Equipment and process for preparing battery-grade lithium carbonate by recycling waste lithium batteries

Abstract

The invention provides equipment and a process for preparing battery-grade lithium carbonate by recycling waste lithium batteries, and relates to the technical field of preparation of battery-grade lithium carbonate, the equipment comprises a bracket, a preparation tank, a driving mechanism and a discharging mechanism; a top disc is installed at the top of the preparation tank, a protective cover is installed at the top of the top disc, a motor is installed on the upper surface of the top disc and located in the protective cover, a key groove of an output shaft of the motor is connected with a driving gear, and a driven gear is rotationally connected to the upper surface of the top disc and located on one side of the driving gear. According to the scheme, solid sodium carbonate can be crushed into fine particles and even powder through cooperation of rotation and lifting crushing, the surface area is increased, the sodium carbonate can make more sufficient contact with a lithium-containing leaching solution, incomplete local reaction of large solids is avoided, the recovery rate of converting lithium into lithium carbonate is increased, continuous rotation and lifting actions are matched, uniform discharging can be achieved, and the production efficiency is improved. Sodium carbonate is prevented from being locally excessive or insufficient, substance concentration fluctuation in a reaction system is prevented, impurity coprecipitation is reduced, and the purity of lithium carbonate is improved.

Description

Technical Field

[0001] This invention relates to the field of battery-grade lithium carbonate preparation, and more particularly to an equipment and process for preparing battery-grade lithium carbonate from recycled waste lithium batteries. Background Technology

[0002] Lithium-ion batteries have been widely used in recent years due to their high energy density, lack of memory effect, long cycle life, and high conversion efficiency. They have become the main energy carrier in fields such as electric vehicles, portable electronic devices, and large-scale energy storage systems. However, the lifespan of lithium-ion batteries is usually 3-5 years. With the rapid growth of market demand, the number of waste lithium-ion batteries is also increasing rapidly.

[0003] Waste lithium-ion batteries contain organic electrolytes, heavy metals, and toxic lithium hexafluorophosphate. If these substances enter the soil and groundwater, they will pose a serious threat to the ecological environment and human health. The recycling of waste lithium-ion batteries is not only an effective way to alleviate resource shortages, but also a key to promoting the sustainable development of the lithium battery industry.

[0004] In existing technologies, sodium carbonate is used for lithium precipitation when preparing battery-grade lithium carbonate from recycled waste lithium batteries. However, since sodium carbonate is in solid form, it is prone to agglomeration during the feeding process, which will eventually lead to insufficient stirring of the lithium-containing slurry in the preparation tank and affect the final lithium carbonate preparation effect.

[0005] Therefore, it is necessary to provide a device and process for recycling waste lithium batteries to produce battery-grade lithium carbonate to solve the above-mentioned technical problems. Summary of the Invention

[0006] This invention provides an equipment and process for recycling waste lithium batteries to prepare battery-grade lithium carbonate, which solves the problem in related technologies that sodium carbonate, being in solid form, is prone to agglomeration during the feeding process, thus affecting the final lithium carbonate preparation effect.

[0007] To solve the above-mentioned technical problems, the present invention provides a device for recycling waste lithium batteries to prepare battery-grade lithium carbonate, including a support frame, a preparation tank, a drive mechanism and a feeding mechanism;

[0008] The top of the preparation tank is equipped with a top plate, the top of the top plate is equipped with a protective cover, a motor is installed on the upper surface of the top plate and inside the protective cover, the output shaft of the motor is connected to a drive gear via a keyway, and a driven gear is rotatably connected to the upper surface of the top plate and on one side of the drive gear.

[0009] The driving mechanism includes a driving pulley and a driven pulley rotatably connected to the upper surface of the top plate. The outer walls of the driving pulley and the driven pulley are fitted with belts. A ratchet sleeve is embedded and fixedly installed at the shaft of the driving pulley. A ratchet is meshed inside the ratchet sleeve. A stirring rod is connected to the keyway at the shaft of the ratchet.

