Solid waste lithium extraction residue leaching equipment and comprehensive recovery process thereof

Abstract

The application provides a solid waste lithium extraction residue leaching equipment and a comprehensive recovery process thereof, and relates to the technical field of solid waste treatment. The equipment comprises a base, a leaching tank and a leaching mechanism. The leaching tank is located inside the base, a top cover is installed on the top of the leaching tank, a mounting frame and a side frame are installed on the top surface of the top cover through bolts, a motor is installed on the top of the mounting frame, and a driving rod is connected to the output end key groove of the motor. A connecting seat is fixedly arranged at the bottom of the top cover and inside the leaching tank, and a hollow pipe is rotatably connected to the connecting seat. When the mixing rod is reversely and rapidly stirred, the side rod will simultaneously revolve and rotate, strong shearing force and turbulent flow effect are generated, the reaction rate in the initial stage of leaching is significantly improved, and the overall leaching period is shortened. When the mixing rod rotates forward, the side rod will automatically stop revolving and rotating, only the mixing rod rotates, the residue material that has not completely reacted can still contact with the liquid phase, and the residual target component is maximally recovered.

Description

Technical Field

[0001] This invention relates to the field of solid waste treatment, and in particular to a solid waste lithium extraction residue leaching equipment and its comprehensive recycling process. Background Technology

[0002] With the widespread application of lithium-ion batteries in new energy vehicles and energy storage, the problem of waste battery recycling has become increasingly prominent. Among them, lithium iron phosphate batteries dominate the market due to their high safety and low cost. During the recycling process, a large amount of lithium extraction residue is generated after lithium is extracted through hydrometallurgy, which has significant resource value.

[0003] Lithium extraction residue, produced by hydrometallurgical extraction of lithium from recycled lithium-ion batteries, is classified as solid waste, mostly industrial solid waste. If it contains toxic or hazardous substances, it may also be classified as hazardous waste. Therefore, the comprehensive recycling and utilization of lithium extraction residue has become a key technological requirement for promoting the sustainable development of the lithium battery industry.

[0004] In existing technologies, waste lithium extraction residue needs to be mixed with hot water for leaching. In the early stage of leaching, there is a solid-liquid interface layer between the lithium extraction residue particles and the hot water, and the dissolution and diffusion rate of the target component is slow. In the later stage of leaching, the concentration of the target component in the system is close to saturation. Continuing to stir vigorously will not only fail to improve the recovery rate, but will also bring side effects.

[0005] Therefore, it is necessary to provide a solid waste lithium extraction residue leaching equipment and its comprehensive recycling process to solve the above-mentioned technical problems. Summary of the Invention

[0006] This invention provides a solid waste lithium extraction residue leaching equipment and its comprehensive recycling process, which solves the problem in related technologies that it is inconvenient to use different mixing modes to adapt to the early and late stages of leaching.

[0007] To solve the above-mentioned technical problems, the present invention provides a solid waste lithium extraction residue leaching device, including a base, a leaching tank and a leaching mechanism;

[0008] The leaching tank is located inside the base, and a top cover is installed on the top of the leaching tank. A mounting bracket and a side bracket are installed on the upper surface of the top cover by bolts. A motor is installed on the top of the mounting bracket, and a drive rod is connected to the output end of the motor via a keyway.

[0009] A connecting seat is fixed at the bottom of the top cover and inside the leaching tank. A hollow tube is rotatably connected inside the connecting seat. A ratchet disk is fixed at the top of the hollow tube and at the axis above the top cover. A first ratchet is connected to the keyway on the outer wall of the drive rod and inside the ratchet disk.

[0010] Fixed brackets are fixed on both sides of the hollow tube, an installation ring is fixed on the inner wall of the leaching tank, a toothed ring is fixed at the bottom of the installation ring, a rotating bracket is provided at the top of the installation ring, multiple mixing rods are fixed on the outer wall of the drive rod and below the hollow tube, a positioning block is slidably connected inside the installation ring, a rotating block is fixed on the outer wall of the positioning block, a gear is rotatably connected at the bottom of the rotating block, a side rod is rotatably connected at the shaft of the gear, and a discharge pipe is installed at the bottom of the leaching tank.

