A method for screening waste lithium battery materials based on air pressure loading assistance

Abstract

The present invention discloses a method for screening waste lithium battery materials based on air pressure loading assistance. The method relies on the vibration of the filter screen to achieve screening of crushed material particles. The method is characterized in that air pressure is introduced below the filter screen and the air pressure airflow is guided to pass through the filter screen upward, so that particles with a larger specific gravity among the crushed material particles of the same particle size range pass through the filter screen and leak out, while particles with a lighter specific gravity remain above the filter screen and are discharged, thereby achieving screening of different material components. The present invention has the effect of being able to achieve screening of materials of different components, and has higher screening efficiency, better effect, and better stability.

Description

Technical Field

[0001] The invention relates to the technical field of waste lithium battery recycling, and in particular to a waste lithium battery material screening method based on air pressure loading assistance. Background Art

[0002] Lithium-ion batteries have the advantages of high energy density, high voltage, low self-discharge, good cycle performance, safe operation, and are relatively friendly to the natural environment. Therefore, they are widely used in electronic products such as mobile phones, tablets, laptops, and digital cameras. In addition, lithium-ion batteries are widely used in energy storage power systems such as hydropower, thermal power, wind power, and solar power, and are gradually becoming the best choice for electric vehicle power batteries. A large amount of lithium, nickel, cobalt, manganese, copper, iron, aluminum and other metals are used in lithium-ion batteries, and scrapped lithium-ion batteries are rich in valuable metals. In addition, lithium-ion batteries contain fluorine-containing inorganic electrolytes and organic binders. If they are not recycled properly, they will cause serious pollution to the environment. Therefore, the recycling of lithium-ion batteries has important economic and environmental significance.

[0003] The steps usually adopted in the recycling technology of waste lithium-ion batteries are to first disassemble the lithium-ion batteries, separate the shell, electrodes, current collectors and even electrolytes, and then concentrate on processing each part of the materials for recycling. Mechanical crushing and screening methods can separate the positive and negative electrode materials, diaphragms and current collector metal materials such as copper and aluminum of waste lithium-ion batteries.

[0004] In order to better realize the screening and processing of waste lithium-ion battery electrode materials, the applicant has applied for patent CN202010565128.8 for a crushed waste lithium-ion battery electrode material screening device. The device includes a shell, a feed port is provided in the middle of the upper end of the shell, a horizontal screen is installed in the inner cavity of the shell, a vibration device is provided below the screen, and corresponding discharge ports are provided on the shells above and below the screen; the shell includes a straight cylindrical sorting cylinder located at the lower part, and also includes a frustum-shaped top cover located at the upper end, wherein the top cover and the sorting cylinder are detachably connected, the feed port is provided in the middle of the top cover, and the inner wall of the sorting cylinder is provided with a screen installation structure for installing the screen, and the screen installation structure includes a mounting ring horizontally installed on the inner side of the shell, and the inner side of the upper surface of the mounting ring is concave to form a screen installation step, and the screen can be detachably installed in the screen installation step. The invention has the advantages of being able to improve the screening effect of the equipment, extend the service life of the screen, and better improve the efficiency of battery electrode recycling. However, the following defects still exist: 1. The device can well screen out material particles with different particle sizes, but after the battery electrode materials are crushed, they will contain different components such as metal materials, positive and negative electrode materials, and diaphragm materials. These materials with different components are mixed together and cannot be screened apart, which will affect the subsequent recycling and processing. 2. The device uses a circular screen. The material is first poured into the middle of the screen. The screen is screened by the uniform vibration provided by the vibrator. After screening, the material is discharged from one side of the periphery of the screen. In this way, the vibration effect of the edge position of the screen connected to the vibrator is better, and the vibration effect of the middle position is worse, but the material first falls to the middle position where the vibration effect is worse, and then shakes and diffuses from the middle to the surrounding side. Therefore, there are defects such as low screening and discharging efficiency, and poor uniform vibration screening effect. Summary of the invention

[0005] In view of the above-mentioned shortcomings of the prior art, the technical problem to be solved by the present invention is: how to provide a waste lithium battery material screening method based on air pressure loading assistance that can better achieve material screening of different components. The lithium battery in this application mainly refers to a lithium-ion battery for vehicle use.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A method for screening waste lithium battery materials based on air pressure loading assistance. The method relies on filter vibration to achieve screening of broken material particles. It is characterized in that air pressure is introduced below the filter and the air pressure flow is guided to pass through the filter upward, so that among the broken material particles in the same particle size range, particles with larger specific gravity pass through the filter and leak out, while particles with lighter specific gravity remain above the filter and are discharged, thereby achieving screening of different material components.

[0008] In this way, when the waste lithium battery materials or waste lithium battery electrode materials are recycled, after being crushed into particles, they will contain material particles of different components including metal materials, positive and negative electrode materials, and diaphragm materials. Background technology The existing screening device can only realize the classification and screening of material particle size, and cannot realize the screening of material material. The use of this method can further realize the screening of material material, and the components of different materials in the waste lithium batteries can be screened out, which is convenient for subsequent processing. Therefore, this method has the advantages of being simple, efficient, fast, and reliable, and can screen out the different material components of waste lithium batteries to facilitate subsequent recycling and processing.

[0009] Furthermore, the method is implemented by using a waste lithium battery material screening device based on air pressure loading, the waste lithium battery material screening device based on air pressure loading comprises a screening box, a feed port is arranged at the top of the screening box, multiple layers of horizontally arranged screens are arranged at intervals above and below in the screening box, a screen vibration device is also arranged in the screening box and connected to each layer of screen, a discharge barrel is arranged on the screening box on one side of each layer of screen, and an air inlet pipe is also connected to the side wall of the screening box below any screen.

