Filtering device for recycling lithium hexafluorophosphate crystallization mother liquor

Abstract

The invention relates to a filtering device for recycling lithium hexafluorophosphate crystallization mother liquor. The filtering device for recycling the lithium hexafluorophosphate crystallization mother liquor comprises a shell, a partition plate is installed in the shell in a sliding and sealing mode and divides the interior of the shell into a filtering cavity and an air cavity, a heater is arranged in the air cavity, a connecting sleeve is rotatably installed at the bottom of the shell, and a rotating shaft is coaxially and rotatably installed in the connecting sleeve; a first driving motor for driving the connecting sleeve to rotate is arranged at the bottom of the shell, a plurality of limiting grooves are formed in the connecting sleeve, a forward thread section and a reverse thread section are arranged on the rotating shaft, first stirring blades are arranged on the forward thread section, second stirring blades are arranged on the reverse thread section, and the first stirring blades and the second stirring blades are matched with the limiting grooves; the partition plate is matched with the reverse thread section and is in sliding sealing fit with the limiting groove. According to the invention, the molecular sieve can fully absorb water and HF in the supernatant, the molecular sieve can be efficiently dried, the recovery efficiency of the lithium hexafluorophosphate crystallization mother liquor is improved, and the recovery cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of lithium hexafluorophosphate waste liquid recovery, and in particular relates to a filtering device for recovering lithium hexafluorophosphate crystallization mother liquid. Background Art

[0002] Lithium hexafluorophosphate is the most commonly used electrolyte in lithium batteries and is also the most expensive part of the battery. Since lithium hexafluorophosphate has a moderate ion migration number and dissociation constant in common organic solvents, it has good antioxidant properties and aluminum foil passivation ability, and can match various positive and negative electrode materials. Therefore, in the short and even medium term, lithium hexafluorophosphate is an irreplaceable raw material for lithium battery electrolytes.

[0003] There are generally four methods for preparing lithium hexafluorophosphate: gas-solid reaction method, hydrogen fluoride solvent method, organic solvent method and ion exchange method. At the end of the preparation process, a crystallization mother liquor containing a large amount of residual lithium hexafluorophosphate is often produced. If these mother liquors are not effectively recycled and reused, they will not only cause environmental pollution and waste of resources, but also cause considerable economic losses. How to effectively utilize the crystallization mother liquor and achieve green chemical industry is one of the problems that the industry needs to solve urgently.

[0004] The Chinese invention patent application with application publication number CN114671443A discloses a method and device for recycling lithium hexafluorophosphate crystallization mother liquor. The recycling method comprises the following steps: 1) subjecting the recovered crystallization mother liquor to low-temperature distillation, condensing and recovering HF solvent; 2) adding an organic solvent to the residual liquid after distillation for extraction, wherein the lower layer liquid is subjected to precipitation filtration, and after filtration, new crystallization mother liquor is re-injected for circulating low-temperature distillation; 3) passing the upper layer liquid through a filtering device to remove a small amount of water and HF; 4) subjecting the upper layer liquid to distillation or reduced pressure distillation, condensing and recovering the organic solvent; 5) vacuum drying the residual material after distillation, and introducing a mixed gas to remove LiF and LiPO x F y Impurities such as lithium hexafluorophosphate are obtained as solid. The recycling device includes a mother liquor inlet, a low-temperature distillation device, an extraction container, a sedimentation tank, a filtering device, a secondary distillation device, a dryer and a finished product outlet. When the upper liquid passes through the filtering device, the molecular sieve in the filtering device filters the upper clear liquid to remove a small amount of water and HF. When the molecular sieve absorption tends to be saturated, the molecular sieve is sent to the exhaust drying device for reuse. The upper clear liquid is removed by passing through the molecular sieve in the filtering device to remove water and HF. The molecular sieve has a poor absorption effect and a low absorption efficiency. In addition, the molecular sieve needs to be frequently taken in and out during use, and an external drying device is also required to dry the molecular sieve, which is inconvenient to operate. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a filtering device for recovering lithium hexafluorophosphate crystallization mother liquor.