[0011] Preferably, the hollow tube is rotatably connected to the top cover at its axis, the first ratchet and the ratchet disc are meshed together, and the drive rod passes through the interior of the hollow tube without contacting it.

[0012] Preferably, the positioning block has a "T" shaped cross-section, the fixed frame and the rotating block are fixedly connected, and the gear and the gear ring mesh with each other.

[0013] Preferably, the positioning block, rotating block, gear, and side rod are mirror-distributed about the axis of the hollow tube.

[0014] Preferably, it also includes auxiliary mechanisms;

[0015] Hot water pipes and feed pipes are respectively installed through both sides of the leaching tank. The auxiliary mechanism includes a rotating shaft rotatably connected inside the top cover. A driven pulley is connected to the top of the rotating shaft via a keyway. A ratchet pulley is rotatably connected inside the side frame. A second ratchet is connected to the outer wall of the drive rod and inside the ratchet pulley via a keyway. A belt is fitted on the outer wall of the driven pulley and the ratchet pulley. A turntable is connected to the bottom of the rotating shaft and inside the leaching tank via a keyway.

[0016] Preferably, the second ratchet and the ratchet pulley mesh with each other, the drive rod passes through the ratchet pulley and does not contact the ratchet pulley, and the hot water pipe outlet is directly opposite the upper surface of the turntable.

[0017] Preferably, it also includes a feeding mechanism;

[0018] The feeding mechanism includes a flap that is rotatably connected to the outlet end of the feeding pipe. A positioning plate is fixedly provided on the inner wall of the leaching tank. A key rod is slidably connected inside the positioning plate. A guide wheel is fixedly provided at the bottom end of the key rod, and a top rod is fixedly provided at the top end of the key rod.

[0019] Preferably, the fixed frame and the rotating frame are fixedly connected, the rotating frame has inclined surfaces on both sides, the guide wheel is in contact with the mounting ring, and the top end of the top rod is in contact with the lower surface of the flip plate.

[0020] A comprehensive recycling process for lithium extraction residue from solid waste includes the following steps:

[0021] S1: Dry the lithium extraction residue at 105 degrees Celsius for 3 hours to remove free water, and then crush and sieve it to a particle size of 1~300μm after drying;

[0022] S2: Heat to 300℃ at 10℃ / min, hold for 15 minutes to decompose Fe(OH)3 and residual organic matter, heat to 850℃ at 5℃ / min, hold for 30 minutes to complete the conversion of FePO4 to Na3PO4+Fe2O3, recover water vapor through condensation device, and CO2 is directly emitted;

[0023] S3: Mix the roasted product with 80℃ hot water at a suitable liquid-solid ratio and leach in two stages: stir vigorously for 10 minutes to quickly dissolve Na3PO4, and stir slowly for 20 minutes to promote the dissociation of slightly soluble substances. Monitor the pH in real time until it is below 9.0 to avoid Fe2O3 redissolution. This step needs to be carried out in the leaching tank during the leaching process. The two states of vigorous stirring and slow stirring can be switched by controlling the clockwise or counterclockwise rotation of the leaching mechanism.

[0024] S4: Vacuum filtration yields iron-rich slag (Fe2O3) and phosphorus-containing leachate. Countercurrent washing is used, with the filter residue washed three times with 60℃ pure water to reduce sodium content. + Residue;

[0025] S5: Concentrate the leachate to a suitable density, add seed crystals (Na3PO4·12H2O microcrystals), and gradually lower the temperature: 80℃→50℃ (2℃ / min). After crystallization for 12 hours, centrifuge to separate the crystals. Wash the crystals with ethanol and dry them to obtain industrial grade Na3PO4·12H2O.

[0026] S6: Collect the washing wastewater, add Ca(OH)2 to adjust the pH to 12, and precipitate Ca5(PO4)3F; after filtration, return the filtrate to step 4 for recycling.

