Lithium hexafluorophosphate crystallizing and filtering system
By designing a lithium hexafluorophosphate crystallization filtration system, which utilizes a circulation flow path and flushing pipeline to maintain material flow, the problems of solid material adhesion and pipeline blockage are solved, thereby improving production efficiency and safety.
Patent Information
- Application Number
- CN202520095381.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-15
- Publication Date
- 2025-12-26
- Estimated Expiration
- 2035-01-15
AI Technical Summary
In the existing technology, during the crystallization process of lithium hexafluorophosphate, solid materials tend to adhere to the equipment wall, resulting in low processing efficiency and high risk. The suspension after dynamic stirring and crystallization is difficult to separate, and the pipeline is prone to blockage, affecting production efficiency.
A lithium hexafluorophosphate crystallization filtration system was designed, including a crystallization kettle, a filter, a crystallization kettle discharge pipeline, a circulation pipeline, and a filter inlet pipeline. By setting up a circulation flow path and a flushing pipeline, the mother liquor is used to maintain the material flow state in the pipeline and avoid solid deposition.
It effectively alleviates or avoids solid accumulation in the pipeline, improves material transfer efficiency, reduces equipment maintenance frequency, and enables continuous conveying of lithium hexafluorophosphate slurry.
Smart Images
Figure CN223716612U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of crystallization filtration, and particularly relates to a lithium hexafluorophosphate crystallization filtration system. BACKGROUND
[0002] Lithium hexafluorophosphate is an important electrolyte of lithium ion batteries. Currently, the common lithium hexafluorophosphate crystallization methods mainly include static crystallization and dynamic stirring crystallization. The static crystallization method requires a sufficiently low process temperature, has a higher requirement for freezing conditions, a longer crystallization time, a larger energy consumption, and a higher production cost. In addition, the static crystallization produces larger crystalline particles, and physical processing methods are usually needed for crushing, which may cause irregular particle shape, uneven particle size, and poor particle flowability. The dynamic stirring crystallization has uniform particles, and the product quality is relatively stable. In addition, the dynamic stirring crystallization has a shorter time, a lower process temperature requirement, and a smaller energy consumption. Therefore, the dynamic stirring crystallization has a shorter production cycle and a higher production efficiency compared with the static crystallization. Based on the above process advantages, the dynamic stirring crystallization is the research focus of the current lithium hexafluorophosphate crystallization process.
[0003] Currently, the method for processing the solid material adhered to the equipment wall in the static crystallization process is to transfer the solid material to a transfer tank after the mother liquor is discharged from the bottom of the crystallization kettle, and then the solid material is transferred to a drying equipment by manual operation. The above method for processing the adhered solid material has a low efficiency, and needs manual disassembly and assembly of the pipeline at the bottom of the equipment, which has a high danger.
[0004] The lithium hexafluorophosphate and the mother liquor after the dynamic stirring crystallization are in a mixed slurry state. The particles of the lithium hexafluorophosphate are in a suspended state in the crystallization kettle after stirring, and the solid and the filtrate cannot be directly separated, and need to be filtered and separated by using a filter. In the process of transferring the lithium hexafluorophosphate mixed slurry, the density difference between the lithium hexafluorophosphate and the mother liquor is large, and the slurry often causes pipe blockage due to the solid deposition in the pipeline during the pipeline conveying. The solid deposition problem of the pipeline in the process of transferring the lithium hexafluorophosphate slurry needs to be solved. CONTENT
[0005] The present application is made in view of the above prior art. The purpose of the present application is to provide a lithium hexafluorophosphate crystallization filtration system, which can keep the material in the pipeline in a flowing state, so that the solid accumulation in the pipeline is not easy to occur.
[0006] The present application provides a lithium hexafluorophosphate crystallization filtration system, which comprises a crystallization kettle, a filter, a crystallization kettle discharge pipeline, a crystallization kettle circulation pipeline and a filter feed pipeline,
[0007] The discharge port of the crystallization kettle is connected with the crystallization kettle discharge pipeline,
[0008] The crystallization kettle circulation line connects the crystallization kettle discharge line and the crystallization kettle to form a circulation flow path of lithium hexafluorophosphate suspension,
[0009] The filter feed line connects the crystallization kettle discharge line and the filter to pass lithium hexafluorophosphate suspension into the filter.
