Method for purifying lithium hexafluorophosphate

Abstract

The invention discloses a lithium hexafluorophosphate purification method based on a purification device, and the purification device comprises a purification tower, a multifunctional feeding mechanism, a material kinetic energy lifting mechanism, a hot nitrogen inlet mechanism and a collection hopper; the purification method comprises the following steps: S1, driving a material dispersing disc to rotate to disperse a lithium hexafluorophosphate material into a purification tower; s2, an ultrasonic transducer generates ultrasonic vibration and transmits the ultrasonic vibration to the lithium hexafluorophosphate material; s3, pumping external hot nitrogen into the purification tower, so that the hot nitrogen heats, gasifies and takes away impurity water and hydrofluoric acid on the surface of the lithium hexafluorophosphate material; and S4, the purified lithium hexafluorophosphate material falls into a collection hopper to be collected and then discharged. According to the invention, continuous processing of purification treatment of the lithium hexafluorophosphate material can be realized, and a relatively high contact rate between the lithium hexafluorophosphate material and hot nitrogen can be continuously maintained, so that the purification effect on the lithium hexafluorophosphate product is continuously maintained.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium hexafluorophosphate purification, and in particular to a method for purifying lithium hexafluorophosphate, which can effectively and continuously purify lithium hexafluorophosphate. Background Art

[0002] Lithium hexafluorophosphate (LiPF6) appears as white crystals or powders, and is easily soluble in water and low-concentration organic solvents such as methanol, ethanol and acetone. LiPF6 is one of the key and new materials for manufacturing lithium-ion batteries due to its excellent electrochemical properties. At present, the hydrogen fluoride solvent method is the main production method, which uses anhydrous HF as a solvent to dissolve the synthesized LiPF6 product, and then obtains crystalline LiPF6 through recrystallization, HF washing and drying. Therefore, the finished product of LiPF6 inevitably contains hydrogen fluoride impurities, which will reduce the performance of lithium-ion batteries.

[0003] The existing purification methods of LiPF6 mainly include recrystallization and thermal drying. The recrystallization method is to dissolve LiPF6 in ether, dimethyl carbonate or diethyl carbonate at a certain temperature, then lower the temperature to recrystallize LiPF6 from the organic solvent, and vacuum dry the filtered LiPF6 crystals to obtain the final product. This process requires the use of a large amount of organic solvents, which increases production costs. The thermal drying method is to directly heat and purify the crude LiPF6 product, which is a purification method suitable for large-scale production, but the main problem is how to avoid that every particle of the crude LiPF6 product can be fully exposed to the vacuum atmosphere during the heating process, and to increase the contact time between LiPF6 and hot nitrogen, so that the final LiPF6 product does not contain hydrogen fluoride.

[0004] Therefore, the research purpose of the present invention is to design a lithium hexafluorophosphate purification method that can achieve continuous processing of lithium hexafluorophosphate material purification and can continuously maintain a high contact rate between the lithium hexafluorophosphate material and hot nitrogen, thereby continuously maintaining the purification effect of the lithium hexafluorophosphate product. Summary of the invention

[0005] In view of the technical problems existing in the above-mentioned prior art, the present invention provides a method for purifying lithium hexafluorophosphate, which can effectively solve the technical problems existing in the above-mentioned prior art.