[0006] The technical solution of a filtering device for recovering lithium hexafluorophosphate crystal mother liquor of the present invention is:

[0007] A filtering device for recovering mother liquor of lithium hexafluorophosphate crystallization, comprising a shell, a partition plate is installed in a sliding seal inside the shell, the partition plate divides the inside of the shell into a filter chamber and an air chamber, a heater is arranged in the air chamber, a connecting sleeve is rotatably installed at the bottom of the shell, a rotating shaft is coaxially rotatably installed in the connecting sleeve, a first driving motor for driving the connecting sleeve to rotate is arranged at the bottom of the shell, a plurality of limiting grooves are arranged on the connecting sleeve, a forward thread section and a reverse thread section are arranged on the rotating shaft, a first stirring blade is arranged on the forward thread section, and a second stirring blade is arranged on the reverse thread section. A stirring blade, the first stirring blade and the second stirring blade are both matched with the limit groove, the partition is matched with the reverse threaded section, the partition is matched with the limit groove sliding seal, a discharge pipe is provided at the bottom of the shell, a first control valve is provided on the discharge pipe, a filter assembly is provided on the discharge pipe, a connecting pipe is provided on the partition, a second control valve is provided on the connecting pipe, a circulating pump is provided on the outer wall of the shell, the air inlet of the circulating pump is connected with the air cavity through the first connecting pipe, the air outlet is connected with the filter cavity through the second connecting pipe, and a third control valve is provided on the second connecting pipe.

[0008] Furthermore, the partition includes an inner plate, a sealed bearing and an outer plate, the inner plate is provided with a threaded hole matching the reverse threaded section, the inner plate is sealed and fixedly connected to the inner ring of the sealed bearing, the outer plate is sealed and fixedly connected to the outer ring of the sealed bearing, the outer wall of the outer plate is slidably sealed with the inner wall of the shell, and the connecting pipe is arranged on the outer plate.

[0009] Furthermore, the first stirring blade includes a first center ring, a plurality of first connecting rods and a plurality of first blade plates, the inner hole of the first center ring is a threaded hole matching the reverse thread segment, a plurality of first connecting rods are evenly fixedly connected to the outer wall of the first center ring along the circumference of the first center ring, a plurality of first blade plates are respectively fixedly connected to the ends of a plurality of first connecting rods, and a plurality of first connecting rods are respectively matched with a plurality of limit grooves.

[0010] Furthermore, the second stirring blade includes a second center ring, a plurality of second connecting rods and a plurality of second blade plates, the inner hole of the second center ring is a threaded hole matching the forward thread segment, a plurality of second connecting rods are evenly fixedly connected to the outer wall of the second center ring along the circumference of the second center ring, a plurality of second blade plates are respectively fixedly connected to the ends of a plurality of second connecting rods, and a plurality of second connecting rods are respectively matched with a plurality of limit grooves.

[0011] Furthermore, a driving mechanism for driving the rotating shaft is provided on the top of the shell.

[0012] Furthermore, the drive mechanism includes a second drive motor, an upper connecting shaft and a split electromagnetic coupling, the second drive motor is fixedly connected to the shell through an upper motor fixing seat, the upper connecting shaft is rotatably installed on the upper end of the shell, the upper end of the upper connecting shaft extends into the upper motor fixing seat, and the lower end extends into the air cavity, the output shaft of the second drive motor is connected to the upper connecting shaft through a coupling, and the split electromagnetic coupling includes an input member and an output member, the input member is fixedly connected to the end of the upper connecting shaft, and the output member is fixedly connected to the end of the rotating shaft.

[0013] Furthermore, the lower end of the connecting sleeve is coaxially fixedly connected with a lower connecting shaft, and the lower connecting shaft is rotatably installed at the lower end of the shell through a bearing. The first drive motor is fixedly connected to the lower end of the shell through a lower motor fixing seat, and the lower end of the lower connecting shaft extends into the lower motor fixing seat and is fixedly connected to the output shaft of the first drive motor through a coupling.

[0014] Furthermore, a socket is provided on the discharge pipe, the filter assembly includes a fixing frame and a filter installed in the fixing frame, the fixing part is inserted in the socket, a supporting edge supporting the fixing frame is provided on the inner wall of the discharge pipe, and a handle is provided on the outer wall of the fixing frame.

[0015] Furthermore, the shell is provided with an upper clear liquid inlet pipe for feeding liquid into the filter cavity and a molecular sieve inlet pipe for adding molecular sieve into the filter cavity.