[0010] In at least one possible implementation, the lithium hexafluorophosphate crystallization and filtration system further comprises a flushing line,
[0011] The filter is connected to at least one of the crystallization kettle discharge line, the crystallization kettle circulation line and the filter feed line via the flushing line to flush the lithium hexafluorophosphate mother liquor filtered by the filter.
[0012] In at least one possible implementation, the lithium hexafluorophosphate crystallization and filtration system further comprises a storage tank connected to the filter to store the lithium hexafluorophosphate mother liquor filtered by the filter,
[0013] The flushing line is connected to the storage tank, and the flushing line is connected to at least one of the crystallization kettle discharge line, the crystallization kettle circulation line and the filter feed line to flush the lithium hexafluorophosphate mother liquor stored in the storage tank.
[0014] In at least one possible implementation, the flushing line comprises a first flushing line and a second flushing line,
[0015] The first flushing line is connected to the crystallization kettle discharge line,
[0016] The second flushing line is connected to the filter feed line.
[0017] In at least one possible implementation, the crystallization kettle discharge line is provided with a pressure sensor to monitor whether the crystallization kettle discharge line is blocked.
[0018] In at least one possible implementation, the crystallization kettle discharge line is provided with a first pump, and / or the flushing line is provided with a second pump.
[0019] In at least one possible implementation, the first pump is a diaphragm pump, and the second pump is a canned pump.
[0020] In at least one possible implementation, the first flushing line is connected to an upstream section of the crystallization kettle discharge line, and / or the second flushing line is connected to an upstream section of the filter feed line.
[0021] In at least one possible implementation, the crystallization kettle is a dynamic stirring crystallization kettle,
[0022] And / or, the filter is a washing and filtering two-in-one device with washing and filtering functions.
[0023] In at least one possible implementation, the crystallization kettle discharge pipeline, the crystallization kettle circulation pipeline and the filter feed pipeline are each provided with a pneumatic on-off valve.
[0024] The lithium hexafluorophosphate crystallization and filtration system provided by the present application can keep the material in the pipeline (especially the crystallization kettle discharge pipeline) in a flowing state, which can effectively alleviate or avoid the formation of solid accumulation that is difficult to remove in the pipeline. BRIEF DESCRIPTION OF DRAWINGS
[0025] Figure 1 FIG. 1 is a structural schematic diagram of a lithium hexafluorophosphate crystallization and filtration system according to an embodiment of the present application.
[0026] REFERENCE SIGNS
[0027] 10 crystallization kettle
[0028] 20 filter
[0029] 30 storage tank
[0030] 41 first pump
[0031] 42 second pump
[0032] 51 crystallization kettle discharge pipeline
[0033] 52 crystallization kettle circulation pipeline
[0034] 53 filter feed pipeline
[0035] 61 pressure sensor
[0036] 62 liquid level meter
[0037] 70 flushing pipeline
[0038] 71 first flushing pipeline
[0039] 72 second flushing pipeline DETAILED DESCRIPTION
[0040] The exemplary embodiments of the present application will be described below with reference to the accompanying drawings. It should be understood that the specific descriptions are only for teaching those skilled in the art how to implement the present application, and are not intended to exhaust all possible ways of the present application, nor to limit the scope of the present application.
[0041] The embodiments of the present application provide a lithium hexafluorophosphate crystallization and filtration system (hereinafter, sometimes referred to as "crystallization and filtration system") as shown in FIG. 1. Figure 1As shown, the crystallization filtration system can include a crystallization kettle 10, a filter 20 and a storage tank 30.