[0010] The feeding mechanism includes a feeding pipe fixed to the inner wall of the preparation tank. A sleeve is fixedly connected to the outlet end of the feeding pipe inside the preparation tank. A conical sleeve is fixedly fixed at the bottom of the sleeve. A connecting plate is rotatably installed at the bearing at the top of the sleeve. A key rod is connected to the axis of the connecting plate via a keyway. A conical column is fixedly fixed at the bottom of the key rod. A rotating column is fixedly fixed at the bottom of the conical column. Multiple grinding balls are fixedly fixed on the outer wall of the rotating column. A turntable is fixedly fixed on the outer wall of the key rod inside the sleeve. Guide wheels are rotatably connected to both sides of the turntable. A trigger plate is fixedly fixed on the inner wall of the sleeve below the two guide wheels. A return spring is sleeved on the outer wall of the key rod above the turntable.

[0011] The preparation tank is equipped with a discharge pipe at the bottom and a feed pipe on the side wall. A heating sleeve is fitted on the outer wall of the preparation tank, and the heating sleeve and the bracket are fixedly installed.

[0012] Preferably, the stirring rod passes through the ratchet and extends to the driven gear shaft, where it is connected to the driven gear via a keyway. The driving gear and the driven gear are meshed together.

[0013] Preferably, the upper and lower ends of the return spring are fixedly connected to the connecting plate and the turntable, the key rod passes through the center of the driven pulley shaft, and the key rod slides vertically about the center of the driven pulley and the connecting plate shaft.

[0014] Preferably, the plurality of grinding balls are equidistantly distributed in a ring around the surface of the rotating column, and there is a gap between the grinding balls and the inner wall of the cone sleeve, the gap being equal to the thickness of the trigger plate, and one side of the two trigger plates is constructed with an inclined surface.

[0015] Preferably, it also includes a rotating mechanism;

[0016] The bottom end of the drive pulley is fixed with a ferrule, the rotating mechanism includes a first gear fixed to the outer wall of the ferrule, an installation frame is installed on the inner wall of the preparation tank and directly below the feeding mechanism, a rotating rod is rotatably connected inside the installation frame, a rotating plate is fixedly provided in a ring at equal intervals on the outer wall of the rotating rod, and a second gear is connected to a keyway on one side of the rotating rod.

[0017] Preferably, the outer wall of the ferrule is rotatably connected to the shaft center of the top plate via a bearing, and the first gear and the second gear mesh with each other.

[0018] Preferably, the sleeve and the drive pulley shaft are hollow, and the stirring rod passes through the sleeve and the drive pulley shaft without contacting the sleeve or the drive pulley.

[0019] Preferably, it also includes auxiliary mechanisms;

[0020] The auxiliary mechanism includes a limiting frame fixed to the inner wall of the preparation tank. An arc-shaped impeller is connected to the bottom end of the stirring rod and below the limiting frame via a keyway. The axis of the arc-shaped impeller is rotatably connected to the limiting frame via a bearing.

[0021] The process for recycling spent lithium batteries to produce battery-grade lithium carbonate includes the following steps:

[0022] S1: Discharge, disassemble, and strip retired lithium batteries to obtain positive electrode powder. The retired lithium batteries include one or more of retired lithium iron phosphate batteries, retired ternary lithium batteries, retired lithium cobalt oxide batteries, and retired lithium manganese oxide batteries.

[0023] S2: The positive electrode powder, tartrate ester, and water are subjected to a leaching reaction to obtain a slurry. The tartrate ester includes one or more of D-diethyl tartrate and L-diethyl tartrate. The mass ratio of the positive electrode powder to the tartrate ester is 1:0.1-15, and the solid-liquid ratio of the positive electrode powder to the tartrate ester aqueous solution is 10-700 g / L. The leaching reaction is carried out by stirring and heating, more preferably by stirring and heating in an oil bath at a temperature of 100-250°C. The stirring rate is 50-600 rpm, and the stirring time is 0.5-8 h.

[0024] S3: The slurry is subjected to solid-liquid separation to obtain leachate and leachate residue;

[0025] S4: Add sodium carbonate to the leachate to carry out a lithium precipitation reaction to obtain a lithium precipitation slurry. The lithium precipitation reaction is carried out by oil bath stirring and heating at a temperature of 60-100°C for 1-3 hours. The lithium precipitation process needs to be carried out in a preparation tank, and the preparation tank is heated by a heating jacket.

