Method for recovering mother liquor based on lithium fluoride

Abstract

The invention belongs to the technical field of lithium fluoride preparation, particularly relates to a lithium fluoride mother liquor recovery method, and aims to solve the problem of low recovery continuity caused by the fact that an independent tank body needs to be arranged for various impurities in mother liquor recovery in the prior art. The supporting base comprises a bottom supporting ring and a rear vertical rod, a mother liquor collecting tank which is internally provided with a cavity and is integrally of a cylindrical structure is fixed in the supporting ring, and a plurality of L-shaped brackets which are distributed in a central symmetry mode are fixed to the position, close to the circumferential edge, of the top end of the mother liquor collecting tank; and the top end of the L-shaped bracket is fixedly provided with a stock solution collecting barrel which has an upward opening and is of a barrel-shaped structure. According to the present invention, the catalyst is added while the mother solution is added, the vortex is generated in the vortex silencing pipe so as to slowly layer the generated impurity precipitate, and then the mother solution at the top layer is subjected to extraction separation so as to control the two piston scraping plates to scrape the solid impurities sinking at the bottom.

Description

Technical Field

[0001] The invention relates to the technical field of lithium fluoride preparation, and in particular to a method based on the recovery of lithium fluoride mother liquor. Background Art

[0002] The process for preparing high-purity lithium fluoride from industrial-grade lithium carbonate is to pass carbon dioxide through industrial-grade lithium carbonate to prepare lithium bicarbonate solution, and obtain lithium bicarbonate refined liquid after rough impurity removal and deep impurity removal by resin. The lithium bicarbonate refined liquid is reacted with hydrofluoric acid to obtain lithium fluoride slurry, and the slurry is centrifuged to obtain lithium fluoride wet material and mother liquor for recycling. In this method, about 30% of lithium fluoride will still remain in the mother liquor after separation. If the mother liquor is discharged directly, it will cause great harm to the environment and waste a large amount of lithium fluoride.

[0003] After searching, it is found that in the prior art, when recovering the mother liquor, multiple large storage tanks need to be filled in sequence and then chemically treated and recovered, and integrated continuous recovery cannot be achieved. This recovery method is not only inefficient but also occupies a large amount of space. Therefore, we propose an integrated continuous recovery device. Summary of the invention

[0004] In view of the technical problem that the mother liquor recovery in the prior art requires the installation of an independent tank for various impurity removal, resulting in low continuity of recovery, the present invention adopts the following technical solution: A method for recovering lithium fluoride mother liquor comprises the following steps: S1: preparing high-purity lithium carbonate into a certain slurry and then adding hydrofluoric acid solution to react to generate lithium fluoride precipitate and carbon dioxide, centrifuging the slurry after the reaction to obtain lithium fluoride and mother liquor, recycling the mother liquor through a lithium fluoride mother liquor recovery device, and drying the lithium fluoride after centrifugation to obtain high-purity lithium fluoride; S2: The mother liquor obtained after centrifugal separation of the slurry is passed into a large pool for treatment, and then the mother liquor is diverted to the small pools around it and a catalyst is added for chemical impurity removal; the mother liquor after impurity removal is then subjected to MVR concentration treatment; S3: Then, sodium chloride is added to the concentrated mother liquor for centrifugal separation to obtain a lithium carbonate solution, and then step S1 is performed to realize the recycling of the mother liquor.

[0005] Preferably, during the mother liquor circulation production process in S2, impurities such as potassium, sodium, and chloride ions in the mother liquor are continuously enriched, and the concentration gradually increases. When the concentration rises to a certain value, the mother liquor needs to be withdrawn for treatment; the other part is the resin impurity removal process, and the resin needs to be activated and regenerated after effective adsorption reaches saturation, and high-impurity wash water will be generated during the activation and regeneration process; these two parts of high-impurity mother liquors contain lithium, and these two parts of high-impurity mother liquors are concentrated with MVR after chemical impurity removal.

[0006] Preferably, the concentrated high-lithium solution in S3 is reacted with sodium carbonate to prepare industrial-grade lithium carbonate, and the obtained industrial-grade lithium carbonate is used as a raw material for preparing high-purity lithium carbonate. The mother liquor after lithium precipitation is concentrated and recovered in an evaporation system.

