second magnet are all inward; S6. Pour the mixture of the ferrofluid solution, the polishing agent, and the polished target powder in the separation disk back into the separation container, and make the mixture reach a stable equilibrium state under the action of gravity, buoyancy, and axial magnetic field force; S7. Move the first magnet in a vertical direction away from the second magnet until only the polished target powder in the mixture in the separation container is subjected to a radially outward magnetic field force in the horizontal direction; continuously supply the ferrofluid solution to the separation container by using the ferrofluid solution supply device, so that the polished target powder enters the separation disk under the action of the ferrofluid solution.

[0018] The innovation of this application lies in using a first magnet and a second magnet with different magnetic field diameters in the horizontal direction to form a region with an outward radial force, and cooperating with the flowing ferrofluid solution, which can realize the flow separation of different metal powders, and can perform polishing treatment on the separated target powder in-situ, and has the following technical advantages: 1. The first magnet and the second magnet with different magnetic field diameters can form a radially outward region on the upper side or the lower side of the separation container, push the target powder to the edge, and cooperate with the flowing ferrofluid solution to complete the separation work without affecting other components in the non-magnetic powder to be separated, and can achieve complete separation; 2. The separation device of this application can not only be used to separate metal powders, but also utilize the characteristic that non-magnetic powders move along the direction of decreasing magnetic field gradient in the ferrofluid solution, rub against each other during the movement of the powders to generate shear stress, and thus perform subsequent polishing processing, greatly improving the efficiency of metal powder processing; 3. This application uses a ferrofluid solution with a higher magnetic susceptibility. According to the formula , in the same gradient field, a larger density range can be achieved, so as to complete the separation work of metal powders; and the ferrofluid solution can be reused, with high economy and wide application range, and is applicable to non-magnetic substances; 4. This application separates metal powders using the physical property of density, without the need to label or pre-treat the samples, and without chemical reactions or pollution, which is environmentally friendly; it does not limit the size and particle size of the metal powders, and has a wide range of applications; 5. The separation device proposed in this application has a simple composition, low operation complexity, and is easy to operate. Operators do not require complex pre-training. Description of the Drawings

[0019] Figure 1 It is a schematic structural diagram of the separation device for non-magnetic powders provided by this application; Figure 2 Schematic diagram of the force on metal powders in a magnetic field; Figure 3 It is a schematic diagram of the separation process in Example 1. The yellow part indicates that the radial magnetic field force is inward, and the white part indicates that the radial magnetic field force is outward; among them, (a) represents the stable equilibrium state, (b) represents a region with a radially outward magnetic field force in the separation interval, (c) represents the completion of the separation of AZ91D alloy powders, and (d) represents the completion of the separation of aluminum powders; Figure 4 It is a schematic diagram of the separation process in Example 2. The yellow part indicates that the radial magnetic field force is inward, and the white part indicates that the radial magnetic field force is outward; among them, (a) represents the stable equilibrium state, (b) represents a region with a radially outward magnetic field force in the separation interval, (c) represents the completion of the separation of copper powders, and (d) represents the completion of the separation of 304 stainless steel powders; In all the drawings, the same reference numerals are used to represent the same elements or structures, where: 1 - First magnet, 2 - Second magnet, 31 - Separation bracket, 32 - Separation table, 33 - Polishing bracket, 5 - Rotating motor, 6 - Pump, 71 - First conveying pipeline, 72 - Second conveying pipeline, 8 - Separation container, 9 - Separation disc, 10 - Magnetic fluid solution supply device, 11 - Bar magnet. Detailed Embodiments

[0020] In order to make the objectives, technical solutions and advantages of this application clearer, the following further details this application in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit this application. In addition, the technical features involved in the various embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0021] Figure 1This is a schematic structural diagram of a separation device for a non-magnetic powder of the present application. As shown in the figure, the separation device includes a first magnet 1, a second magnet 2, a magnetic fluid solution supply device 10, a separation container 8, and a separation disc 9; the first magnet 1 and the second magnet 2 are coaxially arranged in the vertical direction and have the same poles facing each other; the first magnet 1 is adjustable in height in the axial direction; in some embodiments, the first magnet 1 and the second magnet 2 can be selected as the same type of magnet, such as a neodymium iron boron cylindrical magnet; the magnetic field ranges of the two are set by selecting the sizes of the first magnet 1 and the second magnet 2. For example, by selecting the first magnet 1 and the second magnet 2 with a diameter ratio of (1.5~2):1, the magnetic field diameter of the first magnet 1 in the horizontal direction is 1.5 to 2 times that of the second magnet 2.

