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

Abstract

The invention relates to a piston dry-type superconducting magnetic separator and a dry-type magnetic separation impurity removal method thereof.The piston dry-type superconducting magnetic separator comprises a piston-magnetism gathering medium structure assembly, a precision tube assembly and a superconducting magnet; the precision tube assembly penetrates through the superconducting magnet and is relatively fixed in position; a piston-magnetism gathering medium structure assembly capable of reciprocating in the axis direction is installed in the precision pipe assembly. Three groups of inlets and outlets are formed in the precision tube; the piston-magnetism gathering medium structure assembly is provided with two separation areas in the axial direction, and the two separation areas are connected together. A separation area center shaft is arranged in the separation area, piston flanges are arranged at the two ends of the separation area center shaft, and the space between the two piston flanges is filled with a magnetism gathering medium; and the outer wall of the piston flange is in sliding fit with the inner wall of the precision tube. According to the dry type magnetic separation impurity removal method, the piston dry type superconducting magnetic separator is used for conducting dry type impurity removal on the high-purity powder, the impurity removal process of the high-purity powder is shortened, and the production efficiency is improved.

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 powders, 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 powder and Al2O3 powder, generally have a particle diameter of 1μm to 10μm, and are the basic materials for manufacturing high-speed digital circuit substrates; high-speed digital circuit substrates are the hardware foundation of data center servers, high-performance computing systems, and high-speed communication equipment. Since high-speed digital circuits are very sensitive to conductive and magnetic materials in the substrate, they place very stringent requirements on the content of metal impurities in high-purity powders, and expect the content to be infinitely close to zero.

[0003] The analysis results of the high-purity powder production process show that metal impurities will be generated during the crushing, rounding and transportation process; due to the high hardness of the powder itself, a small amount of metal chips will be scraped off the metal container and pipe wall during the above process; these metal chips are usually made of stainless steel and have extremely weak magnetism. Therefore, the characteristics of metal chips in high-purity powder are: small size (1μm~10μm), extremely weak magnetism, and very small quantity, which brings great challenges to the impurity removal process.

[0004] In the early stage of production practice, slurry high gradient magnetic separators based on conventional conductive wires were used in the above impurity removal process. However, since the background magnetic field can only reach 1 Tesla to 1.4 Tesla, the impurity removal effect of the powder in the magnetic field is very limited; therefore, multiple cycles and end detection methods are generally used to ensure that the number of metal chips is reduced to below the allowable value. However, on the one hand, this method itself has low production efficiency, and on the other hand, since metal chips are still generated during the circulation and transportation process, even if the number of cycles is infinitely increased, the number of metal chips cannot be reduced 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 by it with Chinese patent publication number CN117696237A. Since the lifting and lowering time of superconducting magnets is much longer than that of normal conductive magnets, in order to achieve strong magnetic adsorption and weak magnetic regeneration of high-gradient concentrated magnetic media, the magnetic separator in this impurity removal technology refers to the magnetic separation system (Magnetic separation systems) of US Patent Publication No. US5868257A (Application No. US08535021, or WIPO Publication No. WO9426417A1, priority is British Patent Application No. GB9309426, 19930507), which adopts reciprocating tank technology, that is, after the adsorption cycle of the concentrated magnetic medium in the strong magnetic area is completed, it is moved to the weak magnetic area to remove impurities and complete the regeneration of the adsorption function, and so on. In order to achieve the reciprocating motion of the concentrated magnetic medium, the reciprocating tank contains a dummy area of ​​a certain length for magnetic balance; and in order to connect the feed port and discharge port of the reciprocating tank to the feed bin and discharge bin, a rubber hose must be used. This magnetic separator has been applied to the wet magnetic impurity removal process of high-purity powder.

