Piston dry superconducting magnetic separator and dry magnetic separation and impurity removal method thereof

Abstract

The present invention relates to a piston dry superconducting magnetic separator and a dry magnetic separation and impurity removal method thereof, wherein the piston dry superconducting magnetic separator comprises a piston-magnetic medium structural assembly, a precision tube assembly, and a superconducting magnet; the precision tube assembly passes through the superconducting magnet and is relatively fixed in position; a piston-magnetic medium structural assembly capable of reciprocating along an axial direction is installed in the precision tube assembly; three groups of inlets and outlets are provided on the precision tube; the piston-magnetic medium structural assembly is provided with two separation zones along the axial direction, and the two separation zones are connected together; a separation zone central axis is provided in the separation zone, piston flanges are provided at both ends of the separation zone central axis, and magnetic medium is filled between the two piston flanges; a sliding fit is formed between the outer wall of the piston flange and the inner wall of the precision tube. The dry magnetic separation and impurity removal method, namely, using the above-mentioned piston dry superconducting magnetic separator to dryly remove impurities from high-purity powder, shortens the impurity removal process of the high-purity powder, and improves production efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of magnetic separation and mineral processing machinery, in particular to a dry superconducting magnetic separator for high-purity powder, and is applied to the technical field of high-purity powder impurity removal. Background Art

[0002] High-purity powders, such as high-purity quartz sand micropowder and Al2O3 micropowder, typically with particle diameters ranging from 1μm to 10μm, are essential materials for manufacturing high-speed digital circuit substrates, the hardware foundation of data center servers, high-performance computing systems, and high-speed communications equipment. Because high-speed digital circuits are extremely sensitive to the conductive and magnetic materials in the substrates, they place very stringent requirements on the metallic impurity content of high-purity powders, with the goal of achieving a near-zero content.

[0003] Analysis of the high-purity powder production process shows that metallic impurities are generated during the crushing, rounding, and conveying processes. Due to the high hardness of the powder itself, these processes can scrape off trace amounts of metal shavings from metal containers and pipe walls. These shavings are typically made of stainless steel and have very weak magnetic properties. Therefore, the metal shavings in high-purity powders are characterized by their tiny size (1μm to 10μm), extremely weak magnetic properties, and extremely small quantities, posing significant challenges to their removal.

[0004] In the early days of production, slurry-type high-gradient magnetic separators based on conventional conductive wires were used for this impurity removal process. However, because the background magnetic field can only reach 1 Tesla to 1.4 Tesla, a single pass of the powder through the magnetic field is very effective in removing impurities. Therefore, multiple cycles and end-of-line detection are generally used to ensure that the amount of metal chips is reduced to below the allowable value. However, this method is inherently inefficient, and because metal chips are still generated during the circulation process, even increasing the number of cycles indefinitely cannot reduce the amount of metal chips to zero.

[0005] The applicant, Jiangsu Jingkai Zhongke Superconducting High-Tech Co., Ltd., will use a slurry-type high-gradient magnetic separator based on superconducting wires for the above-mentioned impurity removal process in 2022. The background magnetic field of the superconducting magnet reaches 5 Tesla. The powder can reduce the number of metal chips to zero by passing through the magnetic field once. The separation tank can refer to the slurry high-gradient magnetic separator separation tank and the flow equalizing plate used in it with Chinese patent publication number CN117696237A. Because superconducting magnets require much longer magnetic rise and fall times than conventional magnets, the magnetic separator used in this impurity removal technology is based on the magnetic separation system described in U.S. Patent Publication No. US5868257A (Application No. US08535021, or WIPO Publication No. WO9426417A1, with priority based on UK Patent Application No. GB9309426, 19930507). This system utilizes a reciprocating tank technology, whereby the magnetic medium, after the adsorption cycle in the strong magnetic region, is moved to the weak magnetic region to remove impurities and regenerate the adsorption function, repeating the cycle. To achieve the reciprocating motion of the magnetic medium, the reciprocating tank includes a dummy region of a certain length for magnetic balance. Rubber hoses are required to connect the reciprocating tank's feed and discharge ports to the feed and discharge bins. This magnetic separator has been applied in wet magnetic impurity removal processes for high-purity powders.

[0006] The wet impurity removal process for high-purity powders requires the use of a high-purity fluid medium, such as high-purity water. Prior to entering the impurity removal process, the high-purity powder must be mixed with the fluid medium, and after the impurity removal process, the powder must be dried to remove the fluid medium. This results in high impurity removal costs, lengthy processes, and low production efficiency.

[0007] Compared to wet impurity removal processes, dry impurity removal uses dry air as the fluid medium, eliminating the need for mixing and drying. Its advantages include a shorter process and higher production efficiency. However, to minimize pressure loss, prevent powder sedimentation, and reduce the risk of secondary contamination, pneumatic conveying requires short conveying distances. Reciprocating impurity removal magnetic separators require a dummy area for magnetic balancing and a connecting hose. Therefore, the aforementioned superconducting magnetic separator using reciprocating tank technology struggles to meet the requirements of short-distance pneumatic conveying.

[0008] If you want to achieve dry impurity removal under superconducting magnets, you also need to improve the structure of the magnetic separator. Summary of the Invention

[0009] The object of the present invention is to provide a piston dry superconducting magnetic separator and a dry magnetic separation impurity removal method thereof, so as to achieve dry impurity removal, shorten the impurity removal process of high-purity powder, and improve production efficiency.

[0010] To achieve the above-mentioned object, the first aspect of the present invention provides a piston dry superconducting magnetic separator, comprising a piston-magnetic medium structural assembly, a precision tube assembly, and a superconducting magnet;

[0011] The precision tube assembly passes through the superconducting magnet and is relatively fixed in position;

[0012] A piston-magnetic medium structure assembly capable of reciprocating along the axial direction is installed in the precision tube assembly;

[0013] There is a cylindrical magnetic field cavity inside the superconducting magnet;

[0014] A precision tube assembly, comprising a precision tube and end cap assemblies fixed to both ends of the precision tube;

[0015] The precision tube is a long straight cylindrical tube with a smooth inner wall. The precision tube passes through the cylindrical cavity in the middle of the superconducting magnet.