[0010] In this way, the crushed material particles enter the inner cavity of the screening box from the feed port, and the screening is achieved by the vibration of the screen. During screening, the air is taken in by the air intake pipe, so that the air pressure below the screen is relatively large, and the air pressure airflow is guided upward to pass through the filter, so that particles with heavier weight can pass through the filter and leak out, thus achieving the screening of the material. At the same time, due to the characteristics of the waste lithium-ion batteries themselves, a large number of concave polyhedrons or even directly V-shaped granular materials will be generated during the crushing process of particles. This structure is easy to hang on the screen during the screening process and cause blockage. The air pressure is introduced below the screen, and the V-shaped granular materials can be lifted up under the action of air pressure, which can better prevent them from clogging the screen and keep the screening smooth.

[0011] Furthermore, the screen includes a first screen, a second screen and a third screen arranged from top to bottom, a removable aggregate box is horizontally inserted directly below the third screen, a first air outlet pipe is connected on the side wall of the screening box between the first screen and the second screen, a second air outlet pipe is connected on the side wall of the screening box between the second screen and the third screen, and the air inlet pipe is connected on the side wall of the screening box between the third screen and the aggregate box.

[0012] In this way, the air inlet pipe enters the box from the bottom of the third screen, and an upward air flow pressure is formed under the guidance of the air outlet pipe. Then part of the air flow flows out from the second air outlet pipe between the second screen and the third screen to release the pressure, and the remaining air flow pressure continues to pass through the second screen upward, and flows out from the first air outlet pipe between the second screen and the first screen to release the pressure. In this way, there is no upward air flow pressure on the first screen, and the upward air flow pressure from the second screen to the third screen gradually increases. Therefore, after the material enters the first screen, it can be screened normally first, so that the material that meets the particle size requirements leaks from the first screen, and the material with larger particles is discharged from the discharge barrel on the right side of the first screen. Then the material that meets the particle size requirements falls onto the second screen, and is vibrated and screened by the second screen while being subjected to a certain upward air pressure airflow, so that the lighter material (the diaphragm material is the main part) stays above the second screen and finally discharges from the corresponding discharge barrel. The remaining materials fall downward into the third screen, and are vibrated and screened by the third screen while being subjected to a larger upward air pressure flow, so that the lightest materials (mainly positive and negative electrode materials, such as lithium cobalt oxide, ternary materials, graphite materials, etc.) stay above the third screen and are finally discharged from the corresponding discharge barrel. Finally, the remaining heaviest materials (mainly metal materials) pass through the third screen downward and fall into the aggregate box. In this way, the screening of materials with different specific gravities according to different materials can be better completed. At the same time, the device can achieve preliminary screening of the particle size of the material. Therefore, when implemented, it can be directly applied to the screening and recycling of waste lithium battery materials or waste lithium battery electrode materials after crushing, and can also be used in conjunction with the existing screening device described in the background technology. The existing screening device described in the background technology first completes the screening of the particle size requirements, and then enters the device for further processing, which can better meet the screening requirements. In addition, when the device is implemented, the mesh sizes of the three screens are usually set to the same size, but they can also be adjusted to be the same within a certain range on the basis of satisfying the above-mentioned air pressure screening process to better ensure the final screening effect.

[0013] Furthermore, the first air outlet pipe and the second air outlet pipe are both correspondingly provided with flow regulating valves, and a first air pressure sensor is also installed on the side wall of the screening box corresponding to the first air outlet pipe, and the first air pressure sensor and the flow regulating valve on the first air outlet pipe are associated with each other, and a second air pressure sensor is also installed on the side wall of the screening box corresponding to the second air outlet pipe, and the second air pressure sensor and the flow regulating valve on the second air outlet pipe are associated with each other.

[0014] In this way, the air pressure in the corresponding chamber can be detected by the first air pressure sensor and the second air pressure sensor. If the air pressure is too high, the associated flow control valve is adjusted to increase the exhaust flow to reduce the air pressure. In this way, the air pressure control can be better achieved to more reliably ensure the air pressure-assisted filtering and screening effect.

[0015] Furthermore, the air inlet pipe is provided with multiple evenly distributed ones, and the outer end of each air inlet pipe is connected to the air inlet main pipe; the first air outlet pipe is provided with multiple evenly distributed ones, and the outer end of each first air outlet pipe is connected to the first air outlet main pipe; the second air outlet pipe is provided with multiple evenly distributed ones, and the outer end of each second air outlet pipe is connected to the second air outlet main pipe.

[0016] In this way, the air intake and air outlet can be more dispersed and uniform. During implementation, the flow regulating valve can be installed on the first air outlet main pipe and the second air outlet main pipe respectively to reduce the number of installations and facilitate control.

[0017] Furthermore, filter screens are provided at the inlets of the first air outlet pipe and the second air outlet pipe, so as to prevent the materials from being carried out by the outlet air flow.

[0018] Furthermore, the outer ends of the first air outlet pipe and the second air outlet pipe are connected to a bag dust collector, so that dust can be removed better.

[0019] Furthermore, the discharge barrel includes an inclined section inclined outward and downward, the outer end of the inclined section is gathered toward the middle and connected to a downward vertical barrel section, and a discharge switch valve is installed on the vertical barrel section.

[0020] In this way, when the device is used, the discharge switch valve can be closed first to avoid air leakage. After part of the material enters the discharge barrel to form an air flow blockage, the discharge switch valve (with adjustable closing degree) is opened to discharge the material. The material is collected and gathered along the discharge barrel to its outer end to form an air flow blockage and then discharged downward from the vertical barrel section. Therefore, the normal discharge of the material during the screening process can be better guaranteed, and the stability of the air pressure in the cavity can be maintained during the process to ensure the air pressure-assisted screening effect.

[0021] During implementation, a material receiving device is also provided, which includes a material receiving rack, on which three material receiving boxes are arranged along the height direction, and the height of the material receiving boxes corresponds to the height of the corresponding discharge barrel outlet and is used for receiving materials. A roller with a self-locking function is further installed at the lower end of the chassis at the lower part of the material receiving rack to facilitate pushing the material receiving.

