High-purity lithium fluoride preparation system

Abstract

The invention relates to the technical field of lithium fluoride preparation, and discloses a high-purity lithium fluoride preparation system which is characterized in that a solution preparation module is respectively communicated with a precipitation preparation module and a tail gas treatment module and is used for preparing a lithium hydroxide solution and conveying the lithium hydroxide solution to the precipitation preparation module; the precipitate preparation module communicates with the solution preparation module, the purification module and the tail gas treatment module and is used for preparing lithium fluoride precipitates and conveying the lithium fluoride precipitates to the purification module; the purification module communicates with the precipitate preparation module, the drying and roasting module and the tail gas treatment module and is used for purifying the lithium fluoride precipitate and conveying the lithium fluoride precipitate to the drying and roasting module; the tail gas treatment module is used for purifying tail gas generated by the receiving solution preparation module, the precipitation preparation module and the purification module and then discharging the tail gas out of the system. The system can improve the purity of the lithium fluoride product and the stability among batches, optimize the process flow, reduce the energy consumption, realize environment-friendly standard emission, and achieve multiple targets of improving the product quality, improving the production efficiency and protecting the environment.

Description

Technical Field

[0001] This disclosure relates to the field of lithium fluoride preparation technology, and for example to a high-purity lithium fluoride preparation system. Background Technology

[0002] High-purity lithium fluoride is an important raw material in the industrial field, and its purity and performance directly determine the quality of the end product. However, current methods for preparing lithium fluoride, especially the technology using the direct neutralization reaction of lithium hydroxide and hydrofluoric acid, face several significant technical challenges: In related technologies, the preparation of lithium hydroxide solutions lacks effective filtration and impurity removal measures, easily resulting in residual metal ions and particulate impurities. Furthermore, byproducts are easily generated during the neutralization reaction, leading to low product purity and poor batch stability. Moreover, the separation, washing, and drying of the precipitate are mostly step-by-step operations with loose equipment connections, resulting in significant material transfer losses, high energy consumption, and difficulty in achieving continuous production, leading to low overall efficiency. In summary, related technologies have shortcomings in terms of purity, efficiency, and environmental protection, urgently requiring an integrated, efficient, safe, and stable high-purity lithium fluoride preparation system.

[0003] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0004] To provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended as a general commentary, nor is it intended to identify key / important components or describe the scope of protection of these embodiments, but rather as a prelude to the detailed description that follows.

[0005] This disclosure provides a high-purity lithium fluoride preparation system that can improve product purity and batch stability, optimize the process flow, reduce energy consumption, and achieve environmentally compliant emissions.

[0006] The high-purity lithium fluoride preparation system disclosed herein includes a solution preparation module, a precipitation preparation module, a purification module, a drying and calcination module, and a tail gas treatment module; The solution preparation module is connected to the precipitation preparation module and the tail gas treatment module respectively. The solution preparation module is used to prepare lithium hydroxide solution based on pure water and lithium hydroxide solid, and then transport the lithium hydroxide solution to the precipitation preparation module. The precipitation preparation module is connected to the solution preparation module, the purification module and the tail gas treatment module respectively. The precipitation preparation module is used to prepare lithium fluoride precipitate based on the hydrofluoric acid solution and the lithium hydroxide solution prepared by the solution preparation module, and to transport the lithium fluoride precipitate to the purification module. The purification module is connected to the precipitation preparation module, the drying and calcination module and the tail gas treatment module respectively. The purification module is used to purify the lithium fluoride precipitate prepared by the precipitation preparation module and transport the lithium fluoride precipitate to the drying and calcination module. The exhaust gas treatment module is used to receive the exhaust gas generated by the solution preparation module, precipitation preparation module and purification module, and then discharge the exhaust gas from the system after purification treatment.

[0007] In some embodiments, the solution preparation module includes a water tank, a water pump, a dissolving tank, a clear liquid filter, a precision filter, and a clear liquid high-level tank. The water tank is used to store pure water, and the dissolving tank is used to contain lithium hydroxide solid. The water pump is connected to the water tank and the dissolving tank respectively, and is used to introduce pure water from the water tank into the dissolving tank so that pure water and lithium hydroxide solid form a lithium hydroxide solution in the dissolving tank. The dissolving tank, the clear liquid filter, the precision filter, and the clear liquid high-level tank are connected in sequence. The lithium hydroxide solution in the dissolving tank flows into the clear liquid high-level tank through the clear liquid filter and the precision filter. Both the dissolving tank and the high-level clear liquid tank are connected to the exhaust gas treatment module. The high-level clear liquid tank is also connected to the precipitation preparation module. The high-level clear liquid tank is used to transport lithium hydroxide solution to the precipitation preparation module.

