Lithium hexafluorophosphate deacidification and purification integrated device

Abstract

The invention discloses a lithium hexafluorophosphate deacidification and purification integrated device, and relates to the technical field of chemical substance purification, the lithium hexafluorophosphate deacidification and purification integrated device comprises a deacidification tank, the deacidification tank comprises an outer cylinder and an inner cylinder, the inner cylinder is arranged in an inner cavity of the outer cylinder, a space is reserved between the outer cylinder and the inner cylinder, and the inner cavities of the outer cylinder and the inner cylinder are communicated through an overflow port in the upper part of the inner cylinder; the inner cylinder is used for precipitating acid impurities in a lithium hexafluorophosphate solution in a chemical precipitation manner, and the outer cylinder is used for filtering the precipitated lithium hexafluorophosphate solution; the purification tank is connected with the deacidification tank, comprises a transfer bin, a first-stage evaporation concentration bin, a second-stage evaporation concentration bin, a third-stage evaporation concentration bin and a cooling bin, and is used for receiving the filtered lithium hexafluorophosphate solution for third-stage evaporation concentration. According to the device disclosed by the invention, the deacidification and purification processes of lithium hexafluorophosphate are integrated in one device, so that the tedious operation of transferring materials for multiple times in the traditional process is avoided, the process flow is greatly shortened, and the production efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical substance purification, and particularly relates to an integrated device for deacidification and purification of lithium hexafluorophosphate. Background Art

[0002] Lithium hexafluorophosphate (LFP) is an important lithium salt widely used in the electrolyte of lithium-ion batteries. During its production, crude LFP often contains various impurities due to factors such as the raw materials and reaction conditions. The presence of acidic impurities, among others, severely impacts its quality and performance.

[0003] Currently, conventional lithium hexafluorophosphate purification processes typically separate the deacidification and purification processes, requiring multiple equipment sets and multiple steps. This separate treatment approach not only complicates the process flow and increases equipment investment costs, but also introduces new impurities during the multiple material transfers, reducing product purity. It also increases production cycle time and energy consumption, making it unsuitable for large-scale industrial production.

[0004] Chinese patent CN221244029U discloses a lithium hexafluorophosphate deacidification and purification device, comprising a tank body, a receiving box fixedly connected to the inside of the tank body, a condenser fixedly connected to the inside of the tank body, and a liquid level sensing component for detecting the lithium hexafluorophosphate solution in the receiving box movably connected to the inside of the receiving box; a saturated lithium hexafluorophosphate solution is stored in the receiving box, the condenser cools the lithium hexafluorophosphate solution to cause it to cool and crystallize in the receiving box, the filter hopper is lifted and filtered to separate the lithium hexafluorophosphate crystals in the receiving box as the tank cover moves, and the pickling spray plate sprays deacidification liquid to clean the residual acid on the surface of the lithium hexafluorophosphate crystals, thereby achieving an integrated operation of lithium hexafluorophosphate cooling, crystallization and pickling, reducing the production cost and operating difficulty of lithium hexafluorophosphate deacidification and purification, and improving the production efficiency and output of lithium hexafluorophosphate.

[0005] However, the deacidification process of the above-mentioned lithium hexafluorophosphate deacidification and purification device is to clean the residual acid on the surface of the lithium hexafluorophosphate crystal by spraying deacidification liquid through the acid washing spray plate, which cannot remove acidic impurities in the lithium hexafluorophosphate, thereby reducing the purity of the product.

[0006] Therefore, it is of great practical significance to develop an efficient device that can realize the integrated deacidification and purification of lithium hexafluorophosphate. Summary of the Invention

[0007] The purpose of the present invention is to provide an integrated lithium hexafluorophosphate deacidification and purification device to address the problems that the existing lithium hexafluorophosphate deacidification and purification device has a complex structure and cannot improve the purity of the product.

[0008] The present invention is achieved through the following technical solution: a lithium hexafluorophosphate deacidification and purification integrated device, comprising: A deacidification tank, comprising an outer cylinder and an inner cylinder, wherein the inner cylinder is disposed in the inner cavity of the outer cylinder, a space is reserved between the outer cylinder and the inner cylinder, and the inner cavities of the outer cylinder and the inner cylinder are connected through an overflow port at the upper portion of the inner cylinder; the inner cylinder is used to precipitate acid impurities in the lithium hexafluorophosphate solution by chemical precipitation, and the outer cylinder is used to filter the precipitated lithium hexafluorophosphate solution; The purification tank is connected to the deacidification tank and includes a transfer tank, a first-stage evaporation and concentration tank, a second-stage evaporation and concentration tank, a third-stage evaporation and concentration tank, and a cooling tank. It is used to receive the filtered lithium hexafluorophosphate solution for three-stage evaporation and concentration, and complete cooling and crystallization to obtain high-purity lithium hexafluorophosphate.