[0016] Drive air inlet and outlet ports are provided in the end cap assemblies at both ends or on the precision tube wall close to the end cap assemblies;

[0017] There are three groups of inlets and outlets on the precision tube. One group of inlets and outlets includes one inlet and one outlet. The inlets and outlets in the same group are spaced apart.

[0018] The area where the precision tube is located inside the superconducting magnet is the magnetic selection zone. The two ends of the precision tube extend beyond the superconducting magnet, forming impurity exclusion zones at both ends. The magnetic selection zone and the two impurity exclusion zones are each equipped with a set of inlets and outlets. The inlets and outlets are located at the two ends of the magnetic selection zone or the impurity exclusion zone respectively.

[0019] The inlet of the magnetic separation zone is the feed port, and the outlet is the discharge port;

[0020] The impurity discharge areas are the first impurity discharge area and the second impurity discharge area, the corresponding inlets are the first impurity air inlet and the second impurity air inlet, and the corresponding outlets are the first impurity discharge outlet and the second impurity discharge outlet;

[0021] The piston-magnetic medium structural component is provided with two separation areas along the axial direction, and the two separation areas are connected together;

[0022] A separation zone central axis is provided in the separation zone, piston flanges are provided at both ends of the separation zone central axis, and magnetic concentrating medium is filled between the two piston flanges;

[0023] A sliding fit is formed between the outer wall of the piston flange and the inner wall of the precision tube;

[0024] The length of the separation zone matches the length of the magnetic separation zone or the impurity removal zone; when the separation zone overlaps with the magnetic separation zone or the impurity removal zone, a set of inlets and outlets are simultaneously located between the two piston flanges of the separation zone.

[0025] As a further improvement of the present invention, the end cover assembly of the precision tube assembly is detachably mounted on both ends of the precision tube.

[0026] As a further improvement of the present invention, the inlet and outlet of the precision tube are opened in a direction parallel to the tangent line of the outer circle of the tube body.

[0027] Furthermore, each inlet and outlet of the precision tube is connected to an external device through an inlet and outlet assembly;

[0028] The inlet and outlet components include fixed Hough ring, Hough ring with tube, and sealing ring;

[0029] The sealing ring is sleeved outside the precision tube, and an opening is provided on the sealing ring, which is aligned with the inlet and outlet of the precision tube;

[0030] The fixed half ring is paired with the half ring with tube, which is sleeved outside the sealing ring and connected and fixed by bolts;

[0031] The half ring with tube is provided with a connecting tube, which is connected with the opening on the sealing ring and the inlet and outlet on the precision tube;

[0032] The connecting pipe is aligned with the inlet and outlet, and the axis of the connecting pipe is parallel to the tangent line of the outer circle of the precision tube.

[0033] As a further improvement of the present invention, a dummy area is provided between the two separation areas of the piston-magnetic concentrating medium structural assembly;

[0034] A dummy zone central axis is provided in the dummy zone, and the dummy zone central axis is connected to the piston flange of the separation zone or the separation zone central axis.

[0035] Furthermore, a magnetic balance ring is provided in the dummy region, and the magnetic balance ring is arranged outside the central axis of the dummy region.

[0036] Furthermore, the central axis of the dummy area is fixed to two piston flanges close to the dummy area;

[0037] The central axis of the separation zone is detachably fixed on the piston flange close to the dummy zone, or on the central axis of the dummy zone;

[0038] The piston flange outside the separation zone is detachably fixed to the central axis of the separation zone;

[0039] The magnetic concentrating medium is detachably installed in the separation area.

[0040] As a further improvement of the present invention, a piston sealing ring is provided between the outer wall of the piston flange of the separation zone and the inner wall of the precision tube;

[0041] A dynamic sealing interface is formed between the piston sealing ring and the inner wall of the precision tube.

[0042] As a further improvement of the present invention, the inlet and outlet provided on the wall surface of the precision tube overlap axially with the piston flange of the piston-magnetic concentrating medium structural assembly;

[0043] The axial length dimension of the inlet and outlet is smaller than the thickness dimension of the piston flange.

[0044] A second aspect of the present invention provides a dry magnetic separation and impurity removal method, which uses the above-mentioned piston dry superconducting magnetic separator;

[0045] The feed port of the magnetic separation zone is connected to the raw material bin, and the raw material bin is connected to the high-pressure gas source;

[0046] The discharge port of the magnetic separation area is connected to the collection bin;

[0047] The first row of miscellaneous air inlets and the second row of miscellaneous air inlets are connected to a high-pressure gas source;

[0048] The first row of miscellaneous material discharge ports and the second row of miscellaneous material discharge ports are connected to the miscellaneous material collection bin;

[0049] The driving air inlet and outlet ports at both ends of the precision tube assembly are connected to the high-pressure air source and the exhaust device respectively through control valves;

[0050] The working process of dry magnetic separation and impurity removal is as follows:

[0051] Step 1: Move and position; one of them drives the air inlet and outlet to intake air, and the other drives the air inlet and outlet to exhaust air, stabilizing the piston-magnetic medium structure assembly at one end of the precision tube assembly;

[0052] Step 2, working state 1: open the control valves of the feed port and the discharge port, the high-purity powder to be removed is discharged from the raw material bin, mixed with high-pressure air, and then input into the separation chamber of the magnetic separation zone through the feed port. The airflow carries the powder through the magnetic medium in the separation zone, and the magnetic impurities contained in the powder are adsorbed on the magnetic medium. The remaining powder is discharged as the finished product to the collection bin through the discharge port;

[0053] At this time, another separation chamber is located in the first impurity discharge area. The air inlet and outlet of the first impurity discharge area are opened, and high-pressure air enters the separation chamber in the first impurity discharge area through the first impurity discharge air inlet. The air blows through the magnetic concentrating medium and the inner wall of the precision tube in the separation area, and the impurities are discharged into the impurity collection bin along with the air through the first impurity discharge port.

