A non-magnetic powder separation device and its application in metal powder processing

Abstract

The present application provides a non-magnetic powder separation device and its application in metal powder processing. The non-magnetic powder separation device 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 the same poles are opposite, the magnetic field diameter of the first magnet in the horizontal direction is 1.5 to 2 times that of the second magnet, and the height is adjustable in the axial direction; the outlet of the magnetic fluid solution supply device is connected to the first inlet of the separation container, for providing magnetic 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 magnetic fluid solution; the outlet of the separation container is connected to the inlet of the separation disk.

Description

Technical Field

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

[0002] As a key foundational material in modern industrial systems, metal powders have penetrated deeply into high-end manufacturing. For example, in the aerospace industry, ultrafine titanium alloy powders are used in the manufacture of aircraft engine turbine blades through additive manufacturing. In the automotive industry, iron-based powder metallurgy technology achieves near-net-shape formation of complex structural parts, significantly improving lightweighting. With the continued growth in demand for metal powders in these sectors, their large-scale recovery, separation, and high-value utilization have become key strategic issues in building a resource recycling system.

[0003] Metal powders can be categorized as magnetic and non-magnetic based on their magnetic properties, with non-magnetic metal powders occupying the majority of the market. Magnetic separation technology is commonly used for magnetic metal powders, and the graded separation of powders of varying magnetic strengths can be achieved by adjusting the strength of the applied magnetic field. However, due to the complexity of the composition of non-magnetic metal powders resulting from multi-phase coupling, existing separation equipment generally faces technical bottlenecks such as reduced separation efficiency and product cross-contamination, severely restricting their high-value applications.

[0004] The separated metal powder needs to be polished before use. For example, in additive manufacturing, a smooth surface can reduce friction and electrostatic adsorption between powder particles, significantly improving fluidity. Powders with poor fluidity can lead to uneven powder spreading, affecting the quality of printed parts. Polishing can also eliminate surface microcracks and defects, reduce the porosity of the powder after pressing or sintering, and enhance the mechanical strength of the final product. However, existing separation and polishing steps are mostly performed separately and are complex, making it impossible to polish the metal powder in situ after metal separation, resulting in reduced overall processing efficiency.

[0005] Magnetic Archimedean levitation is a type of antimagnetic levitation that incorporates a paramagnetic medium solution, creating buoyancy and enhancing the magnetic field, significantly reducing the magnetic field requirements. Based on material density, the principle of magnetic Archimedean levitation has been used to conduct a series of separation studies, including the separation of polymer particles and the separation and recovery of mixed polymers to simulate waste plastics. Applications include the separation of crystal polymorphs with small density differences and the continuous separation of polymer particles in fluids. For example, patent document JPS51115361A discloses a method for separating powders using magnetic fluid solution density separation. This method creates levitation by overcoming the magnetic attraction of particles. A constant gradient field below the magnetic saturation level of the ferrofluid is applied, causing the ferrofluid to form a density gradient column. In this device, particles are suspended in a magnetic fluid and separated into different layers according to their density differences. However, filtration or centrifugation is still required to recover the particles in each density layer, further complicating the operation and preventing in-situ separation. Furthermore, there is a risk of different particles mixing during subsequent separation. Summary of the Invention

[0006] In view of the defects of the existing technology such as the inability to separate powder in situ and the inconvenience of processing after separation, the present application provides a non-magnetic powder separation device and its application in metal powder processing. The separation of non-magnetic powders of different densities and the processing of the separated metal powder are achieved through the synergistic effect of magnetic field gradient and magnetic fluid solution.

