A lithium hexafluorophosphate crystal production apparatus

Abstract

This invention relates to the field of lithium hexafluorophosphate (LiPF6) crystal production, and particularly to a LiPF6 crystal production apparatus, comprising a reaction chamber, a separator for solid-liquid separation of a LiPF6 solution, a crystallizer for condensing the LiPF6 solution connected to the lower side of the separator, and a dryer for heating and drying the crystals connected to the upper side of the separator. The invention involves preliminary filtration of the solution through a separation cylinder, followed by condensation processing in a feed pipe, where dissolved LiPF6 crystals are condensed and precipitated. The height difference between the falling solution and the feed tray causes the solution to splash onto the feed pipe wall, increasing the contact area between the solution and the pipe wall, thereby increasing the condensation efficiency and improving the production quality of LiPF6 crystals.

Description

Technical Field

[0001] This invention relates to the field of lithium hexafluorophosphate crystal production, and particularly to a lithium hexafluorophosphate crystal production apparatus. Background Technology

[0002] Electrolyte, one of the four main materials in the lithium battery industry, is composed of solvent, solute, and various additives. Lithium hexafluorophosphate (LiPF6) is currently the most widely used lithium salt due to its excellent conductivity, solubility, thermal stability, and good current collector protection. The synthesis processes of LiPF6 mainly include gas-solid reaction, hydrofluoric acid solvent method, organic solvent method, and ion exchange method. Currently, large-scale industrial production mainly uses the hydrofluoric acid solvent method, which involves dissolving lithium halides in anhydrous hydrogen fluoride, then introducing high-purity PF5 gas to react and generate lithium hexafluorophosphate crystals. These crystals are then separated and dried to obtain the final lithium hexafluorophosphate product.

[0003] However, ordinary lithium hexafluorophosphate crystal production equipment often has some problems in daily use. With the development of technology, technicians in related fields have also made a lot of optimizations to lithium hexafluorophosphate crystal production equipment. For a more accurate comparison, Chinese patent with publication number CN215232401U discloses a lithium hexafluorophosphate crystal filtration and drying production device, including a high-efficiency drying mechanism, a solid-liquid separation chamber, a relay, a power regulator, a controller, a frequency converter group, and a solid-liquid separation cylinder, etc. In use, it separates lithium hexafluorophosphate crystals from the liquid. The double-layer heating mesh can heat the air, and the crystals are quickly dried by hot air, reducing the drying time. The device can continuously stir the crystals, so that the crystals are dried more evenly and there are no undried parts, thus improving the practical value of the device.

[0004] However, the aforementioned lithium hexafluorophosphate crystal production equipment has some shortcomings in actual use:

[0005] 1. The above-mentioned device separates the liquid and crystals in the lithium hexafluorophosphate solution through a solid-liquid separation chamber, and drives the filtered crystals into a drying chamber to be dried. However, lithium hexafluorophosphate itself is easily soluble in water, so the filtered liquid still contains mixed lithium hexafluorophosphate. The above-mentioned device does not perform secondary processing on the liquid after filtration, resulting in the lithium hexafluorophosphate solution being discharged after only one filtration. The yield of lithium hexafluorophosphate crystals produced is low, which easily leads to waste and increases production costs.

[0006] 2. After the above-mentioned device performs simple filtration of the lithium hexafluorophosphate solution through the solid-liquid separation chamber, it heats and dries the crystals filtered out. However, a small amount of solution is still attached to the separated crystals. If the crystals are directly heated and dried at this time, it will not only waste the material, but also result in low purity of the finished lithium hexafluorophosphate crystals after drying.

[0007] Therefore, based on the above-stated viewpoints, there is still room for improvement in existing lithium hexafluorophosphate crystal production facilities. Summary of the Invention

[0008] To address the aforementioned problems, this invention provides a lithium hexafluorophosphate crystal production apparatus, comprising a reaction chamber with a hollow interior, wherein a separator for solid-liquid separation of a lithium hexafluorophosphate solution is provided inside the reaction chamber, a crystallizer for condensing the lithium hexafluorophosphate solution is connected to the lower side of the separator, and a dryer for heating and drying the filtered crystals is also connected to the separator.

[0009] The separator includes a horizontally arranged separation cylinder inside the reaction chamber, with several downward-through filter holes on the separation cylinder. A rotating shaft is concentrically arranged inside the separation cylinder, extending out of the reaction chamber, and a spiral blade is connected to the rotating shaft and fits against the inner wall of the separation cylinder.

[0010] Preferably, the crystallizer includes a feed funnel disposed on the lower side of the separation cylinder and connected to a plurality of filter holes on the separation cylinder. The lower end of the feed funnel is connected to a feed pipe, and a feed tray is connected to the feed pipe. A condenser tube that extends out of the reaction chamber is wound around the outer side of the feed pipe.