[0054] Working state: continuous operation for set time;

[0055] Step 3: Move and position. Close all air inlets and outlets on the precision tube, connect the high-pressure air source of the drive inlet and outlet close to the piston-magnetic medium structure assembly, exhaust the air from the other drive inlet and outlet, and pneumatically drive the piston-magnetic medium structure assembly until it moves to the other end and stabilizes.

[0056] Step 4, working state 2; open the control valves of the feed port and the discharge port, and the high-purity powder to be cleaned is mixed with high-pressure air, and then fed into the separation chamber of the magnetic separation zone through the feed port, where it is fully contacted with the magnetic medium. The magnetic impurities contained in the powder are adsorbed on the magnetic medium, and the high-purity powder after impurity removal is discharged to the collection bin as a finished product through the discharge port;

[0057] At this time, another separation chamber is located in the second impurity discharge area. The air inlet and outlet of the second impurity discharge area are opened, and high-pressure air enters the separation chamber in the second impurity discharge area through the second impurity discharge air inlet. The air blows through the magnetic concentrating medium and the inner wall of the precision tube in the separation area, and the impurities are discharged into the impurity collection bin along with the air through the second impurity discharge port.

[0058] Working state 2: continuous operation for set time;

[0059] Repeat steps 1 to 4.

[0060] The present invention first provides a specific structure of a piston dry superconducting magnetic separator, which consists of a piston-magnetic medium structural assembly, a precision tube assembly and a superconducting magnet; the piston-magnetic medium structural assembly consists of a dummy zone central axis, a separation zone central axis, a piston flange, a sealing ring, a magnetic medium and a magnetic balance ring; the precision tube assembly consists of a precision tube with 6 inlets and outlets, an end cover, an inlet and outlet Hough ring with a tangential tube and other components; the piston-magnetic medium structural assembly is installed in the precision tube assembly and performs piston-like reciprocating motion along the axial direction of the precision tube, so that the magnetic medium of the two separation zones switches between the magnetic separation zone and the impurity removal zone, performs ultra-strong magnetic adsorption and impurity removal in the magnetic separation zone, and performs impurity removal in the impurity removal zone, thereby realizing efficient dry magnetic separation and impurity removal operations.

[0061] The piston dry superconducting magnetic separator and dry magnetic separation and impurity removal method of the present invention have the following specific features:

[0062] 1. The reciprocating motion technology is still used, and the superconducting magnet remains in a fixed position. When the magnetic separator is working, the magnetic field is kept constant; however, in the present invention, only the magnetic medium reciprocates between the strong magnetic zone and the weak magnetic zone, while the position of the outer wall of the tank remains fixed.

[0063] 2. A dual-magnetic medium configuration is used. While one magnetic medium attracts metal impurities in the strong magnetic zone, the other magnetic medium removes them in the weak magnetic zone. This allows the dual magnetic medium configuration to operate in two positions during a single impurity removal cycle. The magnetic medium consists of wires or rods made of soft magnetic material, stacked and staggered at regular intervals to fill the entire cavity.

[0064] 3. The two magnetic concentrators are restrained between two pairs of piston flanges. The piston flanges are fitted with two sealing rings, typically two in number, which form an oil-free, self-lubricating dynamic seal with the smooth inner wall of the tank body. A cavity is formed between the two piston flanges and the inner wall of the tank body, which is the separation chamber.

[0065] 4. The two flanges close to each other in the two pairs of piston flanges are welded to the central shaft as a whole, forming a dummy area between the inner wall of the tank body. The central shaft is covered with a certain thickness of metal, the material of which is the same as the magnetic medium. As a magnetic balance component, its thickness matches the filling rate of the magnetic medium material in the separation chamber. This component uses a Hough structure and is fixed to the central shaft by bolts or clamps.

[0066] 5. The two flanges in the two pairs of piston flanges that are far away from each other are fixed to the piston flange in the dummy area through their respective center axes, and they are detachably connected to each other by threaded fastening; all the piston flanges and center axes are coaxial with the cylinder body of the tank.

[0067] 6. The tank body is a precision tube with a smooth inner wall. It passes through the cylindrical inner bore of the superconducting magnet with only a small gap between it and the inner bore wall. The symmetrical cross-section perpendicular to the axis coincides with the symmetrical cross-section of the superconducting magnet. A hole is drilled parallel to the tangent line of the outer diameter of the tube body, extending beyond and close to the end face of the superconducting magnet. The hole is located inside the two piston flanges of the separation chamber. When the hole outside one end face of the superconducting magnet serves as the feed inlet, the hole outside the other end face serves as the discharge inlet. To ensure clean discharge, the hole and the piston flange overlap by 1-2 mm in the axial direction. The diameter of the hole is less than the thickness of the piston flange.

[0068] 7. At the two working positions of the weak magnetic area of ​​the separation chamber, holes are drilled in the same way (along the direction parallel to the tangent line of the outer circle of the cylinder body) and in the same position relationship with the piston flange (the hole and the piston flange overlap 1 to 2 mm in the axial direction). When the hole at one end is used as the air inlet, the hole at the other end is used as the exhaust and impurity discharge port.

[0069] 8. After the four piston flanges, three center shafts and two magnetic concentrators are assembled, a complete piston-magnetic concentrator structure is formed, which can perform piston motion inside the tank body as a whole.