[0007] The lithium fluoride mother liquor recovery device comprises a support base, which comprises a bottom support ring and a vertical rod vertically erected at the rear side, and a mother liquor collection pool with an internal cavity and an overall cylindrical structure is fixed in the support ring, and a plurality of L-shaped brackets symmetrically distributed in the center are fixed to the top of the mother liquor collection pool near the circumferential edge, and a raw liquid collection barrel with the same opening upward in a barrel-shaped structure is fixed to the top of the L-shaped bracket, and a plurality of vortex settling tubes with an opening upward in a barrel-shaped structure are fixed to the circumferential outer wall of the raw liquid collection barrel, and a slag discharge pipe radially passing through the center line of the vortex settling tube is penetrated at the bottom end of the vortex settling tube, and the whole of the slag discharge pipe is a barrel with an opening away from the raw liquid collection barrel. The slag discharge pipe is slidably connected to two piston scrapers parallel to each other near the inner wall of the barrel bottom, and the spacing between the two piston scrapers is greater than the inner diameter of the vortex settling tube; the same axial push-pull rod is inserted between the two piston scrapers, and the raw liquid collecting barrel is provided with a vortex oblique plug hole near each vortex settling tube, and the vortex oblique plug holes are plugged with pressure valves extending into the corresponding vortex settling tubes; a crossbeam frame extending to the top of the raw liquid collecting barrel is fixed to the top of the vertical rod of the supporting base, and the end of the crossbeam frame is rotatably connected to a valve conversion rotating tube vertically extending into the interior of the raw liquid collecting barrel near the bottom, and a C-shaped pressure rod is fixed to the bottom end of the valve conversion rotating tube.

[0008] Preferably, a vertical downward slag discharge pipe is embedded in the circumferential outer wall of the slag discharge pipe near the bottom end, and a slag collecting trough with an opening upward and an annular groove as a whole is fixed on the upper surface of the supporting base. A slag discharge port is reserved at one end of the vertical plate of the slag collecting trough away from the supporting base, and the bottom of the slag collecting trough is lower at one end near the slag discharge port than the other end, ensuring that after receiving all the solid impurities from the slag discharge pipe, they will finally slide down and gather near the slag discharge port, thereby facilitating unified processing of the solid impurities.

[0009] Preferably, a shaft rod folding bracket is fixed to the circumferential outer wall of each slag discharge pipe near the barrel mouth, and a fan-shaped gear is rotatably connected to the side of the shaft rod folding bracket near the top, the arc surface of the fan-shaped gear is provided with teeth, and a compression spring is fixed to the end of the fan-shaped gear away from the arc surface, and a permanent magnet is fixed to the top of the compression spring; an electromagnet is fixed to the top of the shaft rod folding bracket, which is located on the side of the fan gear away from the vortex settling tube, and the electromagnet will push the permanent magnet open when energized; a connecting strip is fixed to the end of the axial push-pull rod away from the raw liquid collecting barrel, and a rack push rod attached to the surface of the slag discharge pipe and parallel to the axial center line of the slag discharge pipe is fixed to the top of the connecting strip; a guard rail matched with the rack push rod is fixed to the outer wall of the slag discharge pipe, and the rack push rod is meshed with the teeth of the fan-shaped gear.

[0010] Preferably, a loading cover is fixed at the top barrel mouth of the raw liquid collection barrel, and a sliding bearing matched with the diameter of the valve conversion rotating tube is embedded in the middle of the loading cover, a valve opening pointing plate with a fan-shaped structure is fixed to the upper surface of the circumferential outer wall of the valve conversion rotating tube close to the loading cover, and a permanent magnet 2 is fixed to the upper surface of the valve opening pointing plate close to the edge; a driven rotating plate is slidably sleeved on the circumferential outer wall of the sliding bearing, and the driven rotating plate is located between the lower surface of the valve opening pointing plate and the loading cover, and the driven rotating plate An external suction pump is fixed to one end of the upper surface of the plate away from the valve conversion rotating tube, and a suction pipe is fixed at the inlet of the external suction pump, and a floating block and a suction ball are respectively sleeved on the pipe mouth of the end of the suction pipe away from the external suction pump, a hard drainage pipe is inserted at the discharge port of the external suction pump, and a plurality of expanded collection pipes corresponding to the vortex settling tubes are fixed to the circumferential outer wall of the mother liquor collection tank; an electromagnet 2 adapted to the position of the permanent magnet 2 is fixed to the top of the driven rotating plate, and the electromagnet 2 repels the permanent magnet 2 after being energized.

[0011] Preferably, a connecting bridge is fixed between the outer walls of the pipe openings of two adjacent vortex settling tubes, and an arc-shaped groove is opened on the upper surface of the connecting bridge, and the suction ball and the floating block can be pulled conveniently during the position change through the arranged connecting bridge, an anti-detachment bearing seat is fixed to the top end of the valve conversion rotating tube, and the anti-detachment bearing seat is embedded in the end of the crossbeam frame, and a driven pulley is fixed to the top end of the valve conversion rotating tube, a driving motor is fixed to the top end of the support base near the rear side, and a driving pulley is fixed to the top end of the output shaft of the driving motor, and the same conveyor belt is wound between the driving pulley and the driven pulley; the driven rotating plate is located above the center of the vortex settling tube and has a strip-shaped perforation, and the strip-shaped perforation is opened on the driven rotating plate. A steering wheel is arranged in the through hole, a spring baffle is fixed on the end of the upper surface of the driven rotating plate away from the external suction pump, and a tension spring is fixed on the spring baffle, a guide wheel frame is fixed on the end of the tension spring spring close to the external suction pump, and an electromagnet three is fixed on the lower surface of the guide wheel frame; to prevent the traction floating block from getting stuck, electromagnet three is added to fix the guide wheel frame on the driven rotating plate, and the suction pipe led out from the external suction pump is in the shape of a "question mark" and bypasses the guide wheel frame and the steering wheel in turn, and finally extends vertically downward to the vortex settling tube, so that the suction position can be adjusted automatically according to the height of the water level in the vortex settling tube, as well as the length of the suction pipe placed in the vortex settling tube, to avoid entanglement and pipe jamming.