[0008] In some embodiments, the solution preparation module includes a residue filter and a high-level tank for residue filtrate; The dissolving tank is connected to the residue filter and the high-level residue filtrate tank respectively. The residue filter is also connected to the high-level residue filtrate tank and the exhaust gas treatment module. The bottom liquid in the dissolving tank flows through the residue filter into the high-level residue filtrate tank, and then flows back into the dissolving tank through the high-level residue filtrate tank.

[0009] In some embodiments, the precipitation preparation module includes a neutralization reactor, a hydrofluoric acid high-level tank, and a mold temperature controller; the neutralization reactor is connected to the solution preparation module, the hydrofluoric acid high-level tank, and the mold temperature controller, respectively, and both the neutralization reactor and the hydrofluoric acid high-level tank are also connected to the tail gas treatment module. The hydrofluoric acid high-level tank is used to contain hydrofluoric acid and allow it to flow into the neutralization reactor. The neutralization reactor is also connected to the purification module. The neutralization reactor is used to contain hydrofluoric acid flowing in from the hydrofluoric acid high-level tank and lithium hydroxide solution flowing in from the solution preparation module, and to make the hydrofluoric acid and lithium hydroxide solution form lithium fluoride precipitate before flowing into the purification module.

[0010] In some embodiments, the precipitation preparation module includes a hydrofluoric acid temporary tank, which is connected to a hydrofluoric acid high-level tank, and is used to contain hydrofluoric acid.

[0011] In some embodiments, the precipitation preparation module includes a horizontal grinder, which is connected to both the neutralization reactor and the purification module. The horizontal grinding mill is used to grind the lithium fluoride precipitate flowing in from the neutralization reactor and to allow the ground lithium fluoride precipitate to flow into the purification module.

[0012] In some embodiments, the purification module includes a filtration device, a filtrate storage tank, and a vacuum buffer tank, wherein the filtrate storage tank is connected to the filtration device and the vacuum buffer tank, respectively. The filtration device is connected to the precipitation preparation module. The filtration device is used to filter the lithium fluoride precipitate flowing in from the precipitation preparation module, so that the filtered lithium fluoride precipitate flows into the filtrate storage tank. The vacuum buffer tank is also connected to the filtrate storage tank and the exhaust gas treatment module. The vacuum buffer tank is used to transport the lithium fluoride precipitate flowing in from the filtrate storage tank to the drying and roasting module.

[0013] In some embodiments, the drying and roasting module includes a drying oven and a high-temperature roasting oven that are interconnected, and both the drying oven and the high-temperature roasting oven are connected to the purification module.

[0014] In some embodiments, the exhaust gas treatment module includes a vacuum water jet unit, a spray tower, and an induced draft fan. The vacuum water jet unit and the spray tower are both connected to the induced draft fan. The solution preparation module is connected to the induced draft fan and the spray tower. The precipitation preparation module is connected to the vacuum water jet unit, the spray tower, and the induced draft fan. The purification module is connected to the spray tower.

[0015] In some embodiments, the exhaust gas treatment module includes a vacuum pump, and the purification module is connected to the spray tower via the vacuum pump.

[0016] The high-purity lithium fluoride preparation system provided in this disclosure can achieve the following technical effects: The precipitation preparation module is connected to the solution preparation module, purification module, and tail gas treatment module, respectively. It prepares lithium fluoride precipitate from hydrofluoric acid solution and lithium hydroxide solution prepared by the solution preparation module, and then transports it to the purification module. This process achieves a direct reaction between hydrofluoric acid and lithium hydroxide solution, reducing the formation of byproducts, improving the purity of lithium fluoride, and ensuring batch-to-batch product quality consistency. The purification module is connected to the precipitation preparation module, drying and calcination module, and tail gas treatment module, respectively, and is used to purify the lithium fluoride precipitate prepared by the precipitation preparation module, and then transport the purified lithium fluoride precipitate to the drying and calcination module. This modular design makes the separation, washing, and drying steps of lithium fluoride precipitate more tightly integrated, reducing material loss during transfer, lowering energy consumption, improving production efficiency, and overcoming the complexity and inefficiency of the step-by-step operation mode in traditional processes. The exhaust gas treatment module receives the exhaust gases generated by the solution preparation module, precipitation preparation module, and purification module, and purifies them before discharging them from the system. This effectively solves the problem of limited removal efficiency caused by the single alkaline absorption method in traditional exhaust gas treatment devices, prevents secondary pollution caused by hydrofluoric acid waste gas, and ensures environmental safety. The aforementioned high-purity lithium fluoride preparation system, through its integrated modular design, precise reaction control, and efficient exhaust gas treatment methods, not only significantly improves product purity and batch stability but also optimizes the process flow, reduces energy consumption, and achieves environmentally compliant emissions, thus achieving multiple goals of improving product quality, increasing production efficiency, and protecting the environment.