[0026] S5: After solid-liquid separation of the lithium precipitation slurry, lithium-containing solid is obtained. After washing and drying the lithium-containing solid, battery-grade lithium carbonate product is obtained.

[0027] Compared with related technologies, the equipment and process for recycling waste lithium batteries to prepare battery-grade lithium carbonate provided by this invention have the following beneficial effects:

[0028] By combining rotation with lifting and crushing, solid sodium carbonate can be crushed into fine particles or even powder, increasing the surface area and allowing for more thorough contact with lithium-containing leaching solutions. This avoids incomplete local reactions in large solid pieces, improves the recovery rate of lithium to lithium carbonate, and the combination of continuous rotation and lifting action can achieve uniform feeding, avoid local over- or under-abundance of sodium carbonate, prevent fluctuations in the concentration of substances in the reaction system, reduce co-precipitation of impurities, and improve the purity of lithium carbonate.

[0029] Lifting and pulverizing can specifically address any localized solid buildup that may occur in the system, ensuring uniform mixing of the entire reaction system, reducing dead zones in the reaction, and further improving the stability and continuity of the preparation process. Attached Figure Description

[0030] 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.

[0031] Figure 1 The optimal structural schematic diagram provided for this invention;

[0032] Figure 2 for Figure 1 The diagram shown is a top-down view of the structure.

[0033] Figure 3 A schematic cross-sectional view of the preparation tank, top plate, and protective cover provided by the present invention;

[0034] Figure 4 for Figure 3 The diagram shows the connection structure between the drive mechanism and the feeding mechanism;

[0035] Figure 5 for Figure 3 The diagram shows a cross-sectional view of the ferrule and drive pulley.

[0036] Figure 6 for Figure 5 The enlarged structural diagram at point A is shown below;

[0037] Figure 7 for Figure 4 The diagram shows the initial working state of the feeding mechanism.

[0038] Figure 8 for Figure 7 The enlarged structural diagram at point B is shown below;

[0039] Figure 9 for Figure 7The diagram shows the rotating working state of the feeding mechanism.

[0040] Figure 10 for Figure 9 The enlarged structural diagram at point C is shown below;

[0041] Figure 11 This is a cross-sectional view of the feeding mechanism provided by the present invention;

[0042] Figure 12 A detailed structural diagram of the rotating mechanism provided by the present invention;

[0043] Figure 13 A detailed structural diagram of the auxiliary mechanism provided by the present invention.

[0044] Explanation of icon numbers:

[0045] 1. Support frame; 2. Heating jacket; 3. Preparation tank;

[0046] 4. Discharge pipe; 5. Protective cover;

[0047] 6. Drive mechanism; 61. Drive pulley; 62. Driven pulley; 63. Belt; 64. Ratchet sleeve; 65. Ratchet; 66. Compression sleeve.

[0048] 7. Feeding mechanism; 71. Feeding tube; 72. Sleeve; 73. Conical sleeve; 74. Key rod; 75. Conical column; 76. Rotating column; 77. Grinding ball; 78. Turntable; 79. Return spring; 710. Guide wheel; 711. Trigger plate; 712. Connecting plate.

[0049] 8. Rotating mechanism; 81. First gear; 82. Mounting bracket; 83. Rotating rod; 84. Second gear; 85. Rotating plate;

[0050] 9. Auxiliary mechanism; 91. Limiting frame; 92. Arc-shaped impeller;

[0051] 10. Feed pipe; 11. Motor; 12. Drive gear; 13. Driven gear;

[0052] 14. Top plate; 15. Stirring rod. Detailed Implementation

[0053] 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.

[0054] This invention provides a device and process for recycling waste lithium batteries to produce battery-grade lithium carbonate.

[0055] First embodiment:

[0056] Please see Figures 1 to 11 A device for recycling waste lithium batteries to produce battery-grade lithium carbonate includes a support frame 1, a preparation tank 3, a drive mechanism 6, and a feeding mechanism 7.

[0057] The top of the preparation tank 3 is equipped with a top plate 14, and a protective cover 5 is installed on the top of the top plate 14. A motor 11 is installed on the upper surface of the top plate 14 and inside the protective cover 5. The output shaft of the motor 11 is connected to a drive gear 12 via a keyway. A driven gear 13 is rotatably connected to the upper surface of the top plate 14 and on one side of the drive gear 12.