[0012] Preferably, a limit rope is fixed on the upper surface of the valve opening pointing plate near the edge, and rope fixing blocks for fixing the limit rope are fixed on the upper surface of the driven rotating plate near the two ends of the electromagnet, ensuring that the distance of each bounce-off just reaches the center position of the next vortex settling tube.

[0013] Preferably, the circumferential inner wall of the raw liquid collection barrel is fixed with an annular groove adapted to the C-shaped pressure rod, and the pressure valve includes an outer tube, the inner wall of the outer tube is plugged with a valve core tube, the end of the valve core tube is fixed with a U-shaped limiting slot opening upward, the tube wall of the outer tube is located above the U-shaped limiting slot and is provided with a rectangular plug hole, and a valve plug plate is sealed and plugged in the rectangular plug hole; a round rod is reserved at the top of the valve plug plate, an extension guard frame is sleeved on the top of the round rod, a triangular abutment plate is fixed on the top of the round rod, and a tightening spring is fixed between the lower surface of the triangular abutment plate and the top of the extension guard frame; when the C-shaped pressure rod passes above the triangular abutment plate, it will press the pop-up valve plug plate, that is, close the pressure valve.

[0014] The beneficial effects of the present invention are: 1. Through the vortex settling tube set around the stock liquid collection barrel, the catalyst can be added while the mother liquid is added, and a vortex is generated in the vortex settling tube, so that the generated impurities can be slowly precipitated and layered. After that, the mother liquid on the top layer is extracted and separated, and the two piston scrapers can be controlled to scrape off the solid impurities settled at the bottom.

[0015] 2. By setting two piston scrapers slidably connected in the slag discharge pipe, when slag discharge is required, it is only necessary to control the electromagnet at the work station to be energized. At this time, the fan gear can move the rack push rod and the axial push-pull rod to pull out the two piston scrapers, and then scrape the solid impurities between the two to the top of the slag discharge pipe and discharge them.

[0016] 3. By setting the guide wheel frame and the tension spring, the suction position and the length of the suction pipe in the vortex settling pipe can be adjusted automatically according to the height of the water level in the vortex settling pipe to avoid entanglement and pipe jamming. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A flow chart of a method for recovering lithium fluoride mother liquor proposed by the present invention; Figure 2 A schematic diagram of the three-dimensional structure of a method for recovering lithium fluoride mother liquor proposed by the present invention; Figure 3 A side view of a method for recovering lithium fluoride mother liquor proposed by the present invention; Figure 4 A method for recovering lithium fluoride mother liquor proposed by the present invention Figure 3 A schematic diagram of the enlarged structure at A in the middle; Figure 5 A top view of a method for recovering lithium fluoride mother liquor proposed by the present invention; Figure 6 A method for recovering lithium fluoride mother liquor proposed by the present invention Figure 5 The schematic diagram of the cross-sectional structure along the BB line; Figure 7 A schematic diagram of a half-sectioned three-dimensional structure of a vortex settling tube and a slag discharge tube in a method for recovering lithium fluoride mother liquor proposed in the present invention; Figure 8 This is a schematic diagram of the assembly structure of a vortex settling tube in a method for recovering lithium fluoride mother liquor proposed by the present invention; Fig. 9 A schematic diagram of the three-dimensional structure of a slag collecting tank based on a method for recovering lithium fluoride mother liquor proposed in the present invention; Fig.10 A schematic diagram of the structure of a method for recovering lithium fluoride mother liquor proposed by the present invention when a suction ball is floated and is ready to be transferred to the next vortex settling tube; Fig.11 This is a schematic diagram of the explosion structure of a pressure valve in a method for recovering lithium fluoride mother liquor proposed in the present invention.