[0027] Compared with related technologies, the solid waste lithium extraction residue leaching equipment and its comprehensive recycling process provided by the present invention have the following beneficial effects:

[0028] When the mixing rod stirs at high speed in the opposite direction, it will simultaneously drive the side rod to revolve and rotate, generating strong shear force and turbulence effect. On the one hand, it can quickly break up the slag agglomerates and increase the contact area between the slag and hot water; on the other hand, it can destroy the solid-liquid interface layer, accelerate the diffusion of dissolved target components into the liquid phase, shorten the induction period of the leaching reaction, and ultimately significantly improve the reaction rate in the initial stage of leaching and shorten the overall leaching cycle.

[0029] When the mixing rod rotates in the forward direction, it will automatically release the rotation of the side rods. The rotation of the mixing rod alone will maintain the slight flow of the system, prevent the solid particles from settling and agglomerating, and ensure that the unreacted residue can still contact the liquid phase, so as to maximize the recovery of residual target components. 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 shows a cross-sectional view of the mounting bracket.

[0033] Figure 3 for Figure 2 The enlarged structural diagram at point A is shown below;

[0034] Figure 4 for Figure 1 The diagram shows a cross-sectional view of the leaching tank and its top cover.

[0035] Figure 5 for Figure 4 The diagram shows a cross-sectional view of the leaching mechanism.

[0036] Figure 6 A detailed structural diagram of the leaching mechanism provided by the present invention;

[0037] Figure 7 for Figure 6 The enlarged structural diagram at point B is shown below;

[0038] Figure 8 This is a schematic diagram of the initial working state of the leaching mechanism provided by the present invention;

[0039] Figure 9 for Figure 8 The enlarged structural diagram at point C is shown below;

[0040] Figure 10 A schematic diagram illustrating the working state of the leaching mechanism driving the feeding mechanism during its rotational operation, as provided by the present invention.

[0041] Figure 11 for Figure 10 The diagram shows an enlarged view of the structure at point D.

[0042] Figure 12 This is a process flow diagram for the comprehensive recycling of lithium extraction residue from solid waste.

[0043] Explanation of icon numbers:

[0044] 1. Base; 2. Leaching tank; 3. Top cover;

[0045] 4. Hot water pipe;

[0046] 5. Leaching mechanism; 51. Connecting seat; 52. Hollow tube; 53. Ratchet disc; 54. First ratchet; 55. Fixing frame;

[0047] 56. Mounting ring; 57. Gear ring; 58. Rotating frame; 59. Mixing rod; 510. Side rod; 511. Positioning block; 512. Rotating block; 513. Gear.

[0048] 6. Auxiliary mechanism; 61. Rotating shaft; 62. Driven pulley; 63. Belt; 64. Ratchet pulley; 65. Second ratchet; 66. Turntable;

[0049] 7. Feeding mechanism; 71. Positioning plate; 72. Key rod; 73. Guide wheel; 74. Top rod; 75. Flip plate;

[0050] 8. Mounting bracket; 9. Motor; 10. Side frame;

[0051] 11. Discharge pipe, 12. Drive rod, 13. Feed pipe. Detailed Implementation

[0052] 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.

[0053] This invention provides a solid waste lithium extraction residue leaching equipment and its comprehensive recycling process.

[0054] First embodiment:

[0055] Please see Figure 1 , Figures 4 to 7 A solid waste lithium extraction residue leaching device includes a base 1, a leaching tank 2 and a leaching mechanism 5;

[0056] The leaching tank 2 is located inside the base 1. A top cover 3 is installed on the top of the leaching tank 2. A mounting bracket 8 and a side bracket 10 are installed on the upper surface of the top cover 3 by bolts. A motor 9 is installed on the top of the mounting bracket 8. A drive rod 12 is connected to the output end of the motor 9 via a keyway.