[0006] The high-purity powder wet impurity removal process must use a high-purity fluid medium, such as high-purity water; before entering the impurity removal process, the high-purity powder must be mixed with the fluid medium, and after the impurity removal process, it must be dried to remove the fluid medium. This leads to problems such as high impurity removal costs, long processes, and low production efficiency.

[0007] Compared with the wet impurity removal process, the dry impurity removal process uses dry air as the fluid medium, does not require mixing and drying processes, and has the outstanding advantages of short process and high production efficiency. However, in order to reduce pressure loss, avoid powder sedimentation, and reduce the probability of secondary pollution, pneumatic conveying requires a short conveying distance. In the reciprocating impurity removal magnetic separator, the dummy area for magnetic balance and the hose for connection are indispensable, so the superconducting magnetic separator using the reciprocating tank technology mentioned above is difficult 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 purpose, the first aspect of the present invention provides a piston dry superconducting magnetic separator, comprising a piston-magnetic medium structure 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 structural component capable of reciprocating along the axial direction is installed in the precision tube component;

[0013] A cylindrical magnetic field cavity is provided inside the superconducting magnet;

[0014] A precision tube assembly, comprising a precision tube and end cap assemblies fixed at 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] Driving 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] The precision tube is provided with three groups of inlets and outlets, one group of inlets and outlets includes one inlet and one outlet; the inlets and outlets in the same group are arranged at intervals;

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

[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 discharge air inlet and the second impurity discharge 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 on the precision tube;

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

[0031] A connecting pipe is provided on the Hough ring with a tube, and the connecting pipe 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 zone is provided between the two separation zones of the piston-magnetic medium structural assembly;

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

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

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

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

[0038] The piston flange outside the separation zone is detachably fixed on 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 arranged on the wall surface of the precision tube overlap with the piston flange of the piston-magnetic medium structural assembly in the axial direction;

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

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

[0045] The feed inlet 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 air 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 the control valve;

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

[0051] Step 1, moving and positioning; one of them drives the air inlet and outlet to intake air, and the other drives the air inlet and outlet to exhaust air, so as to stabilize 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 output 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, the magnetic impurities contained in the powder are adsorbed on the magnetic medium, and the remaining powder is discharged to the collection bin as a finished product 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 through the first impurity discharge port along with the air.

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

[0055] Step 3, moving and positioning; close all the air inlets and outlets on the precision tube, connect the high-pressure air source of the driving air inlet and outlet close to the piston-magnetic medium structural component, exhaust the air at the other driving air inlet and outlet, and pneumatically drive the piston-magnetic medium structural component 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 after the high-purity powder to be cleaned is mixed with high-pressure air, it is input into the separation chamber of the magnetic separation area through the feed port, and 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 cleansing 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 row area. The air inlet and outlet of the second impurity row area are opened, and high-pressure air enters the separation chamber in the second impurity row area through the second impurity row 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 through the second impurity row outlet along with the air.

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

[0059] Repeat steps 1 to 4.

[0060] The present invention firstly provides a specific structure of a piston dry superconducting magnetic separator, which consists of a piston-magnetic medium structural component, a precision tube component and a superconducting magnet; the piston-magnetic medium structural component 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 component 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 component is installed in the precision tube component, and performs piston-like reciprocating motion along the axial direction of the precision tube, so that the magnetic medium of the two separation zones is switched between the magnetic separation zone and the impurity removal zone, ultra-strong magnetic adsorption and impurity removal are performed in the magnetic separation zone, and impurities are removed 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, the superconducting magnet remains in a fixed position, and the magnetic field is kept constant when the magnetic separator is working; however, in the present invention, only the magnetic medium reciprocates between the strong magnetic area and the weak magnetic area, and the position of the outer wall of the tank body remains fixed.

[0063] 2. Use dual magnetic medium configuration. When one of the magnetic mediums absorbs metal impurities in the strong magnetic area, the other magnetic medium blows away the absorbed metal impurities in the weak magnetic area. Therefore, the dual magnetic medium configuration has two working positions in one impurity removal cycle. The so-called magnetic medium refers to wires or rods made of soft magnetic materials, which are staggered and stacked at a certain distance from each other to fill the entire cavity.