[0022] In some embodiments, to facilitate the separation of non-magnetic powders with different densities, the first magnet 1 and the second magnet 2 are both detachably arranged on the separation bracket 31 and are both adjustable in height in the axial direction; when the density of the target powder in the non-magnetic powder is greater than or equal to 5 g / cm 3 ³, the first magnet 1 is arranged above the second magnet 2; when the density of the target powder in the non-magnetic powder is less than 5 g / cm 3 ³, the first magnet 1 is arranged below the second magnet 2.

[0023] Between the first magnet 1 and the second magnet 2, a separation container 8 fixed to the separation table 32 is provided; when the first magnet 1 is above, the outlet of the separation container 8 is located below the separation container 8; when the first magnet 1 is below, the outlet of the separation container 8 is located above the separation container 8; the outlet of the separation container 8 is connected to the inlet of the separation disc 9 through a second conveying pipe 72, and a baffle is provided at the outlet to facilitate opening or closing the second conveying pipe 72 through which the separation container 8 communicates with the separation disc 9; the first inlet of the separation container 8 is connected to the outlet of the magnetic fluid solution supply device 10 through a first conveying pipe 71; a pump 6 is provided on the first conveying pipe 71 for continuously supplying the magnetic fluid solution in the magnetic fluid solution supply device 10 to the separation container 8, and the pumping speed can be adjusted to control the flow rate of the magnetic fluid solution.

[0024] The magnetic fluid solution supply device 10 is used to supply the separation container 8 with a magnetic fluid solution having a density of 1.0 g / cm 3 ~3.0 g / cm 3The magnetorheological fluid solution can adjust the density by adjusting the magnetorheological fluid concentration. The greater the magnetorheological fluid concentration, the greater the density of the magnetorheological fluid solution. A second inlet is provided above the separation container 8 for adding the non-magnetic powder to be separated and suspending it in the magnetorheological fluid solution. As the first magnet 1 is adjusted in height, among the non-magnetic powders to be separated in the separation container 8, only the target powder is subjected to a radially outward magnetic field force in the horizontal direction and enters the separation disk 9 fixed on the polishing bracket 33 under the action of the magnetorheological fluid solution continuously supplied from the first inlet.

[0025] There is a bar magnet 11 arranged horizontally below the separation disk 9. The bar magnet 11 can rotate horizontally under the action of the rotating motor 5, causing the target powder and the non-magnetic polishing agent (such as diamond powder) to continuously move away from the magnetic field center and rub against each other to generate shear stress, so that the target powder is polished.

[0026] Another object of the present application is to provide the application of the above separation device in metal powder processing, which specifically includes the following steps: S1. Adjust the relative height of the first magnet 1 and the second magnet 2 so that the radially inward magnetic field forces between the first magnet 1 and the second magnet 2 are all inward.

[0027] S2. Add the metal powder to be separated to the separation container 8, and supply the magnetorheological fluid solution to the separation container 8 through the magnetorheological fluid solution supply device 10, so that the metal powder to be separated reaches a stable equilibrium state under the action of gravity, buoyancy and axial magnetic field force. Its equilibrium equation is:

[0028] Among them, is the magnetic field force, is the resultant force of gravity and buoyancy, , respectively represent the density and magnetic susceptibility of the target powder, , respectively represent the density and magnetic susceptibility of the magnetorheological fluid solution, represents the volume of the target powder, represents the vacuum permeability. The magnetic field force can be further decomposed into the vector sum of the radial magnetic field force and the axial magnetic field force . determines whether the target powder finally gathers on the central axis or disperses around the separation container 8, then determines the final suspension height of the target powder, and its expression is as follows:

[0029]

[0030] Furthermore, an expression for the target powder density can be derived:

[0031] where is the magnetic field representing the equilibrium height of the target powder; it can be seen that different target powder densities result in different stable heights, and at this point, the static separation of the metal powder to be separated is completed.