[0017] The above general description and the description below are exemplary and illustrative only and are not intended to limit this disclosure. Attached Figure Description

[0018] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations and drawings do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are shown as similar elements. The drawings are not to be scaled. And wherein: Figure 1 This is a component connection diagram of a high-purity lithium fluoride preparation system provided in an embodiment of this disclosure; Figure 2 This is a physical structural diagram of a high-purity lithium fluoride preparation system provided in an embodiment of this disclosure; Figure 3 This is a component connection diagram of a solution preparation module provided in an embodiment of this disclosure; Figure 4 This is a connection diagram of some components of a precipitation preparation module provided in an embodiment of this disclosure; Figure 5 This is a schematic diagram showing the positional relationship of the neutralization reactor, discharge pipe, and piston in the non-discharged state provided in the embodiments of this disclosure; Figure 6This is a schematic diagram showing the positional relationship of the neutralization reactor, discharge pipe, and piston in the discharge state according to an embodiment of this disclosure.

[0019] Explanation of icon numbers: 1. Solution preparation module; 11 Water tank, 12 Water pump, 13 Dissolving tank, 14 Clarified liquid filter, 15 Precision filter, 16 Clarified liquid high-level tank, 17 Residue filter, 18 Residue filtrate high-level tank; 2. Precipitation preparation module; 21 Neutralization reactor, 22 Hydrofluoric acid high-level tank, 23 Mold temperature controller, 24 Hydrofluoric acid temporary tank, 25 Horizontal grinder, 26 Sample liquid collection bottle, 27 Discharge pipe; 28 piston, 281 piston rod, 282 piston head; 3 purification modules; 31 Filtration device, 32 Filtrate storage tank, 33 Vacuum buffer tank; 4. Drying and roasting module; 41 Drying oven, 42 High-temperature roasting oven; 5. Exhaust gas treatment module; 51 Vacuum water jet unit, 52 Spray tower, 53 Exhaust fan, 54 Vacuum pump. Detailed Implementation

[0020] To provide a more detailed understanding of the features and technical content of the embodiments of this disclosure, the implementation of the embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not intended to limit the embodiments of this disclosure. In the following technical description, for ease of explanation, several details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other cases, well-known structures and devices may be simplified in their depiction to simplify the drawings.

[0021] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this disclosure described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0022] Unless otherwise stated, the term "multiple" means two or more.

[0023] In this embodiment of the disclosure, the character " / " indicates that the objects before and after it are in an "or" relationship. For example, A / B means: A or B.

[0024] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0025] The term "correspondence" can refer to an association or binding relationship. The correspondence between A and B means that there is an association or binding relationship between A and B.

[0026] Combination Figure 1 and Figure 2 As shown in the embodiments of this disclosure, a high-purity lithium fluoride preparation system is provided. The high-purity lithium fluoride preparation system includes a solution preparation module 1, a precipitation preparation module 2, a purification module 3, a drying and calcination module 4, and a tail gas treatment module 5.

[0027] Solution preparation module 1 is connected to precipitation preparation module 2 and tail gas treatment module 5, respectively. Solution preparation module 1 is used to prepare lithium hydroxide solution from pure water and lithium hydroxide solid, and then transport the lithium hydroxide solution to precipitation preparation module 2. Precipitation preparation module 2 is connected to solution preparation module 1, purification module 3, and tail gas treatment module 5, respectively. Precipitation preparation module 2 is used to prepare lithium fluoride precipitate from hydrofluoric acid solution and the lithium hydroxide solution prepared by solution preparation module 1, and then transport the lithium fluoride precipitate to purification module 3. Purification module 3 is connected to precipitation preparation module 2, drying and calcination module 4, and tail gas treatment module 5, respectively. Purification module 3 is used to purify the lithium fluoride precipitate prepared by precipitation preparation module 2, and then transport the lithium fluoride precipitate to drying and calcination module 4. Tail gas treatment module 5 is used to receive the tail gas generated by solution preparation module 1, precipitation preparation module 2, and purification module 3, purify the tail gas, and then discharge it from the system.