[0070] 9. The precision tube tank body is sealed at both ends with removable end caps with sealing rings. The end caps have holes and a central boss on the side facing the piston flange to limit the travel of the piston-magnetic medium assembly and form an air chamber. When the working area of ​​the separation chamber needs to be changed, the hole in one end cap serves as the air inlet, and the hole in the other end cap serves as the exhaust port, using gas pressure to propel the separation chamber to the next working area. During the movement of the piston-magnetic medium assembly, the valves on the external pipelines connected to the six inlets and outlets on the tank body are all closed.

[0071] 10. Sealing rings are installed outside the inlet / outlet of the cylinder body. The sealing rings are coaxial at the inlet / outlet positions and have tangential holes of the same diameter. The sealing rings are surrounded by a half ring with a tangential tube and a half ring without a tangential tube. The two half rings are connected and fixed by bolt fasteners. The tangential tube on the half ring is coaxial with the inlet and outlet of the cylinder body, and the inner diameter of the pipe is the same as the inlet and outlet diameter. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1 This is a schematic diagram of the overall appearance of the piston dry superconducting magnetic separator of the present invention;

[0073] Figure 2 This is a front view of the overall appearance of the piston dry superconducting magnetic separator of the present invention;

[0074] Figure 3 This is a front view of the internal structure of the piston dry superconducting magnetic separator of the present invention;

[0075] Figure 4 This is a front view of the internal structure of the piston dry superconducting magnetic separator of the present invention in working state 1;

[0076] Figure 5 This is a front view of the internal structure of the piston dry superconducting magnetic separator of the present invention in working state 2;

[0077] Figure 6 It is a structural schematic diagram of the precision tube assembly of the present invention;

[0078] Figure 7 Schematic diagram of the overall structure of the end cover assembly of the precision tube assembly of the present invention;

[0079] Figure 8 It is a front view of the end cap assembly of the precision tube assembly of the present invention;

[0080] Figure 9 It is a partially enlarged schematic diagram of the end cover portion of the precision tube assembly of the present invention;

[0081] Figure 10 Schematic diagram of the assembly of the inlet and outlet of the precision tube assembly of the present invention;

[0082] Figure 11 This is a schematic diagram of the overall structure of the sealing rings at the inlet and outlet of the precision tube assembly of the present invention;

[0083] Figure 12 A cross-sectional view of the sealing structure of the inlet and outlet of the precision tube assembly of the present invention;

[0084] Figure 13 This is a front view of the internal structure of the piston-magnetic medium structural assembly of the present invention;

[0085] Figure 14 for Figure 13 Local magnification Figure 1 ;

[0086] Figure 15 for Figure 13 Local magnification Figure 2 .

[0087] In the figure: 1-piston-magnetic medium structural assembly; 2-precision tube assembly; 3-superconducting magnet. DETAILED DESCRIPTION

[0088] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0089] The present invention provides a piston dry superconducting magnetic separator and a dry magnetic separation and impurity removal method using the superconducting magnetic separator, which is applied to the field of high-purity powder impurity removal and aims to resolve the contradiction between short-distance pneumatic conveying and current re-tanking technology.

[0090] The piston dry superconducting magnetic separator of the present invention has an external structure as follows Figure 1 、 Figure 2 As shown, the internal structure is as Figure 3 As shown, a precision tube assembly 2 and a superconducting magnet 3 are provided; the precision tube assembly 2 passes through the superconducting magnet 3 and is relatively fixed in position; a piston-magnetic medium structure assembly 1 capable of reciprocating motion in the axial direction is installed in the precision tube assembly 2.

[0091] The piston dry superconducting magnetic separator of the present invention is preferably arranged horizontally, that is, the axes of the components are arranged horizontally.

[0092] The superconducting magnet 3 is a strong magnet formed by winding superconducting wires, and has a cylindrical magnetic field cavity therein.

[0093] Precision tube assembly 2, the specific structure can be further referred to Figure 6, including a precision tube 21 and end cover assemblies 22 at both ends; the precision tube 21 is a long straight cylindrical tube with a smooth inner wall, which can pass through the cylindrical cavity in the middle of the superconducting magnet 3, and the gap between the outer wall of the precision tube 21 and the inner wall of the cylindrical cavity of the superconducting magnet 3 is extremely small, so that it can be easily disassembled and assembled; the symmetrical cross-section of the precision tube 21 perpendicular to the axis coincides with the symmetrical cross-section of the superconducting magnet 3.

[0094] The end cap assembly 22 of the precision tube assembly 2 is preferably detachably mounted on both ends of the precision tube 21. The specific structure of the end cap assembly 22 can be referred to Figure 7 、 Figure 8 、 Figure 9 , a half structure is used for connection and fixation, including an end cover 221 and a half flange (also known as a split flange) 222; the end cover 221 is provided with an insertion end, which is inserted into the end of the precision tube 21, and the wall of the insertion end is provided with a sealing groove, in which an end cover sealing ring 227 is embedded to seal the gap between the end of the precision tube 21 and the insertion end of the end cover 221; the two half flanges 222 are connected and fastened by half flange bolts 223, so that the two half flanges 222 are clamped and fixed to the outside of the end of the precision tube 21, and the end cover 221 and the half flange 222 are fixed by a number of end cover bolts 224, so that the end cover 221 is fixed to the end of the precision tube 21.

[0095] A driving air inlet and outlet 225 is provided in the end cover 221 , connecting the inner chamber of the precision tube 21 with the outside.

[0096] A preferred positioning post 226 is provided within the end cap 221 .

[0097] The precision tube 21 is provided with two or three groups of inlets and outlets, and one group of inlets and outlets includes one inlet and one outlet.

