A device and process method for preparing lithium battery positive electrode material from lithium precipitation mother liquor

Abstract

The application provides a device and a process method for preparing lithium battery positive electrode material from lithium sink solution, relates to the technical field of lithium phosphate preparation, and comprises a reaction tank, a moving mechanism, a crystal removal mechanism and a vibration desorption mechanism. The moving mechanism comprises a reciprocating belt and a reciprocating frame, the reciprocating frame is fixed to the surface of the reciprocating belt, and the reciprocating frame can be driven to reciprocate in the reaction tank through rotation of the reciprocating belt. The scheme finally realizes that when the reciprocating frame is driven to move through the reciprocating belt, the cleaning brush will rotate under the cooperation of the crystal removal tooth plate and the rotating gear, so that the lithium phosphate fine crystals adsorbed on the inner wall of the reaction tank are swept and peeled off, the reciprocating rotation of the cleaning brush can efficiently peel off these fine crystals, the fine crystals re-enter the extraction system, the total recovery rate of lithium phosphate is improved, the raw material loss of battery-grade lithium phosphate with high purity and high value is significantly reduced, and the production cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of lithium phosphate preparation technology, and in particular to an equipment and process for preparing lithium battery cathode materials from lithium precipitation mother liquor. Background Technology

[0002] Lithium precipitation mother liquor is lithium-containing waste liquid generated during the lithium salt production process. Through reasonable processes, high-purity lithium phosphate can be recovered from the waste liquid. Lithium phosphate is a colorless orthorhombic or white crystalline substance with unique electrochemical properties. The mainstream cathode materials prepared with lithium phosphate as a precursor are mostly phosphate systems. These materials are widely used in the field of lithium batteries for automobiles due to their high safety and long cycle life.

[0003] In related technologies, high-purity lithium phosphate can be recovered from lithium precipitation mother liquor for use in the preparation of cathode materials for automotive lithium batteries. Currently, during the lithium phosphate recovery process from lithium precipitation mother liquor, the negatively charged fine lithium phosphate crystals adsorb onto the inner wall of the metal reaction tank. Existing preparation equipment is not suitable for processing these adsorbed fine lithium phosphate crystals, causing them to remain on the tank wall. This directly leads to a decrease in the lithium phosphate recovery rate. Furthermore, randomly detached crystals during the preparation process can mix into new batches, causing fluctuations in the purity of the lithium phosphate product, which fails to meet the requirements for use as a cathode material in lithium batteries.

[0004] Therefore, it is necessary to provide an apparatus for preparing lithium battery cathode materials from lithium precipitation mother liquor to solve the above-mentioned technical problems. Summary of the Invention

[0005] This invention provides an apparatus for preparing lithium battery cathode materials from lithium precipitation mother liquor, which solves the technical problem that existing preparation equipment in related technologies is not convenient for processing the fine lithium phosphate crystals adsorbed on the inner wall of the reaction tank.

[0006] To solve the above-mentioned technical problems, the equipment for preparing lithium battery cathode materials from lithium precipitation mother liquor provided by the present invention includes a reaction tank, a moving mechanism, a crystal removal mechanism, and a vibration desorption mechanism;

[0007] The moving mechanism includes a reciprocating belt and a reciprocating frame. The reciprocating frame is fixed to the surface of the reciprocating belt, and the reciprocating frame can be driven to reciprocate within the reaction tank by the rotation of the reciprocating belt.

[0008] The crystal removal mechanism includes two sliders slidably connected to the inner side of the reciprocating frame. The inner sides of the two sliders are vertically rotatably connected to cleaning brushes. Rotating gears are fixed on the top surfaces of the two cleaning brushes. Crystal removal tooth plates are fixed on the front and rear sides of the inner wall of the reaction tank. The two crystal removal tooth plates mesh with the two rotating gears respectively.

[0009] The vibration desorption mechanism includes adjusting screws threaded to the inner sides of two sliders. The top ends of the two adjusting screws are rotatably connected to contact wheels. Springs are provided on the inner side of the reciprocating frame and on the opposite side of the two sliders. Vibration plates are fixed on the front and rear sides of the inner wall of the reaction tank.

[0010] Preferably, the surface of the vibrating plate has an uneven structure, and when the contact wheel contacts the vibrating plate and moves, the slider can slide back and forth on the inner side of the reciprocating frame through the cooperation of the spring.

[0011] Preferably, mounting brackets are fixedly provided on both sides of the inner wall of the reaction tank, and drive wheels are rotatably connected to the inner sides of the two mounting brackets. The reciprocating belt is sleeved on the surface of the two drive wheels. Two guide seats are slidably connected to the bottom of the reciprocating frame. The two ends of the two guide seats are fixedly connected to the inner wall of the reaction tank. A drive motor is provided on the left side of the reaction tank. A bevel gear is fixedly provided at the output end of the drive motor and the front end of the left drive wheel. The two bevel gears mesh with each other.

