A lithium iron phosphate positive electrode material supercritical water oxidation repair process and a repair device

Abstract

This invention relates to the field of waste battery repair technology, and discloses a supercritical water oxidation repair process and device for lithium iron phosphate cathode materials. The device includes a base, with a flotation tank fixed to the top of the base. Two isolation plates are fixed to the inside of the flotation tank on both sides, with the middle portion of the two isolation plates serving as a feed trough, and the two sides inside the flotation tank serving as flotation cells. A rotating shaft is rotatably connected inside the isolation plates. This supercritical water oxidation repair process and device for lithium iron phosphate cathode materials uses a foam-aggregating plate to gather and scrape away foam, and filters the flotation liquid contained in the foam through filter holes, reducing the probability of the flotation liquid being carried away and scraped away by the foam. This ensures the concentration of the lithium iron phosphate cathode material slurry flotation liquid in the flotation cells. Simultaneously, a scraper and rake teeth remove the scraper and foam-aggregating plate, preventing the probability of foam re-entering the flotation cells, thereby improving the quality and efficiency of lithium iron phosphate cathode material slurry purification.

Description

Technical Field

[0001] This invention relates to the field of waste battery repair technology, specifically to a supercritical water oxidation repair process and device for lithium iron phosphate cathode materials. Background Technology

[0002] The supercritical water oxidation repair process for lithium iron phosphate cathode materials is an advanced technology that utilizes the special physicochemical properties of supercritical water to efficiently repair and regenerate spent lithium iron phosphate battery cathode materials. Its core is to restore the electrochemical performance of failed cathode materials through a specific high-temperature and high-pressure reaction environment.

[0003] When using supercritical water oxidation remediation technology to repair lithium iron phosphate cathode materials, core steps such as disassembly and sorting, supercritical reaction, purification and drying, and high-temperature treatment are involved. In the purification and drying step, flotation machines or plate and frame filter presses are usually used for purification, and vacuum drying ovens are used for drying. When using flotation machines for purification, the filter material (solid powder) obtained after supercritical reaction is mixed with clean water and poured into the slurry tank of the flotation machine to prepare a slurry with a mass concentration of 10%-15%. Then, the agitator is run to stir the slurry, followed by aeration, which allows the bubbles to adsorb impurities in the slurry and float to the surface of the slurry to form a foam layer. The foam is then scraped off and collected by a foam scraper, so that the hydrophilic lithium iron phosphate particles remain in the slurry. However, existing foam scrapers typically use flat plates. When scraping off foam, they also scrape off flotation liquid. The flotation liquid contains chemical agents such as collectors and frothers. When the scraper carries too much flotation liquid, it will cause the concentration of the reagents in the flotation cell to decrease, ultimately affecting the efficiency and quality of the purification of lithium iron phosphate cathode materials. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a supercritical water oxidation repair device for lithium iron phosphate cathode materials, which solves the problems mentioned in the background section.

[0005] The present invention provides the following technical solution: a supercritical water oxidation remediation device for lithium iron phosphate cathode material, comprising a base, a flotation box fixed on the top of the base, and isolation plates fixed on both sides inside the flotation box, wherein the middle part of the two isolation plates serves as a feed trough, and the two sides inside the flotation box serve as flotation tanks, and a rotating shaft is rotatably connected inside the isolation plate, one end of the rotating shaft passing through the flotation box; The surfaces on both sides of the rotating shaft are fixed with sleeves, and two scrapers are symmetrically fixed on the surface of the sleeves. An arc-shaped rod is fixed at the end of the scraper away from the sleeve, and a bubble-forming plate is fixed between every two adjacent arc-shaped rods. Filter holes are opened on the surface of the arc-shaped rod. Both partition plates have a sliding frame fixed to their surfaces. A secondary scraper is slidably connected inside the sliding frame. A first spring is fixed to one end of the secondary scraper. One end of the first spring is fixed to the inner wall of the sliding frame. A scraping port is opened at the end of the secondary scraper away from the first spring. Rake teeth are fixed to the bottom of the scraping port. A discharge trough is opened at the bottom of the secondary scraper.

[0006] Optionally, a reagent dosing system is fixed to one end of the top of the base, a slurry pretreatment system is fixed to one side of the base, a stirring vessel is fixed to the surface of the slurry pretreatment system, a stirring and aeration system is fixed to the side of the top of the base near the flotation tank, and a control cabinet is fixed to the side of the top of the base away from the reagent dosing system.