[0098] In order to improve the efficiency of magnetic separation and impurity removal, the precision tube 21 is set longer, with both ends far exceeding the superconducting magnet 3, forming impurity removal areas at both ends. Figure 2 、 Figure 3 、 Figure 6 ; At a position beyond the end face of the superconducting magnet 3 and close to the end face, there are respectively provided an inlet and an outlet, so that the precision tube 21 located in the area of ​​the superconducting magnet 3 serves as a magnetic selection zone 26, whose inlet is the feed port 261 and the outlet is the discharge port 262; at both ends of the precision tube 21 outside the superconducting magnet 3, a first row of impurities zone 27 and a second row of impurities zone 28 are formed respectively, and the corresponding inlets are the first row of impurities air inlet 271 and the second row of impurities air inlet 281, and the corresponding outlets are the first row of impurities discharge port 272 and the second row of impurities discharge port 282.

[0099] The inlet and outlet on the precision tube 21 are preferably opened in a direction parallel to the tangent line of the outer circle of the tube body; each inlet and outlet on the precision tube 21 is preferably connected to the corresponding external equipment through the inlet and outlet assembly 23, such as Figure 10 、 Figure 11 、 Figure 12 As shown, the inlet and outlet assembly 23 includes a fixed half ring 231, a half ring with a tube 232, and a sealing ring 236; the sealing ring 236 is sleeved on the outside of the precision tube 21, and an opening 237 is provided on the sealing ring 236, which is aligned with the inlet and outlet on the precision tube 21 without forming any obstruction; the fixed half ring 231 is paired with the half ring with a tube 232, sleeved on the outside of the sealing ring 236, connected and fixed by bolts 234, so that it is tightly embraced and fixed to the outside of the precision tube 21 together with the sealing ring 236, and the half ring with a tube 232 is provided with a connecting pipe 233, which is connected with the opening 237 and the inlet and outlet on the precision tube 21, and the connecting pipe 233 is aligned with the inlet and outlet, and the axis of the connecting pipe 233 is parallel to the tangent line of the outer circle of the barrel of the precision tube 21. When the high-pressure air enters the precision tube 21 through the connecting pipe 233, the movement direction is tangent to the inner wall of the precision tube 21, thereby forming a spiral airflow.

[0100] The specific structure of piston-magnetic medium structure component 1 can be referred to Figure 13 、 Figure 14 、 Figure 15 In order to improve the efficiency of magnetic separation and impurity removal, two groups of magnetic concentrating media 14 are preferably provided, respectively located at both ends, with a dummy area in the middle; a dummy area central axis 11 is provided in the dummy area, and a magnetic balance ring 16 is provided outside the dummy area; separation areas are symmetrically provided on both sides of the dummy area, and a separation area central axis 12 is provided in the middle, and the separation area central axis 12 is coaxial with the dummy area central axis 11.

[0101] Each separation zone is provided with a piston flange 13 at both ends, fixed respectively at the two ends of the central axis 12 of the separation zone, and a magnetic medium 14 is filled between the two piston flanges 13, thereby forming a separation zone; the piston flange 13 cooperates with the inner wall of the precision tube 21 to form a sliding fit, and the outer wall of the piston flange 13 is preferably provided with a sealing groove, in which a piston sealing ring 15 is embedded, forming an oil-free, self-lubricating dynamic sealing interface between the piston sealing ring 15 and the inner wall of the precision tube 21; each piston flange 13 is preferably provided with two piston sealing rings 15 for sealing, so that the inner cavity area of ​​the precision tube 21 between the two piston flanges 13 forms an independent closed chamber, which is named as a separation chamber according to its key function of adsorbing impurities in the strong magnetic area. Preferably, the outer diameter of the magnetic medium 14 is slightly smaller than the piston flange 13, so that a gap is formed between the magnetic medium 14 and the inner cavity of the precision tube 21.

[0102] Preferably, the two piston flanges 13 close to the dummy area are welded to the central axis 11 of the dummy area into a whole; the magnetic balance ring 16 is a metal with a certain thickness, and the material is preferably the same as the material of the magnetic medium 14, serving as a magnetic balance component; the thickness of the magnetic balance ring 16 matches the filling rate of the magnetic medium 14 material in the separation area; the magnetic balance ring 16 can be fastened with bolts using a Hough structure, or fixed on the central axis 11 of the dummy area in a detachable and adjustable manner using a clamp.

[0103] Furthermore, the central axis 12 of the separation zone is detachably fixed to the piston flange 13 of the dummy zone, or the central axis 11 of the dummy zone, through a threaded structure. The piston flange 13 outside the separation zone (away from the dummy zone) can also be detachably fixed to the central axis 12 of the separation zone through a threaded structure, thereby making the main components of the entire piston-magnetic medium structural assembly 1 detachable and assembled, which is convenient for transportation, adjustment, and replacement.

[0104] like Figure 3 、 Figure 4 、 Figure 5 As shown, the piston-magnetic medium structural component 1 is installed in the precision tube component 2 and can reciprocate along the axis, thereby having two working positions and forming two working states, namely working state 1 and working state 2.

[0105] One end of the piston-magnetic medium structure assembly 1 rests on the end cover assembly 22 and is limited by the positioning column 226. At this time, one of the separation zones is exactly located in the magnetic separation zone 26, and the other separation zone is exactly located in the first impurity row zone 27 or the second impurity row zone 28.

[0106] Reasonably adjust the spacing between the inlets and outlets so that one set of inlets and outlets is located just inside the piston flange 13 at both ends of the separation zone; further, in order to ensure clean discharge, the inlets and outlets are preferably overlapped axially with the piston flange 13 by 1 to 2 mm, and the diameter of the inlets and outlets is preferably smaller than the thickness of the piston flange 13.

[0107] When the piston-magnetic medium structural assembly 1 is axially displaced in the precision tube assembly 2, high-pressure air is injected through the driving air inlet and outlet 225 on the end cover assembly 22 at one end, so that a driving air cavity is formed between the piston flange 13 and the end cover 221 on that side. Because the positioning column 226 is against the piston flange 13, it can ensure that there is always a suitable driving air cavity cross-section between the piston flange 13 and the end cover 221, thereby pushing the piston-magnetic medium structural assembly 1 to move toward the other end. At this time, the volume of the chamber between the piston flange 13 at the other end and the other end is reduced, and the air therein is discharged outward through the other driving air inlet and outlet 225.