[0009] Preferably, a feeding pipe is provided at the upper end of the outer cylinder, and there are two feeding pipes, namely a lithium hexafluorophosphate solution feeding pipe and a chemical reagent feeding pipe, and the lower ends of the two feeding pipes are connected to the inner cavity of the inner cylinder; a discharge pipe is provided at the lower end of the outer cylinder, the upper end of the discharge pipe is connected to the inner cavity of the outer cylinder, and the lower end thereof passes through the top of the transfer bin and extends inward.

[0010] Preferably, the deacidification tank is further provided with a stirring mechanism, which includes a stirring motor and a stirring assembly. The stirring motor is arranged on the outer top of the outer cylinder, and the stirring assembly is arranged inside the inner cylinder. The output end of the stirring motor passes through the top of the outer cylinder and is connected to the stirring assembly, and drives the stirring assembly to complete the stirring action. The stirring assembly is composed of a plurality of stirring tubes connected to each other, each of which is provided with a storage cavity, and the adjacent lower stirring tube is movably arranged in the storage cavity of the upper stirring tube, and the lower part of the outer wall of each stirring tube is provided with a stirring blade; the output end of the stirring motor is fixedly connected to the upper end of the uppermost stirring tube, and the lower end of the lowermost stirring tube is provided with a counterweight block; During stirring, the stirring tube is fully stretched under the gravity of the counterweight. At this time, the stirring motor starts and can drive all the stirring tubes to rotate at the same time. The rotation of the stirring blades on the stirring tube can fully mix the lithium hexafluorophosphate solution and the chemical reagent.

[0011] A limiting strip is provided on the outer wall of the stirring tube, and a limiting groove is provided on the inner wall of the storage cavity of the stirring tube to match the limiting strip on the adjacent stirring tube. During stirring, the limiting strip and the limiting groove are engaged to ensure that all stirring tubes rotate simultaneously.

[0012] Preferably, a lifting piston is provided at the bottom of the inner cavity of the inner cylinder, and the lifting piston is sealed with the inner wall of the inner cylinder; an air pressure pump is provided at the lower end of the inner cylinder, and the air outlet end of the air pressure pump is connected to the inner cavity of the inner cylinder; when the lithium hexafluorophosphate solution after the reaction needs to be precipitated in the inner cylinder, after the precipitation is completed, the air pressure pump is used to inflate the bottom of the inner cylinder to raise the lifting piston, and the upper layer of lithium hexafluorophosphate solution after precipitation is discharged into the outer cylinder through the overflow port, and the precipitate remains in the inner cylinder. When the lifting piston is raised, the lifting piston supports the stirring tube at the lower end, so that the stirring tube above it shrinks in the receiving chamber, which will not affect the lifting of the lifting piston.

[0013] Preferably, a plurality of filter screens are provided in the inner cavity of the outer cylinder, and the filter screens are fixed by fixed blocks provided on the inner wall of the outer cylinder; and the apertures of the plurality of filter screens gradually decrease from top to bottom, so as to perform progressive filtration on the lithium hexafluorophosphate solution.

[0014] Preferably, a track is provided inside the purification tank, the track passes through the transfer chamber, the first-stage evaporation and concentration chamber, the second-stage evaporation and concentration chamber, the third-stage evaporation and concentration chamber and the cooling chamber, and a transport mechanism is provided on the track; The transport mechanism includes a transport vehicle, the lower end of which is rolled on a track by a plurality of wheels, the upper end of which is fixedly connected to a support column, the upper end of which is provided with a transport platform, and the upper end surface of which is provided with a transport bucket; When in use, the filtered lithium hexafluorophosphate solution is received by a carrier barrel, and the carrier barrel is transported to the first-level evaporation and concentration warehouse, the second-level evaporation and concentration warehouse, the third-level evaporation and concentration warehouse and the cooling warehouse in sequence by a carrier vehicle.