[0012] Preferably, a monitoring mechanism is fixedly provided on the left side of the inner wall of the reaction tank. The monitoring mechanism includes a rotating seat fixedly provided on the left side of the inner wall of the reaction tank. An industrial camera is rotatably connected to the inner side of the rotating seat via a rotating shaft. An adjusting gear is fixedly provided on the industrial camera via the rotating shaft. A drive gear plate is fixedly provided on the front side of the bottom of the reciprocating frame.

[0013] Preferably, a detection mechanism is fixedly installed on the left side of the inner wall of the reaction tank. The detection mechanism includes a mounting plate fixedly installed on the left side of the inner wall of the reaction tank. Two threaded guide rods are fixedly installed on the right side of the mounting plate. A moving block is slidably connected to the surface of the two threaded guide rods. A follower frame is rotatably connected to the inner side of the moving block. A slot is opened on the inner side of the mounting plate. The rear side of the follower frame is located in the slot. A pH detector is installed inside the follower frame. A trigger rod is threadedly connected to the inside of the reciprocating frame. A reset spring is sleeved on the surface of each of the two threaded guide rods.

[0014] Preferably, the top of the reciprocating frame is provided with a pH adjustment mechanism, the pH adjustment mechanism includes a solution tank disposed on the top of the reciprocating frame, the interior of the reciprocating frame is longitudinally rotatably connected to a pipe, the surface of the pipe is connected to multiple nozzles, the surface of the pipe is fixedly provided with two flipping gears, the front and rear sides of the two mounting brackets are fixedly provided with flipping tooth plates, and a water pump is provided on the front side of the top of the reciprocating frame, the water pump being connected to the solution tank and the pipe through a hose.

[0015] Preferably, the inner wall of the reaction tank is rotatably connected to a mixing mechanism, the mixing mechanism including a mixing shaft rotatably connected to the inner wall of the reaction tank, the surface of the mixing shaft being provided with multiple sets of mixing frames, and a mixing motor for driving the mixing shaft to rotate is provided on the right side of the reaction tank.

[0016] Preferably, two arc-shaped plates are fixed to both ends of the mixing shaft by bolts, and a through groove is opened on the inner side of the arc-shaped plate. A scraping plate is fixed to the surface of each of the four arc-shaped plates. Two collection tanks are provided at the bottom of the reaction tank, and a drain pipe is connected to the surface of each of the two collection tanks.

[0017] A process for preparing lithium battery cathode materials from lithium precipitation mother liquor includes the following steps:

[0018] Step S1: Mix lithium precipitation mother liquor and concentrated sulfuric acid in a uniform ratio, adjust the pH to neutral, and remove carbonate ions to obtain decarbonated liquor.

[0019] Step S2: After preheating the obtained decarbonized liquid to a suitable temperature, perform MVR evaporation and concentration to obtain a concentrated liquid;

[0020] Step S3: The obtained concentrate is centrifuged and filtered to obtain a sodium-potassium mixture and a concentrated filtrate;

[0021] Step S4: Cool the obtained concentrated filtrate to a suitable temperature to crystallize and precipitate, filter to obtain Na2SO4·H2O and frozen filtrate, and then dehydrate and dry to obtain sodium sulfate;

[0022] Step S5: Concentrate the frozen filtrate using an MVR evaporator to obtain Li + To obtain a concentrated solution at a suitable concentration;

[0023] Step S6: Prepare di(2-ethylhexyl) phosphate-sulfonated kerosene (volume ratio 1:3) as the extractant, add 5% tributyl phosphate as a co-extractant, extract it with the concentrate in a certain ratio, adjust the pH to a suitable range, and perform three countercurrent washings to obtain the extract.

[0024] Step S7: Back-extract the obtained extract with a phosphoric acid solution of suitable concentration to obtain a LiH2PO4 solution, and adjust the pH to alkaline to generate Li3PO4.

[0025] Compared with related technologies, the equipment and process for preparing lithium battery cathode materials using lithium precipitation mother liquor provided by this invention have the following beneficial effects:

[0026] When the reciprocating belt drives the reciprocating frame to move, the cleaning brush rotates in conjunction with the crystal removal tooth plate and the rotating gear. This sweeps and peels off the fine lithium phosphate crystals adsorbed on the inner wall of the reaction tank. The reciprocating rotation of the cleaning brush can efficiently peel off these fine crystals, allowing them to re-enter the extraction system, thereby improving the overall recovery rate of lithium phosphate. For high-purity, high-value battery-grade lithium phosphate, this can significantly reduce raw material loss and lower production costs. Furthermore, the timely removal by the brush can prevent crystals from accumulating on the tank wall for a long time, reduce the interference of detachment on the uniformity of the reaction solution, ensure the stability of the lithium phosphate crystallization process, and indirectly improve the purity and consistency of the final product.