[0028] In the high-purity lithium fluoride preparation system provided in this embodiment, the precipitation preparation module 2 is connected to the solution preparation module 1, the purification module 3, and the tail gas treatment module 5, respectively. It can prepare lithium fluoride precipitate based on hydrofluoric acid solution and lithium hydroxide solution prepared by the solution preparation module 1, and then transport it to the purification module 3. This process achieves a direct reaction between hydrofluoric acid and lithium hydroxide solution, reduces the generation of by-products, improves the purity of lithium fluoride, and ensures batch-to-batch product quality consistency. The purification module 3 is connected to the precipitation preparation module 2, the drying and calcination module 4, and the tail gas treatment module 5, respectively, and is used to purify the lithium fluoride precipitate prepared by the precipitation preparation module 2, and then transport the purified lithium fluoride precipitate to the drying and calcination module 4. This modular design makes the separation, washing, and drying steps of lithium fluoride precipitate more tightly integrated, reduces material loss during transfer, lowers energy consumption, improves production efficiency, and overcomes the complexity and inefficiency problems caused by the step-by-step operation mode in traditional processes. The exhaust gas treatment module 5 receives the exhaust gas generated by the solution preparation module 1, precipitation preparation module 2, and purification module 3, and purifies it before discharging it from the system. This effectively solves the problem of limited removal efficiency caused by the single alkaline absorption method in traditional exhaust gas treatment devices, prevents secondary pollution caused by hydrofluoric acid waste gas, and ensures environmental safety. The aforementioned high-purity lithium fluoride preparation system, through integrated modular design, precise reaction control, and efficient exhaust gas treatment methods, not only significantly improves product purity and batch stability but also optimizes the process flow, reduces energy consumption, and achieves environmentally compliant emissions, thus achieving multiple goals of improving product quality, increasing production efficiency, and protecting the environment.

[0029] In some embodiments, such as Figure 3 As shown, the solution preparation module 1 includes a water tank 11, a water pump 12, a dissolving tank 13, a clear liquid filter 14, a precision filter 15, and a clear liquid elevation tank 16. The water tank 11 is used to store pure water, and the dissolving tank 13 is used to contain lithium hydroxide solid. The water pump 12 is connected to both the water tank 11 and the dissolving tank 13, and is used to introduce the pure water in the water tank 11 into the dissolving tank 13, so that the pure water and lithium hydroxide solid form a lithium hydroxide solution in the dissolving tank 13. The dissolving tank 13, the clear liquid filter 14, the precision filter 15, and the clear liquid elevation tank 16 are connected in sequence. The lithium hydroxide solution in the dissolving tank 13 flows into the clear liquid elevation tank 16 through the clear liquid filter 14 and the precision filter 15. Both the dissolving tank 13 and the clear liquid elevation tank 16 are connected to the exhaust gas treatment module 5. The clear liquid elevation tank 16 is also connected to the precipitation preparation module 2, and is used to transport the lithium hydroxide solution to the precipitation preparation module 2.

[0030] In this embodiment, the water pump 12 can be a pure PTFE diaphragm pump. The water pump 12 introduces pure water from the water tank 11 into the dissolving tank 13, where it mixes with solid lithium hydroxide to form a solution, ensuring complete dissolution of the lithium hydroxide. This design makes the reaction more uniform and thorough, contributing to improved purity of the final lithium fluoride. The lithium hydroxide solution in the dissolving tank 13 flows into the high-level clear liquid tank 16 after double filtration by the clear liquid filter 14 and the precision filter 15, effectively removing any particulate matter and other impurities that may be present in the solution, further ensuring the high purity of the subsequent lithium fluoride precipitation. Both the dissolving tank 13 and the high-level clear liquid tank 16 are connected to the exhaust gas treatment module 5, allowing for timely treatment of harmful gases generated during the process and reducing environmental impact. Furthermore, the high-level clear liquid tank 16 is directly connected to the precipitation preparation module 2, simplifying material transfer steps, reducing losses due to multiple transfers, and improving the efficiency of the entire production process.

[0031] In some embodiments, the dissolving tank 13 is also connected to an external inert gas (such as nitrogen) module (not shown in the figure), which supplies inert gas to the dissolving tank 13. The inert gas module introduces inert gas into the dissolving tank 13 to prevent potential side reactions between the lithium hydroxide solution and oxygen, CO2, or water vapor in the air.

[0032] In some embodiments, the solution preparation module 1 includes a residue filter 17 and a high-level residue filtrate tank 18. The dissolving tank 13 is connected to both the residue filter 17 and the high-level residue filtrate tank 18. The residue filter 17 is also connected to the high-level residue filtrate tank 18 and the exhaust gas treatment module 5. The bottom liquid in the dissolving tank 13 flows into the high-level residue filtrate tank 18 through the residue filter 17 and then flows back into the dissolving tank 13 through the high-level residue filtrate tank 18.