[0058] The drive mechanism 6 includes a drive pulley 61 and a driven pulley 62 rotatably connected to the upper surface of the top plate 14. The outer walls of the drive pulley 61 and the driven pulley 62 are fitted with belts 63. A ratchet sleeve 64 is embedded and fixedly installed at the shaft center of the drive pulley 61. A ratchet 65 is meshed inside the ratchet sleeve 64. A stirring rod 15 is connected to the keyway at the shaft center of the ratchet 65.

[0059] The feeding mechanism 7 includes a feeding pipe 71 fixed to the inner wall of the preparation tank 3. A sleeve 72 is fixedly connected to the outlet end of the feeding pipe 71 inside the preparation tank 3. A conical sleeve 73 is fixedly fixed at the bottom of the sleeve 72. A connecting plate 712 is rotatably installed at the bearing at the top end of the sleeve 72. A key rod 74 is connected to the axis of the connecting plate 712 via a keyway. A conical column 75 is fixedly fixed at the bottom end of the key rod 74. A rotating column 76 is fixedly fixed at the bottom of the conical column 75. A plurality of grinding balls 77 are fixedly fixed on the outer wall of the rotating column 76. A turntable 78 is fixedly fixed on the outer wall of the key rod 74 inside the sleeve 72. Guide wheels 710 are rotatably connected to both sides of the turntable 78. A trigger plate 711 is fixedly fixed on the inner wall of the sleeve 72 below the two guide wheels 710. A return spring 79 is sleeved on the outer wall of the key rod 74 above the turntable 78.

[0060] The preparation tank 3 is equipped with a discharge pipe 4 at the bottom, a feed pipe 10 is installed on the side wall of the preparation tank 3, and a heating sleeve 2 is fitted on the outer wall of the preparation tank 3. The heating sleeve 2 and the bracket 1 are fixedly installed.

[0061] The stirring rod 15 passes through the ratchet 65 and extends to the axis of the driven gear 13, where it is connected to the keyway of the driven gear 13. The driving gear 12 and the driven gear 13 are meshed together.

[0062] The upper and lower ends of the return spring 79 are fixedly connected to the connecting plate 712 and the turntable 78. The key rod 74 passes through the axis of the driven pulley 62 and slides vertically about the axis of the driven pulley 62 and the connecting plate 712.

[0063] The grinding balls 77 are equidistantly distributed in a ring around the surface of the rotating column 76. There is a gap between the grinding balls 77 and the inner wall of the cone sleeve 73, and the gap is equal to the thickness of the trigger plate 711. One side of the two trigger plates 711 is inclined.

[0064] Please see Figure 3 and Figure 4 The user can start the motor 11 to control the rotation of the drive gear 12. When the drive gear 12 rotates and meshes, it can drive the driven gear 13 to rotate freely clockwise or counterclockwise. Therefore, during the rotation of the driven gear 13, it can drive the stirring rod 15 to rotate clockwise or counterclockwise.

[0065] Please see Figure 4 and Figure 5 When the stirring rod 15 rotates clockwise, the stirring rod 15 will drive the ratchet 65 to rotate clockwise and simultaneously engage the transmission ratchet sleeve 64 to control the drive pulley 61 to rotate. When the drive pulley 61 rotates, the transmission belt 63 controls the driven pulley 62 to rotate clockwise synchronously.

[0066] If the stirring rod 15 rotates counterclockwise, the ratchet 65 driven by the stirring rod 15 will rotate counterclockwise and will avoid the ratchet sleeve 64. Therefore, when the stirring rod 15 rotates clockwise, it will synchronously drive the drive pulley 61 to rotate, while when the stirring rod 15 rotates counterclockwise, the drive pulley 61 will not rotate.

[0067] Please see Figure 5 and Figure 6 Since the entire ferrule 66 and drive pulley 61 are hollow, and the stirring rod 15 is installed through the ferrule 66 and drive pulley 61, the rotation of the stirring rod 15 clockwise or counterclockwise will not affect the ferrule 66 and drive pulley 61, and will not cause interference.

[0068] Please see Figure 7 and Figure 8 In the initial working condition, the grinding ball 77 will not contact the inner wall of the cone sleeve 73, and the guide wheels 710 on both sides of the turntable 78 will not make contact with the two trigger plates 711.