[0007] To achieve the above-mentioned object, the present application provides a non-magnetic powder separation device, the separation device comprising a first magnet, a second magnet, a magnetic fluid solution supply device, a separation container and a separation disk;

[0008] The first magnet and the second magnet are coaxially arranged in the vertical direction with 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 the height in the axial direction is adjustable;

[0009] The outlet of the magnetic fluid solution supply device is connected to the first inlet of the separation container for providing the magnetic fluid solution to the separation container;

[0010] The second inlet of the separation container is located above the separation container and is used to add non-magnetic powder to be separated and suspend it in the magnetic fluid solution; the outlet of the separation container is connected to the inlet of the separation disk;

[0011] As the first magnet is adjusted in height, only the target powder among the non-magnetic powder to be separated in the separation container is subjected to the radially outward magnetic field force in the horizontal direction and enters the separation disk under the action of the magnetic fluid solution continuously provided from the first inlet.

[0012] Preferably, the outlet of the separation container is connected to the inlet of the separation disk via a pipe, so that the separation disk is away from the magnetic field formed by the first magnet and the second magnet.

[0013] As a further preference, there is a horizontally arranged bar magnet under the separation disk, which can rotate horizontally under the action of a rotating motor, so that the target powder and the non-magnetic polishing agent continue to move away from the center of the magnetic field, and rub against each other to generate shear stress, so that the target powder is polished.

[0014] Preferably, the first magnet and the second magnet are neodymium iron boron cylindrical magnets.

[0015] Preferably, the density of the magnetic fluid solution is 1.0 g / cm 3 ~3.0 g / cm 3 .

[0016] 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.

[0017] 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.

[0018] Preferably, it also includes a separation bracket for fixing the first magnet and the second magnet, and a pump for continuously supplying the magnetic fluid solution in the magnetic fluid solution supply device to the separation container is provided between the separation container and the magnetic fluid solution supply device.

[0019] Another object of the present application is to provide an application of the above-mentioned separation device in metal powder processing, wherein the target powder is metal powder.

[0020] Preferably, the application comprises the following steps:

[0021] S1. Adjusting 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 inward;

[0022] S2. The metal powder to be separated is added to the separation container, and the magnetic fluid solution is supplied to the separation container by the magnetic 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;

[0023] S3. The first magnet is moved vertically away from the second magnet until only the target powder of the non-magnetic powder to be separated in the separation container is subjected to a horizontal radially outward magnetic field force; the magnetic fluid solution supply device continuously supplies magnetic fluid solution to the separation container, causing the target powder to enter the separation disk under the action of the magnetic fluid solution;

[0024] S4. Adding polishing agent to the separation disk, the bar magnet rotates horizontally under the action of a rotating motor, causing the target powder and the non-magnetic polishing agent to continuously move away from the center of the magnetic field. During the movement, the friction between them generates shear stress, so that the target powder is polished.

[0025] As further preferred, after step S4, the following steps are further included:

[0026] S5. Adjusting 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 inward;

[0027] S6. Pour the mixture of the magnetic fluid 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 field force;

[0028] 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 horizontal radial outward magnetic field force; utilize the magnetic fluid solution supply device to continuously supply magnetic fluid solution into the separation container, so that the polished target powder enters the separation disk under the action of the magnetic fluid solution.

[0029] The innovation of this application lies in the use of a first magnet and a second magnet with different magnetic field diameters in the horizontal direction to form a region with radial force directed outward. In conjunction with a flowing magnetic fluid solution, this can achieve flow separation of different metal powders and can polish the separated target powders in situ. This application has the following technical advantages:

[0030] 1. The first and second magnets, each with different magnetic field diameters, can form a radially outward area on the upper or lower side of the separation container, pushing the target powder to the edge and cooperating with the flowing magnetic fluid solution to complete the separation without affecting other components in the non-magnetic powder to be separated, thus achieving complete separation.

[0031] 2. The separation device of this application can not only be used to separate metal powders, but also utilizes the property of non-magnetic powders moving along the decreasing magnetic field gradient in a magnetic fluid solution. During the powder movement, friction between the powders generates shear stress, which facilitates subsequent polishing, greatly improving the efficiency of metal powder processing.