[0006] The technical solution of the present invention is: A method for purifying lithium hexafluorophosphate, based on a purification device, the purification device comprising: A purification tower, with a material bulk tray disposed on the upper portion, the material bulk tray being connected to the output shaft end of a drive motor installed on the top of the purification tower through a corresponding drive shaft; A multifunctional feeding mechanism, comprising a feeding pipe fixedly sleeved on the outside of the driving shaft in an interval state, wherein the bottom side of the feeding pipe is connected to a guide plate spaced apart from the upper surface of the material bulk plate; The material kinetic energy lifting mechanism comprises a plurality of ultrasonic transducers evenly distributed on the material guide plate, and the ultrasonic transducers are respectively connected to an external ultrasonic generator; The hot nitrogen inlet mechanism comprises a hot nitrogen conduit fixedly connected to the middle of the purification tower, the cross section of the hot nitrogen conduit is arranged in a triangular shape, a plurality of corresponding hot nitrogen inlet pipes are evenly arranged inwardly from the middle of the hot nitrogen conduit, corresponding baffle blocks are fixedly arranged at the outlet ends of the hot nitrogen inlet pipes, a plurality of corresponding hot nitrogen jet pipes are distributed in an arc shape on the bottom surface of the hot nitrogen conduit, and the rotation directions of the hot nitrogen jet pipes are consistent; A collecting hopper is arranged at the bottom of the purification tower, a discharge pipe with a discharge valve installed is arranged outwardly from the bottom of the collecting hopper, a plurality of spherical isolation plates are sealed and fixedly connected outwardly at equal angles to the outer wall of the collecting hopper, a plurality of corresponding hot nitrogen air holes are evenly distributed on the collecting hopper corresponding to the isolation plates, and the isolation plates and the hot nitrogen conduit are respectively pumped to an external hot nitrogen source; The purification method comprises the following steps: S1, feeding the lithium hexafluorophosphate material to the gap between the material bulk tray and the guide tray through the feeding pipe, and starting the driving motor to drive the material bulk tray to rotate and feed the lithium hexafluorophosphate material into the purification tower; S2, the external ultrasonic generator is started to make the ultrasonic transducer generate ultrasonic vibration, and transmit the ultrasonic vibration to the lithium hexafluorophosphate material flowing between the material bulk disk and the material guide disk; S3, pumping external hot nitrogen into the hot nitrogen conduit, so that the hot nitrogen is ejected inwardly along the hot nitrogen inlet pipe in a turbulent flow shape, so as to stir the lithium hexafluorophosphate material; at the same time, the hot nitrogen is ejected downward along the hot nitrogen jet pipe in a consistent rotation direction, so as to form a vortex in the lower area of ​​the hot nitrogen conduit, thereby increasing the residence time of the lithium hexafluorophosphate material on the lower side of the hot nitrogen conduit, so that the lithium hexafluorophosphate material is fully contacted with the hot nitrogen, and then the hot nitrogen heats and vaporizes the impurities water and hydrofluoric acid on the surface of the lithium hexafluorophosphate material and takes them away; S4, the purified lithium hexafluorophosphate material falls into the collecting hopper for collection and discharge. During this process, hot nitrogen from the outside is continuously pumped into the isolation plate, so that the hot nitrogen is evenly dispersed and blown out along the hot nitrogen air holes to increase the contact rate between the lithium hexafluorophosphate material and the hot nitrogen and prevent the material from forming a compact mass in the collecting hopper.

[0007] The upper part of the discharge pipe is tilted outwardly and connected with a corresponding discharge auger, and a corresponding discharge hopper is fixedly provided at the feeding end of the discharge auger.

[0008] The top of the purification tower is connected to the outside and is provided with a corresponding exhaust pipe, on which a corresponding filter is fixedly installed.

[0009] The filter comprises a filter cartridge which is detachably mounted in the exhaust pipe, and the filter cartridge is filled with corresponding filter cotton.

[0010] The step S4 is followed by a step S5, wherein the hot nitrogen is discharged to the outside through the exhaust pipe and the filter, and the fine particles carried by the hot nitrogen are filtered by the filter; the discharged hot nitrogen is passed through an activated sodium fluoride adsorption column to remove hydrogen fluoride, and then passed through an activated alumina adsorption column to remove moisture to obtain pure high-purity nitrogen for recycling.

[0011] The guide plate is fixedly mounted with corresponding mounting seats at positions corresponding to the ultrasonic transducers. The bottom surface of the mounting seats is spherical and extends to the gap between the guide plate and the material bulk plate.

[0012] The mounting seat is located on the material guide disk and is evenly provided with a number of corresponding vibration-damping microholes. The ultrasonic transducer is fixedly mounted on the mounting seat through a corresponding buffer rubber tube, and the bottom end of the ultrasonic transducer is respectively fixedly abutted against the bottom end of the mounting seat; an isolation cover for isolating the upper space of the material guide disk is fixedly installed on the upper part of the material guide disk.