[0007] Optionally, a motor is fixed to the top of the base near the control cabinet, and the output shaft of the motor is driven by a belt, one end of which is driven by a rotating shaft.

[0008] Optionally, a collection tank is fixed to the surface of the flotation box on the side away from the slurry pretreatment system.

[0009] Optionally, a cylinder is fixed to the surface of the collection tank, and a push rod is fixed to the output shaft of the cylinder. The push rod is slidably connected to the flotation tank. A first connector is fixed to one end of the push rod inside the flotation tank, and a second connector is fixed to the end of the first connector away from the push rod. A material feeding plate is hinged to the end of the second connector away from the first connector.

[0010] Optionally, limit rods are fixed on both sides of the inner wall of the second connector, and a flow stabilizing rod is fixed between the two limit rods.

[0011] Optionally, a sliding groove is provided inside one side of the collection groove, and a limiting groove is provided on the side of the sliding groove away from the collection groove. A sliding plate is slidably connected inside the sliding groove, and a limiting plate is slidably connected inside the limiting groove. The sliding plate is fixed to the limiting plate. A guide plate is fixed to the top of the sliding plate, and a sealing plate is fixed to one side of the top of the guide plate. An embedded groove is provided on the side of the sliding groove near the collection groove. A second spring is fixed inside the embedded groove, and one end of the second spring is fixed to the sliding plate.

[0012] Optionally, a third connector is fixed to one end of the push rod near the cylinder, and the movement trajectory of the third connector intersects with the sliding plate.

[0013] Optionally, a first limiting frame is fixed to the surface of the isolation plate, a sealing plate is slidably connected inside the first limiting frame, a second limiting frame is fixed above the first limiting frame on the surface of the isolation plate, a lead screw is threaded inside the second limiting frame, the bottom of the lead screw is rotatably connected to the sealing plate, and a feed port is opened below the first limiting frame on the surface of the isolation plate.

[0014] A supercritical water oxidation remediation process for lithium iron phosphate cathode materials, using the aforementioned supercritical water oxidation remediation device for lithium iron phosphate cathode materials, includes the following steps: A1: The lithium iron phosphate cathode material is fed into the flotation cell through the feed port. The stirring and aeration system and motor are started through the control cabinet. The stirring and aeration system stirs and aerates the lithium iron phosphate cathode material in the flotation cell. The motor drives the belt-driven shaft to rotate, and the shaft drives the scraper to scrape off the foam on the surface of the lithium iron phosphate cathode material. A2: When the scraper enters the surface of the lithium iron phosphate cathode material mixture, the foam is gathered and scraped off by the foam-aggregating plate. At the same time, the liquid around the gathered foam is filtered through the filter holes, so that the foam reduces the entrainment of liquid by the foam when scraping off the foam. In the subsequent flipping process, the foam adhering to the scraper surface is scraped off by the secondary scraper and collected into the collection tank. A3: Control the cylinder to repeatedly push out and return, so that the cylinder drives the push rod to move repeatedly, and the push rod drives the first connector and the second connector to move repeatedly in the lithium iron phosphate cathode material mixture. During the displacement process, the second connector is subjected to liquid resistance and repeatedly opens and closes. The foam on the side of the mixture away from the scraper is pushed to the bottom of the scraper through the pusher. A4: During the process of the feeding plate pushing the foam to the bottom of the scraper, the pushing rod drives the third connecting piece to push the sliding plate, which causes the sliding plate to move the guide plate and the sealing plate, so that the sealing plate releases the blockage of the flotation box outlet, and the scraper smoothly scrapes the foam into the inside of the collection tank.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The supercritical water oxidation remediation process and device for lithium iron phosphate cathode material uses a foam-aggregating plate to gather and scrape away foam, and filters the flotation liquor contained in the foam through filter holes, reducing the probability of the flotation liquor being carried away and scraped away by the foam, thus ensuring the concentration of the lithium iron phosphate cathode material slurry flotation liquor in the flotation cell. At the same time, the scraper and rake teeth remove the scraper and foam-aggregating plate, avoiding the probability of foam re-entering the flotation cell, thereby improving the quality and efficiency of lithium iron phosphate cathode material slurry purification.