[0064] 3. The two magnetic media are restrained between two pairs of piston flanges. The piston flanges are covered with sealing rings, usually two in number, to form an oil-free, self-lubricating dynamic sealing interface between the sealing rings and 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 cavity.

[0065] 4. The two pairs of piston flanges that are close to each other are welded to the central axis as a whole, forming a dummy area between the inner wall of the tank body. The central axis 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 axis by bolts or clamps.

[0066] 5. The two flanges far away from each other in the two pairs of piston flanges 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 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 hole of the superconducting magnet and has only a small gap with the inner hole wall. The symmetrical section perpendicular to the axis coincides with the symmetrical section of the superconducting magnet. A hole is punched in the direction parallel to the tangent of the outer circle of the cylinder body at a position beyond the end face of the superconducting magnet and close to the end face. The position of the hole is included in the inner side of the two piston flanges of the separation chamber. When the hole outside one end face of the superconducting magnet is used as the feed port, the hole outside the other end face is used as the discharge port; in order to discharge the material cleanly, the hole and the piston flange overlap 1 to 2 mm in the axial direction. The diameter of the hole is smaller than the thickness of the piston flange.

[0068] 7. At the two weak magnetic area working positions 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 along the axial direction). When the hole at one end is used as an air inlet, the hole at the other end is used as an exhaust and impurity exhaust 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 movement inside the tank body as a whole.

[0070] 9. Both ends of the precision tube tank body are sealed with end covers, using a removable sealing method with a sealing ring. A hole is opened on the end cover, and there is a central boss on the side of the end cover facing the piston flange to limit the stroke 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 on one of the end covers is used as the air inlet, and the hole on the other end cover is used as the exhaust hole, and the gas pressure is used to push the separation chamber to another working area. During the movement of the piston-magnetic medium assembly, the valves on the external pipelines connected to the 6 inlets and outlets on the tank body are all in the closed state.

[0071] 10. A sealing ring is provided on the inlet / outlet of the cylinder body. The sealing ring is coaxial at the inlet / outlet position and has tangential holes of the same diameter. A Huff ring with a tangential tube and a Huff ring without a tangential tube are held outside the sealing ring. The two Huff rings are connected and fixed by bolt fasteners. The tangential tube on the Huff 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 It is a schematic diagram of the overall appearance structure of the piston dry superconducting magnetic separator of the present invention;

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

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

[0075] Figure 4 It 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 It is a front view of the internal structure of the piston dry superconducting magnetic separator in working state 2 of the present invention;

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

[0078] Figure 7 It is a 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 cover assembly of the precision tube assembly of the present invention;

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

[0081] Fig.10 It is a schematic diagram of the assembly of the inlet and outlet of the precision tube assembly of the present invention;

[0082] Fig.11 It is a schematic diagram of the overall structure of the sealing ring of the inlet and outlet of the precision tube assembly of the present invention;

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

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

[0085] Fig.14 for Fig.13 Partial magnification Figure 1 ;

[0086] Fig.15 for Fig.13 Partial 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 implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

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

[0090] The piston dry superconducting magnetic separator of the present invention has an appearance 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 a superconducting wire, 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 , Fig. 9 , a half structure is used for connection and fixation, including an end cover 221 and a half flange (also called 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 surface 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 plurality 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 to connect the inner chamber of the precision tube 21 with the outside.