[0018] In the figure: 1, support base; 2, drive motor; 3, driving pulley; 4, conveyor belt; 5, crossbeam frame; 6, driven rotating plate; 601, pull rope fixing block; 7, driven pulley; 8, valve conversion rotating tube; 801, valve opening direction plate; 9, feeding top cover; 10, raw liquid collection barrel; 11, vortex settling tube; 1101, vortex oblique plug hole; 12, flared collection tube; 13, sector gear; 14, shaft rod folding bracket; 15, pressure valve; 151, valve core tube; 152, U-shaped limit slot; 153, valve plug plate; 154, extension guard frame; 15 5. Triangular abutment plate; 16. Slag collecting trough; 17. L-shaped bracket; 18. Mother liquor collecting pool; 19. Slag leakage pipe; 20. Slag discharge pipe; 21. Liquid discharge pipe; 22. Connecting bridge; 23. External suction pump; 24. Permanent magnet 1; 25. Electromagnet 1; 26. Axial push-pull rod; 2601. Connecting plate strip; 2602. Rack push rod; 27. Permanent magnet 2; 28. Limiting pull rope; 29. ​​Electromagnet 2; 30. Tension spring; 31. C-shaped pressure rod; 32. Piston scraper; 33. Suction ball; 34. Floating block; 35. Suction pipe; 36. Guide wheel frame. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0020] Please refer to Figure 1 , a method based on lithium fluoride mother liquor recovery, comprising the following steps: S1: preparing high-purity lithium carbonate into a certain slurry and then adding hydrofluoric acid solution to react to generate lithium fluoride precipitate and carbon dioxide, centrifuging the slurry after the reaction to obtain lithium fluoride and mother liquor, recycling the mother liquor through a lithium fluoride mother liquor recovery device, and drying the lithium fluoride after centrifugation to obtain high-purity lithium fluoride; S2: The mother liquor obtained after centrifugal separation of the slurry is passed into a large pool for treatment, and then the mother liquor is diverted to the small pools around it and a catalyst is added for chemical impurity removal; the mother liquor after impurity removal is then subjected to MVR concentration treatment; S3: Then, sodium chloride is added to the concentrated mother liquor for centrifugal separation to obtain a lithium carbonate solution, and then step S1 is performed to realize the recycling of the mother liquor.

[0021] Among them, during the mother liquor circulation production process in S2, impurities such as potassium, sodium, and chloride ions in the mother liquor are continuously enriched, and the concentration gradually increases. When the concentration rises to a certain value, the mother liquor needs to be withdrawn for treatment; the other part is the resin impurity removal process, and the resin needs to be activated and regenerated after the effective adsorption reaches saturation, and high-impurity wash water will be generated during the activation and regeneration process; these two parts of high-impurity mother liquors contain lithium, and these two parts of high-impurity mother liquors are concentrated with MVR after chemical impurity removal.

[0022] The concentrated high-lithium solution in S3 reacts with sodium carbonate to prepare industrial-grade lithium carbonate, and the obtained industrial-grade lithium carbonate is used as a raw material for preparing high-purity lithium carbonate. The mother liquor after lithium precipitation is concentrated and recovered in an evaporation system.

[0023] Please refer to Figure 2-11 The lithium fluoride mother liquor recovery device comprises a support base 1, which comprises a bottom support ring and a vertical rod vertically arranged at the rear side, and a mother liquor collection pool 18 with an internal cavity and an overall cylindrical structure is fixed in the support ring, and a plurality of L-shaped brackets 17 with central symmetry are fixed at the top of the mother liquor collection pool 18 near the circumferential edge, and a raw liquid collection barrel 10 with the same opening upward and a barrel-shaped structure is fixed at the top of the L-shaped bracket 17, and a plurality of vortex settling tubes 11 with the same opening upward and a barrel-shaped structure are fixed on the circumferential outer wall of the raw liquid collection barrel 10, and a slag discharge pipe 20 radially passing through the center line of the vortex settling tube 11 is penetrated at the bottom of the vortex settling tube 11, and the whole of the slag discharge pipe 20 is a barrel body structure with an opening away from the raw liquid collection barrel 10; the slag discharge pipe 20 is slidably connected to two mutually parallel piston scrapers 32 near the inner wall of the barrel bottom, and the spacing between the two piston scrapers 32 is greater than the inner diameter of the vortex settling tube 11; the same root is inserted between the two piston scrapers 32. Axial push-pull rod 26, the raw liquid collection barrel 10 is provided with a vortex inclined plug hole 1101 near each vortex settling tube 11, and the vortex inclined plug hole 1101 is plugged with a pressure valve 15 extending into the corresponding vortex settling tube 11; the top of the vertical rod of the supporting base 1 is fixed with a crossbeam frame 5 extending to the top of the raw liquid collection barrel 10, and the end of the crossbeam frame 5 is rotatably connected to a valve conversion rotating tube 8 vertically extending into the interior of the raw liquid collection barrel 10 near the bottom, and the bottom end of the valve conversion rotating tube 8 is fixed with a C-shaped pressure rod 31; each time the C-shaped pressure rod 31 rotates once, only one pressure valve 15 is opened in turn, and the remaining pressure valves 15 remain closed; in conjunction with the vortex settling tube 11 arranged around the raw liquid collection barrel 10, the mother liquor can be added while the catalyst is added, and a vortex is generated in the vortex settling tube 11, so that the generated impurities can be slowly precipitated and layered, and then the mother liquor on the top layer is extracted and separated to control the two piston scrapers 32 to scrape off the solid impurities.