[0016] 2. The supercritical water oxidation repair process and device for lithium iron phosphate cathode material uses a cylinder to drive a push rod and a first connector to move toward the collection tank, which in turn causes the second connector to drive a material-pushing plate to move toward the collection tank. During the movement, the material-pushing plate is flipped to a state perpendicular to the slurry surface due to the resistance of the slurry fluid, and pushes the foam on the slurry surface to the bottom of the scraper, thereby improving the efficiency of the scraper in removing foam and thus improving the purification efficiency. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a side view of the structure of the present invention; Figure 3 This is a cross-sectional view of the flotation tank of the present invention; Figure 4 This is a schematic diagram of the structure of the polystyrene foam board of the present invention; Figure 5 This is a cross-sectional view of the flotation box collection tank of the present invention; Figure 6 This is a cross-sectional view of the collection tank of the present invention; Figure 7 This is a schematic diagram of the limiting rod and flow stabilizing rod of the present invention; Figure 8 This is a schematic diagram of the secondary scraper structure of the present invention; Figure 9 for Figure 6 A magnified view of a portion of point A in the middle.

[0018] In the diagram: 1. Base; 11. Reagent dosing system; 12. Slurry pretreatment system; 13. Mixing vessel; 14. Mixing and aeration system; 15. Control cabinet; 2. Flotation tank; 201. Feed trough; 202. Flotation cell; 21. Isolation plate; 211. First limit frame; 212. Sealing plate; 213. Second limit frame; 214. Lead screw; 22. Motor; 23. Belt; 24. Rotary shaft; 3. Sleeve; 31. Scraper; 32. Arc rod; 33. Bubble-forming plate; 34. Filter hole; 35. Sliding frame; 36. Secondary scraper; 37. First spring; 38. Scraper opening; 381. Rake teeth; 39. Discharge chute; 4. Collection chute; 41. Cylinder; 42. Push rod; 43. First connecting piece; 44. Second connecting piece; 45. Pushing plate; 5. Limiting rod; 51. Flow stabilizing rod; 6. Sliding groove; 61. Limiting groove; 62. Sliding plate; 63. Limiting plate; 64. Guide plate; 65. Sealing plate; 66. Embedded groove; 67. Second spring; 7. Third connecting piece. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1: Please see Figure 1-9 A supercritical water oxidation remediation device for lithium iron phosphate cathode material includes a base 1, a flotation tank 2 fixed on the top of the base 1, and isolation plates 21 fixed on both sides inside the flotation tank 2. The middle part of the two isolation plates 21 serves as a feed trough 201, while the two sides inside the flotation tank 2 serve as flotation tanks 202. A rotating shaft 24 is rotatably connected inside the isolation plates 21, and one end of the rotating shaft 24 passes through the flotation tank 2. Sleeves 3 are fixed on both sides of the rotating shaft 24. Two scrapers 31 are symmetrically fixed on the surface of the sleeves 3. An arc-shaped rod 32 is fixed at the end of the scraper 31 away from the sleeve 3, and a bubble-forming plate 33 is fixed between every two adjacent arc-shaped rods 32. Filter holes 34 are opened on the surface of the arc-shaped rod 32. Sliding frames 35 are fixed to the surfaces of both isolation plates 21. A secondary scraper 36 is slidably connected inside the sliding frame 35. A first spring 37 is fixed to one end of the secondary scraper 36. One end of the first spring 37 is fixed to the inner wall of the sliding frame 35. A scraping port 38 is opened at the end of the secondary scraper 36 away from the first spring 37. A rake tooth 381 is fixed to the bottom of the scraping port 38. A discharge trough 39 is opened at the bottom of the secondary scraper 36. A reagent dosing system 11 is fixed to one end of the top of the base 1. A slurry pretreatment system 12 is fixed to one side of the surface of the base 1. A stirring tank 13 is fixed to the surface of the slurry pretreatment system 12. A stirring and aeration system 14 is fixed to the side of the top of the base 1 near the flotation tank 2. A control cabinet 15 is fixed to the side of the top of the base 1 away from the reagent dosing system 11. A motor 22 is fixed on the top of the base 1 near the control cabinet 15. The output shaft of the motor 22 is driven by a belt 23. One end of the belt 23 is driven by a rotating shaft 24. A collection tank 4 is fixed on the surface of the flotation box 2 away from the slurry pretreatment system 12. A first limiting frame 211 is fixed on the surface of the isolation plate 21. A sealing plate 212 is slidably connected inside the first limiting frame 211. A second limiting frame 213 is fixed on the surface of the isolation plate 21 above the first limiting frame 211. A lead screw 214 is threaded inside the second limiting frame 213. The bottom of the lead screw 214 is rotatably connected to the sealing plate 212. A feed inlet is opened on the surface of the isolation plate 21 