[0032] 3. This application uses a magnetic fluid solution with a high magnetic susceptibility, according to the formula Under the same gradient field, a larger density range can be achieved, thereby completing the separation of metal powders; and the magnetic fluid solution can be reused, which is highly economical and has a wide range of applications, and is applicable to non-magnetic materials;

[0033] 4. This application uses density as a physical property to separate metal powders. This method does not require sample labeling or pretreatment, and will not cause chemical reactions or pollution, making it environmentally friendly. It also does not restrict the size or particle size of the metal powder, making it widely applicable.

[0034] 5. The separation device proposed in this application has a simple composition, low operational complexity, is easy to use, and does not require complex pre-training for operators. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic diagram of the structure of the non-magnetic powder separation device provided in this application;

[0036] Figure 2 Schematic diagram of the forces acting on metal powder in a magnetic field;

[0037] Figure 3 Schematic diagram of the separation process in Example 1. The yellow portion indicates an inward radial magnetic field force, and the white portion indicates an outward radial magnetic field force. (a) indicates a stable equilibrium state, (b) indicates the appearance of a radially outward magnetic field force region within the separation interval, (c) indicates the complete separation of AZ91D alloy powder, and (d) indicates the complete separation of aluminum powder.

[0038] Figure 4 Schematic diagram of the separation process in Example 2. The yellow portion indicates an inward radial magnetic field force, and the white portion indicates an outward radial magnetic field force. (a) indicates a stable equilibrium state, (b) indicates the appearance of a radially outward magnetic field force region within the separation interval, (c) indicates the complete separation of copper powder, and (d) indicates the complete separation of 304 stainless steel powder.

[0039] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0040] 1-first magnet, 2-second magnet, 31-separation bracket, 32-separation table, 33-polishing bracket, 5-rotating motor, 6-pump, 71-first delivery pipeline, 72-second delivery pipeline, 8-separation container, 9-separation disk, 10-magnetic fluid solution supply device, 11-bar magnet. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely for explaining this application and are not intended to limit this application. In addition, the technical features involved in the various embodiments of this application described below may be combined with each other as long as they do not conflict with each other.

[0042] Figure 1 This is a structural schematic diagram of a non-magnetic powder separation device 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 disk 9; the first magnet 1 and the second magnet 2 are coaxially arranged in the vertical direction and with the same poles facing each other; the first magnet 1 is height-adjustable in the axial direction; in some embodiments, the first magnet 1 and the second magnet 2 can be selected from the same type of magnets such as neodymium iron boron cylindrical magnets; 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 can be 1.5 times to 2 times that of the second magnet 2.

[0043] In some embodiments, in order to facilitate the separation of non-magnetic powders of different densities, the first magnet 1 and the second magnet 2 are both detachably arranged on the separation bracket 31, and both are axially height-adjustable; when the density of the target powder in the non-magnetic powder is greater than or equal to 5 g / cm 3 When the density of the target powder in the non-magnetic powder is less than 5 g / cm 3 When the first magnet 1 is disposed below the second magnet 2 .

[0044] A separation container 8 fixed on the separation table 32 is provided between the first magnet 1 and the second magnet 2; 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 disk 9 through a second delivery pipe 72, and a baffle is provided at the outlet to facilitate opening or closing the second delivery pipe 72 connecting the separation container 8 and the separation disk 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 delivery pipe 71; a pump 6 is provided on the first delivery pipe 71 for continuously providing 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.

[0045] The magnetic fluid solution supply device 10 is used to provide the separation container 8 with a density of 1.0 g / cm 3 ~3.0 g / cm 3 The density of the magnetic fluid solution can be adjusted by adjusting the concentration of the magnetic fluid. The higher the concentration of the magnetic fluid, the greater the density of the magnetic fluid solution. A second inlet is provided above the separation container 8 for adding non-magnetic powder to be separated and suspending it in the magnetic fluid solution. As the first magnet 1 is adjusted in height, only the target powder among the non-magnetic powder to be separated in the separation container 8 is subjected to the radial 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 magnetic fluid solution continuously provided from the first inlet.