[0042] Preferably, the crystallization kettle 10 can be a dynamic stirring crystallization kettle for lithium hexafluorophosphate, which can include a stirrer, which can be an electric motor driven electric stirrer. The lithium hexafluorophosphate solution (crystallization solution) can be subjected to dynamic stirring crystallization in the crystallization kettle. The solid (lithium hexafluorophosphate crystals) and mother liquor (saturated solution remaining after the precipitation or crystals are separated during the crystallization process) formed after the lithium hexafluorophosphate solution (crystallization solution) is subjected to dynamic stirring can form a lithium hexafluorophosphate suspension (slurry), which is prone to deposit and adhere to the inner wall of the conveying pipeline.
[0043] The outlet of the crystallization kettle 10 can be connected to a crystallization kettle discharge pipeline 51 for discharging the lithium hexafluorophosphate suspension formed after dynamic stirring crystallization in the crystallization kettle 10. The crystallization kettle discharge pipeline 51 can be provided with a first pump 41 to provide liquid conveying power. It can be understood that the density difference between the lithium hexafluorophosphate crystals and the mother liquor is large, and the slurry needs to ensure a certain flow rate when flowing in the pipeline to reduce the amount of solid material deposited on the pipe wall, and the first pump 41 can increase the flow speed of the slurry in the pipeline. Preferably, the first pump 41 can be a diaphragm pump.
[0044] Here, the outlet of the crystallization kettle 10 can be located at the bottom of the crystallization kettle 10.
[0045] Preferably, the crystallization kettle 10 can be provided with a liquid level meter 62 to monitor the liquid level in the crystallization kettle 10.
[0046] The crystallization kettle discharge pipeline 51 (especially the end not connected to the crystallization kettle 10) can be connected to a crystallization kettle circulation pipeline 52 and a filter feed pipeline 53. The crystallization kettle circulation pipeline 52 can convey the lithium hexafluorophosphate suspension conveyed in the crystallization kettle discharge pipeline 51 back to the crystallization kettle 10 to form a circulating flow path of the lithium hexafluorophosphate suspension, which can maintain a continuous liquid flow in the pipeline (especially the crystallization kettle discharge pipeline 51). The other end of the crystallization kettle circulation pipeline 52 (not connected to the crystallization kettle discharge pipeline 51) can be connected to the crystallization kettle 10, especially to the upper part (top) of the crystallization kettle 10. It can be understood that in the case of a continuous liquid flow in the crystallization kettle discharge pipeline 51, the solid is not easy to deposit on the inner wall of the pipeline.
[0047] It can be understood that the crystallization kettle discharge pipeline 51 can be connected to the crystallization kettle circulation pipeline 52 and the filter feed pipeline 53 via a tee joint, and the crystallization kettle discharge pipeline 51 can also be connected to the crystallization kettle circulation pipeline 52 and the filter feed pipeline 53 at different positions, respectively.
[0048] The other end of the filter feed line 53 (not connected to the end of the crystallizer discharge line 51) can be connected to the filter 20 to deliver the lithium hexafluorophosphate suspension output from the crystallizer discharge line 51 to the filter 20. The lithium hexafluorophosphate suspension can be filtered in the filter 20 to separate the lithium hexafluorophosphate crystals and discharge the mother liquor. The lithium hexafluorophosphate crystals filtered from the filter 20 can be fed to a drying device for the next lithium hexafluorophosphate drying process. It can be appreciated that the crystallizer discharge line 51 can be selectively connected to the crystallizer circulation line 52 or the filter feed line 53 by controlling the valves.
[0049] Preferably, the filter 20 can be a washing and filtering two-in-one device having both washing and filtering functions.
[0050] The filter 20 can be connected (via a pipe) to a storage tank 30, which can store the mother liquor discharged from the filter 20. The storage tank 30 can be connected to a flushing line 70 to discharge the mother liquor stored in the storage tank 30 and use the mother liquor to flush at least one of the crystallizer discharge line 51, the crystallizer circulation line 52 and the filter feed line 53. The flushing line 70 can be provided with a second pump 42 to provide the liquid delivery power.
[0051] Preferably, the second pump 42 can be a canned pump.