[0057] The bottom of the top cover 3 and inside the leaching tank 2 is fixedly provided with a connecting seat 51. A hollow tube 52 is rotatably connected inside the connecting seat 51. A ratchet disk 53 is fixed at the top of the hollow tube 52 and at the axis above the top cover 3. A first ratchet 54 is connected to the keyway of the drive rod 12 and inside the ratchet disk 53.

[0058] The hollow tube 52 is fixedly provided with fixing brackets 55 on both sides. The inner wall of the leaching tank 2 is fixedly provided with an installation ring 56. The bottom of the installation ring 56 is fixedly provided with a toothed ring 57. The top of the installation ring 56 is provided with a rotating bracket 58. The outer wall of the drive rod 12 and located below the hollow tube 52 is fixedly provided with multiple mixing rods 59. The installation ring 56 is slidably connected with a positioning block 511. The outer wall of the positioning block 511 is fixedly provided with a rotating block 512. The bottom of the rotating block 512 is rotatably connected with a gear 513. The shaft of the gear 513 is rotatably connected with a side rod 510. The bottom of the leaching tank 2 is installed with a discharge pipe 11.

[0059] The hollow tube 52 is rotatably connected to the top cover 3 at its axis, the first ratchet 54 and the ratchet disc 53 are meshed together, and the drive rod 12 passes through the interior of the hollow tube 52 without contacting the hollow tube 52.

[0060] The positioning block 511 has a "T" shaped cross section, the fixed frame 55 and the rotating block 512 are fixedly connected, and the gear 513 and the gear ring 57 mesh with each other.

[0061] The positioning block 511, rotating block 512, gear 513 and side rod 510 are mirror-distributed about the axis of the hollow tube 52.

[0062] Please see Figure 4 and Figure 5 In the initial stage of lithium extraction residue and hot water leaching, the user starts the motor 9 to control the drive rod 12 to rotate counterclockwise. The drive rod 12 synchronously drives the first ratchet 54 to rotate counterclockwise, controlling the ratchet disc 53 to rotate counterclockwise. The ratchet disc 53 controls the hollow tube 52 to drive the entire fixed frame 55 to rotate counterclockwise.

[0063] Please see Figure 6 and Figure 7 During the counterclockwise rotation of the fixed frame 55, the rotating blocks 512 on both sides are controlled to rotate counterclockwise along the axis of the mounting ring 56. At this time, the rotating blocks 512 synchronously control the gear 513 to revolve counterclockwise along the axis of the gear ring 57. The gear 513 forms a meshing rotation on the basis of the revolve of the gear ring 57. Finally, during the process of the drive rod 12 controlling the rotation of the mixing rod 59, the side rod 510 simultaneously forms a rotation while revolving, which can strongly stir the hot water and lithium extraction residue in the leaching tank 2 during the leaching stage.

[0064] The user controls the drive rod 12 to rotate clockwise via the motor 9. When rotating clockwise, the first ratchet 54 will not drive the ratchet disc 53 to rotate. The drive rod 12 controls the mixing rod 59 to rotate clockwise, which can be adapted to the slow stirring stage in the later stage of leaching, thereby automatically releasing the rotation of the side rod 510.

[0065] It can be understood that the connecting seat 51 positions and connects the middle section of the hollow tube 52, which can ensure the stability of the hollow tube 52 during rotation. Secondly, the drive rod 12 is installed inside the hollow tube 52 through the tube. Whether the drive rod 12 rotates clockwise or counterclockwise, it will not interfere with the hollow tube 52 and the ratchet disc 53.

[0066] Furthermore, during the rotation of the rotating block 512, it rotates within the mounting ring 56 via the positioning block 511, which further ensures the transmission stability of the gear 513 and the gear ring 57.

[0067] This embodiment:

[0068] When the mixing rod 59 stirs at high speed in the opposite direction, it will simultaneously drive the side rod 510 to revolve and rotate, generating strong shear force and turbulence effect. On the one hand, it can quickly break up the slag agglomerates and increase the contact area between the slag and hot water; on the other hand, it can destroy the solid-liquid interface layer, accelerate the diffusion of the dissolved target components into the liquid phase, shorten the induction period of the leaching reaction, and ultimately significantly improve the reaction rate in the initial stage of leaching and shorten the overall leaching cycle.