[0108] The piston dry superconducting magnetic separator of the present invention is assembled and debugged at the work site, and the superconducting magnet 3 is started at an appropriate time.

[0109] When the piston dry superconducting magnetic separator of the present invention is used for dry magnetic separation and impurity removal of high-purity powder, the connecting pipes 233 of each inlet and outlet, and the driving air inlet and outlet 225 at both ends are connected to the outside through control valves; the feed port 261 is connected to the high-purity powder raw material warehouse, and the raw material warehouse is connected to the high-pressure gas source; the discharge port 262 is connected to the high-purity powder finished product collection warehouse, and the collection warehouse has an exhaust device; the first impurity discharge air inlet 271 and the second impurity discharge air inlet 281 are connected to the high-pressure gas source; the first impurity discharge port 272 and the second impurity discharge port 282 are connected to the impurity collection warehouse, and the impurity collection warehouse has an exhaust device; the driving air inlet and outlet 225 are connected to the high-pressure gas source.

[0110] When the piston dry superconducting magnetic separator of the present invention is used for dry magnetic separation and impurity removal of high-purity powder, its working process is as follows:

[0111] Step 1, wherein one of the drive inlet and outlet ports 225 is used for intake, and the other drive inlet and outlet port 225 is used for exhaust, and the piston-magnetic medium structure component 1 is stabilized at one end of the precision tube component 2, as shown in FIG. Figure 4 Close the control valve driving the air inlet and outlet 225, so that the piston - magnetic medium structure component 1 is stable in position.

[0112] Step 2, working state one; open the control valves of the feed port 261 and the discharge port 262, and the high-purity powder to be removed is output from the raw material warehouse, mixed with high-pressure air, and then input into the separation cavity of the magnetic separation zone 26 through the feed port 261. The airflow carries the powder spirally through the magnetic medium 14 in the separation zone. At this time, the magnetic medium 14 is located in the superconducting magnet 3, and the magnetic impurities contained in the powder can be adsorbed on the magnetic medium 14. After multiple adsorptions and the super-strong magnetic field in the superconducting magnet 3, the magnetic impurities in the high-purity powder can be removed cleanly, and the pure high-purity powder is discharged to the high-purity powder finished product collection bin through the discharge port 262.

[0113] At this time, the separation chamber located in the impurity removal area, refer to Figure 4 , that is, the separation cavity located in the first impurity removal zone 27, away from the superconducting magnet 3, and its magnetic field strength drops below 50Gs. The air inlet and outlet of the impurity removal zone are opened, that is, the control valves of the first impurity removal air inlet 271 and the first impurity removal outlet 272 are opened, so that pure high-pressure air is blown into the separation cavity of the impurity removal zone. The airflow spirally blows through the magnetic medium 14 and the inner wall of the precision tube 21 in the separation zone. The magnetic impurities adsorbed on the magnetic medium 14 are blown down by gravity and the high-pressure airflow, and finally enter the impurity collecting bin through the first impurity removal outlet 272 with the airflow.

[0114] At this time, there is no piston-magnetic medium structure assembly 1 in the impurity removal area on the other side, so its air inlet and outlet need to be closed, that is, the second impurity removal air inlet 281 and the second impurity removal outlet 282 need to be closed.

[0115] Step 3, move; after the above step 2 runs for a period of time, a certain amount of magnetic impurities has been adsorbed on the magnetic medium 14 in the magnetic separation zone 26. After the adsorption capacity decreases, in order to ensure the quality of impurity removal, the piston-magnetic medium structure assembly 1 needs to be rotated; at this time, all the inlet and outlet ports on the precision tube 21 are closed, and then as Figure 4 As shown, the control valve of the driving air inlet and outlet 225 at one end is opened and connected to high-pressure air, and the other driving air inlet and outlet 225 is exhausted, and the piston-magnetic medium structure component 1 is pneumatically driven until it moves to the other end, as shown in FIG. Figure 5 In the position shown, the control valve driving the air inlet and outlet 225 is closed, so that the position of the piston-magnetic medium structure assembly 1 is stable.

[0116] In this process, Figure 4 The magnetic medium 14 in the magnetic separation zone 26 gradually moves into the second impurity removal zone 28. After the strong magnetic field is lost, some of the magnetic impurities adsorbed on the magnetic medium 14 will fall due to gravity. However, because a piston sealing ring 15 is provided between the piston flange 13 and the precision tube 21, the magnetic impurities will always be confined in their separation zone.

[0117] In this process, Figure 4 The magnetic medium 14 in the first row of impurities 27 gradually moves into the magnetic separation zone 26. Even if there are some magnetic impurities that have not been removed yet, they will be attracted to the magnetic medium 14 due to the magnetism of the magnetic medium 14.

[0118] Step 4, working state 2; open the control valves of the feed port 261 and the discharge port 262 again, and after the high-purity powder to be decontaminated is mixed with high-pressure air, it is input into the separation chamber of the magnetic separation area 26 through the feed port 261, and is fully contacted with the magnetic medium 14 that has just been decontaminated. The magnetic impurities contained in the powder are adsorbed on the magnetic medium 14, and the pure high-purity powder after decontamination is discharged to the high-purity powder finished product collection bin through the discharge port 262.

[0119] At this time, the air inlet and outlet of the first impurity discharge area 27 are closed, and the air inlet and outlet of the second impurity discharge area 28 are opened. High-pressure air is blown into the separation chamber located in the second impurity discharge area 28. The airflow blows off the magnetic conductive impurities adsorbed on the magnetic collecting medium 14 and enters the impurity collecting bin through the second impurity discharge port 282.