[0096] A preferred positioning post 226 is provided in 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 to be longer, with both ends far beyond the superconducting magnet 3, and impurity removal areas are formed at both ends. Figure 2 , Figure 3 , Figure 6 ; An inlet and an outlet are respectively provided at a position beyond the end face of the superconducting magnet 3 and close to the end face, so that the precision tube 21 located in the superconducting magnet 3 area serves as a magnetic selection zone 26, whose inlet is a feed port 261 and the outlet is a 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 respectively formed, and the corresponding inlets are a first row impurities air inlet 271 and a second row impurities air inlet 281, and the corresponding outlets are a first row impurities discharge port 272 and a second row 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 device through the inlet and outlet assembly 23, such as Fig.10 , Fig.11 , Fig.12 As shown, the inlet and outlet assembly 23 includes a fixed Huff ring 231, a Huff 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 an obstruction; the fixed Huff ring 231 is paired with the Huff 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 Huff 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 motion airflow.

[0100] The specific structure of piston-magnetic medium structure component 1 can be referred to Fig.13 , Fig.14 , Fig.15 In order to improve the efficiency of magnetic separation and impurity removal, two groups of magnetic concentrating media 14 are preferably provided, which are located at both ends respectively, and the middle is a dummy area; 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, which are respectively fixed 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 preferably the outer wall of the piston flange 13 is provided with a sealing groove, and a piston sealing ring 15 is embedded, so that an oil-free, self-lubricating dynamic sealing interface is formed 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 can be fixed on the central axis 11 of the dummy area in a removable 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, by a threaded structure, and 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 by 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, so as to have two working positions and form two working states, namely working state one and working state two.

[0105] One end of the piston-magnetic medium structure assembly 1 is against 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 row of mixed zones 27 or the second row of mixed zones 28.

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

[0107] When the piston-magnetic medium structural component 1 is axially displaced in the precision tube component 2, high-pressure air is injected through the driving air inlet and outlet 225 on the end cover component 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. Since the positioning column 226 is against the piston flange 13, it can be ensured 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 component 1 to move to 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 another 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 a control valve; wherein 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 air inlet 271 and the second impurity 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, such as Figure 4 The position shown; close the control valve driving the air inlet and outlet 225, so that the position of the piston-magnetic medium structure component 1 is stable.

[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 bin, mixed with the high-pressure air, and then input into the separation chamber 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 mixed 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, 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 chamber located in the first impurity removal zone 27, far 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 chamber of the impurity removal zone, and 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 it is necessary to close its air inlet and outlet, that is, close the second impurity removal air inlet 281 and the second impurity removal outlet 282.

[0115] Step 3, move; after the above step 2 is run for a period of time, a certain amount of magnetic impurities have 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, close all the air inlets and outlets on the precision tube 21, and then 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 magnetic impurities adsorbed on the magnetic medium 14 will fall due to gravity. However, since 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 its 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 magnetic impurities that have not been removed yet, they will be adsorbed onto the magnetic medium 14 because of the magnetic properties of the magnetic medium 14.

[0118] Step 4, working state two; open the control valves of the feed port 261 and the discharge port 262 again, and after the impurities-free high-purity powder is mixed with the 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 impurities-free. The magnetic impurities contained in the powder are adsorbed on the magnetic medium 14, and the pure high-purity powder after impurities-free 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 removal area 27 are closed, and the air inlet and outlet of the second impurity removal area 28 are opened, and high-pressure air is blown into the separation chamber located in the second impurity removal area 28. The airflow blows off the magnetic impurities adsorbed on the magnetic collecting medium 14 and enters the impurity collecting bin through the second impurity removal outlet 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 component 1 is a detachable structure, so as to facilitate the replacement and maintenance of the magnetic medium during the long-term operation of the magnetic separator;

[0124] 3. The six inlet and outlet positions on the precision tube always remain fixed; the raw material bin and the finished product collection bin of the high-purity powder are respectively connected to the inlet and outlet on both sides of the separation chamber located in the strong magnetic area. The installation position of the two bins can be close to the magnetic separator, so that only a shorter connecting pipe is needed. Different from the reciprocating tank connection structure in the prior art, the connecting pipe of the present invention has no moving parts and does not need to use a flexible hose;