[0011] Preferably, the dryer includes a guide cylinder connected to the separation cylinder and arranged in a trapezoidal structure. Spiral blades are also inserted into the guide cylinder to push the filtered crystals in the separation cylinder into the guide cylinder. The lower ends of the guide cylinder and the guide pipe are connected to a collection box connected to the inner side wall of the reaction chamber. The collection box is connected downward to a drying cylinder. An electric heating plate is installed inside the drying cylinder. The lower end of the drying cylinder is connected to a discharge pipe that extends downward out of the reaction chamber.

[0012] Preferably, the collection box is provided with at least two filter screens located on both sides of the drying cylinder. One end of the filter screen is connected to the inner side wall of the collection box, and the other end is connected to the outer side wall of the drying cylinder. The two filter screens are used to screen the materials falling from the feed pipe and the feed cylinder, respectively.

[0013] Preferably, the drying cylinder is provided with a partition plate and a receiving plate from top to bottom. Both the partition plate and the receiving plate are provided with discharge ports. The partition plate and the receiving plate are connected by a drive shaft. At least two barrier plates are sleeved on the drive shaft to close the discharge ports on the partition plate and the receiving plate.

[0014] Preferably, the barrier plate includes a drive rotating block sleeved on the active rotating shaft, and at least two arc-shaped cover plates are symmetrically connected to the outer side of the drive rotating block, with the arc-shaped cover plates on the two drive rotating blocks being staggered.

[0015] Preferably, the active rotating shaft is provided with multiple scrapers that abut against the inner wall of the drying cylinder, which are used to stir and displace the crystals in the drying cylinder, thereby increasing the efficiency of heating and drying the crystals.

[0016] Preferably, a heating chamber is formed on the wall of the drying cylinder, and a connecting pipe extending outward from the reaction chamber is connected to the heating chamber. The end of the connecting pipe away from the drying cylinder is connected to a gas storage cylinder.

[0017] Preferably, the outer side of the reaction tank is equipped with a liquid storage chamber that is connected to the collection tank for recycling and collecting the liquid that has been filtered twice in the collection tank.

[0018] Preferably, the reaction tank is also connected to a recovery cylinder for absorbing the exhaust gas generated during the production process.

[0019] In summary, this application includes at least one of the following beneficial technical effects:

[0020] I. This invention uses a separation cylinder to initially filter a lithium hexafluorophosphate solution, then passes the filtered solution into a feed tube for condensation. This condenses and precipitates the lithium hexafluorophosphate crystals dissolved in the solution. The height difference between the solution falling through the feed tube and the feed tray causes the solution to splash onto the tube wall after landing on the tray, increasing the contact area between the solution and the tube wall. This increases the condensation efficiency and improves the production quality of lithium hexafluorophosphate crystals during lithium hexafluorophosphate production.

[0021] Second, this invention drives the feed tray inside the feed tube to slide back and forth within the feed tube, scraping off the crystals produced on the tube wall while also driving the incompletely cooled crystals to slide upwards, thereby increasing the residence time within the feed tube and thus increasing the yield of the solution for condensation and crystallization.

[0022] Third, this invention uses a separation cylinder to initially filter the lithium hexafluorophosphate solution, then transfers the filtered crystals to a drying cylinder. A certain amount of phosphorus pentafluoride (PF5) is added to the drying cylinder, causing the residual lithium fluoride (LiF) in the crystals to react further with the PF5, producing a semi-finished lithium hexafluorophosphate product. The exhaust gas produced is then removed, and the condensed crystals in the drying cylinder and the filtered crystals are simultaneously heated and dried to obtain the finished lithium hexafluorophosphate product. This method improves the quality of crystal production while avoiding material waste and reducing costs. Attached Figure Description

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] Figure 1 This is a schematic diagram of the structure of the present invention.

[0025] Figure 2 This is a cross-sectional structural diagram of the reaction chamber of the present invention.

[0026] Figure 3 This is a schematic diagram of the crystallizer of the present invention.

[0027] Figure 4 This is a schematic diagram of the structure of the drying cylinder of the present invention.

[0028] Figure 5 This is a schematic diagram of the scraper structure of the present invention.

[0029] Figure 6 This is a schematic diagram of the discharge port structure of the present invention.

[0030] Figure 7 This is a schematic diagram of the arc-shaped cover plate of the present invention.

[0031] Figure 8 This is a schematic diagram of the structure of the adjusting component of the present invention.

[0032] Figure 9 This is the present invention. Figure 8 A magnified view of A in the middle.

[0033] Figure 10 This is a schematic diagram of the material guide tube of the present invention.

[0034] Figure 11 This is a schematic diagram of the structure of the toggle block of the present invention.

[0035] Figure 12 This is the present invention. Figure 11 A magnified view of B in the middle.