[0052] Further, the flushing line 70 can include a first flushing line 71 and a second flushing line 72. The first flushing line 71 can be connected to the storage tank 30 and an upstream section of the crystallizer discharge line 51 to flush the crystallizer discharge line 51 with the mother liquor to alleviate or avoid the formation of solid deposits in the crystallizer discharge line 51. It can be appreciated that the mother liquor entering the crystallizer discharge line 51 from the first flushing line 71 can further enter and flush the crystallizer circulation line 52 and / or the filter feed line 53 to alleviate or avoid the formation of solid deposits in the crystallizer circulation line 52 and / or the filter feed line 53.
[0053] The second flushing line 72 can be connected to the storage tank 30 and an upstream section of the filter feed line 53 to flush the filter feed line 53 with the mother liquor to alleviate or avoid the formation of solid deposits in the filter feed line 53. The storage tank 30 can also be connected to the dissolving device to deliver the mother liquor not used for flushing to the dissolving device for processing.
[0054] Preferably, the crystallizer discharge line 51, the crystallizer circulation line 52, the filter feed line 53, the first flushing line 71 and the second flushing line 72 can each be provided with one or more valves to control the opening and closing of the relevant lines. More preferably, the valves can be pneumatic on-off valves.
[0055] Preferably, the pressure sensor 61 can be arranged at the upstream section of the crystallizer discharge pipeline 51. The crystallizer circulation pipeline 52 and the filter feed pipeline 53 can also be provided with pressure sensors to monitor whether the pipelines are blocked.
[0056] It can be understood that during the whole process of transferring the lithium hexafluorophosphate from the crystallizer 10 to the filter 20, the filter feeding process via the filter feed pipeline 53 can be intermittent. The interval of the filter feeding process can be used to continuously form liquid flow in the crystallizer discharge pipeline 51 through the crystallizer circulation pipeline 52. When the transferring process is completed (the first pump 41 stops working) or when the equipment is under maintenance, the pipelines are blocked, etc., the flushing pipeline 70 can be opened to perform flushing operation.
[0057] The possible working process of the lithium hexafluorophosphate crystallization and filtration system provided by the embodiment will be described briefly below.
[0058] The lithium hexafluorophosphate suspension (slurry) including solid (lithium hexafluorophosphate crystals) and mother liquor (the saturated solution remaining after the precipitation or crystals are separated during the crystallization process) formed by dynamic stirring crystallization in the crystallizer 10 is discharged through the crystallizer discharge pipeline 51. The valve of the crystallizer circulation pipeline 52 is closed, the valve of the filter feed pipeline 53 is opened, and the lithium hexafluorophosphate suspension can enter the filter 20 through the crystallizer discharge pipeline 51 and the filter feed pipeline 53. After the filter 20 is fed, the valve of the filter feed pipeline 53 can be closed, and the valve of the crystallizer circulation pipeline 52 can be opened, so that the lithium hexafluorophosphate suspension can return to the crystallizer 10 through the crystallizer discharge pipeline 51 and the crystallizer circulation pipeline 52, and the continuous liquid flow in the crystallizer discharge pipeline 51 can be formed to relieve or avoid the deposition (accumulation, bonding) of lithium hexafluorophosphate solid. After the filter 20 is fed, the filtration operation can be started, the lithium hexafluorophosphate crystals can enter the drying equipment of the next process after being separated, and the mother liquor can be introduced into the storage tank 30 for temporary storage. When the first pump 41 of the crystallizer discharge pipeline 51 stops working, the pressure sensor 61 detects abnormal pressure in the crystallizer discharge pipeline 51, or the equipment is under maintenance, etc., the valves of the first flushing pipeline 71 and / or the second flushing pipeline 72 can be opened, and the mother liquor can be used to flush the crystallizer discharge pipeline 51 or the filter feed pipeline 53.
[0059] The advantages of the above-mentioned embodiments of the present application will be described briefly below.