[0015] Preferably, the first-stage evaporation and concentration bin, the second-stage evaporation and concentration bin, and the third-stage evaporation and concentration bin are all provided with an evaporation mechanism, the evaporation mechanism includes an evaporation bin body, the evaporation bin body is located above the track, an evaporation chamber is provided inside the evaporation bin body, a heating tube is provided on the inner wall of the evaporation chamber, and the heating tube is connected to a heater; a transport opening is provided at the lower end of the evaporation bin body, and when the transport mechanism is transporting, the carrying barrel is located in the evaporation chamber and moves, and the transport opening is used for the support column on the carrying vehicle to pass through.

[0016] Preferably, a cooling coil is provided inside the cooling bin, and the cooling coil is made of corrosion-resistant metal material (such as stainless steel) and is distributed in a spiral or serpentine shape inside the cooling bin. By passing a low-temperature cooling medium (such as chilled brine, cold water, etc.) into the cooling coil, the heat of the material in the bin is taken away by the heat exchange principle.

[0017] Preferably, both ends of the purification tank are provided with sealing doors, and the sealing doors are equipped with hydraulic drive devices for driving the carrier to move back and forth.

[0018] Preferably, partitions are provided between the transfer bin and the first-stage evaporation and concentration bin, the third-stage evaporation and concentration bin and the cooling bin, and a channel for the transport mechanism is provided on the partition. The partition is provided with slide grooves on both sides of the channel, and a partition gate is provided for sliding in the slide groove. The upper end of the partition gate passes through the top of the purification tank, and the partition gate is pulled by the handle on the upper part of the partition gate to realize the opening or closing of the transport channel.

[0019] Compared with the prior art, the present invention has the following advantages: 1. The device of the present invention integrates the deacidification and purification processes of lithium hexafluorophosphate into one device, avoiding the tedious operation of multiple material transfers in traditional processes, greatly shortening the process flow and improving production efficiency; 2. The deacidification tank of the present invention is configured as a combination of an outer cylinder and an inner cylinder. The lithium hexafluorophosphate solution and the chemical reagent are reacted and precipitated in the inner cylinder, and the precipitated lithium hexafluorophosphate solution is automatically transferred to the outer cylinder for filtration, thereby reducing the number of equipment and operating steps, and lowering equipment investment costs and production energy consumption. 3. The stirring assembly of the present invention is composed of multiple retractable stirring tubes, which can be extended during stirring to promote mixing of the lithium hexafluorophosphate solution and chemical reagents. During transportation, the stirring assembly can be retracted under the support of the lifting piston, thereby facilitating the lifting piston to transfer the precipitated lithium hexafluorophosphate solution to the outer cylinder. At the same time, the retractable stirring tubes allow the inner cylinder to serve as both a reaction cylinder and a precipitation cylinder, saving equipment usage. 4. The outer cylinder of the present invention is provided with multiple filter screens, and the apertures of the filter screens gradually decrease from top to bottom, so as to perform progressive filtration on the lithium hexafluorophosphate solution, thereby increasing the filtration effect and accuracy; 5. The carrier vehicle of the present invention transports the filtered lithium hexafluorophosphate solution to the evaporation and concentration bin and the cooling bin, thereby improving the transportation efficiency; 6. The evaporation and concentration chambers in the present invention are divided into a primary evaporation and concentration chamber, a secondary evaporation and concentration chamber, and a tertiary evaporation and concentration chamber, and the temperatures of the three evaporation and concentration chambers are gradually increased, and the lithium hexafluorophosphate solution can be evaporated and concentrated in three stages to improve the evaporation and concentration effect; 7. In the present invention, partitions are provided between the transfer bin and the first-stage evaporation and concentration bin, the third-stage evaporation and concentration bin, and the cooling bin. By lifting the partition gate, the transport channel can be opened or closed, which can prevent heat loss in the evaporation and concentration bin and ensure the evaporation and concentration effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic structural diagram of an integrated device for deacidification and purification of lithium hexafluorophosphate; Figure 2 This is a schematic diagram of the structure of a purification tank in an integrated lithium hexafluorophosphate deacidification and purification device; Figure 3 This is a schematic structural diagram of a deacidification tank in an integrated deacidification and purification device for lithium hexafluorophosphate; Figure 4 A cross-sectional view of a deacidification tank in an integrated deacidification and purification device for lithium hexafluorophosphate; Figure 5 This is a front view of the interior of a deacidification tank in an integrated deacidification and purification device for lithium hexafluorophosphate; Figure 6 This is a schematic structural diagram of a stirring assembly in an integrated device for deacidification and purification of lithium hexafluorophosphate; Figure 7 A schematic diagram of the storage of a stirring component in an integrated device for deacidification and purification of lithium hexafluorophosphate; Figure 8 for Figure 2 Schematic diagram of the enlarged structure of A; Figure 9 This is a schematic diagram of the structure of a transport mechanism in an integrated device for deacidification and purification of lithium hexafluorophosphate; Figure 10 This is a bottom schematic diagram of the transportation mechanism in an integrated lithium hexafluorophosphate deacidification and purification device.