[0032] S3. The first magnet 1 moves away from the second magnet 2 in the vertical direction until only the target powder among the non-magnetic powder to be separated in the separation container 8 is subjected to a radially outward magnetic force in the horizontal direction; when the first magnet 1 is above the second magnet 2, usually the target powder with the largest density among the metal powder to be separated will be the first to be subjected to a radially outward magnetic force in the horizontal direction, so it is preferably to separate the metal powder to be separated in the order of decreasing density; and when the first magnet 1 is below the second magnet 2, it is preferably to separate the metal powder to be separated in the order of increasing density; continuously supplying the magnetic fluid solution to the separation container 8 by the magnetic fluid solution supply device 10 can cause the target powder to enter the separation disk 9 under the action of the magnetic fluid solution.

[0033] In some embodiments, when only the last target powder remains among the metal powder to be separated, all the target powders have been completely separated; otherwise, the separation disk 9 needs to be replaced to continue collecting the next target powder; taking three target powders as an example, the separation disk 9 needs to be replaced once to complete the collection.

[0034] S4. Add a polishing agent such as diamond polishing powder to the separation disk 9 containing the target powder (if it is the last target powder, it may still be in the separation container 8 and needs to be transferred to the separation disk 9). Under the action of the rotating motor 5, the bar magnet 11 rotates in the horizontal direction, causing the polishing agent and the target powder to rotate synchronously with the bar magnet 11 and rub against each other to generate shear stress. Since the polishing agent and the target powder are evenly mixed and the magnetic fluid layer is thin, relative displacement occurs when the polishing agent and the target powder move adjacent to each other, thereby rubbing against each other to generate shear stress, enabling the surface of the target powder to be micro-removed and polished.

[0035] S5. Adjust the relative height of the first magnet 1 and the second magnet 2 again so that the radially inward magnetic forces between the first magnet 1 and the second magnet 2 are all inward.

[0036] S6. Pour the mixture of the ferrofluid solution, the polishing agent, and the polished target powder in the separation disk 9 back into the separation container 8 that has been emptied, and allow the mixture to reach a stable equilibrium state under the action of gravity, buoyancy, and axial magnetic force.

[0037] S7. Move the first magnet 1 in a vertical direction away from the second magnet 2 until only the polished target powder / or the polishing agent in the mixture in the separation container 8 is subjected to a radially outward magnetic force in the horizontal direction; use the ferrofluid solution supply device 10 to continuously supply ferrofluid solution to the separation container 8, so that the polished target powder / or the polishing agent enters the separation disk 9 under the action of the ferrofluid solution; if the polishing agent enters the separation disk 9, then the finally remaining in the separation container 8 is the polished target powder.

[0038] S8. Filter the ferrofluid solution containing the polished target powder to remove the ferrofluid solution and obtain the polished target powder.

[0039] Example 1 A method for separating different non-magnetic metal powders, taking the separation of aluminum powder (2.7 g / cm 3 ), titanium powder (4.506 g / cm 3 ), and AZ91D alloy powder (1.82 g / cm 3 ) as examples, specifically including the following steps: 1. In order to form only a radially outward magnetic force region at the upper end of the separation area during the process of adjusting the permanent magnet spacing, in this embodiment, two magnets with the same thickness but different diameters are selected as the magnetic field sources; a neodymium iron boron cylindrical magnet with a diameter of 60 mm and a thickness of 20 mm is used as the second magnet 2, and a neodymium iron boron cylindrical magnet with a diameter of 100 mm and a thickness of 20 mm is used as the first magnet 1, which is fixed on the separation bracket 31 below the second magnet 2; Adjust the spacing between the two magnets to 55 mm so that the radial magnetic force within the region between the two magnets is inward; Fix the separation container 8 on the separation table 32. In this embodiment, the outlet of the separation container 8 is set at the upper end; ensure that the spacing between the upper and lower magnets remains unchanged, and adjust the positions of the two magnets as a whole until the distance between the lower surface of the upper magnet and the separation container 8 is about 12 mm.