[0022] Furthermore, a feeding mechanism is provided at the feed port, and the feeding mechanism includes a feed box, a horizontally arranged cylindrical feed chamber is provided in the feed box, a feed funnel is provided above one end of the cylindrical feed chamber, and the other end is downwardly connected to the feed port, and a feeding screw shaft (referring to a rotating shaft provided with spiral blades matching the inner cavity of the cylindrical feed chamber) is provided in the cylindrical feed chamber, and one end of the feeding screw shaft is connected to the feeding power equipment.

[0023] In this way, feeding by the feeding screw shaft can not only achieve better feeding control, but more importantly, it can achieve feeding sealing, avoiding the pressure release of the air pressure in the screening box cavity from the feeding port, which affects the filtration and screening. At the same time, during the transmission process, the agglomeration of the electrode material can be pressed apart due to extrusion, which is convenient for screening.

[0024] Furthermore, the horizontal cross-section of the screening box and the screen are corresponding rectangles, one end of the screen in the length direction is the discharge end, the discharge end is placed on the screen mounting table on the inner wall of the screening box and connected to the discharge barrel, the other end of the screen in the length direction is the feed end, the feed end of the screen is connected to the screen vibration device and can be driven to vibrate vertically, and the feed port is arranged on the top surface of the screening box above the screen feed end.

[0025] In this way, when the material is fed, it falls from the feed end of the screen onto the screen. The feed end of the screen vibrates at one end, and the material is gradually shaken from the feed end to the other end and gathered to the discharge port for discharge. In this process, the dynamic flow-type screening and discharging are realized, so that the material screening process and the moving process are combined to better improve the screening efficiency. At the same time, in this screening method, the amount of material falling from the feed end of the screen is large, and the corresponding vibration of this end is also large (amplitude). When the material moves from the feed end of the screen to the discharge end, as the material falls off the screen, the amount of material gradually decreases, and the corresponding amplitude of the screen vibration also gradually decreases. Therefore, it can not only better realize dynamic flow-type screening, but also the sieve movement during the material forward process can perfectly match the vibration size. Therefore, the screening effect and screening efficiency can be better improved. In addition, this single-end vibrating screening method also takes into account the characteristics of lithium-ion battery granular materials. Due to the characteristics of lithium-ion batteries themselves, they are prone to form a large number of concave polyhedrons or even V-shaped granular materials when crushed, which can easily hang on the screen and cause blockage. The single-end vibrating screen is more likely to cause the V-shaped granular materials to shake and fall due to unbalanced forces on both sides, thereby better avoiding blockage.

[0026] Furthermore, a long strip-shaped material mixing chamber is arranged perpendicular to the cylindrical feed chamber at a position between the end of the cylindrical feed chamber and the feed port in the feed box, and an outlet is arranged on the lower surface of one end of the cylindrical feed chamber above the feed port and connected to the middle position of the material mixing chamber, and the length direction of the material mixing chamber is arranged along the width direction of the screening box, and a material mixing shaft is arranged in the material mixing chamber along its own length direction, and two groups of opposite material mixing spiral blades are symmetrically arranged on the material mixing shaft, and the feed port is distributed below the material mixing chamber along the length direction of the material mixing chamber; the end of the feed spiral shaft passes through the cylindrical feed chamber and is fixedly installed with a driving bevel gear, the driving bevel gear is located in the transmission chamber inside the feed box and is meshed with a vertically arranged driven bevel gear, the driven bevel gear is coaxially fixed with a driving gear, and a driven gear is meshed downwardly with the driving gear, and the mounting shaft of the driven gear is connected to the end of the material mixing shaft through a synchronous belt.

[0027] In this way, when the feed box is working, the feed screw shaft rotates, driving the materials leaking from the feed funnel to move orderly to the middle of the material mixing chamber. At the same time, the end of the feed screw shaft relies on a pair of meshing bevel gears and a pair of circular gears and a synchronous belt transmission to drive the material mixing shaft to rotate. The material is evenly transported from the middle to both ends by the symmetrically arranged material mixing spiral blades on the material mixing shaft and falls into the feed end of the screen from the feed port below. In this way, the material can better fall into the feed end of the screen along the width direction, which improves the uniformity of the feed. It is more conducive to improving the reliability and efficiency of screen screening.

[0028] Furthermore, the feed opening is narrower in the middle and its width gradually widens toward both sides.

[0029] In this way, because the material in the feed cavity falls from the middle of the mixing cavity into the mixing cavity, it is easier for more material to fall into the middle of the feed port, and by narrowing the width of the middle of the feed port and gradually widening the two ends, the material falling from the feed port can be better distributed more evenly. It is more conducive to improving the reliability and efficiency of the screen screening. In this way, the material can evenly fall to the feed end of the screen along the width direction of the screen at the beginning, and then move from the feed end of the screen to the discharge end after vibration to achieve screening, thus greatly improving the efficiency and reliability of screening.

[0030] Furthermore, the screen vibration device includes a motor located outside the screening box, a toothless gear is installed on the motor output shaft in the vertical direction, only a section of gear teeth is arranged on the outer circumference of the toothless gear, and a transmission gear frame which can move up and down is arranged on the outer frame of the toothless gear, and a rack is arranged on each side of the inner wall of the transmission gear frame, and after the toothless gear rotates to the corresponding direction, the gear teeth on it can mesh with the corresponding rack and drive the transmission gear frame to move up and down, and a driving connecting plate is fixedly connected downwardly to the lower end of the transmission gear frame, and the driving connecting plate is connected to a horizontally arranged horizontal connecting plate, and the horizontal connecting plate horizontally passes through the through-holes on the side wall of the screening box and is fixedly connected to the vertically arranged baffle, a screen fixing platform is installed in the middle of the side of the baffle facing the screen and is connected to the feed end of the screen, and the side of the baffle facing away from the screen is attached to the inner wall of the screening box and can shield the through-holes.

[0031] In this way, the output rotation of the motor drives the missing tooth gear to rotate, and the missing tooth gear and the two racks inside the transmission gear frame are meshed alternately, driving the transmission gear frame to reciprocate up and down (that is, the missing tooth gear disengages and engages with the rack on one side at the same time as the rack on the other side begins to mesh), and then drives the horizontal connecting plate to reciprocate up and down through the driving connecting plate, realizing the single-end vibration of the screen feed end. Therefore, it can transmit greater vibration power, and it is reliable and efficient.