[0021] Numbers in the figure: 1, purification tank; 2, deacidification tank; 3, support structure; 4, sealing door; 5, partition gate; 6, track; 7, transportation mechanism; 8, evaporation mechanism; 9, partition; 10, chute; 11, hydraulic drive device; 101. Transfer warehouse; 102. Primary evaporation and concentration warehouse; 103. Secondary evaporation and concentration warehouse; 104. Third-stage evaporation and concentration warehouse; 105. Cooling warehouse; 21. Outer cylinder; 22. Feeding pipe; 23. Stirring motor; 24. Discharge pipe; 25. Inner cylinder; 26. Stirring assembly; 27. Lifting piston; 28. Air pump; 29. Overflow hole; 210. Filter; 211. Fixed block; 261. stirring tube; 262. stirring blade; 263. limit bar; 264. counterweight; 701, carrier; 702, support column; 703, carrier platform; 704, carrier barrel; 705, wheel; 801, evaporation chamber; 802, evaporation chamber; 803, heating tube; 804, transport opening. DETAILED DESCRIPTION

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] For examples, see Figures 1-10 , a lithium hexafluorophosphate deacidification and purification integrated device, comprising: The deacidification tank 2 includes an outer cylinder 21 and an inner cylinder 25. The inner cylinder 25 is disposed in the inner cavity of the outer cylinder 21, with a space reserved between the outer cylinder 21 and the inner cylinder 25. The inner cavities of the outer cylinder 21 and the inner cylinder 25 are connected through an overflow port at the upper portion of the inner cylinder 25. The inner cylinder 25 is used to precipitate acid impurities (such as hydrofluoric acid, phosphoric acid, etc.) in the lithium hexafluorophosphate solution by chemical precipitation, and the outer cylinder 21 is used to filter the precipitated lithium hexafluorophosphate solution. The purification tank 1 is connected to the deacidification tank 2 and includes a transfer chamber 101, a first-stage evaporation and concentration chamber 102, a second-stage evaporation and concentration chamber 103, a third-stage evaporation and concentration chamber 104, and a cooling chamber 105. The purification tank 1 is used to receive the filtered lithium hexafluorophosphate solution for three-stage evaporation and concentration, and complete cooling and crystallization to obtain high-purity lithium hexafluorophosphate.

[0024] In this embodiment, the upper end of the outer cylinder 21 is provided with two feeding pipes 22, one for the lithium hexafluorophosphate solution and one for the chemical reagent. The lower ends of both feeding pipes 22 communicate with the inner cavity of the inner cylinder 25. A discharge pipe 24 is provided at the lower end of the outer cylinder 21. The upper end of the discharge pipe 24 communicates with the inner cavity of the outer cylinder 21, and the lower end of the discharge pipe 24 extends inward through the top of the transfer chamber 101. A solenoid valve (not shown) is installed inside the discharge pipe 24 to control discharge.

[0025] When in use, the lithium hexafluorophosphate solution to be treated is added through the lithium hexafluorophosphate solution addition tube, and then the chemical reagent is slowly added through the chemical reagent addition tube to cause precipitation; for example, when a compound containing calcium ions (such as calcium carbonate, calcium hydroxide, etc.) is added, the calcium ions can react with phosphate ions to form calcium phosphate precipitates; when silver ions (such as silver nitrate) are added, the silver ions can react with chloride ions to form silver chloride precipitates.