[0036] In the diagram, 1. Reaction chamber; 10. Feed pipe; 2. Separator; 20. Separation cylinder; 21. Filter hole; 22. Rotating shaft; 23. Spiral blade; 3. Crystallizer; 30. Feed funnel; 31. Feed pipe; 310. Upper end; 311. Lower end; 312. Connecting part; 313. Sliding groove; 32. Condenser; 33. Feed tray; 34. Extension block; 4. Dryer; 40. Feed cylinder; 41. Collection box; 42. Drying cylinder; 420. Divider plate; 421. Receiving plate; 422. Discharge port; 423. Active 424. Rotating shaft; 425. Mounting frame plate; 426. Barrier plate; 427. Drive rotating block; 428. Arc-shaped cover plate; 429. Drive motor; 420. Transmission rotating shaft; 43. Electric heating plate; 44. Discharge pipe; 45. Filter screen plate; 46. Scraper; 460. Heating chamber; 461. Air guide hole; 462. Connecting pipe; 463. Air storage tank; 47. Liquid storage tank; 48. Recovery tank; 59. Adjusting component; 50. Limiting slot; 51. Limiting block; 52. Adjusting sleeve; 53. Adjusting spring; 54. Actuating block; 55. Drive screw. Detailed Implementation

[0037] The following is in conjunction with the appendix Figure 1 To be continued Figure 12 The embodiments of the present invention will be described in detail, but the present invention may be implemented in many different ways as defined and covered by the claims.

[0038] This application discloses a lithium hexafluorophosphate crystal production apparatus. The apparatus is primarily used to precipitate lithium hexafluorophosphate crystals from a solution, effectively precipitating crystals from the prepared lithium hexafluorophosphate solution. Specifically, by reusing the lithium hexafluorophosphate solution during precipitation, crystals are effectively extracted, improving the quality of the precipitated crystals. Furthermore, the apparatus further enhances the quality of crystal precipitation by collecting and utilizing the precipitated and filtered crystals a second time.

[0039] Example 1: Refer to Figure 1 and Figure 2 As shown, a lithium hexafluorophosphate crystal production apparatus includes a reaction chamber 1, a feed pipe 10, a separator 2, a crystallizer 3, and a dryer 4. The reaction chamber 1 is hollow inside, and the feed pipe 10 extends out of the reaction chamber 1. The separator 2 is installed inside the reaction chamber 1 for solid-liquid separation of the lithium hexafluorophosphate solution. The separator 2 is connected to the feed pipe 10. The lower side of the separator 2 is connected to the crystallizer 3 for condensing the lithium hexafluorophosphate solution. The separator 2 is also connected to the dryer 4 for heating and drying the filtered crystals.

[0040] In use, the lithium hexafluorophosphate solution to be treated is injected into the reaction tank 1 through the feed pipe 10. The solution is then preliminarily sieved by the separator 2 to separate the lithium hexafluorophosphate crystals in the solution. These crystals are then guided to the dryer 4 for heating and drying. At the same time, the sieved solution is also condensed by the crystallizer 3. The crystallization temperature is controlled at 10 to -25°C and the pressure is at atmospheric pressure to condense and precipitate the lithium hexafluorophosphate dissolved in the solution, thus obtaining lithium hexafluorophosphate crystals. These crystals are then passed into the dryer 4 for heating and drying to obtain the finished lithium hexafluorophosphate crystals, thereby completing the production and preparation of lithium hexafluorophosphate crystals.

[0041] Reference Figure 2 and Figure 3 As shown, this is a separator 2 used for solid-liquid separation of lithium hexafluorophosphate solution. Specifically, the separator 2 includes a separation cylinder 20, filter holes 21, a rotating shaft 22, and spiral blades 23. The separation cylinder 20 is horizontally arranged inside the reaction chamber 1 and is connected to the feed pipe 10. The separation cylinder 20 is provided with several downward-through filter holes 21. The rotating shaft 22 is concentrically arranged inside the separation cylinder 20 and extends out of the reaction chamber 1. The spiral blades 23 are connected to the rotating shaft 22 and are in contact with the inner wall of the separation cylinder 20. In use, the lithium hexafluorophosphate solution is injected into the separator 20 through the feed pipe 10. The liquid is discharged downward through the filter hole 21 on the lower side of the separator 20 and enters the crystallizer 3 to be condensed and crystallized. The lithium hexafluorophosphate crystals contained in the solution are screened and retained in the separator 20. Then, the rotating shaft 22 and the spiral blade 23 are driven to rotate. After the spiral blade 23 rotates, it pushes the crystals retained in the separator 20 to slide and move towards the dryer 4 until they enter the dryer 4 to be heated and dried, thereby achieving the effect of preliminary filtration and solid-liquid separation of the lithium hexafluorophosphate solution.

[0042] Reference Figure 3 As shown, the crystallizer 3 is used for condensing lithium hexafluorophosphate solution. Specifically, the crystallizer 3 includes a feed funnel 30, a feed pipe 31, a condenser pipe 32, and a feed tray 33. The feed funnel 30 is located below the separation cylinder 20 and is connected to several filter holes 21 on the separation cylinder 20. The lower end of the feed funnel 30 is connected to the feed pipe 31. The outer side of the feed pipe 31 is wound with a condenser pipe 32 that extends out of the reaction chamber 1. After the condenser pipe 32 extends out of the reaction chamber 1, it is connected to a compressor condenser installed on the reaction chamber 1.