[0016] The present invention provides a filtering device for recovering lithium hexafluorophosphate crystallization mother liquor, which has the following beneficial effects:

[0017] In the filtering device for recovering the mother liquor of lithium hexafluorophosphate crystallization of the present invention, the positions of the partition, the first stirring blade, and the second stirring blade can be adjusted. When the molecular sieve absorbs water and HF in the supernatant, the position of the partition is close to the top, the volume of the filter chamber is larger, and the distance between the first stirring blade and the second stirring blade is larger, which can accommodate more supernatant and molecular sieve, and the molecular sieve is more dispersed in the supernatant, and the molecular sieve has a better absorption effect on water and HF in the upper cleaning. During the downward movement of the partition, it can play the role of a piston, which helps to fully discharge the supernatant in the filter chamber, and the first stirring blade and the second stirring blade move closer to the middle. The molecular sieve is dried in a filter chamber with a smaller volume, and the filter chamber with a smaller volume is conducive to maintaining a high temperature state. After the first stirring blade and the second stirring blade move closer to each other, it is equivalent to a stirring blade with more blades. After the same rotation speed, the molecular sieve can be more dispersed, and the molecular sieve is more fully in contact with the high-temperature gas, thereby improving the drying effect and efficiency of the molecular sieve. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic structural diagram of a filtering device for recovering lithium hexafluorophosphate crystal mother liquor of the present invention;

[0019] Figure 2 It is a cross-sectional view of a filtering device for recovering mother liquor of lithium hexafluorophosphate crystals of the present invention;

[0020] Figure 3 yes Figure 2 The enlarged view of point A in the middle;

[0021] Figure 4 yes Figure 2 The enlarged view of point B in the middle;

[0022] Figure 5 It is a partial structural schematic diagram of a filtering device for recovering lithium hexafluorophosphate crystal mother liquor of the present invention;

[0023] Figure 6 It is a schematic structural diagram of a partition in a filtering device for recovering mother liquor of lithium hexafluorophosphate crystals of the present invention;

[0024] Figure 7 It is a schematic structural diagram of a discharge pipe in a filtering device for recovering mother liquor of lithium hexafluorophosphate crystals of the present invention;

[0025] In the figure: 1. shell; 2. supporting leg; 3. upper clear liquid inlet pipe; 4. molecular sieve inlet pipe; 5. partition; 6. air cavity; 7. filter cavity; 8. connecting sleeve; 9. limit groove; 10. rotating shaft; 11. reverse thread section; 12. forward thread section; 13. second stirring blade; 14. first stirring blade; 15. lower connecting shaft; 16. first drive motor; 17. second drive motor; 18. upper connecting shaft; 19. input member; 20. output member; 21. discharge pipe; 22. first control valve; 23. connecting pipe; 24. second control valve; 25. heater; 26. outer plate; 27. inner plate; 28. sealed bearing; 29. ​​circulating pump; 30. first connecting pipe; 31. second connecting pipe; 32. third control valve; 33. filter assembly. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments:

[0027] The specific embodiment of the filtering device for recovering the mother liquor of lithium hexafluorophosphate crystallization of the present invention is as follows: Figures 1 to 7As shown, it includes a shell 1, which is a columnar structure, with a cover plate at the upper end of the shell 1, and a plurality of support legs 2 fixedly connected to the lower end of the shell 1. The shell 1 is fixedly connected with an upper clear liquid inlet pipe 3 for feeding liquid into the filter chamber 7 and a molecular sieve inlet pipe 4 for adding molecular sieves into the filter chamber 7. A partition 5 is installed in the shell 1 in a sliding seal, and the partition 5 divides the interior of the shell 1 into the filter chamber 7 and the air chamber 6. The partition 5 includes an inner plate 27, a sealing bearing 28 and an outer plate 26, the inner plate 27 is sealed and fixedly connected to the inner ring of the sealing bearing 28, the outer plate 26 is sealed and fixedly connected to the outer ring of the sealing bearing 28, and the outer wall of the outer plate 26 is slidably sealed with the inner wall of the shell 1.