[0040] 2. Place the mixture of the metal powders to be separated into the separation container 8; pump a ferrofluid solution with a density of 1.05 g / cm into the separation container 8 through the pump 6 and the first conveying pipeline 71 3A magnetic fluid solution, the main components of the magnetic fluid solution are magnetite nanoparticles modified with oleic acid on the surface and a kerosene carrier liquid. After the solution fills the container 8, stop pumping; Let it stand for a period of time. At this time, the powder agglomerates on the central axis under the action of the radially inward magnetic force. At the same time, the powder is subjected to gravity, buoyancy, and axial magnetic force to reach a stable equilibrium state, and its force state is as Figure 2 shown; Due to the different powder densities, their stable heights are also different. At this time, the preliminary static separation of the powder is completed, as Figure 3 shown in (a); 3-1. Move the first magnet 1 downward by about 35 mm until a radially outward magnetic force region appears in the separation interval, as Figure 3 shown in (b); Slowly move downward by about 5 mm until the AZ91D alloy powder at the uppermost end appears in the radially outward magnetic force region. Turn on the pump 6. Under the cooperation of the radially outward magnetic force and the flow of the paramagnetic liquid, the AZ91D alloy powder is washed into the separation disk 9 by the flowing magnetic fluid, and the separation of this kind of metal powder is completed, as Figure 3 shown in (c); 3-2. Replace the separation disk 9 and continue to move downward slowly by 5 mm. When the aluminum powder with the second highest suspension height appears in the radially outward magnetic force region, repeat the similar method in step 3-1, and the separation of this kind of metal powder is completed, as Figure 3 shown in (d); 3-3. After the separation of the second kind of metal powder is completed, only titanium powder remains in the separation container 8. Drain the magnetic fluid solution in the separation container 8, and then take out the titanium powder to complete the separation; 4-1. In this embodiment, a bar magnet 11 with a length of 80 mm, a width of 20 mm, and a thickness of 10 mm is fixed on the rotating motor 5 for polishing; At this time, the mixture of AZ91D alloy powder and magnetic fluid solution is in the separation disk 9. Add diamond polishing powder as a polishing agent to the separation disk 9 and mix the AZ91D alloy powder and diamond polishing powder evenly; 4-2. Turn on the rotating motor 5 and rotate the bar magnet 11. The diamond polishing powder and AZ91D alloy powder move along the direction of decreasing magnetic field gradient under the action of the gradient magnetic force due to their own magnetic susceptibilities being less than that of the magnetic fluid solution. During the rotation of the magnet, the mixed powder continuously moves away from the magnetic source under the action of the gradient magnetic force and rotates synchronously with the magnet. Since the powder is mixed evenly and the magnetic fluid layer is relatively thin, the diamond particles and AZ91D alloy powder generate shear stress when moving adjacent to each other, and finally the polishing step is achieved; 5. After the polishing step is completed, the mixture of diamond polishing powder, polished AZ91D alloy powder, and magnetic fluid is reinstalled into the separation container 8. Using a method similar to that in step 3, the separation of diamond polishing powder from AZ91D alloy powder is completed; then, the magnetic fluid solution is filtered out by filtration to obtain pure AZ91D alloy powder after polishing treatment. 6. Using methods similar to those in steps 4 - 5, the separation and polishing of aluminum powder and titanium powder are completed in sequence.

[0041] Example 2 A method for separating different non - magnetic metal powders, taking the separation of copper powder (8.96 g / cm 3 ), 304 stainless steel powder (7.93 g / cm 3 ), and yttrium - stabilized zirconia alloy powder (5.8 g / cm 3 ) as examples, specifically includes the following steps: 1. In order to form a radially outward magnetic field force region only at the lower end of the separation area during the process of adjusting the spacing of permanent magnets, in this embodiment, two magnets with the same thickness but different diameters are selected as the magnetic field sources. A neodymium - iron - boron cylindrical magnet with a diameter of 100 mm and a thickness of 20 mm is fixed on the upper magnet lifting platform as the first magnet 1, and a neodymium - iron - boron cylindrical magnet with a diameter of 60 mm and a thickness of 20 is fixed on the lower magnet lifting platform as the second magnet 2. The upper magnet lifting platform and the lower magnet lifting platform together form the separation bracket 31.