below the first limiting frame 211. During the operation, the filter material solid powder obtained after supercritical reaction is first mixed with water and poured into the stirring tank 13 to prepare a slurry with a mass concentration of 10%-15%. At the same time, a dispersant such as sodium hexametaphosphate is added, and the amount is controlled at 0.05%-0.1% of the slurry mass to prevent the lithium iron phosphate particles from agglomerating and ensure that impurities are fully exposed. Then, the slurry prepared in the stirring tank 13 is conveyed into the feed tank 201 through the conveying pipe. Then, the lead screw 214 is rotated. Under the limit of the second limit frame 213, the lead screw 214 drives the sealing plate 212 to slide inside the first limit frame 211 until the sealing plate 212 loses its obstruction to the feed inlet below, so that the slurry in the feed tank 201 enters the interior of the two flotation tanks 202 respectively. Then, the stirring and aeration system 14 is started by the control cabinet 15. The stirring mechanism and aeration mechanism of the stirring and aeration system 14 stir and aerate the lithium iron phosphate cathode material slurry in the flotation tank 202. At the same time, the chemical auxiliary reagents such as frothers are added into the flotation tank 202 through the reagent addition system 11 to cooperate with the slurry foaming. When the slurry foams, the controller starts the motor 22, which drives the belt 23 to rotate, which in turn drives the shaft 24 to rotate. The shaft 24 then drives the sleeve 3 and the scraper 31 to rotate. During the rotation, the scraper 31 scrapes off the foam floating on the surface of the slurry in the flotation cell 202. The above is the operation process of purifying lithium iron phosphate cathode material slurry in the prior art, which will not be repeated in this application. Specifically, during the rotation of the scraper 31, the arc-shaped rod 32 first enters the slurry surface, and then drives the foam-aggregating plate 33 into the slurry surface. When the scraper 31 flips on the slurry surface, the foam-aggregating plate 33 gathers and pushes the foam. During the process of the foam-aggregating plate 33 pushing the foam, the flotation liquid on the slurry surface is filtered through the filter holes 34 until the scraper 31 and the foam-aggregating plate 33 drive the foam away from the slurry surface. After leaving the slurry surface, the filter holes 34 continue to filter the foam that has left the slurry surface, so that the flotation liquid falls back into the interior of the flotation cell 202. This avoids excessive consumption of flotation liquid when the scraper 31 and the foam-aggregating plate 33 scrape off the foam, thereby improving the quality and efficiency of the subsequent purification of lithium iron phosphate cathode material slurry. Subsequently, the scraper 31 and the foam-forming plate 33 drive the foam to tumble. During the tumbling process, the scraper 31 and the foam-forming plate 33 come into contact with the scraper nozzle 38 and the rake teeth 381, respectively. The scraper nozzle 38 scrapes the surface of the scraper 31, and the rake teeth 381 removes the foam-forming plate 33. As a result, the foam wrapped around the surface of the scraper 31 and the foam-forming plate 33 is scraped off and squeezed into the interior of the secondary scraper 36. As the scraper 31 continues to rotate, it pushes the secondary scraper 36 back into the interior of the sliding frame 35 until the scraper 31 is separated from the secondary scraper 36. During the continuous contact between the two scrapers 31 and the secondary scraper 36, the foam impurities on the surface of the scrapers 31 and the foaming plate 33 continuously enter the interior of the secondary scraper 36 through the scraping port 38 and are discharged into the collection tank 4 through the discharge trough 39. This reduces the foam content on the surface of the scrapers 31 and the foaming plate 33, and reduces the probability of foam adhering to the surface of the scrapers 31 and the foaming plate 33 and re-entering into the lithium iron phosphate cathode material slurry, thereby improving the quality of the purified lithium iron phosphate cathode material slurry. Furthermore, when the scraper 31 comes into contact with the secondary scraper 36, under the action of the first spring 37, the scraper 31 and the foam-aggregating plate 33 are kept in contact with the scraper opening 38 and the rake teeth 381 before the foam on the surface of the scraper 31 and the foam-aggregating plate 33 is scraped off. Thus, the scraper opening 38 and the rake teeth 381 play a role in intercepting the foam, avoiding the situation where the scraper 31 and the foam-aggregating plate 33 are thrown away from the foam during the rotation process, avoiding foam splashing, and further reducing the probability of foam re-entering the flotation cell 202, thereby improving the quality of the purification of lithium iron phosphate cathode material slurry of the present invention.