[0028] A heater 25 is installed in the air cavity 6, and a connecting sleeve 8 is rotatably installed on the inner bottom wall of the shell 1. A rotating shaft 10 coaxial with the connecting sleeve 8 is rotatably installed on the bottom of the connecting sleeve 8 through a bearing. The connecting sleeve 8 has a plurality of limit grooves 9 extending vertically to the bottom of the connecting sleeve 8, and the plurality of limit grooves 9 are evenly spaced along the circumference of the connecting sleeve 8. The rotating shaft 10 is provided with a forward threaded section 12 and a reverse threaded section 11, and the reverse threaded section 11 is located on the upper side of the forward threaded section 12. The inner plate 27 has a threaded hole matching the reverse threaded section 11, and the inner plate 27 has a plurality of mounting holes that are sealed one by one with the non-limiting groove 9 part of the connecting sleeve 8. The upper end of the rotating shaft 10 is located on the upper side of the inner plate 27. The upper end surface of the connecting sleeve 8 is at the same height as the upper end surface of the reverse threaded section 11, and the upper end of the connecting sleeve 8 has a retaining ring to prevent the partition 5 from slipping out upward. The lower end of the connecting sleeve 8 is coaxially fixedly connected with a lower connecting shaft 15, which is rotatably mounted on the lower end of the housing 1 through a bearing. The bottom of the housing 1 is fixedly connected with a motor fixing seat, and a first drive motor 16 is fixedly connected to the motor fixing seat. The lower end of the lower connecting shaft 15 extends into the lower motor fixing seat and is fixedly connected to the output shaft of the first drive motor 16 through a coupling.

[0029] The first stirring blade 14 is threadedly connected to the forward threaded section 12 of the rotating shaft 10, and the second stirring blade 13 is threadedly connected to the reverse threaded section 11. The first stirring blade 14 includes a first center ring, a plurality of first connecting rods and a plurality of first blade plates, the inner hole of the first center ring is a threaded hole matching the reverse threaded section 11, a plurality of first connecting rods are evenly fixedly connected to the outer wall of the first center ring along the circumference of the first center ring, a plurality of first blade plates are respectively fixedly connected to the ends of the plurality of first connecting rods, and the plurality of first connecting rods are respectively matched with the plurality of limiting grooves 9. The second stirring blade 13 includes a second center ring, a plurality of second connecting rods and a plurality of second blade plates, the inner hole of the second center ring is a threaded hole matching the forward threaded section 12, a plurality of second connecting rods are evenly fixedly connected to the outer wall of the second center ring along the circumference of the second center ring, a plurality of second blade plates are respectively fixedly connected to the ends of the plurality of second connecting rods, and the plurality of second connecting rods are respectively matched with the plurality of limiting grooves 9.

[0030] The cover plate is fixedly connected with a motor fixing seat, and the upper end of the motor fixing seat is fixedly connected with a second drive motor 17. An upper connecting shaft 18 coaxial with the rotating shaft 10 is rotatably mounted on the cover plate through a bearing, the upper end of the upper connecting shaft 18 extends into the motor fixing seat, and is fixedly connected to the output shaft of the second drive motor 17 through a coupling, and the lower end of the upper connecting shaft 18 extends into the air cavity 6. The lower end of the upper connecting shaft 18 is transmission-connected to the upper end of the rotating shaft 10 through a split electromagnetic coupling, and the split electromagnetic coupling includes an input member 19 and an output member 20, the input member 19 is fixedly connected to the end of the upper connecting shaft 18, and the output member 20 is fixedly connected to the end of the rotating shaft 10.

[0031] A discharge pipe 21 is fixedly connected to the bottom of the housing 1, and a first control valve 22 is provided on the discharge pipe 21. A socket is provided on the discharge pipe 21, and a filter assembly 33 is inserted in the socket. The filter assembly 33 includes a fixing frame and a filter installed in the fixing frame. The fixing member is inserted in the socket. A support edge for supporting the fixing frame is provided on the inner wall of the discharge pipe 21, and a handle is provided on the outer wall of the fixing frame. A connecting pipe 23 connecting the air cavity 6 and the filter cavity 7 is fixedly connected to the outer plate 26 of the partition 5, and a second control valve 24 is installed on the connecting pipe 23. A circulating pump 29 is fixedly connected to the outer wall of the housing 1. The air inlet of the circulating pump 29 is connected to the air cavity 6 through the first connecting pipe 30, and the air outlet is connected to the filter cavity 7 through the second connecting pipe 31. A third control valve 32 is installed on the second connecting pipe 31.

[0032] In order to prevent the rotating shaft 10 from driving the connecting sleeve 8 to rotate when the second driving motor 17 drives the rotating shaft 10 to rotate, the lower end of the housing 1 has a limiting structure to prevent the output shaft of the first driving motor 16 from rotating when the first driving motor 16 stops working. In this embodiment, the limiting structure includes a top screw, which is threadedly connected to the motor fixing seat, and a threaded hole matching the top screw is provided on the output shaft of the second driving motor 17. When the top screw is threadedly connected in the threaded hole, the output shaft of the second driving motor 17 cannot rotate.