[0032] Furthermore, a horizontal connecting plate mounting hole is provided at one end where the driving connecting plate and the horizontal connecting plate are connected, and the end of the horizontal connecting plate can be assembled in the horizontal connecting plate mounting hole so as to move up and down. When the horizontal connecting plate is in the starting state of movement, the end of the horizontal connecting plate is in contact with the lower surface of the horizontal connecting plate mounting hole and a gap is left between the end of the horizontal connecting plate and the upper surface of the horizontal connecting plate mounting hole; when the horizontal connecting plate moves to the horizontal state of the screen, the middle position of the teeth of the toothless gear is meshed with the middle position of the rack on the corresponding side.

[0033] In this way, when the driving connecting plate moves upward and drives the horizontal connecting plate upward to the top, since there is still a gap between the end of the horizontal connecting plate and the upper surface of the horizontal connecting plate mounting hole, the horizontal connecting plate has space to continue to move upward under the action of inertia. The horizontal connecting plate will break away from the constraint of the driving connecting plate and continue to move upward for a short distance before contacting the upper surface of the horizontal connecting plate mounting hole and being driven to move downward. Therefore, during the vibration process, the upward movement amplitude of the horizontal connecting plate will be greater than the downward movement amplitude. In this way, the material on the screen can be better driven to gradually move from the feed end to the discharge end while screening, realizing assembly line screening.

[0034] Furthermore, a vertically arranged variable amplitude spring is fixedly connected inside the perforation and between the horizontal connecting plate.

[0035] This is because the lithium battery shell and the electrode are both flat structures. After being crushed into particles by the crushing mechanism, unlike the conventional granular materials which are convex polyhedrons, a large number of concave polyhedrons will be generated, and even a large number of particles with direct V-shaped structures will be generated. In this way, during the screening process, such concave polyhedrons and even V-shaped particles are easily attached to the screen, which can easily cause the screen to be blocked. The setting of the variable amplitude spring can cooperate with the interval between the upper surface of the end of the horizontal connecting plate and the mounting hole of the horizontal connecting plate, so that the horizontal connecting plate will produce a small elastic movement of at least one reciprocating cycle under the action of its own inertia and the action of the variable amplitude spring during the short period of time after the upward movement to the release of the constraint. In this way, the horizontal connecting plate will generate a small amplitude variable amplitude vibration when it vibrates upward to the highest point, and then be driven to vibrate downward. In this way, the screen is driven downward by the double amplitude variable vibration, and compared with the single amplitude vibration method, it can better shake off the V-shaped particles attached to the screen, which can greatly improve the screening effect. At the same time, the small amplitude rotation is generated after the large amplitude vibration reaches the highest point, so it can also improve the effect of driving the material on the screen to flow toward the discharge end.

[0036] Furthermore, a pad is detachably fixedly connected to the upper surface of the horizontal connecting plate mounting hole by means of screws. In this way, the thickness of the pad can be easily adjusted to adjust the size of the interval between the end of the horizontal connecting plate and the upper surface of the horizontal connecting plate mounting hole, so that the above process can be adjusted smoothly, and it is also convenient to replace and repair it after the effect deteriorates due to wear.

[0037] Furthermore, a transmission box is arranged outside the screening box, and the toothless gear, the transmission gear frame and the driving connecting plate are located in the transmission box, so that the protection effect of the transmission mechanism can be better improved.

[0038] Furthermore, one end of the feeding screw shaft is connected to the output shaft of the motor, and the motor constitutes the feeding power device. In this way, the three powers of the whole device only need to be driven by one motor, which greatly simplifies the device.

[0039] Furthermore, a supporting leg is provided at the lower end of the outer side of the screening box.

[0040] In summary, the present invention has the effect of being able to achieve the screening of materials with different components, and has higher screening efficiency, better effect and better stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic structural diagram of a waste lithium battery material screening device based on air pressure loading used in the implementation of the present invention.

[0042] Figure 2 for Figure 1 Schematic diagram of the structure of the internal transmission mechanism in the separate feeding mechanism in the top view.

[0043] Figure 3 for Figure 1 Left view of the local structure of the separate transmission gear frame.

[0044] Figure 4 for Figure 1 A magnified schematic diagram of the local structure at point A.

[0045] Figure 5 for Figure 1 Schematic diagram of a separate feed port. DETAILED DESCRIPTION

[0046] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0047] Specific implementation method: A method for screening waste lithium battery materials based on air pressure loading assistance. This method relies on the vibration of the filter to achieve the screening of broken material particles. Its characteristics are that air pressure is introduced under the filter and the air pressure airflow is guided upward through the filter, so that among the broken material particles in the same particle size range, the particles with larger specific gravity pass through the filter and leak out, while the particles with lighter specific gravity remain above the filter and are discharged, thereby achieving screening of different material components.

[0048] In this way, when waste lithium battery materials or waste lithium battery electrode materials are recycled, after being crushed into particles, they will contain material particles of different components including metal materials, positive and negative electrode materials, and diaphragm materials. Background technology The existing screening device can only realize the graded screening of material particle size, and cannot realize the screening of material material. The use of this method can further realize the screening of material material. Relying on the difference in specific gravity, the components of different materials in the waste lithium batteries can be screened out with the help of air pressure and airflow, which is convenient for subsequent processing. Therefore, this method has the advantages of being simple, efficient, fast, and reliable, and can screen out the different material components of waste lithium batteries to facilitate subsequent recycling and processing.

[0049] In this embodiment, the Figure 1-5 A waste lithium battery material screening device based on air pressure loading is shown, and the waste lithium battery material screening device based on air pressure loading includes a screening box 1, a feed port 35 is arranged on the top of the screening box, and multiple layers of horizontally arranged screens 30 are arranged at intervals above and below in the screening box 1. A screen vibration device is also arranged in the screening box and connected to each layer of the screen. A discharge barrel is arranged on the screening box on one side of each layer of the screen, and an air inlet pipe 34 is also connected to the side wall of the screening box located below any screen.