[0043] In use, condensate is injected into the condenser tube 32 via a compressor condenser. After passing through the condenser tube 32, the low temperature of the condensate is conducted to the condenser tube 32 and the feed tube 31, causing the temperature inside the feed tube 31 to drop at a certain rate, thereby achieving the effect of cooling and condensing the liquid passing through the feed tube 31. The lithium hexafluorophosphate solution that has been preliminarily filtered by the separator 20 is introduced into the feed funnel 30 and the feed tube 31 through the filter hole 21, thereby achieving the effect of condensing the solution inside the feed tube 31.

[0044] Furthermore, a guide tray 33 is connected to the end of the guide tube 31 away from the guide funnel 30. An extension block 34 inserted into the guide tube 31 is connected circumferentially to the guide tray 33. The end of the extension block 34 away from the guide tray 33 has a certain elastic deformation capability. Since there is a height difference between the guide funnel 30 and the guide tray 33, after the solution falls from the higher guide funnel 30 to the lower guide tray 33, it will hit the guide tray 33, and then splash and adhere to the inner wall of the guide tube 31. This increases the contact area between the solution and the guide tube 31 and improves the efficiency of condensation and crystallization of the solution.

[0045] Reference Figure 4 As shown, the dryer 4 is used to heat and dry the filtered crystals. Specifically, the dryer 4 includes a feed cylinder 40, a collection box 41, a drying cylinder 42, an electric heating plate 43, and a discharge pipe 44. The feed cylinder 40 is connected to the separation cylinder 20 and is arranged in a trapezoidal structure. The spiral blades 23 are also inserted into the feed cylinder 40 to push the filtered crystals in the separation cylinder 20 into the feed cylinder 40. The lower ends of the feed cylinder 40 and the feed pipe 31 are connected to the collection box 41, which is connected to the inner wall of the reaction chamber 1. The collection box 41 is connected downward to the drying cylinder 42. The drying cylinder 42 is equipped with an electric heating plate 43. The lower end of the drying cylinder 42 is connected to the discharge pipe 44, which extends downward out of the reaction chamber 1.

[0046] In use, the spiral blades 23 are driven to rotate. After the spiral blades 23 rotate, they push the lithium hexafluorophosphate crystals that have been filtered and retained in the separation cylinder 20 to move into the feed cylinder 40. Then, they fall along the inner wall of the feed cylinder 40 into the collection box 41 and the drying cylinder 42. The crystals in the drying cylinder 42 are then heated and dried by the electric heating plate 43 in the drying cylinder 42. After drying, the finished lithium hexafluorophosphate crystals are discharged from the reaction box 1 through the discharge port 422, thus completing the production of lithium hexafluorophosphate.

[0047] Reference Figure 4As shown, at least two filter screens 45 are inclinedly arranged inside the collection box 41, located on both sides of the drying cylinder 42. One end of the filter screen 45 is connected to the inner wall of the collection box 41, and the other end is connected to the outer wall of the drying cylinder 42. The two filter screens 45 are used to screen the materials falling from the feed pipe 31 and the feed cylinder 40, respectively. In use, after the materials falling from the feed pipe 31 and the feed cylinder 40 land on the corresponding filter screens 45, the residual droplets in the materials are screened by the filter screens 45 and fall into the collection box 41, while the crystals remaining on the filter screens 45 move down along the inclined filter screens 45 and roll into the drying cylinder 42, thereby completing the further filtration effect of lithium hexafluorophosphate.

[0048] Reference Figure 4 and Figure 5 As shown, a partition plate 420 and a receiving plate 421 are arranged from top to bottom inside the drying cylinder 42. Both the partition plate 420 and the receiving plate 421 have discharge ports 422. The partition plate 420 and the receiving plate 421 are connected by a drive shaft 423. The drive shaft 423 is rotatably fitted with an installation frame plate 424 that is connected to the inner wall of the drying cylinder 42. At least two barrier plates 425 are fitted on the drive shaft 423 to close the discharge ports 422 on the partition plate 420 and the receiving plate 421. In use, the active rotating shaft 423 is driven to rotate, and the rotation of the active rotating shaft 423 causes the two baffle plates 425 to rotate and slide on the partition plate 420 and the receiving plate 421 respectively. After the baffle plate 425 rotates to the position of the discharge port 422, it achieves the effect of restricting the material from continuing to move down on the partition plate 420 and the receiving plate 421. After the baffle plate 425 moves to a position away from the discharge port 422, the material can continue to fall from the discharge port 422.

[0049] Reference Figures 4 to 9 As shown, the barrier plate 425 includes a drive rotating block 4250 sleeved on an active rotating shaft 423. At least two arc-shaped cover plates 4251 are symmetrically connected to the outer surface of the drive rotating block 4250, and the arc-shaped cover plates 4251 on the two drive rotating blocks 4250 are staggered. In use, after driving the active rotating shaft 423 to rotate, the active rotating shaft 423 drives the two drive rotating blocks 4250 to rotate. The rotation of the drive rotating blocks 4250 drives the connected arc-shaped cover plates 4251 to rotate and move, thereby achieving the effect of closing and unclosing the discharge port 422 on the separator plate 420 and the receiving plate 421.