[0033] The working principle of the filtering device for recovering the mother liquor of lithium hexafluorophosphate crystallization of the present invention is as follows: initially, the partition plate 5 is located at the upper end of the reverse threaded section 11, the first stirring blade 14 is located at the upper position of the filter chamber 7, and the second stirring blade 13 is located at the lower position of the filter chamber 7. The supernatant enters the filter chamber 7 of the housing 1 through the supernatant inlet pipe 3, and the molecular sieve enters the filter chamber 7 through the molecular sieve. The split electromagnetic coupling is in a power-off state, and the input member 19 and the output member 20 of the split electromagnetic coupling are in a separated state. Start the first drive motor 16, the first drive motor 16 drives the connecting sleeve 8 to rotate, the first stirring blade 14 and the second stirring blade 13 rotate with the connecting sleeve 8, and stir the supernatant and the molecular sieve in the filter chamber 7, thereby improving the absorption efficiency of the molecular sieve to the water and HF in the upper washing. After the molecular sieve fully absorbs water and HF, turn off the second drive motor 17. The first control valve 22 on the discharge pipe 21 is opened, the second control valve 24 and the third control valve 32 are closed, and the control valves on the supernatant liquid inlet pipe 3 and the molecular sieve inlet pipe 4 are closed. The supernatant liquid flows out from the discharge pipe 21. The split electromagnetic coupling is energized, and the output member 20 is connected to the input member 19. The second drive motor 17 is started, and the second drive motor 17 drives the rotating shaft 10 to rotate. The first stirring blade 14 moves vertically downward under the action of the rotating shaft 10, and the second stirring blade 13 moves vertically upward under the action of the rotating shaft 10. The partition 5 moves downward with the rotating shaft 10. During the movement of the partition 5, the supernatant liquid in the filter chamber 7 is pressed out of the discharge pipe 21, and the filter assembly 33 can prevent the molecular sieve from flowing out. In order to increase the outflow rate of the supernatant liquid, the bottom wall of the housing 1 can also be covered with a layer of filter screen on the nozzle of the discharge pipe 21. The partition 5 acts as a piston during the downward movement, and the supernatant liquid in the filter chamber 7 can be fully discharged by increasing the pressure in the filter chamber 7. After the supernatant is discharged, the first control valve 22 is closed, and the second control valve 24 and the third control valve 32 are opened. The first drive motor 16, the heater 25 and the circulation pump 29 are started, the heater 25 heats the gas in the air cavity 6, the circulation pump 29 pumps the high-temperature gas in the air cavity 6 into the filter cavity 7, the first drive motor 16 drives the first stirring blade 14 and the second stirring blade 13 to stir the molecular sieve in the filter cavity 7, and the high-temperature gas dries the molecular sieve. The low-temperature gas after heat exchange with the molecular sieve enters the air cavity 6 through the connecting pipe 23 for heating, so that the gas circulates in the filter cavity 7 and the air cavity 6. The molecular sieve is dried in the smaller filter cavity 7, and the smaller filter cavity 7 helps to maintain a high-temperature environment, thereby improving the drying efficiency and effect of the molecular sieve. After the molecular sieve is dried, the second drive motor 17 is started to restore the present invention to the initial state and start the next round of operation.

[0034] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A filtering device for recovering lithium hexafluorophosphate crystallization mother liquor, characterized in that: The invention comprises a shell, wherein a partition is installed in a sliding seal inside the shell, wherein the partition divides the interior of the shell into a filter chamber and an air chamber, wherein a heater is arranged in the air chamber, wherein a connecting sleeve is rotatably installed at the bottom of the shell, wherein a rotating shaft is coaxially rotatably installed in the connecting sleeve, wherein a first driving motor for driving the connecting sleeve to rotate is arranged at the bottom of the shell, wherein a plurality of limiting grooves are arranged on the connecting sleeve, wherein a forward thread section and a reverse thread section are arranged on the rotating shaft, wherein a first stirring blade is arranged on the forward thread section, wherein a second stirring blade is arranged on the reverse thread section, wherein the first stirring blade and the second stirring blade are both matched with the limiting groove, wherein the partition cooperates with the reverse thread section, wherein the partition cooperates with the limiting groove in a sliding seal, wherein a discharge pipe is arranged at the bottom of the shell, wherein a first control valve is arranged on the discharge pipe, wherein a filter screen assembly is arranged on the discharge pipe, wherein a connecting pipe is arranged on the partition, wherein a second control valve is arranged on the connecting pipe, wherein a circulating pump is arranged on the outer wall of the shell, wherein an air inlet of the circulating pump is communicated with the air chamber through a first connecting pipe, and an air outlet is communicated with the filter chamber through a second connecting pipe, wherein a third control valve is arranged on the second connecting pipe.