[0069] Please see Figure 9 and Figure 10 When the driven pulley 62 rotates clockwise, it will drive the key rod 74 to rotate. The rotation of the key rod 74 can drive the cone column 75 and the rotating column 76 to rotate and disperse the sodium carbonate particles fed into the feed pipe 71 into the preparation tank 3.

[0070] Secondly, during the rotation of the key rod 74, the turntable 78 is simultaneously driven to control the rotation of the guide wheel 710. When the guide wheel 710 rotates to the position of the trigger plate 711, the guide wheel 710 will follow the inclined surface of the trigger plate 711 to rise. During the rise, the turntable 78 and the key rod 74 drive the cone column 75 and the rotating column 76 to rise. Therefore, the grinding ball 77 in the rotating state can be controlled to rise and contact the inner wall of the cone sleeve 73, thereby performing rotary grinding on the sodium carbonate particles.

[0071] Please see Figure 11 It is understandable that since the sleeve 72 is fixedly installed inside the top plate 14, and the driven pulley 62 is rotatably installed on the top plate 14, the driven pulley 62 will not interfere with the fixed sleeve 72 during rotation. Secondly, the return spring 79 ensures the lifting and resetting of the turntable 78. Therefore, when the turntable 78 rotates, it can drive the return spring 79 and the connecting plate 712 to rotate without causing rotational resetting interference. Furthermore, the key rod 74 is installed throughout the interior of the driven pulley 62 and the connecting plate 712, ensuring that it can also be lifted and lowered during rotation.

[0072] This embodiment:

[0073] By combining rotation with lifting and crushing, solid sodium carbonate can be crushed into fine particles or even powder, increasing the surface area and allowing for more thorough contact with lithium-containing leaching solutions. This avoids incomplete local reactions in large solid pieces, improves the recovery rate of lithium to lithium carbonate, and the combination of continuous rotation and lifting action can achieve uniform feeding, avoid local over- or under-abundance of sodium carbonate, prevent fluctuations in the concentration of substances in the reaction system, reduce co-precipitation of impurities, and improve the purity of lithium carbonate.

[0074] Lifting and pulverizing can specifically address any localized solid buildup that may occur in the system, ensuring uniform mixing of the entire reaction system, reducing dead zones in the reaction, and further improving the stability and continuity of the preparation process.

[0075] Second embodiment:

[0076] Please see 5 and Figure 12 It also includes a rotating mechanism 8;

[0077] The bottom end of the drive pulley 61 is fixed with a sleeve 66. The rotating mechanism 8 includes a first gear 81 fixed on the outer wall of the sleeve 66. An installation frame 82 is installed on the inner wall of the preparation tank 3 and directly below the feeding mechanism 7. A rotating rod 83 is rotatably connected inside the installation frame 82. A rotating plate 85 is fixed in a ring at equal intervals on the outer wall of the rotating rod 83. A second gear 84 is connected to one side of the rotating rod 83 via a keyway.

[0078] The outer wall of the ferrule 66 is rotatably connected to the shaft of the top plate 14 via a bearing, and the first gear 81 and the second gear 84 mesh with each other.

[0079] Please see Figure 5 Since the ferrule 66 is installed at the bottom of the drive pulley 61, the drive pulley 61 will synchronously drive the first gear 81 to rotate during the clockwise rotation.

[0080] Please see Figure 12 During the rotation of the first gear 81, the meshing transmission of the second gear 84 drives the rotating rod 83 to rotate within the mounting frame 82. During the rotation of the rotating rod 83, the transmission control rotating plate 85 rotates below the feeding mechanism 7. The rotation of the rotating plate 85 can fully stir and mix the leachate and sodium carbonate in the preparation tank 3.

[0081] Understandably, due to the ratchet sleeve 64 and ratchet 65, the rotating mechanism 8 will not be activated when the stirring rod 15 rotates counterclockwise.

[0082] This embodiment:

[0083] After being fed, sodium carbonate falls directly onto the synchronously moving rotating plate 85, where it is instantly enveloped and dispersed by the rotating leachate. This prevents solid sodium carbonate from accumulating locally or floating on the surface of the liquid, ensuring rapid contact between sodium carbonate and lithium-containing leachate. The shear force generated by the rotation can break the diffusion resistance at the solid-liquid interface, further reducing reaction dead zones and improving the recovery rate of lithium to lithium carbonate.