[0021] It should be noted that all the equipment in this invention is controlled by the control cabinet 15. The reagent dosing system 11, the slurry pretreatment system 12, the mixing tank 13, the mixing and aeration system 14 and the control cabinet 15 are all existing technologies. The bottom of the mixing tank 13 is provided with a conveying pipe. The slurry in the mixing tank 13 can be conveyed through the conveying pipe to the mixing and aeration system 14 and then into the feed trough 201.

[0022] Example 2: A cylinder 41 is fixed to the surface of the collection tank 4. A push rod 42 is fixed to the output shaft of the cylinder 41. The push rod 42 is slidably connected to the flotation tank 2. A first connector 43 is fixed to one end of the push rod 42 inside the flotation tank 2. A second connector 44 is fixed to the end of the first connector 43 away from the push rod 42. A material feeding plate 45 is hinged to the end of the second connector 44 away from the first connector 43. Limiting rods 5 are fixed to both sides of the inner wall of the second connector 44. A flow stabilizing rod 51 is fixed between the two limiting rods 5. Specifically, based on Embodiment 1, when the motor 22 drives the rotating shaft 24 through the belt 23 and drives the sleeve 3 and scraper 31 to rotate, that is, when the motor 22 drives the scraper 31 to rotate, when the scraper 31 enters the slurry surface and then leaves the slurry surface, a large amount of foam below the sleeve 3 is carried away from the slurry surface, so the amount of foam below the sleeve 3 is reduced. At this time, the cylinder 41 is started by the control cabinet 15. The cylinder 41 drives the push rod 42 to reset, so that the push rod 42 drives the first connecting piece 43 and the second connecting piece 44 to move towards the limit rod 5. The second connecting piece 44 drives the material-pushing plate 45 to move towards the collection tank 4. Since the material-pushing plate 45 is located in the slurry fluid, the material-pushing plate 45 is resisted by the slurry fluid during the movement towards the collection tank 4. This causes the material-pushing plate 45 to gradually flip to a state perpendicular to the slurry surface. In the subsequent movement, it plays the role of agitating the foam layer on the slurry surface, so that the foam in the remaining area is quickly replenished to the bottom of the sleeve 3. This ensures that the scraper 31 has enough foam to scrape off each time it enters the slurry surface, thus avoiding the situation where the scraper 31 spins dry. This improves the efficiency of the scraper 31 in scraping off foam. Then, the control cylinder 41 is pushed out, causing the cylinder 41 to push the push rod 42 and drive the first connecting piece 43 to move towards the slurry pretreatment system 12. This causes the material feeding plate 45 to move towards the slurry pretreatment system 12 in the slurry. Under the action of the slurry fluid, the material feeding plate 45 flips towards the limiting rod 5, thereby reducing the angle between the material feeding plate 45 and the second connecting piece 44. This causes the material feeding plate 45 to sink into the slurry, preventing the material feeding plate 45 from pushing the foam layer on the surface of the slurry away from below the sleeve 3. This ensures that each time the material feeding plate 45 flips to be perpendicular to the surface of the slurry, it can replenish the foam below the sleeve 3 for the scraper 31 to purify and remove impurities. Furthermore, as the second connector 44 moves repeatedly within the slurry, the limiting rod 5 and the flow stabilizing rod 51 stabilize the flow, reducing the probability that the scraper 31 will cause the lithium iron phosphate in the slurry to surge when it flips and detaches from the slurry surface. This, in turn, reduces the probability that the lithium iron phosphate will float to the slurry surface and be scraped off by the scraper 31 and the bubble-forming plate 33, thereby improving the efficiency and quality of purifying the lithium iron phosphate cathode material slurry.