2. The filtering device for recovering lithium hexafluorophosphate crystal mother liquor according to claim 1, characterized in that: The partition includes an inner plate, a sealed bearing and an outer plate. The inner plate is provided with a threaded hole matching the reverse threaded section. The inner plate is sealed and fixedly connected to the inner ring of the sealed bearing. The outer plate is sealed and fixedly connected to the outer ring of the sealed bearing. The outer wall of the outer plate is slidably sealed with the inner wall of the shell. The connecting pipe is arranged on the outer plate.

3. The filtering device for recovering lithium hexafluorophosphate crystal mother liquor according to claim 2, characterized in that: The first stirring blade includes a first center ring, a plurality of first connecting rods and a plurality of first blade plates. The inner hole of the first center ring is a threaded hole matching the reverse thread segment. A plurality of first connecting rods are evenly fixedly connected to the outer wall of the first center ring along the circumference of the first center ring. A plurality of first blade plates are respectively fixedly connected to the ends of a plurality of first connecting rods. A plurality of first connecting rods are respectively matched with a plurality of limiting grooves.

4. The filtering device for recovering lithium hexafluorophosphate crystallization mother liquor according to claim 2, characterized in that: The second stirring blade includes a second center ring, a plurality of second connecting rods and a plurality of second blade plates. The inner hole of the second center ring is a threaded hole matching the forward thread segment. A plurality of second connecting rods are evenly fixedly connected to the outer wall of the second center ring along the circumference of the second center ring. A plurality of second blade plates are respectively fixedly connected to the ends of a plurality of second connecting rods. A plurality of second connecting rods are respectively matched with a plurality of limiting grooves.

5. The filtering device for recovering lithium hexafluorophosphate crystal mother liquor according to claim 1, characterized in that: A driving mechanism for driving the rotating shaft is arranged on the top of the shell.

6. The filtering device for recovering lithium hexafluorophosphate crystal mother liquor according to claim 5, characterized in that: The driving mechanism includes a second driving motor, an upper connecting shaft and a split electromagnetic coupling. The second driving motor is fixedly connected to the shell through an upper motor fixing seat. The upper connecting shaft is rotatably installed on the upper end of the shell. The upper end of the upper connecting shaft extends into the upper motor fixing seat, and the lower end extends into the air cavity. The output shaft of the second driving motor is connected to the upper connecting shaft through a coupling. The split electromagnetic coupling includes an input member and an output member. The input member is fixedly connected to the end of the upper connecting shaft, and the output member is fixedly connected to the end of the rotating shaft.

7. The filtering device for recovering lithium hexafluorophosphate crystal mother liquor according to claim 1, characterized in that: The lower end of the connecting sleeve is coaxially fixedly connected with a lower connecting shaft, and the lower connecting shaft is rotatably mounted on the lower end of the shell through a bearing. The first drive motor is fixedly connected to the lower end of the shell through a lower motor fixing seat, and the lower end of the lower connecting shaft extends into the lower motor fixing seat and is fixedly connected to the output shaft of the first drive motor through a coupling.

8. The filtering device for recovering lithium hexafluorophosphate crystal mother liquor according to claim 1, characterized in that: The discharge pipe is provided with a socket, the filter assembly includes a fixing frame and a filter installed in the fixing frame, the fixing piece is inserted in the socket, the inner wall of the discharge pipe is provided with a supporting edge supporting the fixing frame, and the outer wall of the fixing frame is provided with a handle.

9. The filtering device for recovering lithium hexafluorophosphate crystal mother liquor according to claim 1, characterized in that: The shell is provided with an upper clear liquid inlet pipe for feeding liquid into the filter cavity and a molecular sieve inlet pipe for adding molecular sieve into the filter cavity.

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