[0060] The lithium hexafluorophosphate crystallization filtration system provided by the embodiments of the present application can form a continuous liquid flow in the crystallization kettle discharge pipeline by setting a crystallization kettle circulation pipeline, so as to alleviate or avoid the deposition and adhesion of solid materials on the pipeline wall in the crystallization kettle discharge pipeline. The crystallization filtration system is further provided with a first flushing pipeline and a second flushing pipeline connected with the crystallization kettle discharge pipeline and the filter feed pipeline respectively, so that the mother liquor discharged from the filter can be used to flush the pipeline, thereby further alleviating or preventing the deposition of solid materials. In turn, the maintenance frequency of the pipeline can be reduced, the continuous conveying of lithium hexafluorophosphate slurry for a long time can be realized, and the material transfer efficiency of the crystallization kettle can be improved.
[0061] It can be understood that, in the present application, the number of components or members is one or more when not particularly limited, and the plurality herein refers to two or more. For the case where the number of components or members is specifically described as, for example, two, three, four, etc. in the drawings and / or the description, the specific number is generally exemplary rather than limiting, and can be understood as a plurality, i.e. two or more, but this does not mean that the present application excludes the case of one.
[0062] It should be understood that the above embodiments are only exemplary and are not used to limit the present application. Those skilled in the art can make various modifications and changes to the above embodiments under the teaching of the present application without departing from the scope of the present application.
Claims
1. A lithium hexafluorophosphate crystallization filtration system, characterized by, The system comprises a crystallization kettle, a filter, a crystallization kettle discharge pipeline, a crystallization kettle circulation pipeline and a filter feed pipeline, The discharge outlet of the crystallization kettle is connected to the crystallization kettle discharge pipeline, The crystallization kettle circulation pipeline is connected to the crystallization kettle discharge pipeline and the crystallization kettle to form a circulation flow path of lithium hexafluorophosphate suspension, The filter feed pipeline is connected to the crystallization kettle discharge pipeline and the filter to pass lithium hexafluorophosphate suspension into the filter.
2. The lithium hexafluorophosphate crystallization filtration system of claim 1, wherein, Further comprising a flushing pipeline, The filter is connected to at least one of the crystallization kettle discharge pipeline, the crystallization kettle circulation pipeline and the filter feed pipeline through the flushing pipeline to flush the lithium hexafluorophosphate mother liquor filtered by the filter.
3. The lithium hexafluorophosphate crystallization filtration system of claim 2, wherein, Further comprising a storage tank connected to the filter to store the lithium hexafluorophosphate mother liquor filtered by the filter, The flushing pipeline is connected to the storage tank, and the flushing pipeline is connected to at least one of the crystallization kettle discharge pipeline, the crystallization kettle circulation pipeline and the filter feed pipeline to flush the lithium hexafluorophosphate mother liquor stored in the storage tank.
4. The lithium hexafluorophosphate crystallization filtration system of claim 2, wherein, The flushing pipeline comprises a first flushing pipeline and a second flushing pipeline, The first flushing pipeline is connected to the crystallization kettle discharge pipeline, The second flushing pipeline is connected to the filter feed pipeline.
5. The lithium hexafluorophosphate crystallization filtration system of claim 2, wherein, The crystallization kettle discharge pipeline is provided with a pressure sensor to monitor whether the crystallization kettle discharge pipeline is blocked.
6. The lithium hexafluorophosphate crystallization and filtration system according to claim 2, wherein The crystallization kettle discharge pipeline is provided with a first pump, And / or, the flushing pipeline is provided with a second pump.
7. The lithium hexafluorophosphate crystallization filtration system of claim 6, wherein, The first pump is a diaphragm pump, and the second pump is a canned pump.
8. The lithium hexafluorophosphate crystallization and filtration system according to claim 4, wherein The first flushing pipeline is connected to an upstream section of the crystallization kettle discharge pipeline, And / or, the second flushing pipeline is connected to an upstream section of the filter feed pipeline.
9. The lithium hexafluorophosphate crystallization and filtration system according to claim 1, wherein The crystallization kettle is a dynamic stirring crystallization kettle, And / or, the filter is a washing and filtering two-in-one device with washing and filtering functions.
10. The lithium hexafluorophosphate crystallization filtration system of claim 1, wherein, The crystallization kettle discharge pipeline, the crystallization kettle circulation pipeline and the filter feed pipeline are all provided with pneumatic on-off valves.