[0013] Corresponding clearing devices are respectively arranged in the isolation plates, and the clearing devices include clearing plates connected to the isolation plates through elastic parts, and pushing needles adapted to the hot nitrogen air holes are fixedly connected to the clearing plates, and corresponding electromagnets are respectively fixedly installed on the clearing plates, and the collecting hopper is made of magnetic metal material.

[0014] The isolation plates are respectively fixed with corresponding pressure sensors. When the pressure value detected by the pressure sensors is greater than the set value p1, the electromagnet is energized and adsorbed onto the side wall of the collecting hopper, and the push needles penetrate through the corresponding hot nitrogen vents to perform blockage clearing operations.

[0015] The bottom of the isolation plate is connected to the discharge pipe through corresponding one-way valves. When the electromagnet is energized, the one-way valve opens, and the remaining material in the isolation plate is transported to the discharge pipe for discharge.

[0016] Advantages of the present invention: 1) The present invention can realize continuous processing of lithium hexafluorophosphate material purification treatment, and can continuously maintain a high contact rate between the lithium hexafluorophosphate material and hot nitrogen, thereby continuously maintaining the purification effect of the lithium hexafluorophosphate product.

[0017] 2) The present invention evenly throws out the material through the material dispersing plate. During the process of the material being evenly thrown out, the material can directly or indirectly come into contact with the ultrasonic transducer. Under the ultrasonic vibration of the ultrasonic transducer, the dispersion degree of the thrown-out material can be ensured, and the material evenly entering the purification tower can have a certain kinetic energy, so that it can form a more sufficient contact with the rising high-temperature nitrogen, so as to ensure that the impurity water and hydrofluoric acid on the surface of the lithium hexafluorophosphate particles will be fully heated and vaporized and taken away, thereby significantly improving the purification effect of the lithium hexafluorophosphate product.

[0018] 3) Since the outlet ends of the hot nitrogen inlet pipes are respectively fixedly provided with corresponding baffles, the hot nitrogen can be ejected inwardly along the hot nitrogen inlet pipes in a turbulent flow shape to tumble the lithium hexafluorophosphate material, thereby further increasing the kinetic energy of the material and the contact rate between the material and the high-temperature nitrogen, thereby further improving the purification effect of the lithium hexafluorophosphate product; in addition, since the rotation direction of the hot nitrogen jet pipes is consistent, a hot nitrogen vortex can be formed in the lower area of ​​the hot nitrogen conduit, thereby increasing the residence time of the material after the kinetic energy is increased on the lower side of the hot nitrogen conduit, thereby effectively further increasing the contact rate between the material and the high-temperature nitrogen, thereby further improving the purification effect of the lithium hexafluorophosphate product.

[0019] 4) The outer wall of the collecting hopper of the present invention is sealed and fixedly connected with a plurality of spherical isolation plates at equal angles. The collecting hoppers corresponding to the isolation plates are evenly provided with a plurality of corresponding hot nitrogen vents. During the discharge of the purified material, the high-temperature nitrogen from the outside is blown into the purification tower through the hot nitrogen vents. On the one hand, the purification effect of the material can be further improved; on the other hand, it can effectively prevent the material from being compacted and piled up in the collecting hopper, resulting in unsmooth discharge.

[0020] 5) The material guide disk of the present invention is fixedly installed with corresponding mounting seats at positions corresponding to the ultrasonic transducers, and the bottom surface of the mounting seats is spherical and extends to the gap between the material guide disk and the material bulk disk, so as to ensure that the ultrasonic vibration can be fully transmitted to the material that is evenly thrown out; the mounting seat of the present invention is evenly distributed on the material guide disk and has a plurality of corresponding vibration-damping microholes, and the ultrasonic transducer is fixedly sleeved on the mounting seat through a corresponding buffer rubber tube, and the bottom end of the ultrasonic transducer is fixedly abutted against the bottom end of the mounting seat, thereby ensuring the outward transmission amount of the ultrasonic vibration, and under the vibration isolation of the buffer rubber tube and the resonance energy consumption of the vibration-damping microholes, the transmission amount of the ultrasonic vibration to the material guide disk can be reduced, so as to effectively ensure the practical effect of the present invention.