[0084] At the same time, it can avoid the situation where the local concentration of sodium carbonate is too high at the feeding point. This situation will cause lithium impurities to co-precipitate with lithium carbonate, thus affecting the purity of the product. Therefore, a uniform mixing system can make the reaction pH value and ion concentration distribution more stable, ensure a consistent lithium carbonate crystal growth environment, reduce crystal agglomeration, and improve the uniformity of product particle size.

[0085] Third embodiment:

[0086] Please see Figure 3 and Figure 13 The sleeve 66 and the drive pulley 61 are hollow at their shaft centers, and the stirring rod 15 passes through the sleeve 66 and the drive pulley 61 shaft centers without contacting the sleeve 66 or the drive pulley 61.

[0087] It also includes auxiliary mechanism 9;

[0088] The auxiliary mechanism 9 includes a limiting frame 91 fixed on the inner wall of the preparation tank 3. The bottom end of the stirring rod 15 and located below the limiting frame 91 are connected to an arc-shaped impeller 92 via a keyway. The axis of the arc-shaped impeller 92 is rotatably connected to the limiting frame 91 via a bearing.

[0089] Please see Figure 3 and Figure 13The stirring rod 15 can drive the arc impeller 92 to rotate whether it rotates clockwise or counterclockwise. Since the arc impeller 92 is located above the discharge pipe 4, it can break up the crystallized slurry after lithium precipitation when it rotates.

[0090] This embodiment:

[0091] The auxiliary mechanism 9 can break up agglomerates and blockages, ensuring continuous and stable discharge. Lithium carbonate crystals are prone to agglomerate and form large precipitates, especially at the discharge port, which can easily accumulate and blockage, leading to interruption of discharge. The auxiliary mechanism 9 can break up agglomerates in time to avoid blockage at the discharge port, ensuring continuous output of slurry. The fluidity of the slurry after crushing is improved, which can reduce the conveying resistance during discharge, reduce equipment load and failure risk, and adapt to the needs of continuous industrial production.

[0092] At the same time, the product particles are refined, the subsequent separation efficiency is optimized, and the solid-liquid contact area is increased. During subsequent filtration and washing, the filtrate has stronger penetration and the washing liquid can more fully contact the particle surface, thus improving the impurity removal effect.

[0093] The process for recycling spent lithium batteries to produce battery-grade lithium carbonate includes the following steps:

[0094] S1: Discharge, disassemble, and strip retired lithium batteries to obtain positive electrode powder. The retired lithium batteries include one or more of retired lithium iron phosphate batteries, retired ternary lithium batteries, retired lithium cobalt oxide batteries, and retired lithium manganese oxide batteries.

[0095] S2: The positive electrode powder, tartrate ester, and water are subjected to a leaching reaction to obtain a slurry. The tartrate ester includes one or more of D-diethyl tartrate and L-diethyl tartrate. The mass ratio of the positive electrode powder to the tartrate ester is 1:0.1-15, and the solid-liquid ratio of the positive electrode powder to the tartrate ester aqueous solution is 10-700 g / L. The leaching reaction is carried out by stirring and heating, more preferably by stirring and heating in an oil bath at a temperature of 100-250°C. The stirring rate is 50-600 rpm, and the stirring time is 0.5-8 h.

[0096] S3: The slurry is subjected to solid-liquid separation to obtain leachate and leachate residue;

[0097] S4: Add sodium carbonate to the leachate to carry out a lithium precipitation reaction to obtain a lithium precipitation slurry. The lithium precipitation reaction is carried out by oil bath stirring and heating at a temperature of 60-100°C for 1-3 hours. The lithium precipitation process needs to be carried out in a preparation tank, and the preparation tank is heated by a heating jacket.

[0098] S5: After solid-liquid separation of the lithium precipitation slurry, lithium-containing solid is obtained. After washing and drying the lithium-containing solid, battery-grade lithium carbonate product is obtained.