[0120] Repeat steps 1 to 4, so that the piston-magnetic medium structural assembly 1 performs intermittent piston reciprocating motion in the precision tube assembly 2, so that the magnetic medium 14 on both sides of the piston-magnetic medium structural assembly 1 alternately enters the superconducting magnet 3 to perform magnetic separation and impurity removal operations, and the magnetic medium 14 located outside the superconducting magnet 3 can also be fully flushed with high-pressure gas to remove magnetic impurities.

[0121] The piston dry superconducting magnetic separator of the present invention has the following characteristics:

[0122] 1. The precision tube assembly 2 is a detachable structure, which is convenient for packaging and transportation of the magnetic separator;

[0123] 2. The piston-magnetic medium structural assembly 1 is a detachable structure, so that the magnetic medium can be easily replaced and maintained during the long-term operation of the magnetic separator;

[0124] 3. The six inlet and outlet positions on the precision tube remain fixed at all times; the raw material bin and the finished product collection bin for high-purity powder are respectively connected to the inlets and outlets on both sides of the separation chamber located in the strong magnetic area. The two bins can be installed close to the magnetic separator, thus only short connecting pipes are required. In addition, unlike the reciprocating tank connection structure in the prior art, the connecting pipes of the present invention have no moving parts and do not require the use of flexible hoses.

[0125] 4. The dual-magnetic medium 14 configuration retains the advantage of the reciprocating tank technology with two adsorption times in one impurity removal cycle, which doubles the production efficiency compared to the single-magnetic medium configuration;

[0126] 5. To reduce metal chips generated by the impact of high-purity powder, the inner wall of the precision tube 21 is smooth; the dynamic sealing interface between the piston seal 15 and the precision tube 21 utilizes this smooth wall surface. At the same time, the dynamic sealing interface is oil-free and self-lubricating to avoid grease contamination of the high-purity powder;

[0127] 6. A dummy zone of a certain length is provided so that the maximum value of the weak magnetic region in the off-field separation chamber is less than 50 Gs; the magnetic balance ring 16 sleeved on the central axis 11 of the dummy zone is used to reduce the peak axial residual magnetic field force acting on the piston-magnetic concentrator medium assembly 1 during the reciprocating motion, thereby reducing the peak gas driving force and thus reducing the peak gas pressure, saving energy consumption of the pneumatic components and improving the intrinsic safety performance of the magnetic separator;

[0128] 7. The six inlets and outlets on the precision tube are all tangentially parallel to the outer circle, which is used to form a vortex of air-powder mixed fluid in the separation chamber, increasing the probability of powder colliding with the magnetic medium, thereby increasing the probability of impurities being adsorbed;

[0129] 8. There is only a small gap between the precision tube 21 and the inner wall of the superconducting magnet 3. On the one hand, this is to make the most of the strong magnetic space in the inner hole of the superconducting magnet, and on the other hand, it is to facilitate the installation of the precision tube into the inner hole of the superconducting magnet. In the working position, the inlet and outlet holes overlap with the piston flange 13 axially by 1 to 2 mm to ensure clean discharge. The diameter of the hole is smaller than the thickness of the piston flange to avoid large fluctuations in the driving force caused by the connection between the two adjacent air chambers through the inlet and outlet holes during the movement of the piston-magnetic medium assembly.

[0130] 9. During the movement of the piston-magnetic medium structure assembly 1, the valves on the external pipelines connected to the six inlets and outlets on the tank body are all in the closed state in order to maintain the continuity and stability of the pneumatic force acting on the end piston flange.

[0131] 10. Using pneumatic force as the driving force for pushing the piston-magnetic medium structure component 1, the conditions of the existing precision tube similar to the cylinder are borrowed, and the air source equipment for pneumatic conveying of powder materials is also borrowed. Compared with the external driving method (such as winding rope), the equipment composition is simplified and the equipment cost is reduced.

[0132] The preferred embodiments of the present invention have been specifically described above, but the present invention is not limited to the described embodiments. Those skilled in the art may make various equivalent modifications or substitutions without departing from the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. Piston dry superconducting magnetic separator, characterized in that: It includes a piston-magnetic medium structural assembly, a precision tube assembly, and a superconducting magnet; The precision tube assembly passes through the superconducting magnet and is relatively fixed in position; A piston-magnetic medium structure assembly capable of reciprocating along the axial direction is installed in the precision tube assembly; There is a cylindrical magnetic field cavity inside the superconducting magnet; A precision tube assembly, comprising a precision tube and end cap assemblies fixed to both ends of the precision tube; The precision tube is a long straight cylindrical tube with a smooth inner wall. The precision tube passes through the cylindrical cavity in the middle of the superconducting magnet. Drive air inlet and outlet ports are provided in the end cap assemblies at both ends or on the precision tube wall close to the end cap assemblies; There are three groups of inlets and outlets on the precision tube. One group of inlets and outlets includes one inlet and one outlet. The inlets and outlets in the same group are spaced apart. The area where the precision tube is located inside the superconducting magnet is the magnetic selection zone. The two ends of the precision tube extend beyond the superconducting magnet, forming impurity exclusion zones at both ends. The magnetic selection zone and the two impurity exclusion zones are each equipped with a set of inlets and outlets. The inlets and outlets are located at the two ends of the magnetic selection zone or the impurity exclusion zone respectively. The inlet of the magnetic separation zone is the feed port, and the outlet is the discharge port; The impurity discharge areas are the first impurity discharge area and the second impurity discharge area, the corresponding inlets are the first impurity air inlet and the second impurity air inlet, and the corresponding outlets are the first impurity discharge outlet and the second impurity discharge outlet; The piston-magnetic medium structural component is provided with two separation areas along the axial direction, and the two separation areas are connected together; A separation zone central axis is provided in the separation zone, piston flanges are provided at both ends of the separation zone central axis, and magnetic concentrating medium is filled between the two piston flanges; A sliding fit is formed between the outer wall of the piston flange and the inner wall of the precision tube; The length of the separation zone matches the length of the magnetic separation zone or the impurity removal zone; when the separation zone overlaps with the magnetic separation zone or the impurity removal zone, a set of inlets and outlets are simultaneously located between the two piston flanges of the separation zone.