[0021] 6) The isolation plates of the present invention are respectively provided with corresponding clearing devices and pressure sensors. When the pressure value detected by the pressure sensor is greater than the set value p1, it can be determined that some of the hot nitrogen vents are blocked. At this time, the electromagnet is energized to drive the clearing plate inward, so that the push pins provided on the clearing plate pass through the corresponding hot nitrogen vents, respectively, to automatically perform the clearing operation, thereby further effectively ensuring the practical effect of the present invention.

[0022] 7) The bottom of the isolation plate of the present invention is connected to the discharge pipe of the purification tower through the corresponding one-way valve. When the electromagnet is energized, the one-way valve opens, and high-temperature nitrogen continues to be filled in, so that the remaining material in the isolation plate can be transported to the discharge pipe under positive pressure for discharge, thereby further effectively ensuring the practical effect of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic structural diagram of the purification device of the present invention.

[0024] Figure 2 It is a cross-sectional view of the purification device of the present invention.

[0025] Figure 3 It is a process flow chart of the purification process of the present invention.

[0026] Figure 4 It is a structural schematic diagram of the multifunctional feeding mechanism.

[0027] Figure 5 It is a structural diagram of the material kinetic energy lifting mechanism.

[0028] Figure 6 It is a structural schematic diagram of the hot nitrogen intake mechanism.

[0029] Figure 7 Schematic diagram of the filter structure.

[0030] Figure 8 This is a schematic diagram of the structure of the plug clearer.

[0031] In the accompanying drawings: purification tower 1, material bulk tray 2, drive shaft 3, drive motor 4, multifunctional feeding mechanism 5, discharge pipe 501, guide plate 502, material kinetic energy lifting mechanism 6, ultrasonic transducer 601, mounting seat 602, buffer rubber cylinder 603, hot nitrogen intake mechanism 7, hot nitrogen conduit 701, hot nitrogen intake pipe 702, hot nitrogen jet pipe 703, baffle block 8, collecting hopper 9, discharge valve 10, discharge pipe 11, isolation plate 12, hot nitrogen air permeability 13, discharge auger 14, discharge hopper 15, exhaust pipe 16, filter 17, filter cartridge 1701, filter cotton 1702, vibration-damping micropores 18, isolation cover 19, blockage remover 20, blockage remover plate 2001, push needle 2002, electromagnet 2003, elastic member 21, one-way valve 22. DETAILED DESCRIPTION