[0046] There is a horizontally arranged bar magnet 11 below the separation disk 9. The bar magnet 11 can rotate horizontally under the action of the rotating motor 5, so that the target powder and the non-magnetic polishing agent (such as diamond powder) continue to move away from the center of the magnetic field and rub against each other to generate shear stress, so that the target powder is polished.

[0047] Another object of the present application is to provide an application of the above-mentioned separation device in metal powder processing, which specifically includes the following steps:

[0048] S1. Adjust the relative heights of the first magnet 1 and the second magnet 2 so that the radial magnetic field forces between the first magnet 1 and the second magnet 2 are both inward.

[0049] S2. The metal powder to be separated is added to the separation container 8, and the magnetic fluid solution is supplied to the separation container 8 by the magnetic 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. The equilibrium equation is:

[0050]

[0051] in, is the magnetic field force, is the combined force of gravity and buoyancy, 、 represent the density of the target powder and its magnetic susceptibility, respectively. 、 denote the density of the magnetic fluid solution and its magnetic susceptibility, respectively. represents the volume of target powder, Represents the magnetic permeability of vacuum. It can also be decomposed into radial magnetic field force With axial magnetic field force The vector sum of It determines whether the target powder will eventually gather on the central axis or disperse around the separation container 8. This determines the final suspension height of the target powder, and its expression is as follows:

[0052]

[0053]

[0054] Furthermore, the expression for the target powder density can be derived:

[0055]

[0056] in, The magnetic field represents the equilibrium height of the target powder. It can be seen that the target powder has different density and its stable height is also different. At this time, the static separation of the metal powder to be separated is completed.

[0057] 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 the radially outward magnetic field force in the horizontal direction; when the first magnet 1 is located above the second magnet 2, the target powder with the largest density among the metal powder to be separated will usually be subjected to the radially outward magnetic field force in the horizontal direction first, so it is preferred to separate the metal powders to be separated in order of density from large to small; and when the first magnet 1 is located below the second magnet 2, it is preferred to separate the metal powders to be separated in order of density from small to large; and by continuously providing the magnetic fluid solution to the separation container 8 using the magnetic fluid solution supply device 10, the target powder can be allowed to enter the separation disk 9 under the action of the magnetic fluid solution.

[0058] In some embodiments, when only the last target powder remains in the metal powder to be separated, all 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 the collection is complete.

[0059] S4. A polishing agent such as diamond polishing powder is added 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, so that the polishing agent and the target powder rotate synchronously with the bar magnet 11 at the same time, 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 relatively thin, the polishing agent and the target powder are relatively displaced when they move in proximity, thereby rubbing against each other to generate shear stress, so that the target powder is micro-removed from the surface and polished.

[0060] S5. Adjust the relative height of the first magnet 1 and the second magnet 2 again so that the radial magnetic field forces between the first magnet 1 and the second magnet 2 are both inward.

[0061] S6. Pour the mixture of the magnetic fluid solution, the polishing agent, and the polished target powder in the separation disk 9 back into the emptied separation container 8, and allow the mixture to reach a stable equilibrium state under the action of gravity, buoyancy, and axial magnetic field force.

[0062] S7. Move the first magnet 1 in a vertical direction away from the second magnet 2 until only the polished target powder / or polishing agent in the mixture in the separation container 8 is subjected to the radially outward magnetic field force in the horizontal direction; use the magnetic fluid solution supply device 10 to continuously supply magnetic fluid solution to the separation container 8, so that the polished target powder / or polishing agent enters the separation disk 9 under the action of the magnetic fluid solution; if it is the polishing agent that enters the separation disk 9, then what remains in the separation container 8 is the polished target powder.

[0063] S8. Filtering the magnetic fluid solution containing the polished target powder to remove the magnetic fluid solution and obtain the polished target powder.