[0050] In this way, the crushed material particles enter the inner cavity of the screening box from the feed port, and the screening is achieved by the vibration of the screen. During screening, the air is taken in by the air intake pipe, so that the air pressure below the screen is relatively large, and the air pressure airflow is guided upward to pass through the filter, so that particles with heavier weight can pass through the filter and leak out, thus achieving the screening of the material. At the same time, due to the characteristics of the waste lithium-ion batteries themselves, a large number of concave polyhedrons or even directly V-shaped granular materials will be generated during the crushing process of particles. This structure is easy to hang on the screen during the screening process and cause blockage. The air pressure is introduced below the screen, and the V-shaped granular materials can be lifted up under the action of air pressure, which can better prevent them from clogging the screen and keep the screening smooth.

[0051] Among them, the screen 30 includes a first screen, a second screen and a third screen arranged from top to bottom, a removable aggregate box 15 is horizontally inserted directly below the third screen, a first air outlet pipe 32 is connected on the side wall of the screening box between the first screen and the second screen, a second air outlet pipe 33 is connected on the side wall of the screening box between the second screen and the third screen, and the air inlet pipe 34 is connected on the side wall of the screening box between the third screen and the aggregate box.

[0052] In this way, the air inlet pipe enters the box from the bottom of the third screen, and an upward air flow pressure is formed under the guidance of the air outlet pipe. Then part of the air flow flows out from the second air outlet pipe between the second screen and the third screen to release the pressure, and the remaining air flow pressure continues to pass through the second screen upward, and flows out from the first air outlet pipe between the second screen and the first screen to release the pressure. In this way, there is no upward air flow pressure on the first screen, and the upward air flow pressure from the second screen to the third screen gradually increases. Therefore, after the material enters the first screen, it can be screened normally first, so that the material that meets the particle size requirements leaks from the first screen, and the material with larger particles is discharged from the discharge barrel on the right side of the first screen. Then the material that meets the particle size requirements falls onto the second screen, and is vibrated and screened by the second screen while being subjected to a certain upward air pressure airflow, so that the lighter material (the diaphragm material is the main part) stays above the second screen and finally discharges from the corresponding discharge barrel. The remaining materials fall downward into the third screen, and are vibrated and screened by the third screen while being subjected to a larger upward air pressure flow, so that the lightest materials (mainly positive and negative electrode materials, such as lithium cobalt oxide, ternary materials, graphite materials, etc.) stay above the third screen and are finally discharged from the corresponding discharge barrel. Finally, the remaining heaviest materials (mainly metal materials) pass through the third screen downward and fall into the aggregate box. In this way, the screening of materials with different specific gravities according to different materials can be better completed. At the same time, the device can achieve preliminary screening of the particle size of the material. Therefore, when implemented, it can be directly applied to the screening and recycling of waste lithium battery materials or waste lithium battery electrode materials after crushing, and can also be used in conjunction with the existing screening device described in the background technology. The existing screening device described in the background technology first completes the screening of the particle size requirements, and then enters the device for further processing, which can better meet the screening requirements. In addition, when the device is implemented, the mesh sizes of the three screens are usually set to the same size, but they can also be adjusted to be the same within a certain range on the basis of satisfying the above-mentioned air pressure screening process to better ensure the final screening effect.

[0053] Among them, the first air outlet pipe and the second air outlet pipe are both correspondingly provided with flow regulating valves, and a first air pressure sensor (not shown in the figure) is also installed on the side wall of the screening box corresponding to the first air outlet pipe, and the first air pressure sensor and the flow regulating valve (not shown in the figure) on the first air outlet pipe are associated with each other, and a second air pressure sensor (not shown in the figure) is also installed on the side wall of the screening box corresponding to the second air outlet pipe, and the second air pressure sensor and the flow regulating valve (not shown in the figure) on the second air outlet pipe are associated with each other.

[0054] In this way, the air pressure in the corresponding chamber can be detected by the first air pressure sensor and the second air pressure sensor. If the air pressure is too high, the associated flow control valve is adjusted to increase the exhaust flow to reduce the air pressure. In this way, the air pressure control can be better achieved to more reliably ensure the air pressure-assisted filtering and screening effect.

[0055] Among them, the air inlet pipe 34 is provided with multiple evenly distributed ones, and the outer end of each air inlet pipe is connected to the air inlet main pipe (not shown in the figure); the first air outlet pipe is provided with multiple evenly distributed ones, and the outer end of each first air outlet pipe is connected to the first air outlet main pipe (not shown in the figure); the second air outlet pipe is provided with multiple evenly distributed ones, and the outer end of each second air outlet pipe is connected to the second air outlet main pipe (not shown in the figure).

[0056] In this way, the air intake and air outlet can be more dispersed and uniform. During implementation, the flow regulating valve can be installed on the first air outlet main pipe and the second air outlet main pipe respectively to reduce the number of installations and facilitate control.

[0057] Wherein, filter screens are also provided at the entrances of the first air outlet pipe 32 and the second air outlet pipe 33. This can prevent the material from being carried out by the outlet air flow.

[0058] The outer ends of the first air outlet pipe and the second air outlet pipe are connected to a bag dust collector (not shown in the figure), so that dust can be removed better.

[0059] The discharge barrel includes an inclined section 20 inclined outward and downward, the outer end of the inclined section 20 is gathered toward the middle and connected to a downward vertical cylinder section 24, and a discharge switch valve 25 is installed on the vertical cylinder section.

[0060] In this way, when the device is used, the discharge switch valve can be closed first to avoid air leakage. After part of the material enters the discharge barrel to form an air flow blockage, the discharge switch valve (with adjustable closing degree) is opened to discharge the material. The material is collected and gathered along the discharge barrel to its outer end to form an air flow blockage and then discharged downward from the vertical barrel section. Therefore, the normal discharge of the material during the screening process can be better guaranteed, and the stability of the air pressure in the cavity can be maintained during the process to ensure the air pressure-assisted screening effect.