[0050] Furthermore, due to the staggered arrangement of the arc-shaped cover plates 4251 on the two drive rotating blocks 4250, when the drive rotating shaft 423, drive rotating blocks 4250 and arc-shaped cover plates 4251 are driven to rotate, the two discharge ports 422 on the partition plate 420 and the receiving plate 421 are alternately opened and closed, thereby controlling the downward movement rate of the material and keeping a closed chamber in the drying cylinder 42 at all times, so as to improve the heating and drying effect of the crystals in the drying cylinder 42.

[0051] In the initial state, the discharge port 422 on the lower receiving plate 421 is open, while the discharge port 422 on the upper partition plate 420 is closed.

[0052] It should be noted that, in order to drive the drive block 4250, the active shaft 423, and the rotating shaft 22 to rotate, a drive motor 426 is horizontally installed on the bottom wall of the reaction chamber 1. The output shaft of the drive motor 426 is connected to a transmission shaft 427 that extends out of the reaction chamber 1. The transmission shaft 427 and the active shaft 423 are connected by bevel gear meshing. The section of the transmission shaft 427 that extends out of the reaction chamber 1 is connected to the rotating shaft 22 by belt drive.

[0053] In this embodiment, both the bevel gear meshing transmission and the belt drive are existing known technologies. Specifically, the bevel gear meshing transmission involves a transmission shaft 427 and a drive shaft 423 with meshing drive bevel gears mounted on them. In use, the drive motor 426 drives the transmission shaft 427 and the connected drive bevel gear to rotate. The rotation of the drive bevel gear drives the other meshing drive bevel gear and the drive shaft 423 to rotate. The two meshing drive bevel gears achieve synchronous rotation between the transmission shaft 427 and the drive shaft 423. The belt drive involves a synchronous pulley mounted on both the transmission shaft 427 and the drive shaft 22. The two synchronous pulleys are connected by a synchronous belt. The transmission shaft 427 is driven to rotate, which drives the connected synchronous pulley to rotate. The rotation of the synchronous pulley drives the other synchronous pulley and the drive shaft 22 to rotate, thereby achieving synchronous rotation between the transmission shaft 427 and the drive shaft 22.

[0054] Reference Figures 5 to 9 As shown, the active rotating shaft 423 is equipped with multiple scrapers 46 that abut against the inner wall of the drying cylinder 42. These scrapers are used to agitate and reposition the crystals within the drying cylinder 42, thereby increasing the efficiency of heating and drying the crystals. In operation, the active rotating shaft 423 rotates, causing the scrapers 46 to rotate within the drying cylinder 42. This repositions the crystals located on the partition plate 420 and the receiving plate 421 within the drying cylinder 42, increasing the contact area between the crystals and the heated gas within the drying cylinder 42, thus improving the efficiency of heating and drying the crystals.

[0055] Reference Figure 4 and Figure 5 As shown, a heating chamber 460 is formed on the wall of the drying cylinder 42. Several gas guide holes 461 are evenly opened on the lower side of the heating chamber 460 and are connected to the drying cylinder 42. These holes are used to introduce the gas in the heating chamber 460 into the drying cylinder 42 to improve the efficiency of heating and drying the crystal. A connecting pipe 462 is connected to the heating chamber 460 and extends outward from the reaction box 1. The end of the connecting pipe 462 away from the drying cylinder 42 is connected to a gas storage cylinder 463. In use, the gas stored in the gas storage cylinder 463 is introduced into the heating chamber 460 through the connecting pipe 462, allowing the gas to dissipate within the heating chamber 460. When the drying chamber is heated by the electric heating plate 43, since the heating chamber 460 also contains gas, the electric heating plate 43 simultaneously heats the gas within the heating chamber 460, thereby improving the heating efficiency within the drying cylinder 42. Furthermore, the heated gas outside the drying cylinder 42 ensures that the crystals within the drying cylinder 42 are heated uniformly, resulting in even heating of the crystals and improved quality after crystal production.

[0056] It should be noted that when a chemically stable gas, such as nitrogen, is introduced into the heating chamber 460, a certain amount of PF5 (phosphorus pentafluoride) is also introduced into it, so that the residual LiF (lithium fluoride) in the crystal reacts further with PF5, thereby increasing the precipitation of the crystal.

[0057] Reference Figure 4 As shown, a liquid storage tank 47 connected to the collection tank 41 is installed on the outer side of the reaction tank 1. It is used to recover and collect the liquid that has been filtered twice in the collection tank 41. In order to facilitate the guidance of the droplets filtered by the filter screen 45 into the liquid storage tank 47, the lower end of the collection tank 41 is inclined. The vertical cross-section of the collection tank 41 is a trapezoidal structure.