[0027] When the reciprocating belt moves the reciprocating frame to the right and continues to move to the right, the contact wheel and the vibrating plate work together to make the slider move the cleaning brush back and forth. Combined with the reaction liquid, the crystals attached to the surface can be shaken off in time, preventing fine lithium phosphate crystals from adhering to or accumulating on the brush bristles. It has a self-cleaning function, which can effectively prevent the cleaning brush from deteriorating due to oxidation and adsorption of impurities in the reaction system, thus affecting the precision of lithium phosphate products. It ensures that the brush always remains clean and continuously and efficiently peels off the crystals from the tank wall. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0029] Figure 1 The optimal structural schematic diagram provided for this invention;

[0030] Figure 2 This is a schematic diagram of the structure of the reaction tank (right view) provided by the present invention.

[0031] Figure 3 A schematic diagram of the structure of the moving mechanism provided by the present invention;

[0032] Figure 4 This is a schematic diagram of the structure of the crystal removal mechanism and the vibration desorption mechanism provided by the present invention;

[0033] Figure 5 for Figure 4 The enlarged structural diagram at point A is shown below;

[0034] Figure 6 A schematic diagram showing the state in which the reset frame provided by the present invention moves to the right and the contact wheel contacts the vibration plate;

[0035] Figure 7This is a schematic diagram of the monitoring mechanism provided by the present invention;

[0036] Figure 8 A schematic diagram showing the state in which the reset frame provided by the present invention moves to the left, and the driving gear plate drives the adjusting gear to rotate.

[0037] Figure 9 This is a schematic diagram of the detection mechanism provided by the present invention;

[0038] Figure 10 for Figure 9 The diagram shown is a structural schematic of the follower frame;

[0039] Figure 11 This is a schematic diagram of the pH adjustment mechanism provided by the present invention;

[0040] Figure 12 A schematic diagram showing the state in which the reciprocating frame provided by the present invention moves to the left and the flipping gear rotates under the action of the flipping tooth plate.

[0041] Figure 13 A schematic diagram of the structure of the mixing mechanism provided by the present invention;

[0042] Figure 14 for Figure 13 The enlarged structural diagram at point B is shown below;

[0043] Figure 15 This is a schematic diagram of the process method provided by the present invention.

[0044] Explanation of icon numbers:

[0045] 1. Reaction tank;

[0046] 2. Moving mechanism; 21. Reciprocating belt; 22. Reciprocating frame; 23. Mounting bracket; 24. Drive wheel; 25. Guide seat; 26. Drive motor; 27. Bevel gear;

[0047] 3. Crystal removal mechanism; 31. Slider; 32. Cleaning brush; 33. Rotating gear; 34. Crystal removal toothed plate;

[0048] 4. Vibration desorption mechanism; 41. Adjusting screw; 42. Contact wheel; 43. Spring; 44. Vibrating plate;

[0049] 5. Monitoring mechanism; 51. Rotary seat; 52. Industrial camera; 53. Adjusting gear; 54. Drive gear plate;

[0050] 6. Testing mechanism; 61. Mounting plate; 62. Threaded guide rod; 63. Moving block; 64. Follower frame; 65. Groove; 66. pH detector; 67. Trigger rod; 68. Return spring;

[0051] 7. pH adjustment mechanism; 71. Solution tank; 72. Pipeline; 73. Nozzle; 74. Rotating gear; 75. Rotating toothed plate; 76. Water pump;

[0052] 8. Mixing mechanism; 81. Mixing shaft; 82. Mixing frame; 83. Mixing motor;

[0053] 9. Curved plate; 10. Scraper; 11. Collection tank; 12. Drain pipe.

[0054] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0055] 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 a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0056] This invention provides an apparatus and process for preparing lithium battery cathode materials from lithium precipitation mother liquor.

[0057] First embodiment:

[0058] Please see Figures 1 to 6 An apparatus for preparing lithium battery cathode materials from lithium precipitation mother liquor, comprising a reaction tank 1, a moving mechanism 2, a crystal removal mechanism 3, and a vibration desorption mechanism 4;

[0059] Preferably, the reaction tank 1 has heating and temperature regulation functions to control the reaction temperature;

[0060] The moving mechanism 2 includes a reciprocating belt 21 and a reciprocating frame 22. The reciprocating frame 22 is fixed on the surface of the reciprocating belt 21. The reciprocating frame 22 can be driven to reciprocate within the reaction tank 1 by rotating the reciprocating belt 21.

[0061] Mounting brackets 23 are fixedly provided on both sides of the inner wall of the reaction tank 1. Drive wheels 24 are rotatably connected to the inner sides of the two mounting brackets 23. The reciprocating belt 21 is sleeved on the surface of the two drive wheels 24. Two guide seats 25 are slidably connected to the bottom of the reciprocating frame 22. The two ends of the two guide seats 25 are fixedly connected to the inner wall of the reaction tank 1. A drive motor 26 is provided on the left side of the reaction tank 1. A bevel gear 27 is fixedly provided at the output end of the drive motor 26 and the front end of the left drive wheel 24. The two bevel gears 27 mesh with each other.