[0061] During implementation, a material receiving device is also provided, which includes a material receiving frame 22, on which three material receiving boxes 23 are arranged along the height direction, and the height of the material receiving boxes 23 corresponds to the height of the corresponding discharge barrel outlet and is used for receiving materials. A roller 28 with a self-locking function is further installed at the lower end of the chassis 21 at the lower part of the material receiving frame to facilitate the pushing of material receiving.

[0062] Among them, a feeding mechanism is arranged at the feed port, and the feeding mechanism includes a feed box 16, wherein a horizontally arranged cylindrical feed cavity is provided in the feed box, a feed funnel 19 is arranged above one end of the cylindrical feed cavity, and the other end is downwardly connected to the feed port, and a feed screw shaft 17 (referring to a rotating shaft provided with spiral blades matching the inner cavity of the cylindrical feed cavity) is arranged in the cylindrical feed cavity, and one end of the feed screw shaft is connected to the feeding power equipment.

[0063] In this way, feeding by the feeding screw shaft can not only achieve better feeding control, but more importantly, it can achieve feeding sealing, avoiding the pressure release of the air pressure in the screening box cavity from the feeding port, which affects the filtration and screening. At the same time, during the transmission process, the agglomeration of the electrode material can be pressed apart due to extrusion, which is convenient for screening.

[0064] Among them, the horizontal cross-section of the screening box 1 and the screen 30 are corresponding rectangles, one end of the screen in the length direction is the discharge end, the discharge end is placed on the screen mounting table on the inner wall of the screening box and connected to the discharge barrel, and the other end of the screen in the length direction is the feed end, the feed end of the screen 30 is connected to the screen vibration device and can be driven to vibrate vertically, and the feed port is arranged on the top surface of the screening box above the screen feed end.

[0065] In this way, when the material is fed, it falls from the feed end of the screen onto the screen. The feed end of the screen vibrates at one end, and the material is gradually shaken from the feed end to the other end and gathered to the discharge port for discharge. In this process, the dynamic flow-type screening and discharging are realized, so that the material screening process and the moving process are combined to better improve the screening efficiency. At the same time, in this screening method, the amount of material falling from the feed end of the screen is large, and the corresponding vibration of this end is also large (amplitude). When the material moves from the feed end of the screen to the discharge end, as the material falls off the screen, the amount of material gradually decreases, and the corresponding amplitude of the screen vibration also gradually decreases. Therefore, it can not only better realize dynamic flow-type screening, but also the sieve movement during the material forward process can perfectly match the vibration size. Therefore, the screening effect and screening efficiency can be better improved. In addition, this single-end vibrating screening method also takes into account the characteristics of lithium-ion battery granular materials. Due to the characteristics of lithium-ion batteries themselves, they are prone to form a large number of concave polyhedrons or even V-shaped granular materials when crushed, which can easily hang on the screen and cause blockage. The single-end vibrating screen is more likely to cause the V-shaped granular materials to shake and fall due to unbalanced forces on both sides, thereby better avoiding blockage.

[0066] Among them, a long strip-shaped material mixing chamber is arranged in the feed box 16 at a position between the end of the cylindrical feed chamber and the feed port, and is perpendicular to the cylindrical feed chamber. The cylindrical feed chamber is located at one end above the feed port, and an outlet is arranged on the lower surface thereof, which is connected to the middle position of the material mixing chamber. The length direction of the material mixing chamber is arranged along the width direction of the screening box. A material mixing shaft is arranged in the material mixing chamber along its own length direction, and two groups of opposite material mixing spiral blades 26 are symmetrically arranged on the material mixing shaft. The feed port is distributed below the material mixing chamber along the length direction of the material mixing chamber; the end of the material mixing spiral shaft passes through the cylindrical feed chamber and is fixedly installed with a driving bevel gear 18, the driving bevel gear is located in the transmission chamber inside the feed box and is meshed with a vertically arranged driven bevel gear 13, the driven bevel gear 13 is coaxially fixed with a driving gear 14, the driving gear 14 is meshed with a driven gear 29 downwardly, and the mounting shaft of the driven gear 29 is connected to the end of the material mixing shaft through a synchronous belt 31.

[0067] In this way, when the feed box is working, the feed screw shaft rotates, driving the materials leaking from the feed funnel to move orderly to the middle of the material mixing chamber. At the same time, the end of the feed screw shaft relies on a pair of meshing bevel gears and a pair of circular gears and a synchronous belt transmission to drive the material mixing shaft to rotate. The material is evenly transported from the middle to both ends by the symmetrically arranged material mixing spiral blades on the material mixing shaft and falls into the feed end of the screen from the feed port below. In this way, the material can better fall into the feed end of the screen along the width direction, which improves the uniformity of the feed. It is more conducive to improving the reliability and efficiency of screen screening.

[0068] The feed opening is narrow in the middle and its width gradually widens toward both sides.

[0069] In this way, because the material in the feed cavity falls from the middle of the mixing cavity into the mixing cavity, it is easier for more material to fall into the middle of the feed port, and by narrowing the width of the middle of the feed port and gradually widening the two ends, the material falling from the feed port can be better distributed more evenly. It is more conducive to improving the reliability and efficiency of the screen screening. In this way, the material can evenly fall to the feed end of the screen along the width direction of the screen at the beginning, and then move from the feed end of the screen to the discharge end after vibration to achieve screening, thus greatly improving the efficiency and reliability of screening.

[0070] Wherein, the screen vibration device includes a motor 9 located outside the screening box, and a toothless gear 10 is installed on the motor output shaft in the vertical direction. Only a section of gear teeth is arranged on the outer periphery of the toothless gear. The outer frame of the toothless gear 10 is provided with a transmission gear frame 12 which can move up and down, and a rack is arranged on each side of the inner wall of the transmission gear frame 12. After the toothless gear rotates to the corresponding direction, the gear teeth on it can mesh with the corresponding rack and drive the transmission gear frame to move up and down. The lower end of the transmission gear frame is fixedly connected downwardly with a driving connecting plate 8, and the driving connecting plate 8 is connected to a horizontally arranged horizontal connecting plate 3. The horizontal connecting plate 3 horizontally passes through the through-hole 2 on the side wall of the screening box and is fixedly connected to the vertically arranged baffle 4. A screen fixing platform 6 is installed in the middle of the side of the baffle 4 facing the screen and is connected to the feeding end of the screen 30. The side of the baffle facing away from the screen is attached to the inner wall of the screening box and can shield the through-hole.