[0069] When the mixing rod 59 rotates in the forward direction, it will automatically release the rotation of the side rod 510. The rotation of the mixing rod 59 alone will maintain the slight flow of the system, prevent the solid particles from settling and agglomerating, and ensure that the unreacted residue can still contact the liquid phase, so as to maximize the recovery of the residual target components.

[0070] On the other hand, reducing the disturbance of the liquid phase by stirring creates conditions for subsequent solid-liquid separation. If strong stirring is continued in the later stage, it will make it difficult for the fine particles suspended in the liquid phase to settle, increasing the difficulty and cost of subsequent separation.

[0071] Lithium extraction residue, as an industrial solid waste, may still contain valuable metals such as lithium, cobalt, and nickel. By switching between forward and reverse rotation and stirring, and combining different leaching stages, the harmless treatment of solid waste can be upgraded to resource utilization, thereby increasing the economic value of solid waste and conforming to the principles of solid waste reduction and resource utilization.

[0072] Second embodiment:

[0073] Please refer to Figures 1 to 4 It also includes auxiliary mechanisms 6;

[0074] Hot water pipe 4 and feed pipe 13 are respectively installed through both sides of the leaching tank 2. The auxiliary mechanism 6 includes a rotating shaft 61 rotatably connected inside the top cover 3. The top of the rotating shaft 61 is connected to a driven pulley 62 via a keyway. A ratchet pulley 64 is rotatably connected inside the side frame 10. A second ratchet 65 is connected via a keyway on the outer wall of the drive rod 12 and inside the ratchet pulley 64. A belt 63 is sleeved on the outer wall of the driven pulley 62 and the ratchet pulley 64. A turntable 66 is connected via a keyway at the bottom of the rotating shaft 61 and inside the leaching tank 2.

[0075] The second ratchet 65 and the ratchet pulley 64 mesh with each other. The drive rod 12 passes through the ratchet pulley 64 and does not contact the ratchet pulley 64. The outlet end of the hot water pipe 4 is directly opposite the upper surface of the turntable 66.

[0076] Please see Figures 2 to 4 In the first embodiment, during the initial strong stirring stage of leaching, the drive rod 12 rotates counterclockwise. During the counterclockwise rotation, the drive rod 12 drives the second ratchet 65 to rotate counterclockwise, but does not drive the ratchet pulley 64 to rotate. Therefore, during the strong stage, the turntable 66 is in a stopped state, and the hot water injected from the hot water pipe 4 will fall onto the turntable 66 and be distributed by gravity in the leaching tank 2.

[0077] In the later stage of leaching, when the drive rod 12 rotates clockwise, the drive rod 12 controls the second ratchet 65 to rotate clockwise, which in turn controls the ratchet pulley 64, the transmission belt 63, the driven pulley 62, and the rotating shaft 61 to drive the turntable 66 to rotate. At this time, the hot water injected from the hot water pipe 4 can be injected into the leaching tank 2 in a dispersed manner through the rotating turntable 66.

[0078] This embodiment:

[0079] Traditional hot water injection methods can easily cause excessively high water temperature and volume in some areas, while other areas may not have sufficient contact, leading to slag agglomeration or reaction dead zones. The turntable 66, through its own rotation, can cut the injected hot water into fine liquid streams and spray them evenly in a radial pattern onto the slag in the leaching tank 2. This dispersion method allows hot water to quickly penetrate to all layers of the slag, avoiding local solid-liquid imbalance and significantly increasing the contact area between the solid and liquid phases.

[0080] The rotation of turntable 66 generates continuous turbulent disturbance, which can break the diffusion boundary layer at the solid-liquid interface, accelerate the diffusion rate of dissolved target components from the slag surface to the liquid phase, and further disperse small agglomerates of slag formed due to insufficient stirring, expose more unreacted slag surface, shorten the induction period of leaching reaction, and improve overall leaching efficiency.