[0033] After lithium hydroxide solid dissolves in dissolving tank 13, undissolved solid particles or insoluble impurities may remain at the bottom. By introducing the bottom liquid from dissolving tank 13 into residue filter 17, undissolved lithium hydroxide particles can be separated from impurities. The filtrate (containing a high concentration of lithium hydroxide) then flows back to dissolving tank 13 after entering residue filtrate elevating tank 18 to continue the dissolving process. This recycling design significantly improves the utilization rate of lithium hydroxide raw materials, reduces waste, and lowers production costs. Residue filter 17 effectively intercepts insoluble impurities (such as inert particles or impurities in the raw material), preventing them from entering subsequent processes and contaminating lithium fluoride precipitation. Continuous purification of the bottom liquid through circulating filtration helps obtain a purer and more stable lithium hydroxide solution, providing high-quality raw materials for subsequent precipitation reactions, thereby improving the purity and batch consistency of the final product. Residue filtrate elevating tank 18 acts as a buffer and reflux device, allowing the filtered lithium-rich solution to automatically return to dissolving tank 13 by gravity or pumping without manual intervention. This closed-loop circulation structure supports continuous operation, reducing the frequency of downtime for cleaning or refueling, and improving the system's automation level and operational stability. The residue filter 17 is connected to the exhaust gas treatment module 5, which can extract and treat potentially escaping harmful gases during the filtration process, preventing their accumulation or leakage inside the equipment and improving the safety of the operating environment.

[0034] In this embodiment, a weighed amount of lithium hydroxide solid is added through the handhole of the dissolving tank 13. The water pump 12 is started, and a certain amount of pure water is added to the dissolving tank 13 from the water tank 11. Stirring is then initiated to completely dissolve the lithium hydroxide solid. After dissolution, the lithium hydroxide solution is allowed to settle. The supernatant enters the clear liquid filter 14, then the precision filter 15 to thoroughly remove any impurities that may be present in the solution. Finally, it enters the clear liquid high-level tank 16 for buffering. The bottom liquid in the dissolving tank 13 enters the residue filter 17, then the residue filtrate high-level tank 18 for buffering, and finally returns to the dissolving tank 13.

[0035] In some embodiments, the precipitation preparation module 2 includes a neutralization reactor 21, a hydrofluoric acid high-level tank 22, and a mold temperature controller 23. The neutralization reactor 21 is connected to the solution preparation module 1, the hydrofluoric acid high-level tank 22, and the mold temperature controller 23, and both the neutralization reactor 21 and the hydrofluoric acid high-level tank 22 are also connected to the tail gas treatment module 5. The hydrofluoric acid high-level tank 22 is used to contain hydrofluoric acid and allow it to flow into the neutralization reactor 21. The neutralization reactor 21 is also connected to the purification module 3. The neutralization reactor 21 is used to contain the hydrofluoric acid flowing in from the hydrofluoric acid high-level tank 22 and the lithium hydroxide solution flowing in from the solution preparation module 1, and allows the hydrofluoric acid and lithium hydroxide solution to form a lithium fluoride precipitate before flowing into the purification module 3.

[0036] In this embodiment, the neutralization reactor 21 is connected to the water pump 12 and the high-level clarified liquid tank 16 in the solution preparation module 1. The water pump 12 is used to supply pure water to the neutralization reactor 21, and the high-level clarified liquid tank 16 is used to transport the lithium hydroxide solution to the precipitation preparation module 2. Here, the neutralization reactor 21 uses a high-boiling-point fluorinated oil with good temperature resistance and hydrofluoric acid resistance as a sealing surface liquid film, which can adhere to the contact surface for a long time, thereby effectively avoiding powder contamination of the material caused by friction on the contact surface.

[0037] In this embodiment, the hydrofluoric acid high-level tank 22 serves as a constant-pressure storage device, stably supplying hydrofluoric acid solution to the neutralization reactor 21. This prevents violent reactions or localized over-acidity due to flow fluctuations, thereby reducing the occurrence of side reactions. The mold temperature controller 23 is connected to the neutralization reactor 21, enabling precise heating or cooling control of the reaction system to maintain the reaction within the optimal temperature range. Both the neutralization reactor 21 and the hydrofluoric acid high-level tank 22 are connected to the tail gas treatment module 5, allowing for real-time extraction of potentially escaping harmful gases during the reaction and acid storage processes.

[0038] In some embodiments, the precipitation preparation module 2 includes a temporary hydrofluoric acid tank 24. The temporary hydrofluoric acid tank 24 is connected to a high-level hydrofluoric acid tank 22 and is used to contain hydrofluoric acid. As an intermediate storage device, the temporary hydrofluoric acid tank 24 acts as a buffer during the hydrofluoric acid supply process. When the hydrofluoric acid in the high-level hydrofluoric acid tank 22 is insufficient, the temporary tank can be quickly replenished, avoiding interruptions caused by directly obtaining hydrofluoric acid from a large storage tank or an external supplier.