[0062] Please combine Figure 3Start the drive motor 26. The drive motor 26 rotates and drives the left drive wheel 24 to rotate through the two bevel gears 27. The rotation of the left drive wheel 24 drives the reciprocating belt 21 to rotate. The rotation of the reciprocating belt 21 drives the reciprocating frame 22 to move. By controlling the rotation direction of the drive motor 26, the reciprocating belt 21 can drive the reciprocating frame 22 to move back and forth.

[0063] Preferably, the two guide seats 25 are provided so that the reciprocating frame 22 can move stably left and right;

[0064] The crystal removal mechanism 3 includes two sliders 31 slidably connected to the inner side of the reciprocating frame 22. The inner sides of the two sliders 31 are vertically rotatably connected to cleaning brushes 32. The top surfaces of the two cleaning brushes 32 are fixed with rotating gears 33. The front and rear sides of the inner wall of the reaction tank 1 are fixed with crystal removal tooth plates 34. The two crystal removal tooth plates 34 are respectively engaged with the two rotating gears 33.

[0065] Please combine Figure 4 and Figure 5 When the reciprocating belt 21 drives the reciprocating frame 22 to move, the reciprocating frame 22 will simultaneously drive the cleaning brush 32 and the rotating gear 33 to move. With the cooperation of the crystal removal plate 34 and the rotating gear 33, the cleaning brush 32 will rotate during the movement, thereby sweeping and peeling off the fine lithium phosphate crystals adsorbed on the inner wall of the reaction tank 1.

[0066] Preferably, the bristles of the cleaning brush 32 are made of nylon, and the bristle length is slightly longer than the gap between the groove walls. By rotating the gear 33 at low speed, the flexible sweeping action of the bristles is used to peel off the crystals.

[0067] The vibration desorption mechanism 4 includes an adjusting screw 41 threadedly connected to the inner side of two sliders 31. The top ends of the two adjusting screws 41 are rotatably connected to contact wheels 42. Springs 43 are provided on the inner side of the reciprocating frame 22 and on the opposite side of the two sliders 31. Vibration plates 44 are fixed on the front and rear sides of the inner wall of the reaction tank 1.

[0068] Please combine Figure 6When the reciprocating belt 21 drives the reciprocating frame 22 to move to the right, the contact wheel 42 contacts the vibrating plate 44 and continues to move to the right, after the contact wheel 42 contacts the protruding part of the vibrating plate 44, the adjusting screw 41 will cause the slider 31 to slide backward on the inner side of the reciprocating frame 22, causing the spring 43 to contract. The slider 31 moves and drives the cleaning brush 32 to move backward. Conversely, when the contact wheel 42 contacts the concave part of the vibrating plate 44, the expansion of the spring 43 will cause the slider 31 to drive the cleaning brush 32 to move forward. Through the back and forth movement of the cleaning brush 32, under the action of water flow, the fine lithium phosphate crystals attached to the surface of the cleaning brush 32 are removed.

[0069] Preferably, by replacing the vibrating plate 44 with a different size, the vibration frequency and magnitude of the cleaning brush 32 can be adjusted. When the contact wheel 42 is rotated downward using the adjusting screw 41 and the position of the contact wheel 42 is adjusted downward, the reciprocating frame 22 moves to the right side, and the contact wheel 42 and the vibrating plate 44 will not come into contact.

[0070] The surface of the vibrating plate 44 has an uneven structure. When the contact wheel 42 contacts the vibrating plate 44 and moves, the slider 31 can slide back and forth on the inner side of the reciprocating frame 22 through the cooperation of the spring 43.

[0071] In this embodiment, when the reciprocating belt 21 drives the reciprocating frame 22 to move, the cleaning brush 32 will rotate under the cooperation of the crystal removal tooth plate 34 and the rotating gear 33, thereby sweeping and peeling off the fine lithium phosphate crystals adsorbed on the inner wall of the reaction tank 1. The reciprocating rotation of the cleaning brush 32 can efficiently peel off these fine crystals and allow them to re-enter the extraction system, thereby improving the total recovery rate of lithium phosphate. For high-purity, high-value battery-grade lithium phosphate, this can significantly reduce raw material loss and reduce production costs. In addition, the timely removal by the brush can prevent crystals from accumulating on the tank wall for a long time, reduce the interference of falling off on the uniformity of the reaction liquid, ensure the stability of the lithium phosphate crystallization process, and indirectly improve the purity and consistency of the final product.