[0024] Please refer to Figure 6A vertical downward slag discharge pipe 19 is embedded near the bottom of the circumferential outer wall of the slag discharge pipe 20, and a slag collecting groove 16 with an opening upward and an annular groove as a whole is fixed on the upper surface of the support base 1. A slag discharge port is reserved at one end of the vertical plate of the slag collecting groove 16 away from the support base 1, and the bottom of the slag collecting groove 16 near the slag discharge port is lower than the other end, ensuring that after receiving all the solid impurities from the slag discharge pipe 19, they will finally slide down to gather near the slag discharge port, thereby facilitating unified processing of the solid impurities.

[0025] Please refer to Figure 7 , an axial rod folding bracket 14 is fixed to the circumferential outer wall of each slag discharge pipe 20 near the barrel mouth, and a fan-shaped gear 13 is rotatably connected to the side of the axial rod folding bracket 14 near the top, and the arc surface of the fan-shaped gear 13 is provided with teeth, and a compression spring is fixed to the end of the fan-shaped gear 13 away from the arc surface, and a permanent magnet 24 is fixed to the top of the compression spring; an electromagnet 25 is fixed to the top of the axial rod folding bracket 14 on the side of the fan-shaped gear 13 away from the eddy current settling tube 11, and the electromagnet 25 will push the permanent magnet 24 open after power is turned on; a connecting rod 26 is fixed to the end away from the raw liquid collection barrel 10 The connecting strip 2601 is connected, and a rack push rod 2602 is fixed on the top of the connecting strip 2601, which is attached to the surface of the slag discharge pipe 20 and parallel to the axis of the slag discharge pipe 20; the outer wall of the slag discharge pipe 20 is fixed with a guard rail compatible with the rack push rod 2602, and the teeth of the rack push rod 2602 and the fan gear 13 are meshed with each other; when slag discharge is required, it is only necessary to control the electromagnet 25 of the work station to be energized, and the fan gear 13 can move the rack push rod 2602 and the axial push-pull rod 26 to pull out the two piston scrapers 32, and then scrape the solid impurities between the two to the top of the slag discharge pipe 19 and discharge them.

[0026] Please refer to Figure 2 , Figure 7 , Fig.10A loading cover 9 is fixed at the top of the barrel mouth of the raw liquid collection barrel 10, and a sliding bearing that matches the diameter of the valve conversion tube 8 is embedded in the middle of the loading cover 9. A fan-shaped valve opening pointing plate 801 is fixed on the circumferential outer wall of the valve conversion tube 8 near the upper surface of the loading cover 9, and a permanent magnet 27 is fixed on the upper surface of the valve opening pointing plate 801 near the edge; a driven rotating plate 6 is slidably sleeved on the circumferential outer wall of the sliding bearing, and the driven rotating plate 6 is located between the lower surface of the valve opening pointing plate 801 and the loading cover. 9, an external suction pump 23 is fixed to one end of the upper surface of the driven rotating plate 6 away from the valve conversion rotating tube 8, and a suction pipe 35 is fixed at the inlet of the external suction pump 23, and a floating block 34 and a suction ball 33 are respectively sleeved at the end of the suction pipe 35 away from the external suction pump 23, a hard liquid discharge pipe 21 is inserted at the drainage port of the external suction pump 23, and a plurality of expanded collection pipes 12 corresponding to the vortex settling tube 11 are fixed to the circumferential outer wall of the mother liquid collection tank 18; The electromagnet 29 is matched with the position of the permanent magnet 27, and the electromagnet 29 repels the permanent magnet 27 after being energized; so that when the pressure valve 15 below the valve opening pointing plate 801 indicates that the gate is opened to release water, the electromagnet 29 is not energized, that is, the pumping position of the external suction pump 23, that is, the position of the suction ball 33 and the water discharge area are located in the same vortex settling tube 11. After the water is full, the suction ball 33 and the floating block 34 at the mouth of the suction pipe 35 have also reached the top, and the electromagnet 29 is energized again. , since the valve conversion rotating tube 8 and the valve opening pointing plate 801 remain stationary, the driven rotating plate 6 and the pumping position of the external suction pump 23 will be pushed to the next station, and the next station is the mother liquor put in a circle before, which has been reacted and solidified. At this time, the external suction pump 23 will be turned on again to slowly extract the reacted mother liquor from the upper layer to the mother liquor collection pool 18 at the bottom of the device; after the extraction, the slag discharge work will be carried out, and the slag discharge will be reset after the slag discharge is completed; then the valve conversion rotating tube 8 will be turned to start a new round of water discharge.