[0064] Example 1

[0065] A method for separating different non-magnetic metal powders to separate aluminum powder (2.7 g / cm 3 ), titanium powder (4.506 g / cm 3 ) and AZ91D alloy powder (1.82 g / cm 3 ) as an example, the specific steps include:

[0066] 1. In order to form a radially outward magnetic field force region only at the upper end of the separation region during the process of adjusting the permanent magnet spacing, two magnets of the same thickness but different diameters are selected as the magnetic field source in this embodiment; a NdFeB cylindrical magnet with a diameter of 60 mm and a thickness of 20 mm is used as the second magnet 2, and a NdFeB cylindrical magnet with a diameter of 100 mm and a thickness of 20 mm is used as the first magnet 1, which is located below the second magnet 2 and fixed to the separation bracket 31;

[0067] Adjust the distance between the two magnets to 55 mm so that the radial magnetic field force in the area between the two magnets is inward;

[0068] The separation container 8 is fixed on the separation table 32. In this embodiment, the outlet of the separation container 8 is set at the upper end; ensure that the distance 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.

[0069] 2. Place the metal powder mixture to be separated into the separation container 8; pump the metal powder mixture with a density of 1.05 g / cm2 into the separation container 8 through the pump 6 and the first delivery pipe 71. 3 The main components of the magnetic fluid solution are ferroferric oxide nanoparticles with surface modified oleic acid and kerosene carrier liquid. The pumping is stopped after the solution fills the container 8.

[0070] After standing for a period of time, the powders gather on the central axis under the radial inward magnetic field force. At the same time, the powders are subjected to gravity, buoyancy and axial magnetic field force to reach a stable equilibrium state. The force state is as follows: Figure 2 As shown;

[0071] Due to the different density of powders, their stable heights are also different. At this time, the initial static separation of powders is completed, such as Figure 3 As shown in (a);

[0072] 3-1. Move the first magnet 1 downward by about 35 mm until a radially outward magnetic field force region appears in the separation interval, such as Figure 3 As shown in (b), it slowly moves downward for about 5 mm until the AZ91D alloy powder at the top appears in the radially outward magnetic field force area, and the pump 6 is turned on. Under the conditions of the radially outward magnetic field force and the flow of the paramagnetic liquid, the AZ91D alloy powder is flushed into the separation disk 9 by the flowing magnetic fluid, and the metal powder is separated. Figure 3 As shown in (c);

[0073] 3-2. Replace the separation disc 9 and continue to slowly move it downward by 5 mm. When the aluminum powder with the second highest suspension height appears in the radially outward magnetic field force area, repeat the similar method in step 3-1. The metal powder is separated. Figure 3 As shown in (d);

[0074] 3-3. After the second metal powder is separated, only titanium powder remains in the separation container 8. The magnetic fluid solution in the separation container 8 is discharged, and the titanium powder is taken out to complete the separation.

[0075] 4-1. In this embodiment, a bar magnet 11 having a length of 80 mm, a width of 20 mm, and a thickness of 10 mm is fixed to a rotating motor 5 for polishing. At this time, a mixture of AZ91D alloy powder and magnetic fluid solution is in a separation disk 9. Diamond polishing powder is added to the separation disk 9 as a polishing agent and the AZ91D alloy powder and diamond polishing powder are uniformly mixed.

[0076] 4-2. Turn on the rotary motor 5 and rotate the bar magnet 11. Because the diamond polishing powder and AZ91D alloy powder have lower magnetic susceptibilities than the magnetic fluid solution, they move in the direction of decreasing magnetic field gradients under the action of the gradient magnetic field force. As the magnet rotates, the mixed powder continues to move away from the magnetic source under the action of the gradient magnetic field force while rotating synchronously with the magnet. Because the powders are evenly mixed and the magnetic fluid layer is thin, friction between the diamond particles and the AZ91D alloy powder during their adjacent motion generates shear stress, ultimately achieving the polishing step.