[0072] When the reciprocating belt 21 drives the reciprocating frame 22 to move to the right and continues to move to the right, the contact wheel 42 and the vibrating plate 44 work together to make the slider 31 drive the cleaning brush 32 to move back and forth. Combined with the reaction liquid, the crystals attached to the surface can be shaken off in time, avoiding the adhesion or accumulation of fine lithium phosphate crystals on the brush bristles. It has a self-cleaning function, which can effectively prevent the cleaning brush 32 from deteriorating due to oxidation and adsorption of impurities in the reaction system, thus affecting the precision of lithium phosphate products. It ensures that the brush always stays clean and continuously and efficiently peels off the crystals from the tank wall.

[0073] Second embodiment:

[0074] Please see Figures 7 to 10A monitoring mechanism 5 is fixedly installed on the left side of the inner wall of the reaction tank 1. The monitoring mechanism 5 includes a rotating seat 51 fixedly installed on the left side of the inner wall of the reaction tank 1. An industrial camera 52 is rotatably connected to the inner side of the rotating seat 51 through a rotating shaft. An adjusting gear 53 is fixedly installed on the industrial camera 52 through a rotating shaft. A drive tooth plate 54 is fixedly installed on the front side of the bottom of the reciprocating frame 22.

[0075] Please combine Figure 7 and Figure 8 When the reciprocating frame 22 drives the drive gear plate 54 to move to the left, the drive gear plate 54 comes into contact with the adjusting gear 53 and continues to move to the left, the drive gear plate 54 drives the adjusting gear 53 to rotate. The rotation of the adjusting gear 53 drives the industrial camera 52 to rotate through the rotating shaft, thereby switching the industrial camera 52 to the working state. The industrial camera 52 monitors the adsorption of lithium phosphate fine crystals on the tank wall and the working status of the cleaning brush 32.

[0076] A detection mechanism 6 is fixedly installed on the left side of the inner wall of the reaction tank 1. The detection mechanism 6 includes a mounting plate 61 fixedly installed on the left side of the inner wall of the reaction tank 1. Two threaded guide rods 62 are fixedly installed on the right side of the mounting plate 61. A moving block 63 is slidably connected to the surface of the two threaded guide rods 62. A follower frame 64 is rotatably connected to the inner side of the moving block 63. A slot 65 is opened on the inner side of the mounting plate 61. The rear side of the follower frame 64 is located in the slot 65. A pH detector 66 is installed inside the follower frame 64. A trigger rod 67 is threadedly connected to the inside of the reciprocating frame 22. A reset spring 68 is sleeved on the surface of each of the two threaded guide rods 62.

[0077] Please combine Figure 9 and Figure 10 By rotating the trigger rod 67, the working position of the left side of the trigger rod 67 is adjusted. When the reciprocating frame 22 drives the trigger rod 67 to move continuously to the left, the trigger rod 67 contacts the moving block 63, which pushes the moving block 63 to the left, causing the two return springs 68 to contract. The movement of the moving block 63 to the left drives the follower frame 64 to move to the left. Under the action of the slot 65, the follower frame 64 drives the pH detector 66 to rotate, so that the detection end of the pH detector 66 is inserted into the reaction solution, thereby detecting the pH concentration of the reaction solution.

[0078] Furthermore, when the reciprocating frame 22 drives the trigger rod 67 to move to the right, the expansion of the reset spring 68 causes the moving block 63 to slide to the right on the surface of the threaded guide rod 62. The movement of the moving block 63 drives the follower frame 64 to move to the right. Under the action of the slot 65, the follower frame 64 drives the PH detector 66 to rotate clockwise, thereby resetting the position of the PH detector 66.

[0079] In this embodiment, when the reciprocating frame 22 continuously drives the drive tooth plate 54 to move to the left, the drive tooth plate 54 drives the adjusting gear 53 and the industrial camera 52 to rotate, thereby adjusting the industrial camera 52 to the working state. The industrial camera 52 can capture the crystal distribution in each area of ​​the tank wall in real time, and can then control the moving speed of the reciprocating frame 22 or the vibration frequency of the cleaning brush 32 in a coordinated manner, thereby enhancing the crystal stripping effect. It can also monitor the abnormal state of the cleaning brush 32, so as to adjust or replace the cleaning brush 32 in a timely manner.

[0080] When the reciprocating frame 22 continuously drives the trigger rod 67 to move to the left, the trigger rod 67 will push the moving block 63 to move to the left. With the cooperation of the follower frame 64 and the slot 65, the bottom end of the pH detector 66 is inserted into the reaction solution. This avoids the lag of manual intermittent detection and ensures that the reaction system is always in the optimal pH range, providing a stable chemical environment for the efficient and high-purity crystallization of lithium phosphate. At the same time, it can also avoid the problem of the pH detector 66 constantly processing the scaling in the reaction solution.