[0058] In practical use, the material falling from the feed pipe 31 and feed cylinder 40 falls onto the filter screen plate 45, and the droplets fall through the filter screen plate 45 onto the inner bottom wall of the collection box 41. Since the lower end of the collection box 41 is inclined, the droplets flow along the inner bottom wall of the collection box 41 after falling into it, and then enter the storage tank 47 to be collected. This achieves unified collection and treatment of the solution that has not completely precipitated crystals, so that the staff can reuse it and perform other processing.

[0059] Reference Figure 1 and Figure 2As shown, the reaction chamber 1 is also connected to a recovery cylinder 48 for absorbing the exhaust gas generated during the production process. In one embodiment, a negative pressure condition is created inside the recovery cylinder 48 by extracting the gas, and then the exhaust gas generated in the reaction chamber 1, such as HF (hydrogen fluoride), is uniformly absorbed and treated by the negative pressure adsorption inside the recovery cylinder 48, thereby preventing the exhaust gas generated therefrom from leaking out and affecting the environment.

[0060] Example 2: Refer to Figures 4 to 9 As shown, based on Embodiment 1, after the active rotating shaft 423 and the two driving rotating blocks 4250 are driven to rotate, the two driving rotating blocks 4250 will simultaneously drive the connected arc-shaped cover plate 4251 to rotate. When the two driving rotating blocks 4250 drive the connected arc-shaped cover plate 4251 to rotate by an angle, and neither of them covers or closes the corresponding discharge port 422, a closed chamber will not be formed in the drying cylinder 42. This causes the drying cylinder 42 and the discharge pipe 44 to be connected to the outside. During the production and preparation of lithium hexafluorophosphate solution, a certain amount of harmful gas will be generated, causing the hot air in the drying chamber to leak out and causing environmental pollution.

[0061] Based on this, in order to prevent the gas inside the drying cylinder 42 from leaking out, an adjusting component 5 is also provided inside the drying cylinder 42. Specifically, the adjusting component 5 includes a limiting slot 50, a limiting block 51, an adjusting sleeve 52, an adjusting spring 53, and a toggle block 54. The driving rotating block 4250 is provided with several limiting slots 50 circumferentially. The active rotating shaft 423 is provided with multiple limiting blocks 51 that are adapted to the limiting slots 50. The multiple limiting blocks 51 correspond one-to-one with the limiting slots 50. The active rotating shaft 423 is also rotatably fitted with a bent adjusting sleeve 52. The adjusting sleeve 52 and the mounting frame plate 424 are connected by an adjusting spring 53. The transmission rotating shaft 427 is fitted with a toggle block 54 with a rhomboid structure. The toggle block 54 abuts against the lower end of the adjusting sleeve 52. The adjusting spring 53 drives the adjusting sleeve 52 to always abut against the toggle block 54.

[0062] In the initial state, the lower limiting block 51 is inserted into the limiting through slot 50 of the lower driving rotating block 4250, while the upper limiting block 51 is not inserted into the limiting through slot 50 of the upper driving rotating block 4250 and is located below the upper driving rotating block 4250. At the same time, the actuating block 54 is in a horizontal state and its short axis side abuts against the lower end of the adjusting sleeve 52.

[0063] In practical use, after driving the transmission shaft 427 to rotate, the rotation of the transmission shaft 427 drives the drive shaft 423 to rotate through the meshing of the drive bevel gear. The rotation of the drive shaft 423 drives the lower drive block 4250, the limiting block 51, and all the connected scrapers 46 to rotate. The rotation of the drive block 4250 drives the connected arc-shaped cover plate 4251 to rotate and shift, thereby closing the discharge port 422 on the lower side of the receiving plate 421. At the same time, the rotation of the transmission shaft 427 also drives the actuating block 54 to rotate. As the short shaft of the actuating block 54 rotates to the point where the long shaft contacts the adjusting sleeve 52, the actuating block 54 gradually pushes the adjusting sleeve 52. As the active rotating shaft 423 moves upward, it drives all the connected limiting blocks 51 to move upward simultaneously. This causes the lower limiting block 51 to disengage from the lower limiting slot 50, while the upper limiting block 51 is inserted into the upper limiting slot 50. If the active rotating shaft 423 continues to rotate at this time, it will drive the upper driving block 4250 and the connected arc-shaped cover plate 4251 to rotate and shift, thereby achieving staggered position adjustment of the arc-shaped cover plate 4251. This causes the discharge port 422 located on the partition plate 420 and the receiving plate 421 to be staggeredly opened and closed, so that a sealed chamber is always formed inside the drying cylinder 42.