[0081] Third embodiment:

[0082] Please see Figures 8 to 11 It also includes the feeding mechanism 7;

[0083] The feeding mechanism 7 includes a flap 75 rotatably connected to the outlet end of the feeding pipe 13. A positioning plate 71 is fixedly provided on the inner wall of the leaching tank 2. A key rod 72 is slidably connected inside the positioning plate 71. A guide wheel 73 is fixedly provided at the bottom end of the key rod 72. A top rod 74 is fixedly provided at the top end of the key rod 72.

[0084] The fixed frame 55 and the rotating frame 58 are fixedly connected. The rotating frame 58 has inclined surfaces on both sides. The guide wheel 73 is in contact with the mounting ring 56. The top of the top rod 74 is in contact with the lower surface of the flip plate 75.

[0085] Please see Figure 8 and Figure 9 In the first embodiment, when the rotating frame 58 does not contact the guide wheel 73, the flip plate 75 is at its initial flip angle, and the lithium extraction residue falling through the feed pipe 13 will fall into the leaching tank 2 through the obstruction of the flip plate 75.

[0086] Please see Figure 10 and Figure 11 During the rotation of the fixed frame 55, the rotating frame 58 will be driven to rotate. At this time, the inclined surface of the rotating frame 58 will control the guide wheel 73 to drive the key rod 72 to control the top rod 74 to rise. When the top rod 74 rises, it controls the flip plate 75 to flip, thereby changing the feeding trajectory of the feeding pipe 13 and dispersing the lithium extraction residue evenly in the leaching tank 2 in a parabolic manner.

[0087] This embodiment:

[0088] Lithium extraction residue is mostly fine particles or slurry residue. Traditional gravity feeding is prone to particle agglomeration, resulting in fluctuating feeding amounts and affecting the stability of the solid-liquid ratio of the leaching system. During the mixing and stirring process, the flipping motion of the flap 75 is controlled simultaneously with the stirring. The flipping can change the discharge range of the feeding pipe 13, switching the fixed-point feeding to parabolic feeding, ensuring that the lithium extraction residue can be evenly dispersed in the leaching tank 2, ensuring that the residue enters the leaching tank 2 at a uniform speed and continuously, and maintaining the precise control of the solid-liquid ratio during the leaching process.

[0089] During the synchronous flipping process of the 75-inch flipper, the falling slag is dispersed and homogenized a second time, so that slag of different particle sizes is fully mixed during the flipping and pushing process, and then falls into the hot water system of the leaching tank 2. This can avoid particle size stratification and allow the slag and hot water to quickly form a uniform suspension system.

[0090] A comprehensive recycling process for lithium extraction residue from solid waste includes the following steps:

[0091] S1: Dry the lithium extraction residue at 105 degrees Celsius for 3 hours to remove free water, and then crush and sieve it to a particle size of 1-300 μm after drying.

[0092] S2: Heat to 300℃ at 10℃ / min, hold for 15 minutes to decompose Fe(OH)3 and residual organic matter, heat to 850℃ at 5℃ / min, hold for 30 minutes to complete the conversion of FePO4 to Na3PO4+Fe2O3, recover water vapor through condensation device, and CO2 is directly emitted;

[0093] S3: Mix the roasted product with 80℃ hot water at a suitable liquid-solid ratio and leach in two stages: stir vigorously for 10 minutes to quickly dissolve Na3PO4, and stir slowly for 20 minutes to promote the dissociation of slightly soluble substances. Monitor the pH in real time until it is below 9.0 to avoid Fe2O3 redissolution. This step needs to be carried out in leaching tank 2 during the leaching process. The two states of vigorous stirring and slow stirring can be switched by controlling the leaching mechanism 5 to rotate clockwise or counterclockwise.