[0081] Third embodiment:

[0082] Please see Figure 1 , Figures 11 to 14 The reciprocating frame 22 is provided with a pH adjustment mechanism 7 at its top. The pH adjustment mechanism 7 includes a solution tank 71 located at the top of the reciprocating frame 22. The reciprocating frame 22 is longitudinally rotatably connected to a pipe 72. Multiple nozzles 73 are connected to the surface of the pipe 72. Two flipping gears 74 are fixed to the surface of the pipe 72. Flipping tooth plates 75 are fixed to the front and rear sides of the two mounting brackets 23. A water pump 76 is provided at the front of the top of the reciprocating frame 22. The water pump 76 is connected to the solution tank 71 and the pipe 72 through a hose.

[0083] Please combine Figure 11 and Figure 12 : Start the water pump 76. The water pump 76 draws out the pH adjustment solution in the solution tank 71 and delivers it to the pipeline 72. Then, the pH adjustment solution is sprayed into the reaction solution through the nozzle 73.

[0084] Furthermore, when the reciprocating frame 22 moves to the left or right, the flip gear 74 contacts the flip tooth plate 75, and the flip gear 74 drives the pipe 72 to rotate, thereby adjusting the working angle of the nozzle 73.

[0085] The inner wall of the reaction tank 1 is rotatably connected to a mixing mechanism 8. The mixing mechanism 8 includes a mixing shaft 81 rotatably connected to the inner wall of the reaction tank 1. Multiple mixing frames 82 are provided on the surface of the mixing shaft 81. A mixing motor 83 for driving the mixing shaft 81 to rotate is provided on the right side of the reaction tank 1.

[0086] Please combine Figure 13 Start the mixing motor 83. The mixing motor 83 rotates, which in turn drives the mixing shaft 81 to rotate. The rotation of the mixing shaft 81 drives multiple sets of mixing frames 82 to rotate, thereby mixing the pH adjustment solution and the reaction solution.

[0087] Two arc-shaped plates 9 are fixed to both ends of the mixing shaft 81 by bolts. A through groove is opened on the inner side of the arc-shaped plate 9. A scraping plate 10 is fixed to the surface of the four arc-shaped plates 9. Two collection tanks 11 are provided at the bottom of the reaction tank 1. A drain pipe 12 is connected to the surface of the two collection tanks 11.

[0088] Please combine Figure 14 By loosening the bolts, the working position of the arc plate 9 can be adjusted, thereby adjusting the contact distance between the scraper plate 10 and the tank wall, avoiding excessive scraping force that could damage the fine lithium phosphate crystals. When the mixing shaft 81 rotates, it will simultaneously drive the arc plate 9 and the scraper plate 10 to rotate, thereby peeling off the crystals attached to the tank wall.

[0089] In this embodiment, the pH adjustment liquid is sprayed evenly using the nozzle 73 to avoid sudden changes in local pH, ensuring the optimal chemical environment for lithium phosphate crystallization or extraction, and reducing the generation of impurities. The rotating gear 74 and the rotating toothed plate 75 work together to drive the pipe 72 to rotate. The angle of the nozzle 73 can be adjusted. By loosening the bolts, the working position of the arc plate 9 can be adjusted, thereby adjusting the contact distance between the scraping plate 10 and the tank wall, avoiding excessive scraping force that could damage the fine lithium phosphate crystals.

[0090] Fourth embodiment:

[0091] Please see Figure 15 A process for preparing lithium battery cathode materials from lithium precipitation mother liquor includes the following steps:

[0092] Step S1: Mix lithium precipitation mother liquor and concentrated sulfuric acid in a uniform ratio, adjust the pH to neutral, and remove carbonate ions to obtain decarbonated liquor.

[0093] Step S2: After preheating the obtained decarbonized liquid to a suitable temperature, perform MVR evaporation and concentration to obtain a concentrated liquid;

[0094] Step S3: The obtained concentrate is centrifuged and filtered to obtain a sodium-potassium mixture and a concentrated filtrate;

[0095] Step S4: Cool the obtained concentrated filtrate to a suitable temperature to crystallize and precipitate, filter to obtain Na2SO4·H2O and frozen filtrate, and then dehydrate and dry to obtain sodium sulfate;

[0096] Step S5: Concentrate the frozen filtrate using an MVR evaporator to obtain Li + To obtain a concentrated solution at a suitable concentration;

[0097] Step S6: Prepare di(2-ethylhexyl) phosphate-sulfonated kerosene (volume ratio 1:3) as the extractant, add 5% tributyl phosphate as a co-extractant, extract it with the concentrate in a certain ratio, adjust the pH to a suitable range, and perform three countercurrent washings to obtain the extract.

[0098] Step S7: Back-extract the obtained extract with a phosphoric acid solution of suitable concentration to obtain a LiH2PO4 solution, and adjust the pH to alkaline to generate Li3PO4.

[0099] In this embodiment, impurities are efficiently removed through precise decarbonization and separation of sodium, potassium, and sodium sulfate, ensuring product purity and meeting battery-grade raw material requirements. The use of MVR evaporation technology twice significantly reduces energy consumption and saves production costs. Byproducts such as sodium sulfate are recovered, improving resource utilization and economic efficiency. In the extraction stage, di(2-ethylhexyl) phosphate is used as the extractant, and tributyl phosphate is added as a co-extractant. Combined with three countercurrent washing processes, the selective separation of lithium is enhanced, and the back-extraction process is gentle and efficient.