[0077] 5. After the polishing step is completed, the mixture of the diamond polishing powder, the polished AZ91D alloy powder, and the magnetic fluid is returned to the separation container 8, and the diamond polishing powder and the AZ91D alloy powder are separated using a method similar to step 3; the magnetic fluid solution is then filtered to obtain pure AZ91D alloy powder after polishing;

[0078] 6. Use a method similar to steps 4-5 to complete the separation and polishing of aluminum powder and titanium powder in sequence.

[0079] Example 2

[0080] A method for separating different non-magnetic metal powders to separate copper powder (8.96 g / cm 3 )、304 stainless steel powder (7.93 g / cm 3 ) and yttria-stabilized zirconia alloy powder (5.8 g / cm 3 ) as an example, the specific steps include:

[0081] 1. To create a radially outward magnetic field force region only at the lower end of the separation region during adjustment of the permanent magnet spacing, this embodiment uses two magnets of equal thickness but different diameters as the magnetic field source. A 100 mm diameter, 20 mm thick NdFeB cylindrical magnet, serving as the first magnet 1, is affixed to the upper magnet lift platform. A 60 mm diameter, 20 mm thick NdFeB cylindrical magnet, serving as the second magnet 2, is affixed to the lower magnet lift platform. Together, the upper and lower magnet lift platforms form a separation bracket 31.

[0082] The distance between the upper and lower magnets was adjusted to 55 mm so that the radial magnetic field force in the area between the two magnets was directed inward.

[0083] Secure separation container 8 to separation table 32. In this embodiment, the outlet of separation container 8 is located at the bottom and equipped with a baffle that remains open only when metal powder is being flushed away by the fluid. Ensure the spacing between the upper and lower magnets remains constant and adjust the positions of the two magnets until the upper surface of the second magnet 2 is approximately 10 mm from the separation container 8.

[0084] 2. Place the metal powder mixture to be separated into the separation container 8; pump a mixture having a density of 1.3 g / cm2 into the separation container 8 through the pump 6 and the first delivery pipe 71. 3 The main components of the magnetic fluid solution are ferroferric oxide nanoparticles with surface modified oleic acid and kerosene carrier liquid. The pumping is stopped after the solution fills the container 8.

[0085] After standing for a period of time, the powders agglomerate on the central axis under the action of the radial inward magnetic field force. At the same time, the powders reach a stable equilibrium state under the influence of gravity, buoyancy and axial magnetic field force.

[0086] Due to the different density of powders, their stable heights are also different. At this time, the initial static separation of powders is completed, such as Figure 4 As shown in (a).

[0087] 3-1. Start the lower magnet translation stage and move the first magnet 1 upward by about 38 mm until a radially outward magnetic field force area appears in the separation interval, such as Figure 4 As shown in (b), the copper powder is slowly moved downward for about 6 mm until the copper powder at the bottom appears in the radially outward magnetic field force area. The pump 6 is turned on. Under the conditions of the radially outward magnetic field force and the flow of the paramagnetic liquid, the copper powder is flushed into the separation disk 9 by the flowing magnetic fluid. The metal powder is separated, as shown in FIG. Figure 4 As shown in (c).

[0088] 3-2. Replace the separation disc 9 and continue to slowly move it downward by 4 mm. When the 304 stainless steel powder with the second highest suspension height appears in the radially outward magnetic field force area, repeat the similar method in step 3-1. The metal powder is separated. Figure 4 As shown in (d).

[0089] 3-3. After the second metal powder is separated, only the yttrium-stabilized zirconia alloy powder remains in the separation container 8. The magnetic fluid solution in the separation container 8 is discharged, and the yttrium-stabilized zirconia alloy powder is taken out to complete the separation.

[0090] 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. The bar magnet is moved upward until it is in contact with the surface of the polishing bracket 33. At this time, the mixture of copper powder and magnetic fluid solution is in the separation disk 9. Diamond polishing powder is added to the separation disk 9 and the copper powder and diamond polishing powder are evenly mixed.