[0026] In this embodiment, the deacidification tank 2 is further provided with a stirring mechanism, which includes a stirring motor 23 and a stirring assembly 26. The stirring motor 23 is arranged on the outer top of the outer cylinder 21, and the stirring assembly 26 is arranged inside the inner cylinder 25. The output end of the stirring motor 23 passes through the top of the outer cylinder 21 and is connected to the stirring assembly 26, and drives the stirring assembly 26 to complete the stirring action; See also Figure 6-Figure 7The stirring assembly 26 is composed of a plurality of stirring tubes 261 connected to each other. Each stirring tube 261 has a receiving cavity inside. The adjacent lower stirring tube 261 is movably arranged in the receiving cavity of the upper stirring tube 261, and a stirring blade 262 is provided on the lower part of the outer wall of each stirring tube 261. The output end of the stirring motor 23 is fixedly connected to the upper end of the uppermost stirring tube 261, and the lower end of the lowermost stirring tube 261 is provided with a counterweight block 264. During stirring, the stirring tube 261 is fully stretched under the gravity of the counterweight 264. At this time, the stirring motor 23 is started, which can drive all the stirring tubes 261 to rotate at the same time. The rotation of the stirring blades on the stirring tube 261 can fully mix the lithium hexafluorophosphate solution and the chemical reagent.

[0027] A limiting bar 263 is provided on the outer wall of the stirring tube 261, and a limiting groove matching the limiting bar 263 on the adjacent stirring tube 261 is provided on the inner wall of the storage cavity of the stirring tube 261. During stirring, the limiting bar 263 and the limiting groove are engaged to ensure that all stirring tubes 261 rotate at the same time.

[0028] In this embodiment, a lifting piston 27 is provided at the bottom of the inner cavity of the inner cylinder 25, and the lifting piston 27 is sealed with the inner wall of the inner cylinder 25; an air pressure pump 28 is provided at the lower end of the inner cylinder 25, and the air outlet end of the air pressure pump 28 is connected to the inner cavity of the inner cylinder 25, and the air inlet end is connected to the outside of the outer cylinder; when the lithium hexafluorophosphate solution after the reaction needs to be precipitated in the inner cylinder 25, after the precipitation is completed, the air pressure pump 28 is used to inflate the bottom of the inner cylinder 25, so that the lifting piston 27 is raised, and the upper layer of lithium hexafluorophosphate solution after precipitation is discharged into the outer cylinder 21 through the overflow port, and the precipitate remains in the inner cylinder 25. When the lifting piston 27 is raised, the lifting piston 27 supports the stirring tube 261 at the lower end, so that the stirring tube 261 above it shrinks in the receiving cavity, which will not affect the lifting of the lifting piston 27.

[0029] In this embodiment, a plurality of filter screens 210 are provided in the inner cavity of the outer cylinder 21, and the filter screens 210 are fixed by fixed blocks 211 provided on the inner wall of the outer cylinder 21; and the apertures of the plurality of filter screens 210 gradually decrease from top to bottom, and are used for progressive filtration of the lithium hexafluorophosphate solution.

[0030] In this embodiment, a track 6 is provided inside the purification tank 1, and the track 6 passes through the transfer chamber 101, the first evaporation and concentration chamber 102, the second evaporation and concentration chamber 103, the third evaporation and concentration chamber 104 and the cooling chamber 105. A transport mechanism 7 is provided on the track 6; The transport mechanism 7 includes a transport vehicle 701. The lower end of the transport vehicle 701 is rolled on the track 6 via a plurality of wheels 705. The upper end of the transport vehicle 701 is fixedly connected to a support column 702. The upper end of the support column 702 is provided with a transport platform 703. The upper end surface of the transport platform 703 is mounted with a transport bucket 704. During use, the filtered lithium hexafluorophosphate solution is received by the carrier barrel 704 and transported in sequence to the first evaporation and concentration warehouse 102 , the second evaporation and concentration warehouse 103 , the third evaporation and concentration warehouse 104 and the cooling warehouse 105 by the carrier vehicle 701 .

[0031] In this embodiment, an evaporation mechanism 8 is provided in the first-stage evaporation and concentration bin 102, the second-stage evaporation and concentration bin 103, and the third-stage evaporation and concentration bin 104. The evaporation mechanism 8 includes an evaporation bin body 801. The evaporation bin body 801 is located above the track 6. An evaporation chamber 802 is provided inside the evaporation bin body 801. A heating tube 803 is provided on the inner wall of the evaporation chamber 802. The heating tube 803 is connected to a heater. A transport opening 804 is provided at the lower end of the evaporation bin body 801. When the transport mechanism 7 is transporting, the carrying barrel 704 is located in the evaporation chamber 802 and moves. The transport opening 804 is used for the support column 702 on the transport vehicle 701 to pass through.

[0032] The temperatures of the first-stage evaporation and concentration chamber 102, the second-stage evaporation and concentration chamber 103, and the third-stage evaporation and concentration chamber 104 are 175°C, 225°C, and 275°C, respectively.