2. The piston dry superconducting magnetic separator according to claim 1, characterized in that: The end cap assembly of the precision tube assembly is detachably mounted on both ends of the precision tube.

3. The piston dry superconducting magnetic separator according to claim 1, characterized in that: The inlet and outlet of the precision tube are opened in a direction parallel to the tangent line of the outer circle of the tube body.

4. The piston dry superconducting magnetic separator according to claim 1 or 3, characterized in that: Each inlet and outlet on the precision tube is connected to external equipment through an inlet and outlet assembly; The inlet and outlet components include fixed Hough ring, Hough ring with tube, and sealing ring; The sealing ring is sleeved outside the precision tube, and an opening is provided on the sealing ring, which is aligned with the inlet and outlet of the precision tube; The fixed half ring is paired with the half ring with tube, which is sleeved outside the sealing ring and connected and fixed by bolts; The half ring with tube is provided with a connecting tube, which is connected with the opening on the sealing ring and the inlet and outlet on the precision tube; The connecting pipe is aligned with the inlet and outlet, and the axis of the connecting pipe is parallel to the tangent line of the outer circle of the precision tube.

5. The piston dry superconducting magnetic separator according to claim 1, characterized in that: A dummy area is provided between the two separation areas of the piston-magnetic medium structural component; A dummy zone central axis is provided in the dummy zone, and the dummy zone central axis is connected to the piston flange of the separation zone or the separation zone central axis.

6. The piston dry superconducting magnetic separator according to claim 5, characterized in that: A magnetic balance ring is provided in the dummy element area and is arranged outside the central axis of the dummy element area.

7. The piston dry superconducting magnetic separator according to claim 5 or 6, characterized in that: Furthermore, the central axis of the dummy area is fixed to two piston flanges close to the dummy area; The central axis of the separation zone is detachably fixed on the piston flange close to the dummy zone, or on the central axis of the dummy zone; The piston flange outside the separation zone is detachably fixed to the central axis of the separation zone; The magnetic concentrating medium is detachably installed in the separation area.

8. The piston dry superconducting magnetic separator according to claim 1, characterized in that: A piston sealing ring is provided between the outer wall of the piston flange in the separation zone and the inner wall of the precision tube; A dynamic sealing interface is formed between the piston sealing ring and the inner wall of the precision tube.

9. The piston dry superconducting magnetic separator according to claim 1, characterized in that: The inlet and outlet provided on the wall of the precision tube overlap axially with the piston flange of the piston-magnetic concentrating medium structural assembly; The axial length dimension of the inlet and outlet is smaller than the thickness dimension of the piston flange.

10. Dry magnetic separation impurity removal method, characterized in that: A piston dry superconducting magnetic separator according to any one of claims 1 to 9; The feed port of the magnetic separation zone is connected to the raw material bin, and the raw material bin is connected to the high-pressure gas source; The discharge port of the magnetic separation area is connected to the collection bin; The first row of miscellaneous air inlets and the second row of miscellaneous air inlets are connected to a high-pressure gas source; The first row of miscellaneous material discharge ports and the second row of miscellaneous material discharge ports are connected to the miscellaneous material collection bin; The driving air inlet and outlet ports at both ends of the precision tube assembly are connected to the high-pressure air source and the exhaust device respectively through control valves; The working process of dry magnetic separation and impurity removal is as follows: Step 1: Move and position; one of them drives the air inlet and outlet to intake air, and the other drives the air inlet and outlet to exhaust air, stabilizing the piston-magnetic medium structure assembly at one end of the precision tube assembly; Step 2, working state 1: open the control valves of the feed port and the discharge port, the high-purity powder to be removed is discharged from the raw material bin, mixed with high-pressure air, and then input into the separation chamber of the magnetic separation zone through the feed port. The airflow carries the powder through the magnetic medium in the separation zone, and the magnetic impurities contained in the powder are adsorbed on the magnetic medium. The remaining powder is discharged as the finished product to the collection bin through the discharge port; At this time, another separation chamber is located in the first impurity discharge area. The air inlet and outlet of the first impurity discharge area are opened, and high-pressure air enters the separation chamber in the first impurity discharge area through the first impurity discharge air inlet. The air blows through the magnetic concentrating medium and the inner wall of the precision tube in the separation area, and the impurities are discharged into the impurity collection bin along with the air through the first impurity discharge port. Working state: continuous operation for set time; Step 3: Move and position. Close all air inlets and outlets on the precision tube, connect the high-pressure air source of the drive inlet and outlet close to the piston-magnetic medium structure assembly, exhaust the air from the other drive inlet and outlet, and pneumatically drive the piston-magnetic medium structure assembly until it moves to the other end and stabilizes. Step 4, working state 2; open the control valves of the feed port and the discharge port, and the high-purity powder to be cleaned is mixed with high-pressure air, and then fed into the separation chamber of the magnetic separation zone through the feed port, where it is fully contacted with the magnetic medium. The magnetic impurities contained in the powder are adsorbed on the magnetic medium, and the high-purity powder after impurity removal is discharged to the collection bin as a finished product through the discharge port; At this time, another separation chamber is located in the second impurity discharge area. The air inlet and outlet of the second impurity discharge area are opened, and high-pressure air enters the separation chamber in the second impurity discharge area through the second impurity discharge air inlet. The air blows through the magnetic concentrating medium and the inner wall of the precision tube in the separation area, and the impurities are discharged into the impurity collection bin along with the air through the second impurity discharge port. Working state 2: continuous operation for set time; Repeat steps 1 to 4.

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