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

[0126] 5. In order to reduce the 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 uses the smooth wall surface, and the dynamic sealing interface has the characteristics of oil-free and self-lubricating to avoid grease contamination of high-purity powder;

[0127] 6. A dummy zone of a certain length is set so that the maximum value of the weak magnetic region where the off-field separation chamber is located is less than 50Gs; 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 medium assembly 1 during the reciprocating motion, so as to reduce the peak gas driving force, thereby reducing the peak gas pressure, saving energy consumption of pneumatic components, and increasing 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, so as to form a vortex of air-powder mixed fluid in the separation chamber, increase the probability of powder colliding with the magnetic medium, and thus increase the probability of impurities being adsorbed;

[0129] 8. There is only a small gap between the precision tube 21 and the inner hole wall of the superconducting magnet 3. On the one hand, it is to make the best use 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 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 a closed state in order to keep the pneumatic force acting on the end piston flange continuous and stable.

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

[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 violating 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 structural component capable of reciprocating along the axial direction is installed in the precision tube component; The superconducting magnet has a cylindrical magnetic field cavity; A precision tube assembly, comprising a precision tube and end cap assemblies fixed at 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. Driving 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; The precision tube is provided with three groups of inlets and outlets, one group of inlets and outlets includes one inlet and one outlet; the inlets and outlets in the same group are arranged at intervals; The area where the precision tube is located in the superconducting magnet is the magnetic selection area. The two ends of the precision tube extend beyond the superconducting magnet, forming impurity exclusion areas at both ends. The magnetic selection area and the two impurity exclusion areas are respectively provided with a set of inlets and outlets. The inlets and outlets are respectively located at the two ends of the magnetic selection area or the impurity exclusion area. 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 discharge air inlet and the second impurity discharge 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.

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 on the precision tube; The fixed Hough ring is matched with the Hough ring with tube, which is sleeved outside the sealing ring and connected and fixed by bolts; A connecting pipe is provided on the Hough ring with a tube, and the connecting pipe 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 zone is provided between two separation zones of the piston-magnetic medium structural assembly; A dummy zone central axis is arranged in the dummy zone, and the dummy zone central axis is connected with 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 arranged in the dummy element area, and the magnetic balance ring 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: Further, the central axis of the dummy area is fixed together with two piston flanges close to the dummy area; The center axis of the separation zone is detachably fixed on the piston flange close to the dummy zone, or on the center axis of the dummy zone; The piston flange outside the separation zone is detachably fixed on 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 of 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 arranged on the wall surface of the precision tube overlap with the piston flange of the piston-magnetic medium structural assembly in the axial direction; The axial length dimension of the inlet and outlet is smaller than the thickness dimension of the piston flange.

10. A 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 inlet 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 air 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 the control valve; The working process of dry magnetic separation and impurity removal is as follows: Step 1, moving and positioning; one of them drives the air inlet and outlet to intake air, and the other drives the air inlet and outlet to exhaust air, so as to stabilize 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 output 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, the magnetic impurities contained in the powder are adsorbed on the magnetic medium, and the remaining powder is discharged to the collection bin as a finished product 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 through the first impurity discharge port along with the air. Working state: continuous operation for set time; Step 3, moving and positioning; close all the air inlets and outlets on the precision tube, connect the high-pressure air source of the driving air inlet and outlet close to the piston-magnetic medium structural component, exhaust the air at the other driving air inlet and outlet, and pneumatically drive the piston-magnetic medium structural component 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 after the high-purity powder to be cleaned is mixed with high-pressure air, it is input into the separation chamber of the magnetic separation area through the feed port, and 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 cleansing 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 row area. The air inlet and outlet of the second impurity row area are opened, and high-pressure air enters the separation chamber in the second impurity row area through the second impurity row 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 through the second impurity row outlet along with the air. Working state 2: continuous operation for set time; Repeat steps 1 to 4.

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