[0064] Furthermore, the rotation of the actuating block 54 pushes the adjusting sleeve 52 and the driving shaft 423 upward, causing the driving bevel gear between the driving shaft 423 and the transmission shaft 427 to disengage. Therefore, the driving shaft 423 is constructed such that a spline shaft is slidably inserted inside the spline sleeve, so that when the driving shaft 423 is moved in the vertical direction, the two driving bevel gears will not disengage. Based on this, the driving bevel gear is sleeved on the spline sleeve, and the adjusting sleeve 52 is sleeved on the spline shaft. In use, the rotation of the driving bevel gear drives the transmission shaft 427 and the spline sleeve to rotate synchronously. The rotation of the spline sleeve drives the spline shaft to rotate. After the actuating block 54 pushes the adjusting sleeve 52 to move, the adjusting sleeve 52 drives the spline shaft to slide along the spline sleeve.

[0065] Example 3: Refer to Figures 10 to 12As shown, based on Embodiment 1 and Embodiment 2, in order to improve the quality of solution condensation and crystallization in the feed pipe 31, a drive screw 55 is provided in the feed pipe 31 to drive the feed tray 33 to slide within the feed pipe 31. Specifically, the drive screw 55 is threaded through the feed tray 33, and two intersecting threads are provided on the outer side of the upper end of the drive screw 55. The drive screw 55 and the transmission shaft 427 are connected by bevel gear meshing. Specifically, driven bevel gears that mesh with each other are sleeved on the drive screw 55 and the transmission shaft 427. Through the meshing transmission of the two driven bevel gears, the synchronous rotation effect of the transmission shaft 427 and the drive screw 55 is achieved. After the drive screw 55 passes through the feed pipe 31, it also passes through the filter screen 45 and the collection box 41.

[0066] In use, the drive shaft 427 is driven to rotate shaft 22. The drive shaft 427 drives the drive screw 55 to rotate through two driven bevel gears. After the drive screw 55 rotates, the guide tray 33 slides back and forth in the guide tube 31 through the thread on the drive screw 55. This causes the solution in the guide tray 33 to reciprocate upwards and come into contact with the cold air in the guide tube 31, thereby improving the condensation effect of the solution and thus improving the quality of crystallization.

[0067] Furthermore, the guide pipe 31 includes an upper end 310 connected to the guide funnel 30 on the upper side, a lower end 311 connected to the collection box 41 on the lower side, and a connecting part 312 between the upper end 310 and the lower end 311. The diameter of the lower end 311 is larger than that of the upper end 310, and the inner diameter of the guide tray 33 corresponds to that of the upper end 310. The connecting part 312 is arc-shaped to connect the upper end 310 and the lower end 311. A sliding groove 313 is provided between the connecting part 312 and the upper end 310 for the extension block 34 on the guide tray 33 to slide vertically. In the initial state, the guide tray 33 is located at the middle of the connecting part 312, which is also the lower end of the sliding groove 313.

[0068] In use, as the drive screw 55 rotates, the guide tray 33 drives the extension block 34 to slide within the sliding groove 313 via the thread of the drive screw 55. After the guide tray 33 slides into the upper end 310, it pushes the solution located on the upper side upward and scrapes off the condensed crystals adhering to the tube wall of the upper end 310, pushing it upward to continue condensation. After the guide tray 33 moves down to the bottom of the sliding groove 313, the crystals on the guide tray 33 fall into the collection box 41 through the gap between the guide tray 33 and the lower end 311. Through the continuous up-and-down reciprocating movement of the guide tray 33 within the guide tube 31, the condensed crystals adhering to the guide tube 31 are scraped off, while the uncondensed solution and crystals are pushed upward, increasing the retention time of the solution and crystals within the guide tube 31 and improving the quality of the crystals precipitated from the solution.

[0069] During operation: First step, solution preparation; anhydrous hydrogen fluoride and lithium fluoride are conveyed to the preparation vessel in a closed manner through the feeding equipment to form LiF▪HF solution. Then, phosphorus pentafluoride (PF5) gas is depressurized and introduced into the lithium fluoride solution to react and generate lithium hexafluorophosphate (LiPF6) solution. The produced lithium hexafluorophosphate solution is introduced into the separation cylinder 20 through the feed pipe 10 for preliminary filtration.

[0070] Step 2: Condensation and crystallization; the liquid filtered by the separator 20 falls from the filter hole 21 on the separator 20 into the feed pipe 31, and the solution in the feed pipe 31 is condensed and cooled by the condenser pipe 32, so that the lithium hexafluorophosphate crystals dissolved in the solution are precipitated.

[0071] Step 3: Separation of solid phase; by driving the spiral blades 23 inside the separation cylinder 20 to rotate, the lithium hexafluorophosphate crystals that remain in the separation cylinder 20 after being filtered are driven into the collection box 41 for drying. At the same time, phosphorus pentafluoride is introduced into the drying cylinder 42, so that the residual LiF (lithium fluoride) in the crystals reacts further with phosphorus pentafluoride (PF5). The harmful gases are removed by the recovery cylinder 48 on the reaction tank 1.

[0072] Step 4: Heating and drying; The crystals condensed and precipitated in the feed pipe 31 and the crystals reacted in the collection box 41 are introduced into the drying cylinder 42. The drying cylinder 42 is heated to dry the lithium hexafluorophosphate crystals inside, thereby obtaining the finished lithium hexafluorophosphate crystals and completing the production and preparation of lithium hexafluorophosphate crystals.