[0027] Among them, a connecting bridge 22 is fixed between the outer walls of the pipe openings of two adjacent vortex settling tubes 11, and an arc groove is opened on the upper surface of the connecting bridge 22. Through the set connecting bridge 22, the suction ball 33 and the floating block 34 can be pulled conveniently during the position change. An anti-slip bearing seat is fixed to the top of the valve conversion rotating tube 8, and the anti-slip bearing seat is embedded in the end of the crossbeam frame 5, and a driven pulley 7 is fixed to the top of the valve conversion rotating tube 8. A driving motor 2 is fixed to the top of the support base 1 near the rear side, and a driving pulley 3 is fixed to the top of the output shaft of the driving motor 2, and the same conveyor belt 4 is wound between the driving pulley 3 and the driven pulley 7; the driven rotating plate 6 is located above the center of the vortex settling tube 11 and has a strip-shaped perforation, and a strip-shaped perforation is provided in the perforation Steering wheel, a spring baffle is fixed on the end of the upper surface of the driven rotating plate 6 away from the external suction pump 23, and a tension spring 30 is fixed on the spring baffle, and a guide wheel frame 36 is fixed on the end of the tension spring 30 close to the external suction pump 23, and an electromagnet three is fixed on the lower surface of the guide wheel frame 36; to prevent the traction floating block 34 from getting stuck, electromagnet three is added to fix the guide wheel frame 36 on the driven rotating plate 6, and the suction pipe 35 led out from the external suction pump 23 is in the shape of a "question mark" and bypasses the guide wheel frame 36 and the steering wheel in turn, and finally extends vertically downward to the vortex settling tube 11, so that the suction position can be adjusted according to the height of the water level in the vortex settling tube 11, as well as the length of the suction pipe 35 placed in the vortex settling tube 11, to avoid entanglement and pipe jamming.

[0028] Please refer to Figure 4 and Fig.10 A limit rope 28 is fixed on the upper surface of the valve opening pointing plate 801 near the edge, and a rope fixing block 601 for fixing the limit rope 28 is fixed on the upper surface of the driven rotating plate 6 near the end of the electromagnet 29, ensuring that the distance of each bounce-opening just reaches the center position of the next vortex settling tube 11.

[0029] Please refer to Figure 6 and Fig.11 The circumferential inner wall of the raw liquid collection barrel 10 is fixed with an annular groove adapted to the C-shaped pressure rod 31, and the pressure valve 15 includes an outer tube, the inner wall of the outer tube is plugged with a valve core tube 151, the end of the valve core tube 151 is fixed with a U-shaped limiting slot 152 opening upward, the tube wall of the outer tube is located above the U-shaped limiting slot 152 and is provided with a rectangular plug hole, and a valve plug plate 153 is sealed and plugged in the rectangular plug hole; a round rod is reserved at the top of the valve plug plate 153, and an extension guard frame 154 is sleeved on the top of the round rod, a triangular abutment plate 155 is fixed at the top of the round rod, and a tightening spring is fixed between the lower surface of the triangular abutment plate 155 and the top of the extension guard frame 154; when the C-shaped pressure rod 31 passes above the triangular abutment plate 155, it will press the popped-up valve plug plate 153, that is, close the pressure valve 15.

[0030] Before using the device, the mother liquid discharged after the reaction in the previous process is continuously injected from the top of the valve conversion tube 8 using a funnel. When it is about to be full, the injection speed is reduced so that the filling speed is equal to the water discharge speed of a single pressure valve 15; at this time, the pressure valve 15 below the valve opening pointing plate 801 will lose the squeezing of the C-shaped pressure rod 21 and be in a water discharge state. When the gate is opened to discharge water, the electromagnet 29 is not energized, that is, the pumping position of the external suction pump 23, that is, the position of the suction ball 33 and the water discharge area are located in the same vortex settling tube 11. After the water is full, the suction at the mouth of the suction tube 35 The ball 33 and the floating block 34 have also reached the top. At this time, the electromagnet 29 is energized again. Since the valve conversion tube 8 and the valve opening pointing plate 801 remain stationary, the driven rotating plate 6 and the pumping position of the external suction pump 23 will be pushed to the next station. The next station is the mother liquor put in a circle before. At this time, the reaction and solidification are completed. At that time, the external suction pump 23 is turned on again to slowly extract the reacted mother liquor from the upper layer into the mother liquor collection pool 18 at the bottom of the device; after the extraction, the slag discharge work is carried out, and the slag discharge is completed and reset; then the valve conversion tube 8 is turned to start a new round of water discharge.