[0032] In order to facilitate understanding by those skilled in the art, the structure of the present invention is further described in detail with reference to the embodiments in conjunction with the accompanying drawings: refer to Figure 1-8 , a method for purifying lithium hexafluorophosphate, based on a purification device, the purification device comprising: The purification tower 1 is provided with a material bulk tray 2 at the top, and the material bulk tray 2 is connected to the output shaft end of the driving motor 4 installed on the top of the purification tower 1 through a corresponding driving shaft 3; The multifunctional feeding mechanism 5 comprises a feeding tube 501 fixedly sleeved on the outside of the driving shaft 3 in an interval state, and the bottom side of the feeding tube 501 is connected to a guide plate 502 spaced apart from the upper surface of the material bulk plate 2; The material kinetic energy lifting mechanism 6 comprises a plurality of ultrasonic transducers 601 evenly arranged on the material guide plate 502, and the ultrasonic transducers 601 are respectively connected to an external ultrasonic generator; The hot nitrogen inlet mechanism 7 comprises a hot nitrogen conduit 701 fixedly connected to the middle of the purification tower 1. The cross section of the hot nitrogen conduit 701 is arranged in a triangular shape. A plurality of corresponding hot nitrogen inlet pipes 702 are evenly arranged inwardly from the middle of the hot nitrogen conduit 701. The outlet ends of the hot nitrogen inlet pipes 702 are respectively fixedly provided with corresponding baffle blocks 8. The bottom surface of the hot nitrogen conduit 701 is arranged in an arc shape with a plurality of corresponding hot nitrogen jet pipes 703. The rotation directions of the hot nitrogen jet pipes 703 are consistent. A collecting hopper 9 is arranged at the bottom of the purification tower 1. A discharge pipe 11 equipped with a discharge valve 10 is arranged outward from the bottom of the collecting hopper 9. A plurality of spherical isolation plates 12 are sealed and fixedly connected outward at equal angles to the outer wall of the collecting hopper 9. A plurality of corresponding hot nitrogen vents 13 are evenly distributed on the collecting hopper 9 corresponding to the isolation plates 12. The isolation plates 12 and the hot nitrogen conduit 701 are respectively pumped to an external hot nitrogen source; The purification method comprises the following steps: S1, discharge the lithium hexafluorophosphate material to the gap between the material dispersing tray 2 and the guide tray 502 through the discharge pipe 501, and start the drive motor 4 to drive the material dispersing tray 2 to rotate and distribute the lithium hexafluorophosphate material into the purification tower 1; S2, the external ultrasonic generator is started to make the ultrasonic transducer 601 generate ultrasonic vibration, and transmit the ultrasonic vibration to the lithium hexafluorophosphate material flowing between the material bulk tray 2 and the guide tray 502; S3, pumping external hot nitrogen into the hot nitrogen conduit 701, so that the hot nitrogen is ejected inwardly along the hot nitrogen inlet pipe 702 in a turbulent flow shape, so as to stir the lithium hexafluorophosphate material; at the same time, the hot nitrogen is ejected downward along the hot nitrogen jet pipe 703 in a consistent rotation direction, so as to form a vortex in the lower area of ​​the hot nitrogen conduit 701, thereby increasing the residence time of the lithium hexafluorophosphate material on the lower side of the hot nitrogen conduit 701, so that the lithium hexafluorophosphate material is fully contacted with the hot nitrogen, and then the hot nitrogen heats and vaporizes the impurities water and hydrofluoric acid on the surface of the lithium hexafluorophosphate material and takes them away; S4, the purified lithium hexafluorophosphate material falls into the collecting hopper 9 for collection and discharge. During this process, the external hot nitrogen is continuously pumped into the isolation plate 12, so that the hot nitrogen is evenly dispersed and blown out along the hot nitrogen air holes 13 to increase the contact rate between the lithium hexafluorophosphate material and the hot nitrogen and prevent the material from forming a compact mass in the collecting hopper 9.

[0033] The present invention can realize continuous processing of lithium hexafluorophosphate material purification treatment, and can continuously maintain a high contact rate between the lithium hexafluorophosphate material and hot nitrogen, thereby continuously maintaining the purification effect of the lithium hexafluorophosphate product.

[0034] The material is uniformly thrown out through the material dispersing plate 2. During the process of being uniformly thrown out, the material can directly or indirectly come into contact with the ultrasonic transducer 601. Under the ultrasonic vibration of the ultrasonic transducer 601, the dispersion degree of the thrown out material can be ensured, and the material uniformly entering the purification tower 1 can have a certain kinetic energy, so that it can form a more sufficient contact with the rising high-temperature nitrogen, so as to ensure that the impurity water and hydrofluoric acid on the surface of the lithium hexafluorophosphate particles will be fully heated and vaporized and taken away, thereby significantly improving the purification effect of the lithium hexafluorophosphate product.

[0035] Since the outlet ends of the hot nitrogen inlet pipe 702 are respectively fixedly provided with corresponding baffle blocks 8, the hot nitrogen can be ejected inwardly in a turbulent flow along the hot nitrogen inlet pipe 702 to cause the lithium hexafluorophosphate material to be turned over, thereby further increasing the kinetic energy of the material and the contact rate between the material and the high-temperature nitrogen, thereby further improving the purification effect of the lithium hexafluorophosphate product; in addition, since the rotation direction of the hot nitrogen jet pipe 703 is consistent, a hot nitrogen vortex can be formed in the lower area of ​​the hot nitrogen conduit 701, thereby increasing the residence time of the material after the kinetic energy is increased on the lower side of the hot nitrogen conduit 701, thereby effectively further increasing the contact rate between the material and the high-temperature nitrogen, thereby further improving the purification effect of the lithium hexafluorophosphate product.