[0094] S4: Vacuum filtration yields iron-rich slag (Fe2O3) and phosphorus-containing leachate. Countercurrent washing is used, with the filter residue washed three times with 60℃ pure water to reduce sodium content. + Residue;

[0095] S5: Concentrate the leachate to a suitable density, add seed crystals (Na3PO4·12H2O microcrystals), and gradually lower the temperature: 80℃→50℃ (2℃ / min). After crystallization for 12 hours, centrifuge to separate the crystals. Wash the crystals with ethanol and dry them to obtain industrial grade Na3PO4·12H2O.

[0096] S6: Collect the washing wastewater, add Ca(OH)2 to adjust the pH to 12, and precipitate Ca5(PO4)3F; after filtration, return the filtrate to step 4 for recycling.

[0097] Please refer to the reference again. Figures 1 to 12 The working principle of the solid waste lithium extraction residue leaching equipment and its comprehensive recycling process provided by this invention is as follows:

[0098] Step S1: Initial leaching stage of lithium extraction residue and hot water;

[0099] The start motor 9 controls the drive rod 12 to rotate counterclockwise. The drive rod 12 synchronously drives the first ratchet 54 to rotate counterclockwise, controlling the ratchet disc 53 to rotate counterclockwise. The ratchet disc 53 controls the hollow tube 52 to drive the entire fixed frame 55 to rotate counterclockwise. During the counterclockwise rotation of the fixed frame 55, the rotating blocks 512 on both sides are controlled to rotate counterclockwise along the axis of the mounting ring 56. At this time, the rotating blocks 512 synchronously control the gear 513 to revolve counterclockwise along the axis of the toothed ring 57. The gear 513 forms a meshing rotation motion based on the revolve of the toothed ring 57. Finally, during the process of the drive rod 12 controlling the rotation of the mixing rod 59, the side rod 510 is synchronously rotated while revolving. This can strongly stir the hot water and lithium extraction residue in the leaching tank 2 during the leaching stage.

[0100] Step S2: Lithium extraction residue and hot water leaching stage;

[0101] The motor 9 controls the drive rod 12 to rotate clockwise. When rotating clockwise, the first ratchet 54 will not drive the ratchet disc 53 to rotate. The drive rod 12 controls the mixing rod 59 to rotate clockwise, which can be adapted to the slow stirring stage in the later stage of leaching. Thus, the rotation of the side rod 510 is automatically released, and the lithium extraction residue and hot water in the leaching tank 2 are slowly stirred and leached only by the mixing rod 59.

[0102] 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 solid waste lithium extraction residue leaching device, characterized in that, Includes a base, leaching tank, and leaching mechanism; The leaching tank is located inside the base, and a top cover is installed on the top of the leaching tank. A mounting bracket and a side bracket are installed on the upper surface of the top cover by bolts. A motor is installed on the top of the mounting bracket, and a drive rod is connected to the output end of the motor via a keyway. A connecting seat is fixed at the bottom of the top cover and inside the leaching tank. A hollow tube is rotatably connected inside the connecting seat. A ratchet disk is fixed at the top of the hollow tube and at the axis above the top cover. A first ratchet is connected to the keyway on the outer wall of the drive rod and inside the ratchet disk. Fixed brackets are fixed on both sides of the hollow tube, an installation ring is fixed on the inner wall of the leaching tank, a toothed ring is fixed at the bottom of the installation ring, a rotating bracket is provided at the top of the installation ring, multiple mixing rods are fixed on the outer wall of the drive rod and below the hollow tube, a positioning block is slidably connected inside the installation ring, a rotating block is fixed on the outer wall of the positioning block, a gear is rotatably connected at the bottom of the rotating block, a side rod is rotatably connected at the shaft of the gear, and a discharge pipe is installed at the bottom of the leaching tank.

2. The solid waste lithium extraction residue leaching equipment according to claim 1, characterized in that, The hollow tube is rotatably connected to the top cover at its axis, the first ratchet and the ratchet disc are meshed together, and the drive rod passes through the inside of the hollow tube without contacting it.

3. The solid waste lithium extraction residue leaching equipment according to claim 1, characterized in that, The positioning block has a "T" shaped cross-section, the fixed frame and the rotating block are fixedly connected, and the gear and the gear ring mesh with each other.