[0039] In some embodiments, the precipitation preparation module 2 includes a horizontal grinder 25, which is connected to both the neutralization reactor 21 and the purification module 3. The horizontal grinder 25 is used to grind the lithium fluoride precipitate flowing into the neutralization reactor 21 and to allow the ground lithium fluoride precipitate to flow into the purification module 3. The lithium fluoride precipitate generated by the neutralization reaction may exist in the form of agglomerates or large particles. Mechanical grinding of the precipitate by the horizontal grinder 25 can effectively break the agglomerate structure, refine the particles, and fully release the encapsulated mother liquor, thereby significantly improving the removal efficiency of impurity ions in the subsequent purification module 3 (such as filtration and washing) and reducing the content of soluble impurities in the product.

[0040] In this embodiment, the horizontal grinder 25 is also connected to a water pump 12 and an external inert gas (such as nitrogen) module. The water pump 12 supplies pure water to the horizontal grinder 25, and the inert gas module supplies inert gas to the horizontal grinder 25. The water pump 12 continuously supplies pure water to the horizontal grinder 25, forming a liquid-solid mixed wet grinding environment, which can effectively suppress the dust generation of lithium fluoride fine powder. The inert gas module introduces inert gas into the grinding chamber, which can prevent potential side reactions between lithium fluoride and oxygen, CO2, or water vapor in the air during high-energy grinding.

[0041] In some embodiments, such as Figure 4 As shown, the precipitation preparation module 2 also includes a sample liquid collection bottle 26, which is connected to the neutralization reactor 21. Here, primary quantitative analysis can be achieved by setting the amount of lithium hydroxide solution and hydrofluoric acid added, and then fine-tuning can be performed by sampling and detecting the pH value, thereby improving work efficiency. To avoid material waste, the bypass pH measurement line is opened, allowing the solution to be discharged into the pH measurement container. At this time, the amount of lithium hydroxide or hydrofluoric acid added is fine-tuned according to the actual measured pH value, and the sample liquid is finally discharged into the sample liquid collection bottle 26.

[0042] In this embodiment, the lithium hydroxide solution in the high-level clear liquid tank 16 enters through the inlet of the neutralization reactor 21. The amount of lithium hydroxide solution entering can be controlled by the internal level gauge of the neutralization reactor 21. After the amount of lithium hydroxide solution entering reaches the set value, the valve of the high-level hydrofluoric acid tank 22 is opened, allowing hydrofluoric acid to flow into the neutralization reactor 21 by gravity. The initial amount of hydrofluoric acid added should be set according to the calculated value (the lithium hydroxide concentration here is obtained from the amount of lithium hydroxide added previously and the amount of pure water added), combined with the changes in the liquid level during the reaction period. The valve is closed when the amount of hydrofluoric acid added reaches the calculated value. Then, the stirrer of the neutralization reactor 21 is turned on to ensure that the neutralization reaction is complete. At this time, the bypass pH measurement line is opened to discharge the solution into the pH measurement container. The amount of lithium hydroxide or hydrofluoric acid added is then finely adjusted according to the actual measured pH value. Finally, the sample solution is discharged into the sample solution collection bottle 26. After the neutralization reaction is complete, allow the mixture to stand and age. Discharge the supernatant from the supernatant outlet, add pure water, heat and stir, and repeatedly wash the precipitate. At the same time, discharge the washing liquid from the supernatant outlet.

[0043] In this embodiment of the disclosure, combined with Figure 5 and Figure 6 As shown, a discharge pipe 27 is provided at the bottom of the neutralization reactor 21, and the discharge pipe 27 is bent. Furthermore, a piston 28 is provided for the discharge pipe 27, wherein the piston 28 includes a piston rod 281 and a piston head 282. The piston head 282 is disposed inside the discharge pipe 27 and matches the diameter of the discharge pipe 27, while the piston rod 281 is slidably disposed in the bent area of ​​the discharge pipe 27. By moving the piston 28 up and down, the piston head 282 can seal or open the inlet of the discharge pipe 27. This arrangement completely prevents slurry accumulation in the discharge pipe 27.

[0044] Neutralization reactor 21 is a closed system with a mechanical seal. To prevent external dust and other impurities from entering the contaminated material, all pipelines are equipped with precision air filters with a filtration accuracy of less than 1µm. To prevent contamination of the material by the metal tank, all parts in contact with the medium are made of 304 stainless steel with a hot-rolled lining and an inner PTFE (polytetrafluoroethylene) liner. All other parts in contact with the material must be lined with PTFE.