[0036] The outer wall of the collecting hopper 9 of the present invention is sealed and fixedly connected with a plurality of spherical isolation plates 12 at equal angles. The collecting hopper 9 corresponding to the isolation plates 12 is evenly provided with a plurality of corresponding hot nitrogen vents 13. During the discharge of the purified material, the external high-temperature nitrogen is blown into the purification tower 1 through the hot nitrogen vents 13. On the one hand, the purification effect of the material can be further improved; on the other hand, it can effectively prevent the material from being compacted and piled up in the collecting hopper 9, which leads to unsmooth discharge.

[0037] The upper part of the discharge pipe 501 is tilted outward and connected to a corresponding discharge auger 14 , and a corresponding discharge hopper 15 is fixedly provided at the feeding end of the discharge auger 14 . Through the setting of the discharge auger 14 , the lithium iron hexafluorophosphate material in the discharge hopper 15 can be smoothly discharged into the discharge pipe 501 .

[0038] The top of the purification tower 1 is connected to the outside and is provided with a corresponding exhaust pipe 16, on which a corresponding filter 17 is fixedly installed. The filter 17 comprises a filter cartridge 1701 detachably installed in the exhaust pipe 16, and the filter cartridge 1701 is filled with corresponding filter cotton 1702.

[0039] After fully contacting the lithium iron hexafluorophosphate material, the hot nitrogen is discharged outward along the exhaust pipe 16 and the filter 17 for treatment. Therefore, the step S4 also includes a step S5, in which the hot nitrogen is discharged outward through the exhaust pipe 16 and the filter 17, and the fine particles entrained in the hot nitrogen are filtered by the filter 17; the discharged hot nitrogen is passed through an activated sodium fluoride adsorption column to remove hydrogen fluoride, and then passed through an activated alumina adsorption column to remove moisture to obtain pure high-purity nitrogen for recycling.

[0040] The guide plate 502 is fixedly mounted with corresponding mounting seats 602 at positions corresponding to the ultrasonic transducers 601 , and the bottom surface of the mounting seats 602 is spherical and extends to the gap between the guide plate 502 and the material bulk plate 2 .

[0041] The mounting seat 602 is located on the material guide plate 502 and is evenly provided with a number of corresponding vibration-damping microholes 18. The ultrasonic transducer 601 is fixedly mounted on the mounting seat 602 through a corresponding buffer rubber tube 603. The bottom ends of the ultrasonic transducer 601 are respectively fixedly abutted against the bottom ends of the mounting seat 602. An isolation cover 19 is fixedly installed on the upper part of the material guide plate 502 to isolate the upper space of the material guide plate 502.

[0042] Through the vibration-damping microholes 18 on the mounting seat 602 and the intervention of the buffer rubber tube, the ultrasonic transducer 601 can be installed in a vibration-isolating manner and the amount of ultrasonic vibration transmitted to the guide tray 502 can be reduced, so as to effectively ensure the practical effect of the present invention.

[0043] The isolation plates 12 are respectively provided with corresponding clearing devices 20, and the clearing devices 20 include clearing plates 2001 connected to the isolation plates 12 through elastic members 21, and the clearing plates 2001 are fixedly connected with push pins 2002 adapted to the hot nitrogen air holes 13, and the clearing plates 2001 are respectively fixedly installed with corresponding electromagnets 2003, and the collecting hopper 9 is made of magnetic metal material.

[0044] The isolation plates 12 are respectively fixed with corresponding pressure sensors. When the pressure value detected by the pressure sensors is greater than the set value p1, the electromagnet 2003 is energized and adsorbed onto the side wall of the collecting hopper 9, and the push needles 2002 penetrate through the corresponding hot nitrogen vents 13 to perform the clearing operation.