[0091] 4-2. Turn on the rotary motor 5, rotating the bar magnet 11. Because the diamond polishing powder and copper powder have lower magnetic susceptibilities than the magnetic fluid solution, they are driven by the gradient magnetic field force in the direction of decreasing magnetic field gradient. As the magnet rotates, the mixed powder is continuously moved away from the magnetic source by the gradient magnetic field force, while rotating synchronously with the magnet. Because the powder mix is ​​uniform and the magnetic fluid layer is thin, friction between the diamond particles and the copper powder during their adjacent movement generates shear stress, ultimately achieving the polishing step.

[0092] 5. After the polishing step is completed, the mixture of diamond polishing powder, polished copper powder, and magnetic fluid is returned to separation container 8 and separated from the copper powder using a method similar to step 3. The magnetic fluid solution is then filtered to obtain pure copper powder after polishing.

[0093] 6. Use a method similar to steps 4-5 to complete the separation and polishing of 304 stainless steel powder and yttrium-stabilized zirconia alloy powder in sequence.

[0094] It is easy for those skilled in the art to understand that the above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A device for separating non-magnetic powder, characterized in that: It 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 with 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 the height in the axial direction is adjustable; The outlet of the magnetic fluid solution supply device is connected to the first inlet of the separation container for providing the magnetic fluid solution to the separation container; The second inlet of the separation container is located above the separation container and is used to add non-magnetic powder to be separated and suspend it in the magnetic fluid solution; the outlet of the separation container is connected to the inlet of the separation disk; A first magnet and a second magnet having different magnetic field diameters in the horizontal direction are used to form a region in which the magnetic field force is directed radially outward. As the height of the first magnet is adjusted, only the target powder among the non-magnetic powder to be separated in the separation container is subjected to the magnetic field force directed 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, thereby achieving flow separation of different non-magnetic powders. The outlet of the separation container is connected to the inlet of the separation disk through a pipe, so that the separation disk is away from the magnetic field formed by the first magnet and the second magnet; There is a horizontally arranged bar magnet below the separation disk. The bar magnet is used to rotate in the horizontal direction, causing the target powder and the non-magnetic polishing agent to continuously move away from the center of the magnetic field and rub against each other to generate shear stress, so that the target powder is polished in situ.

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

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

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

5. The separation device according to claim 1, wherein It also includes a separation bracket for fixing the first magnet and the second magnet. Between the separation container and the magnetic fluid solution supply device, a pump is provided for continuously supplying the magnetic fluid solution in the magnetic fluid solution supply device to the separation container.

6. Use of the separation device according to any one of claims 1 to 5 in metal powder processing, characterized in that: The target powder is metal powder.

7. The use according to claim 6, characterized in that The following steps are involved: S1. Adjusting 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 both inward; S2. The metal powder to be separated is added to the separation container, and the magnetic fluid solution is provided to the separation container by the magnetic 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. The first magnet is moved vertically away from the second magnet until only the target powder of the non-magnetic powder to be separated in the separation container is subjected to a horizontal radially outward magnetic field force; the magnetic fluid solution supply device is used to continuously supply the magnetic fluid solution to the separation container, so that the target powder enters the separation disk under the action of the magnetic fluid solution; S4. Add polishing agent to the separation disk, and rotate the bar magnet in the horizontal direction, so that the target powder and the non-magnetic polishing agent continue to move away from the center of the magnetic field, and rub against each other to generate shear stress, so that the target powder is polished.

8. The use according to claim 7, characterized in that After step S4, the following steps are further included: S5. Adjusting 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 inward; S6. Pour the mixture of the magnetic fluid 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 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; use the magnetic fluid solution supply device to continuously supply magnetic fluid solution to the separation container, so that the polished target powder enters the separation disk under the action of the magnetic fluid solution.

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