[0033] In this embodiment, a cooling coil is provided inside the cooling bin 105. The cooling coil is made of a corrosion-resistant metal material such as stainless steel and is distributed in a spiral or serpentine shape inside the cooling bin 105. By introducing a low-temperature cooling medium such as chilled brine, cold water, etc. into the cooling coil, the heat of the material in the bin is taken away by the heat exchange principle.

[0034] In this embodiment, both ends of the purification tank 1 are provided with sealing doors 4, and the sealing doors 4 are equipped with hydraulic drive devices 11 for driving the carrier 701 to move back and forth. The hydraulic drive device 11 can be a hydraulic cylinder or a coiled rope drive.

[0035] In this embodiment, partitions 9 are provided between the transfer bin 101 and the first-stage evaporation and concentration bin 102, the third-stage evaporation and concentration bin 104, and the cooling bin 105. A channel for the transport mechanism 7 is provided on the partition 9. The partition 9 is provided with chutes 10 on both sides of the channel. A partition gate 5 is provided for sliding in the chute 10. The upper end of the partition gate 5 passes through the top of the purification tank 1, and the partition gate 5 is pulled by the handle on the upper part of the partition gate 5 to realize the opening or closing of the transport channel.

[0036] Working principle of the present invention: First, accurately measure a certain volume of crude lithium hexafluorophosphate solution and add it to inner cylinder 25 through feeding tube 22. Start stirring motor 23, and the stirring tube 261, under the gravity of counterweight 264, stretches completely through the upper and lower portions of inner cylinder 25. While stirring, slowly add a precisely calculated amount of chemical precipitant solution dropwise. During this addition, closely monitor the solution to ensure sufficient reaction progress.

[0037] After the reaction is complete, the stirring motor 23 is turned off, and the mixed solution is allowed to rest in the inner cylinder 25 for a period of time to allow the precipitate to fully settle. Then, the air pressure pump 28 is used to inflate the bottom of the inner cylinder 25, causing the lifting piston 27 to rise. The upper layer of the precipitated lithium hexafluorophosphate solution is discharged into the outer cylinder 21 through the overflow port, while the precipitate remains in the inner cylinder 25. As the lifting piston 27 rises, it supports the stirring tube 261 at the lower end, causing the stirring tube 261 above it to retract in the receiving chamber without affecting the lifting of the lifting piston 27. The lithium hexafluorophosphate solution is then filtered through multiple filters 210 within outer cylinder 21 to separate the precipitate. The filtered lithium hexafluorophosphate solution enters carrier barrel 704 within purification tank 1 and is transported by carrier vehicle 701 to primary evaporation and concentration chamber 102, secondary evaporation and concentration chamber 103, and tertiary evaporation and concentration chamber 104, sequentially. After evaporation and concentration, the solution is then transported to cooling chamber 105 for cooling and crystallization, yielding preliminarily purified lithium hexafluorophosphate crystals.

[0038] When the sediment in the inner cylinder 25 needs to be cleaned, clean water is injected into the inner cylinder 25 and the stirring motor 23 is started to stir the sediment and mix the water. The mixture is then lifted by the lifting piston 27 and discharged into the outer cylinder and into the carrying barrel 704. The sealed door 4 of the transfer bin 101 is opened to discharge the flushed mixture to maintain the purification effect of the device.

[0039] The device of the present invention integrates the deacidification and purification processes of lithium hexafluorophosphate into one device, avoiding the tedious operation of multiple material transfers in traditional processes, greatly shortening the process flow and improving production efficiency.

[0040] The deacidification tank 2 in the present invention is configured as a combination of an outer cylinder 21 and an inner cylinder 25. The lithium hexafluorophosphate solution and the chemical reagent are reacted and precipitated through the inner cylinder 25. The precipitated lithium hexafluorophosphate solution is then automatically transferred to the outer cylinder 21 for filtration, thereby reducing the number of equipment and operating steps, and lowering equipment investment costs and production energy consumption.

[0041] The stirring assembly 26 in the present invention is composed of a plurality of retractable stirring tubes 261, which can be extended to stir during stirring, thereby promoting the mixing of the lithium hexafluorophosphate solution and the chemical reagent. During transportation, the stirring assembly 26 can be retracted under the support of the lifting piston 27, thereby facilitating the lifting piston 27 to transfer the precipitated lithium hexafluorophosphate solution to the outer cylinder 21. At the same time, the retractable stirring tube allows the inner cylinder to serve as both a reaction cylinder and a precipitation cylinder, saving equipment use.