[0100] Please refer to the reference again. Figures 1 to 14 The working principle of the equipment for preparing lithium battery cathode materials from lithium precipitation mother liquor provided by the present invention is as follows:

[0101] Step S1: Start the drive motor 26. The drive motor 26 rotates and drives the left drive wheel 24 to rotate through two bevel gears 27. The rotation of the left drive wheel 24 drives the reciprocating belt 21 to rotate. The rotation of the reciprocating belt 21 drives the reciprocating frame 22 to move. By controlling the rotation direction of the drive motor 26, the reciprocating belt 21 can drive the reciprocating frame 22 to move back and forth.

[0102] Step S2: Start the water pump 76. The water pump 76 draws out the pH adjustment solution in the solution tank 71 and delivers it to the pipeline 72. Then, the pH adjustment solution is sprayed into the reaction solution through the nozzle 73.

[0103] When the reciprocating frame 22 moves to the left or right, the flip gear 74 contacts the flip tooth plate 75, and the flip gear 74 will drive the pipe 72 to rotate, thereby adjusting the working angle of the nozzle 73.

[0104] Start the mixing motor 83. The rotation of the mixing motor 83 drives the mixing shaft 81 to rotate, which in turn drives multiple sets of mixing frames 82 to rotate, thus mixing the pH adjustment solution and the reaction solution.

[0105] In step S3, by rotating the trigger rod 67, the working position of the left side of the trigger rod 67 is adjusted. When the reciprocating frame 22 drives the trigger rod 67 to move continuously to the left, and the trigger rod 67 contacts the moving block 63, it will push the moving block 63 to the left, causing the two reset springs 68 to contract. The movement of the moving block 63 to the left drives the follower frame 64 to move to the left. Under the action of the slot 65, the follower frame 64 drives the pH detector 66 to rotate, so that the detection end of the pH detector 66 is inserted into the reaction solution, thereby detecting the pH concentration of the reaction solution.

[0106] In step S4, when the reciprocating frame 22 drives the drive tooth plate 54 to move to the left, the drive tooth plate 54 contacts the adjusting gear 53 and continues to move to the left, the drive tooth plate 54 drives the adjusting gear 53 to rotate. The rotation of the adjusting gear 53 drives the industrial camera 52 to rotate through the rotating shaft, thereby switching the industrial camera 52 to the working state and monitoring the adsorption of lithium phosphate fine crystals on the tank wall through the industrial camera 52.

[0107] Step S5: When the reciprocating belt 21 drives the reciprocating frame 22 to move, the reciprocating frame 22 will simultaneously drive the cleaning brush 32 and the rotating gear 33 to move. With the cooperation of the crystal removal plate 34 and the rotating gear 33, the cleaning brush 32 will rotate during the movement, thereby sweeping and peeling off the fine lithium phosphate crystals adsorbed on the inner wall of the reaction tank 1.

[0108] When the reciprocating belt 21 moves the reciprocating frame 22 to the right, the contact wheel 42 contacts the vibrating plate 44, and continues to move to the right, after the contact wheel 42 contacts the protruding part of the vibrating plate 44, the adjusting screw 41 will cause the slider 31 to slide backward on the inner side of the reciprocating frame 22, causing the spring 43 to contract. The slider 31 moves and drives the cleaning brush 32 to move backward. Conversely, when the contact wheel 42 contacts the concave part of the vibrating plate 44, the expansion of the spring 43 will cause the slider 31 to drive the cleaning brush 32 to move forward. Through the back-and-forth movement of the cleaning brush 32, under the action of the water flow, the fine lithium phosphate crystals attached to the surface of the cleaning brush 32 are removed.