[0042] Adjust the spacing between the upper and lower magnets to 55 mm so that the radial magnetic field force within the region between the two magnets is all inward.

[0043] Fix the separation container 8 on the separation table 32. In this embodiment, the outlet of the separation container 8 is set at the lower end and is equipped with a baffle, which remains open only when metal powder is washed away by the fluid. Ensure that the spacing between the upper and lower magnets remains unchanged, and adjust the positions of the two magnets as a whole until the distance between the upper surface of the second magnet 2 and the separation container 8 is about 10 mm.

[0044] 2. Place the mixture of metal powders to be separated into the separation container 8; pump a magnetic fluid solution with a density of 1.3 g / cm 3 into the separation container 8 through the pump 6 and the first conveying pipeline 71. The main components of the magnetic fluid solution are iron - oxide - based magnetic nanoparticles with surface - modified oleic acid and a kerosene carrier liquid. Stop pumping after the solution fills the container 8. Let it stand for a period of time. At this time, the powders agglomerate on the central axis under the action of the radially inward magnetic field force, and at the same time, the powders reach a stable equilibrium state under the action of gravity, buoyancy, and axial magnetic field force. Due to the different powder densities, their stable heights are also different. At this time, the preliminary static separation of the powder is completed, as shown in Figure 4 Figure (a).

[0045] 3-1. Start the lower magnet displacement stage and move the first magnet 1 upward by about 38 mm until a radially outward magnetic force region appears within the separation interval, as shown in Figure 4 Figure (b). Slowly move it downward by about 6 mm until the copper powder at the lowest end appears in the radially outward magnetic force region. Then turn on the pump 6. With the cooperation of the radially outward magnetic force and the flow of the paramagnetic liquid, the copper powder is washed into the separation disk 9 by the flowing magnetic fluid, and the separation of this metal powder is completed, as shown in Figure 4 Figure (c).

[0046] 3-2. Replace the separation disk 9 and continue to move it slowly downward by 4 mm. When the 304 stainless steel powder with the second highest suspension height appears in the radially outward magnetic force region, repeat a similar method as in step 3-1, and the separation of this metal powder is completed, as shown in Figure 4 Figure (d).

[0047] 3-3. After the separation of the second metal powder is completed, only the yttrium-stabilized zirconia alloy powder remains in the separation container 8. Drain the magnetic fluid solution in the separation container 8 and take out the yttrium-stabilized zirconia alloy powder to complete the separation.

[0048] 4-1. In this embodiment, a bar magnet 11 with a length of 80 mm, a width of 20 mm, and a thickness of 10 mm is fixed on the rotating motor 5 for polishing. Move the bar magnet upward until it fits the surface of the polishing bracket 33. At this time, the mixture of copper powder and the magnetic fluid solution is in the separation disk 9. Add diamond polishing powder into the separation disk 9 and mix the copper powder and the diamond polishing powder evenly.

[0049] 4-2. Turn on the rotating motor 5 to rotate the bar magnet 11. Since the magnetic susceptibilities of the diamond polishing powder and the copper powder are less than that of the magnetic fluid solution, they move along the direction of decreasing magnetic field gradient under the action of the gradient magnetic force. During the rotation of the magnet, the mixed powder continuously moves away from the magnetic source under the action of the gradient magnetic force and rotates synchronously with the magnet. Due to the uniform mixing of the powder and the thin magnetic fluid layer, the diamond particles and the copper powder generate shear stress when moving adjacent to each other, and finally the polishing step is achieved.

[0050] 5. After the polishing step is completed, put the mixture of the diamond polishing powder, the polished copper powder, and the magnetic fluid back into the separation container 8, and use a method similar to step 3 to complete the separation of the diamond polishing powder and the copper powder. Then filter the magnetic fluid solution to obtain the pure polished copper powder.

[0051] 6. Using a method similar to that in steps 4 - 5, sequentially complete the separation and polishing of 304 stainless steel powder and yttrium-stabilized zirconia alloy powder.

[0052] Those skilled in the art can easily understand that the above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included within the protection scope of the present application.