[0023] It should be noted that the limiting rod 5 also serves to limit the material-pulling plate 45, so that when the material-pulling plate 45 is flipped in the direction of the first connecting member 43, it cannot be completely retracted into the interior of the second connecting member 44. This makes the angle between the second connecting member 44 and the material-pulling plate 45 acute, so that when the subsequent material-pulling plate 45 is displaced in the direction of the collecting tank 4, it can be subjected to sufficient resistance of the slurry fluid, thereby ensuring that the material-pulling plate 45 can be flipped to a state perpendicular to the slurry surface.

[0024] Example 3: A sliding groove 6 is provided inside one side of the collection tank 4. A limiting groove 61 is provided on the side of the sliding groove 6 away from the collection tank 4. A sliding plate 62 is slidably connected inside the sliding groove 6. A limiting plate 63 is slidably connected inside the limiting groove 61. The sliding plate 62 and the limiting plate 63 are fixed. A guide plate 64 is fixed to the top of the sliding plate 62, and a sealing plate 65 is fixed to one side of the top of the guide plate 64. An embedded groove 66 is opened on the side of the sliding groove 6 near the collection groove 4. A second spring 67 is fixed inside the embedded groove 66. One end of the second spring 67 is fixed to the sliding plate 62. A third connecting piece 7 is fixed to the end of the push rod 42 near the cylinder 41. The movement trajectory of the third connecting piece 7 intersects with the sliding plate 62. Specifically, based on Embodiment 1 and Embodiment 2, when the cylinder 41 returns, the cylinder 41 drives the push rod 42 to move toward the collection groove 4, so that the push rod 42 drives the third connecting member 7 to move toward the collection groove 4, so that the distance between the third connecting member 7 and the sliding plate 62 gradually shortens until the third connecting member 7 contacts the sliding plate 62, and pushes the sliding plate 62 to slide inside the sliding groove 6, so that the sliding plate 62 drives the guide plate 64 and the sealing plate 65 to move horizontally; During the contact between the third connector 7 and the sliding plate 62, the connector contacts and pushes the sliding plate 62, causing the sliding plate 62 and the guide plate 64 to vibrate. This causes the guide plate 64 to shake the foam accumulated on its surface into the collection tank 4, thereby avoiding the accumulation of foam on the surface of the guide plate 64 and improving the smoothness of the subsequent scraper 31 and foam-collecting plate 33 scraping and collecting foam. Meanwhile, after the cylinder 41 is pushed out, the push rod 42 drives the third connecting piece 7 to release the pressure on the sliding plate 62. The sliding plate 62 is reset under the reset pull of the second spring 67. During the reset process, it contacts and pushes the inner wall of the sliding groove 6, causing the guide plate 64 to vibrate again, thereby improving the efficiency of the guide plate 64 in shaking off foam and also improving the efficiency of the collection groove 4 in collecting foam. Furthermore, after the sliding plate 62 drives the guide plate 64 to reset, the guide plate 64 drives the sealing plate 65 to reset, so that the sealing plate 65 blocks the upper outlet of the flotation cell 202, thereby preventing foam and flotation liquid from overflowing from the inside of the flotation cell 202 during the slurry agitation process.

[0025] It should be noted that the start of cylinder 41 can be coordinated with the rotation speed of scraper 31, so that when scraper 31 enters the slurry surface, cylinder 41 is in the return state, that is, push rod 42 drives third connecting piece 7 and material feeding plate 45 to move towards collection tank 4. At this time, material feeding plate 45 pushes foam to replenish below sleeve 3 for scraping by scraper 31. At the same time, push rod 42 drives third connecting piece 7 to push sliding plate 62, so that sliding plate 62 drives guide plate 64 and sealing plate 65 to move away from scraper 31, thereby releasing the obstruction of sealing plate 65 to the upper outlet of flotation cell 202.