[0042] The outer cylinder 21 of the present invention is provided with a plurality of filter screens 210 , and the apertures of the filter screens 210 gradually decrease from top to bottom, so as to perform progressive filtration on the lithium hexafluorophosphate solution, thereby increasing the filtration effect and accuracy.

[0043] The carrier vehicle 701 of the present invention transports the filtered lithium hexafluorophosphate solution to the evaporation and concentration bin and the cooling bin 105, thereby improving the transportation efficiency.

[0044] The evaporation and concentration chambers in the present invention are divided into a primary evaporation and concentration chamber 102, a secondary evaporation and concentration chamber 103, and a tertiary evaporation and concentration chamber 104, and the temperatures of the three evaporation and concentration chambers gradually increase, so that the lithium hexafluorophosphate solution can be evaporated and concentrated in three stages, thereby improving the evaporation and concentration effect.

[0045] In the present invention, partitions 9 are provided between the transfer bin 101 and the first-stage evaporation and concentration bin 102, the third-stage evaporation and concentration bin 104, and the cooling bin 105. By pulling up the partition gate 5, the transport channel can be opened or closed, which can prevent the heat loss in the evaporation and concentration bin and ensure the evaporation and concentration effect.

[0046] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include," "comprise," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations. The phrase "includes an element defined by..." does not exclude the presence of other identical elements in the process, method, article, or device that includes the element.

[0047] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A lithium hexafluorophosphate deacidification and purification integrated device, characterized in that: include: A deacidification tank (2), comprising an outer cylinder (21) and an inner cylinder (25), wherein the inner cylinder (25) is arranged in the inner cavity of the outer cylinder (21), and a space is reserved between the outer cylinder (21) and the inner cylinder (25), and the inner cavities of the outer cylinder (21) and the inner cylinder (25) are connected through an overflow port at the upper part of the inner cylinder (25); the inner cylinder (25) is used to precipitate acid impurities in the lithium hexafluorophosphate solution by chemical precipitation, and the outer cylinder (21) is used to filter the precipitated lithium hexafluorophosphate solution; The purification tank (1) is connected to the deacidification tank (2), and comprises a transfer chamber (101), a first-stage evaporation and concentration chamber (102), a second-stage evaporation and concentration chamber (103), a third-stage evaporation and concentration chamber (104), and a cooling chamber (105), and is used to receive the filtered lithium hexafluorophosphate solution for third-stage evaporation and concentration, and complete cooling and crystallization to obtain high-purity lithium hexafluorophosphate.

2. A lithium hexafluorophosphate deacidification and purification integrated device according to claim 1, characterized in that: A feeding pipe (22) is provided at the upper end of the outer cylinder (21), and there are two feeding pipes (22), one for feeding lithium hexafluorophosphate solution and the other for feeding chemical reagents, and the lower ends of the two feeding pipes (22) are both connected to the inner cavity of the inner cylinder (25); a discharge pipe (24) is provided at the lower end of the outer cylinder (21), the upper end of the discharge pipe (24) is connected to the inner cavity of the outer cylinder (21), and the lower end thereof passes through the top of the transfer bin (101) and extends inward.

3. The integrated device for deacidification and purification of lithium hexafluorophosphate according to claim 1, characterized in that: The deacidification tank (2) is further provided with a stirring mechanism, which includes a stirring motor (23) and a stirring assembly (26). The stirring motor (23) is arranged on the outer top of the outer cylinder (21), and the stirring assembly (26) is arranged inside the inner cylinder (25). The output end of the stirring motor (23) passes through the top of the outer cylinder (21) and is connected to the stirring assembly (26), and drives the stirring assembly (26) to complete the stirring action. The stirring assembly (26) is formed by a plurality of stirring tubes (261) that are sleeved together. Each stirring tube (261) is provided with a receiving cavity inside. The adjacent lower stirring tube (261) is movably arranged in the receiving cavity of the upper stirring tube (261), and a stirring blade (262) is provided on the lower portion of the outer wall of each stirring tube (261). The output end of the stirring motor (23) is fixedly connected to the upper end of the uppermost stirring tube (261), and the lower end of the lowermost stirring tube (261) is provided with a counterweight (264). A limiting strip (263) is provided on the outer wall of the stirring tube (261), and a limiting groove matching the limiting strip (263) on the adjacent stirring tube (261) is provided on the inner wall of the receiving cavity of the stirring tube (261). During stirring, the limiting strip (263) and the limiting groove engage to ensure that all stirring tubes (261) rotate simultaneously.