[0071] In this way, the output rotation of the motor drives the missing tooth gear to rotate, and the missing tooth gear and the two racks inside the transmission gear frame are meshed alternately, driving the transmission gear frame to reciprocate up and down (that is, the missing tooth gear disengages and engages with the rack on one side at the same time as the rack on the other side begins to mesh), and then drives the horizontal connecting plate to reciprocate up and down through the driving connecting plate, realizing the single-end vibration of the screen feed end. Therefore, it can transmit greater vibration power, and it is reliable and efficient.

[0072] Among them, a horizontal connecting plate mounting hole 11 is provided at one end where the driving connecting plate and the horizontal connecting plate are connected, and the end of the horizontal connecting plate 3 can be assembled in the horizontal connecting plate mounting hole 11 so as to move up and down. When the horizontal connecting plate 3 is in the initial state of movement, the end of the horizontal connecting plate is in contact with the lower surface of the horizontal connecting plate mounting hole and a gap is left between the end of the horizontal connecting plate and the upper surface of the horizontal connecting plate mounting hole 11; when the horizontal connecting plate 3 moves to the horizontal state of the screen, the middle position of the gear teeth of the toothless gear is meshed with the middle position of the rack on the corresponding side.

[0073] In this way, when the driving connecting plate moves upward and drives the horizontal connecting plate upward to the top, since there is still a gap between the end of the horizontal connecting plate and the upper surface of the horizontal connecting plate mounting hole, the horizontal connecting plate has space to continue to move upward under the action of inertia. The horizontal connecting plate will break away from the constraint of the driving connecting plate and continue to move upward for a short distance before contacting the upper surface of the horizontal connecting plate mounting hole and being driven to move downward. Therefore, during the vibration process, the upward movement amplitude of the horizontal connecting plate will be greater than the downward movement amplitude. In this way, the material on the screen can be better driven to gradually move from the feed end to the discharge end while screening, realizing assembly line screening.

[0074] A vertically arranged variable amplitude spring 5 is also fixedly connected in the through hole and between the horizontal connecting plate.

[0075] This is because the lithium battery shell and the electrode are both flat structures. After being crushed into particles by the crushing mechanism, unlike the conventional granular materials which are convex polyhedrons, a large number of concave polyhedrons will be generated, and even a large number of particles with direct V-shaped structures will be generated. In this way, during the screening process, such concave polyhedrons and even V-shaped particles are easily attached to the screen, which can easily cause the screen to be blocked. The setting of the variable amplitude spring can cooperate with the interval between the upper surface of the end of the horizontal connecting plate and the mounting hole of the horizontal connecting plate, so that the horizontal connecting plate will produce a small elastic movement of at least one reciprocating cycle under the action of its own inertia and the action of the variable amplitude spring during the short period of time after the upward movement to the release of the constraint. In this way, the horizontal connecting plate will generate a small amplitude variable amplitude vibration when it vibrates upward to the highest point, and then be driven to vibrate downward. In this way, the screen is driven downward by the double amplitude variable vibration, and compared with the single amplitude vibration method, it can better shake off the V-shaped particles attached to the screen, which can greatly improve the screening effect. At the same time, the small amplitude rotation is generated after the large amplitude vibration reaches the highest point, so it can also improve the effect of driving the material on the screen to flow toward the discharge end.

[0076] Among them, a pad is detachably fixedly connected to the upper surface of the horizontal connecting plate installation hole by means of screws. In this way, the thickness of the pad can be easily adjusted to adjust the size of the interval between the end of the horizontal connecting plate and the upper surface of the horizontal connecting plate installation hole, so that the above process can be adjusted smoothly, and it is also convenient to replace and repair it after the effect deteriorates due to wear.

[0077] Wherein, a transmission box 7 is arranged outside the screening box, and the toothless gear, the transmission gear frame and the driving connecting plate are located in the transmission box. This can better improve the protection effect of the transmission mechanism.

[0078] Among them, one end of the feeding screw shaft is connected to the output shaft of the motor, and the motor constitutes the feeding power device. In this way, the three powers of the whole device only need to be driven by one motor, which greatly simplifies the equipment.

[0079] Among them, a supporting leg 27 is arranged at the lower end of the outer side of the screening box.

Claims

1. A method for screening waste lithium battery materials based on air pressure loading assistance, the method relies on filter vibration to achieve screening of crushed material particles, characterized in that: Air pressure is introduced under the filter and the air pressure flow is guided upward through the filter, so that the particles with larger specific gravity in the crushed material particles of the same particle size range pass through the filter and leak out, while the particles with lighter specific gravity remain above the filter and are discharged, thus achieving the screening of different material components; The method is implemented by using a waste lithium battery material screening device based on air pressure loading, the waste lithium battery material screening device based on air pressure loading comprises a screening box, a feeding port is arranged at the top of the screening box, multiple layers of horizontally arranged screens are arranged at intervals above and below in the screening box, a screen vibration device is also arranged in the screening box and connected to each layer of screens, a discharge cylinder is arranged on the screening box on one side of each layer of screens, and an air inlet pipe is also connected to the side wall of the screening box below any screen; The screen comprises a first screen, a second screen and a third screen arranged from top to bottom, a removable aggregate box is horizontally inserted and arranged directly below the third screen, a first air outlet pipe is connected on the side wall of the screening box between the first screen and the second screen, a second air outlet pipe is connected on the side wall of the screening box between the second screen and the third screen, and the air inlet pipe is connected on the side wall of the screening box between the third screen and the aggregate box; the air inlet pipe draws air into the box from below the third screen, and an upward air flow pressure is formed under the guidance of the air outlet pipe, and then part of the air flow flows out from the second outlet pipe between the second screen and the third screen to release the pressure, and the remaining part of the air flow pressure continues to pass through the second screen upward, and flows out from the first outlet pipe between the second screen and the first screen to release the pressure; so that there is no upward air flow pressure on the first screen, while the upward air flow pressure from the second screen to the third screen gradually increases; Filter screens are also provided at the inlets of the first air outlet pipe and the second air outlet pipe.