[0099] Using environmentally friendly tartrate esters as the reaction medium, they can be hydrolyzed into tartaric acid and ethanol under mild conditions. The hydrolyzed components have a synergistic effect, resulting in a high lithium leaching rate. Therefore, this invention has the advantages of simple operation, low energy consumption, high selective recovery rate of lithium, and closed-loop circulation of the leaching solution after lithium recovery. Tartrate esters are especially suitable for environments with strict reaction requirements, as they are green, environmentally friendly, and highly applicable.

[0100] By recovering the valuable lithium element and converting it into lithium dihydrogen phosphate, a short-range value-added resource recovery of waste lithium iron phosphate leaching purification solution is achieved. This reduces the production cost of producing lithium hydroxide or lithium carbonate from lithium-containing brine, while also reducing energy consumption.

[0101] Please refer to the reference again. Figures 1 to 13 The working principle of the equipment and process for recycling waste lithium batteries to prepare battery-grade lithium carbonate provided by this invention is as follows:

[0102] Step S1: The leachate enters the preparation tank 3 through the feed pipe 10. The user can start the motor 11 to control the drive gear 12 to rotate. When the drive gear 12 rotates and meshes, it can drive the driven gear 13 to rotate freely clockwise or counterclockwise. Therefore, during the rotation of the driven gear 13, it can drive the stirring rod 15 to rotate clockwise or counterclockwise. During the clockwise rotation of the driven pulley 62, it will drive the key rod 74 to rotate. The rotation of the key rod 74 can drive the cone column 75 and the rotating column 76 to rotate and disperse the sodium carbonate particles fed into the feed pipe 71 in the preparation tank 3.

[0103] Step S2: During the rotation of the key rod 74, the turntable 78 is driven to control the rotation of the guide wheel 710. When the guide wheel 710 rotates to the position of the trigger plate 711, the guide wheel 710 will follow the inclined surface of the trigger plate 711 to rise. During the rise, the turntable 78 and the key rod 74 drive the cone column 75 and the rotating column 76 to rise. Therefore, the grinding ball 77 in the rotating state can be controlled to rise and contact the inner wall of the cone sleeve 73, thereby performing rotational grinding on the sodium carbonate particles. Sodium carbonate and leachate are then fed into the preparation tank 3 for stirring and processing, and finally the lithium precipitation work is completed. The lithium precipitation slurry is discharged from the discharge pipe 4. During the stirring process, the user can start the heating jacket 2 to heat the preparation tank 3 with an oil bath.

[0104] 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. A device for recycling waste lithium batteries to produce battery-grade lithium carbonate, characterized in that, Includes a support frame, preparation tank, drive mechanism, and feeding mechanism; The top of the preparation tank is equipped with a top plate, the top of the top plate is equipped with a protective cover, a motor is installed on the upper surface of the top plate and inside the protective cover, the output shaft of the motor is connected to a drive gear via a keyway, and a driven gear is rotatably connected to the upper surface of the top plate and on one side of the drive gear. The driving mechanism includes a driving pulley and a driven pulley rotatably connected to the upper surface of the top plate. The outer walls of the driving pulley and the driven pulley are fitted with belts. A ratchet sleeve is embedded and fixedly installed at the shaft of the driving pulley. A ratchet is meshed inside the ratchet sleeve. A stirring rod is connected to the keyway at the shaft of the ratchet. The feeding mechanism includes a feeding pipe fixed to the inner wall of the preparation tank. A sleeve is fixedly connected to the outlet end of the feeding pipe inside the preparation tank. A conical sleeve is fixedly fixed at the bottom of the sleeve. A connecting plate is rotatably installed at the bearing at the top of the sleeve. A key rod is connected to the axis of the connecting plate via a keyway. A conical column is fixedly fixed at the bottom of the key rod. A rotating column is fixedly fixed at the bottom of the conical column. Multiple grinding balls are fixedly fixed on the outer wall of the rotating column. A turntable is fixedly fixed on the outer wall of the key rod inside the sleeve. Guide wheels are rotatably connected to both sides of the turntable. A trigger plate is fixedly fixed on the inner wall of the sleeve below the two guide wheels. A return spring is sleeved on the outer wall of the key rod above the turntable. The preparation tank is equipped with a discharge pipe at the bottom and a feed pipe on the side wall. A heating sleeve is fitted on the outer wall of the preparation tank, and the heating sleeve and the bracket are fixedly installed.