[0026] A supercritical water oxidation remediation process for lithium iron phosphate cathode materials, using the aforementioned supercritical water oxidation remediation device for lithium iron phosphate cathode materials, includes the following steps: A1: The lithium iron phosphate cathode material is fed into the flotation cell 202 through the feed inlet. The stirring and aeration system 14 and the motor 22 are started through the control cabinet 15. The stirring and aeration system 14 stirs and aerates the lithium iron phosphate cathode material in the flotation cell 202. The motor 22 drives the belt 23 to drive the rotating shaft 24 to rotate. The rotating shaft 24 drives the scraper 31 to scrape off the foam on the surface of the lithium iron phosphate cathode material. A2: When the scraper 31 enters the surface of the lithium iron phosphate cathode material mixture, the foaming plate 33 gathers and scrapes away the foam. At the same time, the liquid around the gathered foam is filtered through the filter hole 34, so that the foam reduces the entrainment of the liquid by the foam when scraping away the foam. In the subsequent turning process, the foam adhering to the surface of the scraper 31 is scraped away by the secondary scraper 36 and collected into the collection tank 4. A3: Control cylinder 41 repeatedly pushes out and returns, causing cylinder 41 to drive push rod 42 to move repeatedly, causing push rod 42 to drive first connector 43 and second connector 44 to move repeatedly in lithium iron phosphate cathode material mixture. During the displacement process, second connector 44 is subjected to liquid resistance and repeatedly opens and closes the material feeding plate 45. Through the material feeding plate 45, the foam on the side of the mixture away from scraper 31 is pushed to below scraper 31. A4: During the process of pushing the foam to the bottom of the scraper 31 by the feeding plate 45, the pushing rod 42 drives the third connecting piece 7 to push the sliding plate 62, so that the sliding plate 62 drives the guide plate 64 and the sealing plate 65 to move, so that the sealing plate 65 releases the blockage of the outlet of the flotation box 2, and the scraper 31 smoothly scrapes the foam into the interior of the collection tank 4.

[0027] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A lithium iron phosphate positive electrode material supercritical water oxidation repair device, comprising a base (1), characterized in that: A flotation tank (2) is fixed to the top of the base (1). Two isolation plates (21) are fixed to the two sides inside the flotation tank (2). The middle part of the two isolation plates (21) serves as a feed trough (201), while the two sides inside the flotation tank (2) serve as flotation tanks (202). A rotating shaft (24) is rotatably connected inside the isolation plate (21). One end of the rotating shaft (24) passes through the flotation tank (2). The rotating shaft (24) has sleeves (3) fixed on both sides of its surface. Two scrapers (31) are symmetrically fixed on the surface of the sleeves (3). An arc-shaped rod (32) is fixed at the end of the scraper (31) away from the sleeve (3). A bubble plate (33) is fixed between every two adjacent arc-shaped rods (32). Filter holes (34) are opened on the surface of the arc-shaped rod (32). Both partition plates (21) have a sliding frame (35) fixed on their surfaces. A secondary scraper (36) is slidably connected inside the sliding frame (35). A first spring (37) is fixed at one end of the secondary scraper (36). One end of the first spring (37) is fixed to the inner wall of the sliding frame (35). A scraping port (38) is opened at the end of the secondary scraper (36) away from the first spring (37). A rake tooth (381) is fixed at the bottom of the scraping port (38). A discharge groove (39) is opened at the bottom of the secondary scraper (36).

2. The lithium-iron-phosphate cathode material supercritical water oxidation remediation device according to claim 1, characterized in that: A reagent dosing system (11) is fixed at one end of the top of the base (1), a slurry pretreatment system (12) is fixed on one side of the surface of the base (1), a stirring tank (13) is fixed on the surface of the slurry pretreatment system (12), a stirring and aeration system (14) is fixed on the side of the top of the base (1) near the flotation tank (2), and a control cabinet (15) is fixed on the side of the top of the base (1) away from the reagent dosing system (11).

3. The lithium-iron-phosphate cathode material supercritical water oxidation remediation device of claim 2, wherein: A motor (22) is fixed on the top of the base (1) near the control cabinet (15). The output shaft of the motor (22) is connected to a belt (23), and one end of the belt (23) is connected to a rotating shaft (24).

4. The lithium-iron-phosphate cathode material supercritical water oxidation remediation device of claim 3, wherein: A collection tank (4) is fixed on the surface of the flotation box (2) away from the slurry pretreatment system (12).