2. The method for screening waste lithium battery materials based on air pressure loading assistance according to claim 1, characterized in that: The first air outlet pipe and the second air outlet pipe are both correspondingly provided with flow regulating valves. A first air pressure sensor is also installed on the side wall of the screening box corresponding to the first air outlet pipe. The first air pressure sensor and the flow regulating valve on the first air outlet pipe are associated with each other. A second air pressure sensor is also installed on the side wall of the screening box corresponding to the second air outlet pipe. The second air pressure sensor and the flow regulating valve on the second air outlet pipe are associated with each other.

3. The method for screening waste lithium battery materials based on air pressure loading assistance according to claim 1, characterized in that: The air inlet pipes are provided with multiple evenly distributed ones, and the outer end of each air inlet pipe is connected to the air inlet main pipe; the first air outlet pipes are provided with multiple evenly distributed ones, and the outer end of each first air outlet pipe is connected to the first air outlet main pipe; the second air outlet pipes are provided with multiple evenly distributed ones, and the outer end of each second air outlet pipe is connected to the second air outlet main pipe; The outer ends of the first air outlet pipe and the second air outlet pipe are connected to the bag filter.

4. The method for screening waste lithium battery materials based on air pressure loading assistance according to claim 1, characterized in that: The discharging barrel comprises an inclined section inclined outward and downward, the outer end of the inclined section is gathered toward the middle and connected with a downward vertical barrel section, and a discharging switch valve is installed on the vertical barrel section.

5. The method for screening waste lithium battery materials based on air pressure loading assistance according to claim 1, characterized in that: A feeding mechanism is provided at the feed port, and the feeding mechanism includes a feed box, a horizontally arranged cylindrical feed chamber is provided in the feed box, a feed funnel is provided above one end of the cylindrical feed chamber, and the other end is downwardly connected to the feed port, a feed screw shaft is provided in the cylindrical feed chamber, and one end of the feed screw shaft is connected to the feeding power equipment.

6. The method for screening waste lithium battery materials based on air pressure loading assistance according to claim 5, characterized in that: The horizontal cross-section of the screening box and the screen are in corresponding rectangular shapes. One end of the screen in the length direction is a discharge end, which is placed on a screen mounting table on the inner wall of the screening box and connected to a discharge cylinder. The other end of the screen in the length direction is a feed end, which is connected to a screen vibration device and can be driven to vibrate vertically, and the feed port is arranged on the top surface of the screening box above the screen feed end. The feed box is located between the end of the cylindrical feed chamber and the feed port, and a long strip-shaped material mixing chamber is arranged perpendicular to the cylindrical feed chamber. The lower surface of the end of the cylindrical feed chamber above the feed port is provided with an outlet connected to the middle position of the material mixing chamber. The length direction of the material mixing chamber is arranged along the width direction of the screening box. A material mixing shaft is arranged in the material mixing chamber along its own length direction, and two groups of opposite material mixing spiral blades are symmetrically arranged on the material mixing shaft. The feed port is distributed below the material mixing chamber along the length direction of the material mixing chamber; the end of the feed spiral shaft passes through the cylindrical feed chamber and is fixedly installed with a driving bevel gear, the driving bevel gear is located in the transmission chamber inside the feed box and is meshed with a vertically arranged driven bevel gear, the driven bevel gear is coaxially fixed with a driving gear, and a driven gear is meshed downwardly with the driving gear, and the mounting shaft of the driven gear is connected to the end of the material mixing shaft through a synchronous belt.

7. The method for screening waste lithium battery materials based on air pressure loading assistance according to claim 1, characterized in that: The screen vibration device includes a motor located outside the screening box, a toothless gear is installed on the motor output shaft in the vertical direction, only a section of gear teeth is arranged on the outer circumference of the toothless gear, a transmission gear frame which can move up and down is arranged on the outer frame of the toothless gear, a rack is arranged on each side of the inner wall of the transmission gear frame, after the toothless gear rotates to the corresponding direction, the gear teeth on it can mesh with the corresponding rack and drive the transmission gear frame to move up and down, a driving connecting plate is fixedly connected downwardly to the lower end of the transmission gear frame, the driving connecting plate is connected to a horizontally arranged horizontal connecting plate, the horizontal connecting plate horizontally passes through the through-holes on the side wall of the screening box and is fixedly connected to the vertically arranged baffle, a screen fixing platform is installed in the middle of the side of the baffle facing the screen and is connected to the feed end of the screen, the side of the baffle facing away from the screen is attached to the inner wall of the screening box and can shield the through-holes.

8. The method for screening waste lithium battery materials based on air pressure loading assistance according to claim 7, characterized in that: A horizontal connecting plate mounting hole is provided at one end where the driving connecting plate and the horizontal connecting plate are connected. The end of the horizontal connecting plate can be assembled in the horizontal connecting plate mounting hole so as to move up and down. When the horizontal connecting plate is in the initial state of movement, the end of the horizontal connecting plate is in contact with the lower surface of the horizontal connecting plate mounting hole and a gap is left between the end of the horizontal connecting plate and the upper surface of the horizontal connecting plate mounting hole. When the horizontal connecting plate moves to the horizontal state of the screen, the middle position of the gear teeth of the toothless gear meshes with the middle position of the rack on the corresponding side. A vertically arranged variable amplitude spring is also fixedly connected in the perforation and between the horizontal connecting plate; A pad is detachably fixedly connected to the upper surface of the mounting hole of the horizontal connecting plate by means of screws; A transmission box is arranged outside the screening box, and the toothless gear, the transmission gear frame and the driving connecting plate are located in the transmission box.

Images