[0073] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A lithium hexafluorophosphate crystal production apparatus, comprising a reaction chamber (1) with an internally hollow interior, characterized in that: The reaction chamber (1) is equipped with a separator (2) for solid-liquid separation of lithium hexafluorophosphate solution. The lower side of the separator (2) is connected to a crystallizer (3) for condensing the lithium hexafluorophosphate solution. The separator (2) is also connected to a dryer (4) for heating and drying the filtered crystals. The separator (2) includes a horizontally arranged separation cylinder (20) inside the reaction chamber (1), a plurality of downwardly penetrating filter holes (21) are provided on the separation cylinder (20), and a rotating shaft (22) that passes through the reaction chamber (1) is concentrically arranged inside the separation cylinder (20), and a spiral blade (23) that fits against the inner side wall of the separation cylinder (20) is connected to the rotating shaft (22). The crystallizer (3) includes a feed funnel (30) located on the lower side of the separation cylinder (20) and connected to several filter holes (21) on the separation cylinder (20). The lower end of the feed funnel (30) is connected to a feed pipe (31). A feed tray (33) is connected to the feed pipe (31) and the outer side of the feed pipe (31) is wound with a condenser pipe (32) that passes through the reaction chamber (1). A drive motor (426) is horizontally installed on the bottom wall of the reaction chamber (1), and a transmission shaft (427) that passes through the reaction chamber (1) is connected to the output shaft of the drive motor (426). A drive screw (55) is installed on the guide tray (33). Two intersecting threads are opened on the outer side of the upper end of the drive screw (55). The drive screw (55) and the transmission shaft (427) are connected by bevel gear meshing.

2. The lithium hexafluorophosphate crystal production apparatus according to claim 1, characterized in that: The dryer (4) includes a guide cylinder (40) connected to the separation cylinder (20) and arranged in a trapezoidal structure. The spiral blades (23) are also inserted into the guide cylinder (40) to push the crystals filtered in the separation cylinder (20) into the guide cylinder (40). The lower ends of the guide cylinder (40) and the guide pipe (31) are connected to a collection box (41) connected to the inner wall of the reaction chamber (1). The collection box (41) is connected downward to a drying cylinder (42). An electric heating plate (43) is installed inside the drying cylinder (42). The lower end of the drying cylinder (42) is connected to a discharge pipe (44) that extends downward out of the reaction chamber (1).

3. The lithium hexafluorophosphate crystal production apparatus according to claim 2, characterized in that: The collection box (41) is inclinedly provided with at least two filter screens (45) located on both sides of the drying cylinder (42). One end of the filter screen (45) is connected to the inner side wall of the collection box (41), and the other end is connected to the outer side wall of the drying cylinder (42). The two filter screens (45) are used to screen the materials falling from the feed pipe (31) and the feed cylinder (40).

4. The lithium hexafluorophosphate crystal production apparatus according to claim 3, characterized in that: The drying cylinder (42) is provided with a partition plate (420) and a receiving plate (421) from top to bottom. Both the partition plate (420) and the receiving plate (421) are provided with discharge ports (422). The partition plate (420) and the receiving plate (421) are provided with a drive shaft (423). At least two barrier plates (425) are sleeved on the drive shaft (423) to close the discharge ports (422) on the partition plate (420) and the receiving plate (421).

5. The lithium hexafluorophosphate crystal production apparatus according to claim 4, characterized in that: The barrier plate (425) includes a drive rotating block (4250) sleeved on an active rotating shaft (423). At least two arc-shaped cover plates (4251) are symmetrically connected to the outer side of the drive rotating block (4250), and the arc-shaped cover plates (4251) on the two drive rotating blocks (4250) are staggered.

6. The lithium hexafluorophosphate crystal production apparatus according to claim 5, characterized in that: The active rotating shaft (423) is provided with multiple scrapers (46) that abut against the inner wall of the drying cylinder (42) to stir the crystals in the drying cylinder (42) and move them, thereby increasing the efficiency of heating and drying the crystals.

7. The lithium hexafluorophosphate crystal production apparatus according to claim 6, characterized in that: A heating chamber (460) is formed on the wall of the drying cylinder (42). A connecting pipe (462) extending outward from the reaction chamber (1) is connected to the heating chamber (460). A gas storage cylinder (463) is connected to one end of the connecting pipe (462) away from the drying cylinder (42).

8. The lithium hexafluorophosphate crystal production apparatus according to claim 1, characterized in that: The outer side of the reaction tank (1) is equipped with a liquid storage chamber (47) that is connected to the collection tank (41) for recycling and collecting the liquid that has been filtered twice in the collection tank (41).

9. The lithium hexafluorophosphate crystal production apparatus according to claim 1, characterized in that: The reaction chamber (1) is also connected to a recovery cylinder (48) for absorbing the tail gas generated during the production process.

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