4. The integrated device for deacidification and purification of lithium hexafluorophosphate according to claim 3, characterized in that: A lifting piston (27) is provided at the bottom of the inner cavity of the inner cylinder (25), and the lifting piston (27) is sealed with the inner wall of the inner cylinder (25); an air pressure pump (28) is provided at the lower end of the inner cylinder (25), and the air outlet end of the air pressure pump (28) is communicated with the inner cavity of the inner cylinder (25); when the lithium hexafluorophosphate solution after the reaction needs to be precipitated in the inner cylinder (25), after the precipitation is completed, the air pressure pump (28) is used to inflate the bottom of the inner cylinder (25), so that the lifting piston (27) is raised, and the upper layer of lithium hexafluorophosphate solution after precipitation is discharged into the outer cylinder (21) through the overflow port, and the precipitate remains in the inner cylinder (25). When the lifting piston (27) is raised, the lifting piston (27) supports the stirring tube (261) at the lower end, so that the stirring tube (261) above it shrinks in the receiving chamber, which will not affect the lifting of the lifting piston (27).

5. The integrated device for deacidification and purification of lithium hexafluorophosphate according to claim 1, characterized in that: A plurality of filter screens (210) are provided in the inner cavity of the outer cylinder (21), and the filter screens (210) are fixed by fixed blocks (211) provided on the inner wall of the outer cylinder (21); and the apertures of the plurality of filter screens (210) gradually decrease from top to bottom, so as to perform progressive filtration on the lithium hexafluorophosphate solution.

6. The integrated device for deacidification and purification of lithium hexafluorophosphate according to claim 1, characterized in that: A track (6) is provided inside the purification tank (1), and the track (6) passes through the transfer chamber (101), the first-stage evaporation and concentration chamber (102), the second-stage evaporation and concentration chamber (103), the third-stage evaporation and concentration chamber (104), and the cooling chamber (105). A transport mechanism (7) is provided on the track (6); The transport mechanism (7) comprises a transport vehicle (701), the lower end of the transport vehicle (701) being rollingly arranged on a track (6) via a plurality of wheels (705), the upper end of the transport vehicle (701) being fixedly connected to a support column (702), the upper end of the support column (702) being provided with a transport platform (703), and the upper end surface of the transport platform (703) being mounted with a transport bucket (704).

7. The integrated device for deacidification and purification of lithium hexafluorophosphate according to claim 6, characterized in that: The first-stage evaporation and concentration bin (102), the second-stage evaporation and concentration bin (103), and the third-stage evaporation and concentration bin (104) are all provided with an evaporation mechanism (8). The evaporation mechanism (8) comprises an evaporation bin body (801). The evaporation bin body (801) is located above the track (6). An evaporation chamber (802) is provided inside the evaporation bin body (801). A heating pipe (803) is provided on the inner wall of the evaporation chamber (802). The heating pipe (803) is connected to a heater. A transport opening (804) is provided at the lower end of the evaporation bin body (801). When the transport mechanism (7) is used for transport, the transport barrel (704) is located in the evaporation chamber (802) and moves. The transport opening (804) is used for the support column (702) on the transport vehicle (701) to pass through.

8. The integrated device for deacidification and purification of lithium hexafluorophosphate according to claim 6, characterized in that: A cooling coil is provided inside the cooling bin (105), and the cooling coil is made of a corrosion-resistant metal material and is distributed in a spiral or serpentine shape inside the cooling bin (105).

9. The integrated device for deacidification and purification of lithium hexafluorophosphate according to claim 6, characterized in that: Both ends of the purification tank (1) are provided with sealing doors (4), and a hydraulic drive device for driving the carrier (701) to move back and forth is installed on the sealing door (4).

10. The integrated device for deacidification and purification of lithium hexafluorophosphate according to claim 1, characterized in that: A partition (9) is provided between the transfer bin (101) and the first-stage evaporation and concentration bin (102), the third-stage evaporation and concentration bin (104) and the cooling bin (105). A passage for the transport mechanism (7) is provided on the partition (9). Slide grooves (10) are provided on both sides of the passage. A partition gate (5) is provided in the slide groove (10) for sliding. The upper end of the partition gate (5) passes through the top of the purification tank (1). The partition gate (5) is lifted by a handle on the upper part of the partition gate (5) to open or close the transport passage.

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