[0045] The mold temperature controller 23 can heat the reaction solution, maintaining the temperature between 100℃ and 150℃. The neutralization reactor 21 uses an anchor-type stirring method with a frequency-adjustable stirring speed of 0~80 rpm. The neutralization reactor 21 has acid inlet, alkali inlet, inert gas inlet / outlet, vacuum port, supernatant outlet, and discharge port. The pipes for the alkali and acid inlets should extend 100~200mm into the equipment. A supernatant outlet is located approximately 100L from the bottom of the neutralization reactor 21. The bottom discharge valve of the neutralization reactor 21 is a ball valve, installed flush with the bottom of the reactor. This valve is a no-dead-angle discharge ball valve, with the ball valve core flush with the bottom of the equipment. The discharge valve is a top-discharge valve with no dead-angle discharge. The precipitated slurry is discharged using a top-discharge valve to ensure the ball valve core is flush with the bottom of the equipment, preventing the precipitate from being insufficiently washed by pure water. To prevent slurry blockage in the pipeline, the feed pipe is equipped with high-purity inert gas flushing.

[0046] In some embodiments, the purification module 3 includes a filtration device 31, a filtrate storage tank 32, and a vacuum buffer tank 33. The filtrate storage tank 32 is connected to both the filtration device 31 and the vacuum buffer tank 33. The filtration device 31 is connected to the precipitation preparation module 2 and is used to filter the lithium fluoride precipitate flowing into the precipitation preparation module 2, so that the filtered lithium fluoride precipitate flows into the filtrate storage tank 32. The vacuum buffer tank 33 is also connected to the filtrate storage tank 32 and the exhaust gas treatment module 5, and is used to transport the lithium fluoride precipitate flowing into the filtrate storage tank 32 to the drying and calcination module 4.

[0047] In this embodiment, the filtration device 31 is connected to the neutralization reactor 21 in the precipitation preparation module 2. Furthermore, the filtration device 31 is connected to the horizontal grinder 25 in the precipitation preparation module 2, and the horizontal grinder is connected to the neutralization reactor 21.

[0048] The filtration device 31 is directly connected to the precipitation preparation module 2, enabling rapid filtration of the lithium fluoride slurry supplied from the precipitation preparation module 2. Moisture and soluble impurities are quickly removed, while the solid lithium fluoride is retained on the filter membrane or filter cloth, achieving highly efficient solid-liquid separation. The vacuum buffer tank 33 is connected to the filtrate storage tank 32 and the tail gas treatment module 5. Using vacuum negative pressure, it smoothly transports the lithium fluoride precipitate in the filtrate storage tank 32 to the drying and roasting module 4, avoiding wear, contamination, or blockage caused by mechanical scraping or pumping, thus providing pressure buffering and airflow isolation. The vacuum buffer tank 33 is also connected to the tail gas treatment module 5, allowing for the timely extraction and introduction of harmful gases or water vapor emitted during filtration and transportation into the tail gas treatment module 5 for treatment.

[0049] In some embodiments, the drying and calcining module 4 includes a drying furnace 41 and a high-temperature calcining furnace 42 that are interconnected, both of which are connected to the purification module 3. Specifically, both the drying furnace 41 and the high-temperature calcining furnace 42 are connected to the vacuum buffer tank 33 in the purification module 3. The drying furnace 41 first performs low-temperature dehydration treatment on the lithium fluoride precipitate from the purification module 3 to avoid particle bursting, splashing, or agglomeration caused by direct high-temperature heating. Subsequently, the lithium fluoride precipitate enters the high-temperature calcining furnace 42 for deep dehydroxylation and crystal form improvement, promoting the transformation of amorphous or low-crystallinity lithium fluoride into highly crystalline and structurally stable lithium fluoride crystals. Stepwise temperature control effectively prevents material loss and performance degradation caused by rapid vaporization of moisture, ensuring that the final product has excellent thermal stability, chemical purity, and electrochemical performance.

[0050] In some embodiments, the exhaust gas treatment module 5 includes a vacuum water jet unit 51, a spray tower 52, and an induced draft fan 53. The vacuum water jet unit 51 and the spray tower 52 are both connected to the induced draft fan 53. The solution preparation module 1 is connected to the induced draft fan 53 and the spray tower 52. The precipitation preparation module 2 is connected to the vacuum water jet unit 51, the spray tower 52, and the induced draft fan 53. The purification module 3 is connected to the spray tower 52.

[0051] In this embodiment of the disclosure, the dissolving tank 13 in the solution preparation module 1 is connected to the induced draft fan 53 and the spray tower 52, and the residue filtrate high-level tank 18 and the semen high-level tank in the solution preparation module 1 are connected to the vacuum water jet unit 51.