5. The lithium-iron-phosphate cathode material supercritical water oxidation remediation device of claim 4, wherein: A cylinder (41) is fixed to the surface of the collection tank (4). A push rod (42) is fixed to the output shaft of the cylinder (41). The push rod (42) is slidably connected to the flotation tank (2). A first connector (43) is fixed to one end of the push rod (42) inside the flotation tank (2). A second connector (44) is fixed to the end of the first connector (43) away from the push rod (42). A material feeding plate (45) is hinged to the end of the second connector (44) away from the first connector (43).

6. The lithium-iron-phosphate cathode material supercritical water oxidation remediation device of claim 5, wherein: Limiting rods (5) are fixed on both sides of the inner wall of the second connector (44), and a flow stabilizing rod (51) is fixed between the two limiting rods (5).

7. The lithium-iron-phosphate cathode material supercritical water oxidation remediation device of claim 6, wherein: A sliding groove (6) is provided inside one side of the collection groove (4), and a limiting groove (61) is provided on the side of the sliding groove (6) away from the collection groove (4). A sliding plate (62) is slidably connected inside the sliding groove (6), and a limiting plate (63) is slidably connected inside the limiting groove (61). The sliding plate (62) and the limiting plate (63) are fixed. A guide plate (64) is fixed to the top of the sliding plate (62), and a sealing plate (65) is fixed to one side of the top of the guide plate (64). An embedded groove (66) is provided on the side of the sliding groove (6) near the collection groove (4). A second spring (67) is fixed inside the embedded groove (66), and one end of the second spring (67) is fixed to the sliding plate (62).

8. The lithium-iron-phosphate cathode material supercritical water oxidation remediation device of claim 7, wherein: The push rod (42) is fixed with a third connector (7) at one end near the cylinder (41), and the movement trajectory of the third connector (7) intersects with the sliding plate (62).

9. The lithium-iron-phosphate cathode material supercritical water oxidation remediation device of claim 8, wherein: The surface of the isolation plate (21) is fixed with a first limiting frame (211), and a sealing plate (212) is slidably connected inside the first limiting frame (211). The surface of the isolation plate (21) is fixed above the first limiting frame (211), and a lead screw (214) is threaded inside the second limiting frame (213). The bottom of the lead screw (214) is rotatably connected to the sealing plate (212). The surface of the isolation plate (21) is provided with a feed port below the first limiting frame (211).

10. A process for the supercritical water oxidation remediation of lithium iron phosphate cathode material using the supercritical water oxidation remediation device for lithium iron phosphate cathode material according to any one of claims 1 to 9, characterized in that: Includes the following steps: A1: The lithium iron phosphate cathode material is fed into the flotation cell (202) through the feed port. The stirring and aeration system (14) and motor (22) are started through the control cabinet (15). The stirring and aeration system (14) stirs and aerates the lithium iron phosphate cathode material in the flotation cell (202). The motor (22) drives the belt (23) to drive the rotating shaft (24) to rotate. The rotating shaft (24) drives the scraper (31) to scrape off the foam on the surface of the lithium iron phosphate cathode material. A2: When the scraper (31) enters the surface of the lithium iron phosphate cathode material mixture, the foam is gathered and scraped by the foam-gathering plate (33). At the same time, the liquid around the gathered foam is filtered through the filter hole (34), so that the foam reduces the entrainment of the liquid by the foam when the scraper (31) scrapes the foam. In the subsequent flipping process, the foam adhering to the surface of the scraper (31) is scraped off by the secondary scraper (36) and collected into the collection tank (4). A3: Control the cylinder (41) to repeatedly push out and return, so that the cylinder (41) drives the push rod (42) to repeatedly move, so that the push rod (42) drives the first connector (43) and the second connector (44) to repeatedly move in the lithium iron phosphate cathode material mixture. During the displacement process, the second connector (44) is subjected to liquid resistance and repeatedly opens and closes. The foam on the side of the mixture away from the scraper (31) is pushed to the bottom of the scraper (31) through the scraper (45). A4: During the process of pushing the foam to the bottom of the scraper (31) by the feeding plate (45), the pushing rod (42) drives the third connecting piece (7) to push the sliding plate (62), so that the sliding plate (62) drives the guide plate (64) and the sealing plate (65) to move, so that the sealing plate (65) releases the blockage of the outlet of the flotation box (2), and the scraper (31) smoothly scrapes the foam into the inside of the collection tank (4).

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