2. The equipment for recycling waste lithium batteries to produce battery-grade lithium carbonate according to claim 1, characterized in that, The stirring rod passes through the ratchet and extends to the driven gear shaft, where it connects with the driven gear keyway. The driving gear and the driven gear are meshed together.

3. The equipment for recycling waste lithium batteries to produce battery-grade lithium carbonate according to claim 1, characterized in that, The upper and lower ends of the reset spring are fixedly connected to the connecting plate and the turntable, and the key rod passes through the center of the driven pulley shaft. The key rod slides vertically about the center of the driven pulley and the connecting plate shaft.

4. The equipment for recycling waste lithium batteries to produce battery-grade lithium carbonate according to claim 1, characterized in that, The grinding balls are equidistantly distributed in a ring around the surface of the rotating column. There is a gap between the grinding balls and the inner wall of the cone sleeve, and the gap is equal to the thickness of the trigger plate. One side of the two trigger plates has an inclined structure.

5. The equipment for recycling waste lithium batteries to produce battery-grade lithium carbonate according to claim 1, characterized in that, It also includes a rotating mechanism; The bottom end of the drive pulley is fixed with a ferrule, the rotating mechanism includes a first gear fixed to the outer wall of the ferrule, an installation frame is installed on the inner wall of the preparation tank and directly below the feeding mechanism, a rotating rod is rotatably connected inside the installation frame, a rotating plate is fixedly provided in a ring at equal intervals on the outer wall of the rotating rod, and a second gear is connected to a keyway on one side of the rotating rod.

6. The equipment for recycling waste lithium batteries to produce battery-grade lithium carbonate according to claim 5, characterized in that, The outer wall of the ferrule is rotatably connected to the top plate shaft via a bearing, and the first gear and the second gear mesh with each other.

7. The equipment for recycling waste lithium batteries to produce battery-grade lithium carbonate according to claim 5, characterized in that, The sleeve and the drive pulley shaft are hollow, and the stirring rod passes through the sleeve and the drive pulley shaft without contacting the sleeve or the drive pulley.

8. The equipment for recycling waste lithium batteries to produce battery-grade lithium carbonate according to claim 7, characterized in that, It also includes auxiliary mechanisms; The auxiliary mechanism includes a limiting frame fixed to the inner wall of the preparation tank. An arc-shaped impeller is connected to the bottom end of the stirring rod and below the limiting frame via a keyway. The axis of the arc-shaped impeller is rotatably connected to the limiting frame via a bearing.

9. A process for recycling waste lithium batteries to produce battery-grade lithium carbonate, characterized in that, The process for recycling waste lithium batteries to produce battery-grade lithium carbonate includes an equipment for recycling waste lithium batteries to produce battery-grade lithium carbonate as described in any one of claims 1-8, comprising the following steps: S1: Discharge, disassemble, and strip retired lithium batteries to obtain positive electrode powder. The retired lithium batteries include one or more of retired lithium iron phosphate batteries, retired ternary lithium batteries, retired lithium cobalt oxide batteries, and retired lithium manganese oxide batteries. S2: The positive electrode powder, tartrate ester, and water are subjected to a leaching reaction to obtain a slurry. The tartrate ester includes one or more of D-diethyl tartrate and L-diethyl tartrate. The mass ratio of the positive electrode powder to the tartrate ester is 1:0.1-15, and the solid-liquid ratio of the positive electrode powder to the tartrate ester aqueous solution is 10-700 g / L. The leaching reaction is carried out by stirring and heating, more preferably by stirring and heating in an oil bath at a temperature of 100-250°C. The stirring rate is 50-600 rpm, and the stirring time is 0.5-8 h. S3: The slurry is subjected to solid-liquid separation to obtain leachate and leachate residue; S4: Add sodium carbonate to the leachate to carry out a lithium precipitation reaction to obtain a lithium precipitation slurry. The lithium precipitation reaction is carried out by oil bath stirring and heating at a temperature of 60-100°C for 1-3 hours. The lithium precipitation process needs to be carried out in a preparation tank, and the preparation tank is heated by a heating jacket. S5: After solid-liquid separation of the lithium precipitation slurry, lithium-containing solid is obtained. After washing and drying the lithium-containing solid, battery-grade lithium carbonate product is obtained.

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