[0109] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made under the concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. An apparatus for preparing lithium battery cathode materials from lithium precipitation mother liquor, characterized in that, Includes a reaction tank, a moving mechanism, a crystal removal mechanism, and a vibration desorption mechanism; The moving mechanism includes a reciprocating belt and a reciprocating frame. The reciprocating frame is fixed to the surface of the reciprocating belt, and the reciprocating frame can be driven to reciprocate within the reaction tank by the rotation of the reciprocating belt. The crystal removal mechanism includes two sliders slidably connected to the inner side of the reciprocating frame. The inner sides of the two sliders are vertically rotatably connected to cleaning brushes. Rotating gears are fixed on the top surfaces of the two cleaning brushes. Crystal removal tooth plates are fixed on the front and rear sides of the inner wall of the reaction tank. The two crystal removal tooth plates mesh with the two rotating gears respectively. The vibration desorption mechanism includes adjusting screws threaded to the inner sides of two sliders, with contact wheels rotatably connected to the top of each of the two adjusting screws. Springs are provided on the inner side of the reciprocating frame and on the opposite side of the two sliders. Vibration plates are fixed on the front and rear sides of the inner wall of the reaction tank. The surface of the vibrating plate has an uneven structure. When the contact wheel contacts the vibrating plate and moves, the slider can slide back and forth on the inner side of the reciprocating frame through the cooperation of the spring. Mounting brackets are fixedly provided on both sides of the inner wall of the reaction tank. Drive wheels are rotatably connected to the inner sides of the two mounting brackets. The reciprocating belt is sleeved on the surface of the two drive wheels. Two guide seats are slidably connected to the bottom of the reciprocating frame. The two ends of the two guide seats are fixedly connected to the inner wall of the reaction tank. A drive motor is provided on the left side of the reaction tank. A bevel gear is fixedly provided at the output end of the drive motor and the front end of the left drive wheel. The two bevel gears mesh with each other. A monitoring mechanism is fixedly installed on the left side of the inner wall of the reaction tank. The monitoring mechanism includes a rotating seat fixedly installed on the left side of the inner wall of the reaction tank. An industrial camera is rotatably connected to the inner side of the rotating seat via a rotating shaft. An adjusting gear is fixedly installed on the industrial camera via the rotating shaft. A drive gear plate is fixedly installed on the front side of the bottom of the reciprocating frame. A detection mechanism is fixedly installed on the left side of the inner wall of the reaction tank. The detection mechanism includes a mounting plate fixedly installed on the left side of the inner wall of the reaction tank. Two threaded guide rods are fixedly installed on the right side of the mounting plate. A moving block is slidably connected to the surface of the two threaded guide rods. A follower frame is rotatably connected to the inner side of the moving block. A slot is opened on the inner side of the mounting plate. The rear side of the follower frame is located in the slot. A pH detector is installed inside the follower frame. A trigger rod is threadedly connected to the inside of the reciprocating frame. A reset spring is sleeved on the surface of each of the two threaded guide rods.

2. The apparatus for preparing lithium battery cathode materials from lithium-ion mother liquor according to claim 1, characterized in that, The top of the reciprocating frame is equipped with a pH adjustment mechanism, which includes a solution tank located on the top of the reciprocating frame. The reciprocating frame is longitudinally rotatably connected to a pipe, and the surface of the pipe is connected to multiple nozzles. Two flipping gears are fixed on the surface of the pipe. Flipping tooth plates are fixed on the front and rear sides of the two mounting brackets. A water pump is located on the front side of the top of the reciprocating frame, and the water pump is connected to the solution tank and the pipe through a hose.

3. The apparatus for preparing lithium battery cathode materials from lithium-ion mother liquor according to claim 1, characterized in that, The inner wall of the reaction tank is rotatably connected to a mixing mechanism. The mixing mechanism includes a mixing shaft rotatably connected to the inner wall of the reaction tank. Multiple mixing frames are provided on the surface of the mixing shaft. A mixing motor for driving the mixing shaft to rotate is provided on the right side of the reaction tank.

4. The apparatus for preparing lithium battery cathode materials from lithium-ion mother liquor according to claim 3, characterized in that, Two arc-shaped plates are fixed to both ends of the mixing shaft by bolts. A through groove is opened on the inner side of the arc-shaped plate. A scraping plate is fixed to the surface of each of the four arc-shaped plates. Two collection tanks are provided at the bottom of the reaction tank. A drain pipe is connected to the surface of each of the two collection tanks.

5. A process for preparing lithium battery cathode materials from lithium precipitation mother liquor, characterized in that, The process method includes the equipment and the following steps as described in any one of claims 1-4: Step S1: Mix lithium precipitation mother liquor and concentrated sulfuric acid in a uniform ratio, adjust the pH to neutral, and remove carbonate ions to obtain decarbonated liquor. Step S2: After preheating the obtained decarbonized liquid to a suitable temperature, perform MVR evaporation and concentration to obtain a concentrated liquid; Step S3: The obtained concentrate is centrifuged and filtered to obtain a sodium-potassium mixture and a concentrated filtrate; Step S4: Cool the obtained concentrated filtrate to a suitable temperature to crystallize and precipitate, filter to obtain Na2SO4·H2O and frozen filtrate, and then dehydrate and dry to obtain sodium sulfate; Step S5: Concentrate the frozen filtrate using an MVR evaporator to obtain Li + To obtain a concentrated solution at a suitable concentration; Step S6: Prepare di(2-ethylhexyl) phosphate-sulfonated kerosene (volume ratio 1:3) as the extractant, add 5% tributyl phosphate as a co-extractant, extract it with the concentrate in a certain ratio, adjust the pH to a suitable range, and perform three countercurrent washings to obtain the extract. Step S7: Back-extract the obtained extract with a phosphoric acid solution of suitable concentration to obtain a LiH2PO4 solution, and adjust the pH to alkaline to generate Li3PO4.

Images