[0045] The isolation plate 12 of the present invention is respectively provided with a corresponding clearing device 20 and a pressure sensor. When the pressure value detected by the pressure sensor is greater than the set value p1, it can be determined that part of the hot nitrogen vents are blocked. At this time, the electromagnet 2003 is energized to drive the clearing plate 2001 inward, so that the pushing needles 2002 provided on the clearing plate 2001 pass through the corresponding hot nitrogen vents 13, respectively, to automatically perform the clearing operation, thereby further effectively ensuring the practical effect of the present invention.

[0046] The bottom of the isolation plate 12 is connected to the discharge pipe 11 through the corresponding one-way valve 22. When the electromagnet 2003 is energized, the one-way valve 22 opens, and the remaining material in the isolation plate 12 is transported to the discharge pipe 11 for discharge. When the electromagnet 2003 is energized, the one-way valve 22 opens, and the high-temperature nitrogen continues to be filled, so that the remaining material in the isolation plate 12 can be transported to the discharge pipe 11 under positive pressure for discharge, thereby further effectively ensuring the practical effect of the present invention.

[0047] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for purifying lithium hexafluorophosphate, based on a purification device, characterized in that: The purification device comprises: A purification tower (1) is provided with a material bulk tray (2) at the top, and the material bulk tray (2) is transmission-connected to the output shaft end of a drive motor (4) installed on the top of the purification tower (1) via a corresponding drive shaft (3); The multifunctional feeding mechanism (5) comprises a feed pipe (501) fixedly sleeved on the outside of the driving shaft (3) in a spaced state, and the bottom side of the feed pipe (501) is connected to a guide plate (502) spaced from the upper surface of the material bulk plate (2); The material kinetic energy lifting mechanism (6) comprises a plurality of ultrasonic transducers (601) evenly distributed on the material guide plate (502), wherein the ultrasonic transducers (601) are respectively connected to an external ultrasonic generator; A hot nitrogen inlet mechanism (7) comprises a hot nitrogen conduit (701) fixedly connected to the middle of the purification tower (1), the cross section of the hot nitrogen conduit (701) being arranged in a triangular shape, a plurality of corresponding hot nitrogen inlet pipes (702) being evenly arranged inwardly from the middle of the hot nitrogen conduit (701), corresponding baffle blocks (8) being fixedly arranged at the outlet ends of the hot nitrogen inlet pipes (702), a plurality of corresponding hot nitrogen jet pipes (703) being distributed in an arc shape on the bottom surface of the hot nitrogen conduit (701), and the hot nitrogen jet pipes (703) having the same rotation direction; A collecting hopper (9) is arranged at the bottom of the purification tower (1), and a discharge pipe (11) equipped with a discharge valve (10) is arranged outward from the bottom of the collecting hopper (9). A plurality of spherical isolation plates (12) are sealed and fixedly connected outward at equal angles to the outer wall of the collecting hopper (9). A plurality of corresponding hot nitrogen air holes (13) are evenly distributed on the collecting hopper (9) corresponding to the isolation plates (12). The isolation plates (12) and the hot nitrogen conduit (701) are respectively pumped to an external hot nitrogen source; The purification method comprises the following steps: S1, the lithium hexafluorophosphate material is discharged to the gap between the material dispersing plate (2) and the guide plate (502) through the discharge pipe (501), and the drive motor (4) is started to drive the material dispersing plate (2) to rotate and discharge the lithium hexafluorophosphate material into the purification tower (1); S2, the external ultrasonic generator is activated to cause the ultrasonic transducer (601) to generate ultrasonic vibration, and transmit the ultrasonic vibration to the lithium hexafluorophosphate material flowing between the material bulk tray (2) and the material guide tray (502); S3, pumping external hot nitrogen into the hot nitrogen conduit (701), so that the hot nitrogen is ejected inwardly along the hot nitrogen inlet pipe (702) in a turbulent flow shape, so as to stir the lithium hexafluorophosphate material; at the same time, the hot nitrogen is ejected downward along the hot nitrogen jet pipe (703) in a consistent rotation direction, so as to form a vortex in the lower area of ​​the hot nitrogen conduit (701), thereby increasing the residence time of the lithium hexafluorophosphate material on the lower side of the hot nitrogen conduit (701), so that the lithium hexafluorophosphate material is fully in contact with the hot nitrogen, and the hot nitrogen heats and vaporizes the impurities water and hydrofluoric acid on the surface of the lithium hexafluorophosphate material and removes them; S4, the purified lithium hexafluorophosphate material falls into the collecting hopper (9) for collection and discharge. During this process, hot nitrogen from the outside is continuously pumped into the isolation plate (12), so that the hot nitrogen is evenly dispersed and blown out along the hot nitrogen air holes (13), thereby increasing the contact rate between the lithium hexafluorophosphate material and the hot nitrogen and preventing the material from forming a compact mass in the collecting hopper (9).