[0031] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for recovering lithium fluoride mother liquor, characterized in that: The following steps are involved: S1: preparing high-purity lithium carbonate into a certain slurry and then adding hydrofluoric acid solution to react to generate lithium fluoride precipitate and carbon dioxide, centrifuging the slurry after the reaction to obtain lithium fluoride and mother liquor, recycling the mother liquor through a lithium fluoride mother liquor recovery device, and drying the lithium fluoride after centrifugation to obtain high-purity lithium fluoride; S2: The mother liquor obtained after centrifugal separation of the slurry is passed into a large pool for treatment, and then the mother liquor is diverted to the small pools around it and a catalyst is added for chemical impurity removal; the mother liquor after impurity removal is then subjected to MVR concentration treatment; S3: Then, sodium chloride is added to the concentrated mother liquor for centrifugal separation to obtain a lithium carbonate solution, and then step S1 is performed to realize the recycling of the mother liquor.

2. A method for recovering lithium fluoride mother liquor according to claim 1, characterized in that: During the mother liquor circulation production process in S2, the impurities potassium, sodium and chloride ions in the mother liquor are continuously enriched and the concentration gradually increases. When the concentration increases, the mother liquor needs to be withdrawn for treatment; the other part is the resin impurity removal process, and the resin needs to be activated and regenerated after the effective adsorption reaches saturation; these two parts of high-impurity mother liquor contain lithium, and these two parts of high-impurity mother liquor are concentrated by MVR after chemical impurity removal.

3. A method for recovering lithium fluoride mother liquor according to claim 1, characterized in that: The concentrated high-lithium solution in S3 reacts with sodium carbonate to prepare industrial-grade lithium carbonate. The obtained industrial-grade lithium carbonate is used as a raw material for preparing high-purity lithium carbonate. The mother liquor after lithium precipitation is concentrated and recovered in an evaporation system.

4. A method for recovering lithium fluoride mother liquor according to claim 1, characterized in that: The lithium fluoride mother liquor recovery device comprises a support base (1), the support base (1) comprises a bottom support ring and a vertical rod vertically erected at the rear side, and a mother liquor collection pool (18) with an internal cavity and an overall cylindrical structure is fixed in the support ring, and a plurality of L-shaped brackets (17) are fixed at the top of the mother liquor collection pool (18) near the circumferential edge, and a raw liquid collection barrel (10) with an opening upward and a barrel-shaped structure is fixed at the top of the L-shaped bracket (17), and a plurality of vortex settling tubes (11) with an opening upward and a barrel-shaped structure are fixed to the circumferential outer wall of the raw liquid collection barrel (10), and a slag discharge pipe (20) radially passing through the center line of the vortex settling tube (11) is penetrated at the bottom of the vortex settling tube (11), and the whole of the slag discharge pipe (20) is a barrel structure with an opening away from the raw liquid collection barrel (10); the slag discharge pipe (20) is close to the barrel bottom. Two piston scrapers (32) are slidably connected to the inner wall and are parallel to each other, and the distance between the two piston scrapers (32) is greater than the inner diameter of the vortex settling tube (11); the same axial push-pull rod (26) is inserted between the two piston scrapers (32); the raw liquid collection barrel (10) is provided with a vortex inclined insertion hole (1101) near each vortex settling tube (11), and the vortex inclined insertion hole (1101) is inserted with a pressure valve (15) extending into the corresponding vortex settling tube (11); the top of the vertical rod of the support base (1) is fixed with a crossbeam frame (5) extending above the raw liquid collection barrel (10), and the end of the crossbeam frame (5) is rotatably connected with a valve conversion rotating tube (8) extending vertically into the interior of the raw liquid collection barrel (10) near the bottom, and the bottom end of the valve conversion rotating tube (8) is fixed with a C-shaped pressure rod (31).

5. A method for recovering lithium fluoride mother liquor according to claim 4, characterized in that: A slag discharge pipe (19) is embedded in the circumferential outer wall of the slag discharge pipe (20) near the bottom end, and a slag collecting groove (16) with an opening upward and in the shape of an annular groove is fixed on the upper surface of the support base (1). A slag discharge port is reserved at one end of the vertical plate of the slag collecting groove (16) away from the support base (1), and one end of the bottom of the slag collecting groove (16) near the slag discharge port is lower than the other end.

6. A method for recovering lithium fluoride mother liquor according to claim 4, characterized in that: A shaft rod folding bracket (14) is fixed to the circumferential outer wall of each slag discharge pipe (20) near the barrel mouth, and a fan-shaped gear (13) is rotatably connected to the side of the shaft rod folding bracket (14) near the top end, and the arc surface of the fan-shaped gear (13) is provided with teeth, and a compression spring is fixed to the end of the fan-shaped gear (13) away from the arc surface, and a permanent magnet (24) is fixed to the top of the compression spring; an electromagnet (25) is fixed to the top of the shaft rod folding bracket (14) located on the side of the fan-shaped gear (13) away from the eddy current settling tube (11), and the electromagnet (25) is fixed to the top of the shaft rod folding bracket (14). When energized, magnet one (25) will push permanent magnet one (24) away; a connecting strip (2601) is fixed to the end of the axial push-pull rod (26) away from the raw liquid collection barrel (10), and a rack push rod (2602) is fixed to the top of the connecting strip (2601) and is attached to the surface of the slag discharge pipe (20) and is parallel to the axis of the slag discharge pipe (20); a guard rail matched with the rack push rod (2602) is fixed to the outer wall of the slag discharge pipe (20), and the rack push rod (2602) is meshed with the teeth of the fan gear (13).