4. The solid waste lithium extraction residue leaching equipment according to claim 1, characterized in that, The positioning block, rotating block, gear, and side rod are mirror-distributed about the axis of the hollow tube.

5. The solid waste lithium extraction residue leaching equipment according to claim 1, characterized in that, It also includes auxiliary mechanisms; Hot water pipes and feed pipes are respectively installed through both sides of the leaching tank. The auxiliary mechanism includes a rotating shaft rotatably connected inside the top cover. A driven pulley is connected to the top of the rotating shaft via a keyway. A ratchet pulley is rotatably connected inside the side frame. A second ratchet is connected to the outer wall of the drive rod and inside the ratchet pulley via a keyway. A belt is fitted on the outer wall of the driven pulley and the ratchet pulley. A turntable is connected to the bottom of the rotating shaft and inside the leaching tank via a keyway.

6. The solid waste lithium extraction residue leaching equipment according to claim 5, characterized in that, The second ratchet and the ratchet pulley mesh with each other, the drive rod passes through the ratchet pulley and does not contact the ratchet pulley, and the hot water pipe outlet is directly opposite the upper surface of the turntable.

7. The solid waste lithium extraction residue leaching equipment according to claim 5, characterized in that, It also includes the feeding mechanism; The feeding mechanism includes a flap that is rotatably connected to the outlet end of the feeding pipe. A positioning plate is fixedly provided on the inner wall of the leaching tank. A key rod is slidably connected inside the positioning plate. A guide wheel is fixedly provided at the bottom end of the key rod, and a top rod is fixedly provided at the top end of the key rod.

8. The solid waste lithium extraction residue leaching equipment according to claim 7, characterized in that, The fixed frame and the rotating frame are fixedly connected. The rotating frame has inclined surfaces on both sides. The guide wheel is in contact with the mounting ring. The top of the top rod is in contact with the lower surface of the flip plate.

9. A comprehensive recycling process for lithium extraction residue from solid waste through leaching, characterized in that, The comprehensive recycling process for leaching lithium extraction residue from solid waste includes a leaching device for lithium extraction residue from solid waste as described in any one of claims 1-8, comprising the following steps: S1: Dry the lithium extraction residue at 105 degrees Celsius for 3 hours to remove free water, and then crush and sieve it to a particle size of 1~300μm after drying; S2: Heat to 300℃ at 10℃ / min, hold for 15 minutes to decompose Fe(OH)3 and residual organic matter, heat to 850℃ at 5℃ / min, hold for 30 minutes to complete the conversion of FePO4 to Na3PO4+Fe2O3, recover water vapor through condensation device, and CO2 is directly emitted; S3: Mix the roasted product with 80℃ hot water at a suitable liquid-solid ratio and leach in two stages: stir vigorously for 10 minutes to quickly dissolve Na3PO4, and stir slowly for 20 minutes to promote the dissociation of slightly soluble substances. Monitor the pH in real time until it is below 9.0 to avoid Fe2O3 redissolution. This step needs to be carried out in the leaching tank during the leaching process. The two states of vigorous stirring and slow stirring can be switched by controlling the clockwise or counterclockwise rotation of the leaching mechanism. S4: Vacuum filtration yields iron-rich slag (Fe2O3) and phosphorus-containing leachate. Countercurrent washing is used, with the filter residue washed three times with 60℃ pure water to reduce sodium content. + Residue; S5: Concentrate the leachate to a suitable density, add seed crystals (Na3PO4·12H2O microcrystals), and gradually lower the temperature: 80℃→50℃ (2℃ / min). After crystallization for 12 hours, centrifuge to separate the crystals. Wash the crystals with ethanol and dry them to obtain industrial grade Na3PO4·12H2O. S6: Collect the washing wastewater, add Ca(OH)2 to adjust the pH to 12, and precipitate Ca5(PO4)3F; after filtration, return the filtrate to step 4 for recycling.

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