2. A method for purifying lithium hexafluorophosphate according to claim 1, characterized in that: The upper portion of the discharge pipe (501) is tilted outwardly and connected to a corresponding discharge auger (14), and a corresponding discharge hopper (15) is fixedly provided at the feeding end of the discharge auger (14).

3. A method for purifying lithium hexafluorophosphate according to claim 2, characterized in that: The top of the purification tower (1) is connected to the outside and is provided with a corresponding exhaust pipe (16), and a corresponding filter (17) is fixedly mounted on the exhaust pipe (16).

4. A method for purifying lithium hexafluorophosphate according to claim 3, characterized in that: The filter (17) comprises a filter cartridge (1701) which is detachably mounted in the exhaust pipe (16), and the filter cartridge (1701) is filled with corresponding filter cotton (1702).

5. A method for purifying lithium hexafluorophosphate according to claim 4, characterized in that: The step S4 is followed by a step S5, wherein the hot nitrogen is discharged to the outside through the exhaust pipe (16) and the filter (17), and fine particles carried in the hot nitrogen are filtered by the filter (17); the discharged hot nitrogen passes through an activated sodium fluoride adsorption column to remove hydrogen fluoride, and then passes through an activated alumina adsorption column to remove moisture to obtain pure high-purity nitrogen for recycling.

6. The method for purifying lithium hexafluorophosphate according to claim 1, characterized in that: The guide plate (502) is fixedly mounted with corresponding mounting seats (602) at positions corresponding to the ultrasonic transducers (601), and the bottom surface of the mounting seats (602) is spherically arranged and extends to the gap between the guide plate (502) and the material bulk plate (2).

7. A method for purifying lithium hexafluorophosphate according to claim 6, characterized in that: The mounting seat (602) is located on the material guide disc (502) and is evenly provided with a plurality of corresponding vibration-damping microholes (18); the ultrasonic transducer (601) is fixedly sleeved on the mounting seat (602) via a corresponding buffer rubber tube (603); the bottom end of the ultrasonic transducer (601) is respectively fixedly abutted against the bottom end of the mounting seat (602); and an isolation cover (19) for isolating the upper space of the material guide disc (502) is fixedly installed on the upper part of the material guide disc (502).

8. The method for purifying lithium hexafluorophosphate according to claim 1, characterized in that: The isolation plates (12) are each provided with a corresponding clearing device (20), the clearing device (20) comprising a clearing plate (2001) connected to the isolation plate (12) via an elastic member (21), a pushing needle (2002) adapted to the hot nitrogen air permeable hole (13) being fixedly connected to the clearing plate (2001), and corresponding electromagnets (2003) being fixedly mounted on the clearing plate (2001), and the collecting hopper (9) is made of a magnetic metal material.

9. The method for purifying lithium hexafluorophosphate according to claim 8, characterized in that: The isolation plates (12) are respectively fixedly connected with corresponding pressure sensors. When the pressure value detected by the pressure sensors is greater than a set value p1, the electromagnet (2003) is energized to be adsorbed onto the side wall of the collecting hopper (9), and the push pin (2002) passes through the corresponding hot nitrogen vent holes (13) to perform a clearing operation.

10. A method for purifying lithium hexafluorophosphate according to claim 9, characterized in that: The bottom of the isolation plate (12) is connected to the discharge pipe (11) via a corresponding one-way valve (22); when the electromagnet (2003) is energized, the one-way valve (22) opens, and the remaining material in the isolation plate (12) is transported to the discharge pipe (11) for discharge.

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