7. A method for recovering lithium fluoride mother liquor according to claim 4, characterized in that: A loading cover (9) is fixed at the top of the barrel mouth of the raw liquid collection barrel (10), and a sliding bearing that matches the diameter of the valve conversion rotating tube (8) is embedded in the middle of the loading cover (9). A fan-shaped valve opening pointing plate (801) is fixed on the circumferential outer wall of the valve conversion rotating tube (8) near the upper surface of the loading cover (9), and a permanent magnet (27) is fixed on the upper surface of the valve opening pointing plate (801) near the edge; a driven rotating plate (6) is slidably sleeved on the circumferential outer wall of the sliding bearing, and the driven rotating plate (6) is located between the lower surface of the valve opening pointing plate (801) and the loading cover (9), and the upper surface of the driven rotating plate (6) is away from the valve conversion rotating tube (8). An external suction pump (23) is fixed to one end of the tube (8), and a suction pipe (35) is fixed at the inlet of the external suction pump (23); a floating block (34) and a suction ball (33) are respectively sleeved at the end of the suction pipe (35) away from the external suction pump (23); a hard liquid discharge pipe (21) is inserted at the drainage port of the external suction pump (23), and a plurality of expanded collection pipes (12) corresponding to the vortex settling pipe (11) are fixed to the circumferential outer wall of the mother liquid collection tank (18); and a second electromagnet (29) adapted to the position of the second permanent magnet (27) is fixed to the top of the driven rotating plate (6); the second electromagnet (29) repels the second permanent magnet (27) after being energized.

8. A method for recovering lithium fluoride mother liquor according to claim 7, characterized in that: A connecting bridge (22) is fixed between the outer walls of the pipe openings of two adjacent vortex settling tubes (11), and an arc-shaped groove is opened on the upper surface of the connecting bridge (22). An anti-slip bearing seat is fixed to the top of the valve conversion rotating tube (8), and the anti-slip bearing seat is embedded in the end of the crossbeam frame (5). A driven pulley (7) is fixed to the top of the valve conversion rotating tube (8). A driving motor (2) is fixed to the top of the support base (1) near the rear side, and a driving pulley (3) is fixed to the top of the output shaft of the driving motor (2), and a same conveyor belt (4) is wound between the driving pulley (3) and the driven pulley (7); the driven pulley (3) and the driven pulley (7) are connected to the valve conversion rotating tube (8). The plate (6) is provided with a strip-shaped perforation located above the center of the vortex silencing tube (11), and a steering wheel is arranged in the strip-shaped perforation. A spring baffle is fixed to the end of the upper surface of the driven rotating plate (6) away from the external suction pump (23), and a tension spring (30) is fixed to the spring baffle. A guide wheel frame (36) is fixed to the end of the tension spring (30) close to the external suction pump (23), and an electromagnet is fixed to the lower surface of the guide wheel frame (36). The suction pipe (35) led out from the external suction pump (23) is in the shape of a "question mark" and successively bypasses the guide wheel frame (36) and the steering wheel, and finally extends vertically downward into the vortex silencing tube (11).

9. A method for recovering lithium fluoride mother liquor according to claim 7, characterized in that: A limit pull rope (28) is fixed on the upper surface of the valve opening pointing plate (801) near the edge, and a rope fixing block (601) for fixing the limit pull rope (28) is fixed on the upper surface of the driven rotating plate (6) near the second end of the electromagnet (29).

10. The method for recovering lithium fluoride mother liquor according to claim 4, characterized in that: The inner circumferential wall of the raw liquid collection barrel (10) is fixed with an annular groove matched with the C-shaped pressure rod (31), and the pressure valve (15) comprises an outer tube, the inner wall of the outer tube is plugged with a valve core tube (151), the end of the valve core tube (151) is fixed with a U-shaped limit slot (152) opening upward, the tube wall of the outer tube is provided with a rectangular insertion hole above the U-shaped limit slot (152), and a valve plug plate (153) is sealed and plugged in the rectangular insertion hole; a round rod is reserved at the top end of the valve plug plate (153), an extension protection frame (154) is sleeved at the top end of the round rod, a triangular abutment plate (155) is fixed at the top end of the round rod, and a tightening spring is fixed between the lower surface of the triangular abutment plate (155) and the top end of the extension protection frame (154).

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