Claims

1. A separation device for non-magnetic powder, characterized in that, It includes a first magnet, a second magnet, a magnetorheological fluid solution supply device, a separation container, and a separation disc; The first magnet and the second magnet are coaxially arranged in the vertical direction and have the same poles facing each other. The magnetic field diameter of the first magnet in the horizontal direction is 1.5 to 2 times that of the second magnet, and it is adjustable in height in the axial direction; The outlet of the magnetorheological fluid solution supply device is connected to the first inlet of the separation container for supplying the magnetorheological fluid solution to the separation container; The second inlet of the separation container is located above the separation container for adding non-magnetic powder to be separated and suspending it in the magnetorheological fluid solution; the outlet of the separation container is connected to the inlet of the separation disc; As the first magnet is adjusted in height, among the non-magnetic powder to be separated in the separation container, only the target powder is subjected to a magnetic field force radially outward in the horizontal direction and enters the separation disc under the action of the magnetorheological fluid solution continuously supplied from the first inlet.

2. The separation device according to claim 1, wherein The outlet of the separation container is connected to the inlet of the separation disc through a pipeline, so that the separation disc is away from the magnetic field formed by the first magnet and the second magnet.

3. The separation device according to claim 2, wherein, There is a bar magnet arranged horizontally below the separation disc. The bar magnet is used to rotate in the horizontal direction to make the target powder and the non-magnetic polishing agent continuously move away from the magnetic field center and rub against each other to generate shear stress, so that the target powder is polished.

4. The separation device according to claim 1, characterized in that, The first magnet and the second magnet are neodymium iron boron cylindrical magnets.

5. The separation device according to claim 1, characterized in that, The density of the target powder is greater than or equal to 5 g / cm 3 , the first magnet is located above the second magnet, and the outlet of the separation container is located below the separation container.

6. The separation device according to claim 1, characterized in that, The density of the target powder is less than 5 g / cm 3 , the first magnet is located below the second magnet, and the outlet of the separation container is located above the separation container.

7. The separation device according to claim 1, characterized in that, It further includes a separation bracket for fixing the first magnet and the second magnet. Between the separation container and the magnetorheological fluid solution supply device, there is also a pump for continuously supplying the magnetorheological fluid solution in the magnetorheological fluid solution supply device to the separation container.

8. Use of the separation device according to any one of claims 1-7 in metal powder processing, characterized in that, The target powder is metal powder.

9. The application according to claim 8, wherein It includes the following steps: S1. Adjust the relative height of the first magnet and the second magnet so that the radial magnetic field forces between the first magnet and the second magnet are all inward; S2. Add the metal powder to be separated to the separation container, and supply the magnetorheological fluid solution to the separation container through the magnetorheological fluid solution supply device, so that the metal powder to be separated reaches a stable equilibrium state under the action of gravity, buoyancy, and axial magnetic field force; S3. Move the first magnet away from the second magnet in the vertical direction until among the non-magnetic powder to be separated in the separation container, only the target powder is subjected to a magnetic field force radially outward in the horizontal direction; use the magnetorheological fluid solution supply device to continuously supply the magnetorheological fluid solution to the separation container, so that the target powder enters the separation disc under the action of the magnetorheological fluid solution; S4. Add a polishing agent to the separation disc, and the bar magnet rotates in the horizontal direction to make the target powder and the non-magnetic polishing agent continuously move away from the magnetic field center and rub against each other to generate shear stress, so that the target powder is polished.

10. The application according to claim 9, characterized in that, After step S4, it further includes the following steps: S5. Adjust the relative height of the first magnet and the second magnet so that the radial magnetic field forces between the first magnet and the second magnet are all inward; S6. Pour the mixture of the ferrofluid solution, the polishing agent, and the polished target powder in the separation disk back into the separation container, and allow the mixture to reach a stable equilibrium state under the action of gravity, buoyancy, and axial magnetic force; S7. Move the first magnet in a vertical direction away from the second magnet until only the polished target powder in the mixture in the separation container is subjected to a radially outward magnetic force in the horizontal direction; Continuously supply the ferrofluid solution into the separation container by using the ferrofluid solution supply device, so that the polished target powder enters the separation disk under the action of the ferrofluid solution.

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