[0052] In this embodiment of the disclosure, the neutralization reactor 21 in the precipitation preparation module 2 is connected to the vacuum water jet unit 51, the spray tower 52 and the induced draft fan 53, and the hydrofluoric acid high-level tank 22 in the precipitation preparation module 2 is connected to the vacuum water jet unit 51, the spray tower 52 and the induced draft fan 53.

[0053] In this embodiment of the present disclosure, the vacuum buffer tank 33 in the purification module 3 is connected to the spray tower 52.

[0054] The solution preparation module 1 (e.g., dissolving tank 13), precipitation preparation module 2 (e.g., neutralization reactor 21, hydrofluoric acid high-level tank 22), and purification module 3 may release harmful components such as hydrofluoric acid vapor, alkaline gas, or water vapor during operation. By connecting each module to the induced draft fan 53 and / or spray tower 52, it is ensured that all gas generation points are within the effective suction range, protecting the health of operators and the safety of the production environment. The exhaust gas treatment module 5, through the organic integration of the vacuum water jet unit 51, spray tower 52, and induced draft fan 53, and employing a differentiated connection strategy, achieves efficient capture, graded purification, and safe emission of various harmful gases during the preparation of high-purity lithium fluoride.

[0055] In some embodiments, the exhaust gas treatment module 5 includes a vacuum pump 54, and the purification module 3 is connected to the spray tower 52 via the vacuum pump 54. Specifically, the vacuum buffer tank 33 in the purification module 3 is connected to the spray tower 52 via the vacuum pump 54. The vacuum pump 54, as an active power source, can forcibly extract and pressurize the gas in the vacuum buffer tank 33, ensuring that harmful components such as hydrofluoric acid vapor and water vapor are quickly and directionally delivered to the spray tower 52, shortening the residence time and improving the response efficiency and reliability of exhaust gas treatment.

[0056] The foregoing has shown and described the basic principles, main features, and advantages of this invention. Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection claimed by this invention is defined by the appended claims and their equivalents.

Claims

1. A high-purity lithium fluoride preparation system, characterized in that, It includes a solution preparation module, a precipitation preparation module, a purification module, a drying and calcination module, and a tail gas treatment module; The solution preparation module is connected to the precipitation preparation module and the tail gas treatment module respectively. The solution preparation module is used to prepare lithium hydroxide solution based on pure water and lithium hydroxide solid, and then transport the lithium hydroxide solution to the precipitation preparation module. The precipitation preparation module is connected to the solution preparation module, the purification module and the tail gas treatment module respectively. The precipitation preparation module is used to prepare lithium fluoride precipitate based on the hydrofluoric acid solution and the lithium hydroxide solution prepared by the solution preparation module, and to transport the lithium fluoride precipitate to the purification module. The purification module is connected to the precipitation preparation module, the drying and calcination module and the tail gas treatment module respectively. The purification module is used to purify the lithium fluoride precipitate prepared by the precipitation preparation module and transport the lithium fluoride precipitate to the drying and calcination module. The exhaust gas treatment module is used to receive the exhaust gas generated by the solution preparation module, precipitation preparation module and purification module, and then discharge the exhaust gas from the system after purification treatment.

2. The high-purity lithium fluoride preparation system according to claim 1, characterized in that, The solution preparation module includes a water tank, a water pump, a dissolving tank, a clear liquid filter, a precision filter, and a clear liquid high-level tank. The water tank is used to store pure water, and the dissolving tank is used to contain lithium hydroxide solid. The water pump is connected to the water tank and the dissolving tank respectively, and is used to introduce pure water from the water tank into the dissolving tank so that pure water and lithium hydroxide solid can form a lithium hydroxide solution in the dissolving tank; The dissolving tank, the clear liquid filter, the precision filter, and the clear liquid high-level tank are connected in sequence. The lithium hydroxide solution in the dissolving tank flows into the clear liquid high-level tank through the clear liquid filter and the precision filter. Both the dissolving tank and the high-level clear liquid tank are connected to the exhaust gas treatment module. The high-level clear liquid tank is also connected to the precipitation preparation module. The high-level clear liquid tank is used to transport lithium hydroxide solution to the precipitation preparation module.

3. The high-purity lithium fluoride preparation system according to claim 2, characterized in that, The solution preparation module includes a residue filter and a high-level tank for residue and filtrate; The dissolving tank is connected to the residue filter and the high-level residue filtrate tank respectively. The residue filter is also connected to the high-level residue filtrate tank and the exhaust gas treatment module. The bottom liquid in the dissolving tank flows through the residue filter into the high-level residue filtrate tank, and then flows back into the dissolving tank through the high-level residue filtrate tank.

4. The high-purity lithium fluoride preparation system according to claim 1, characterized in that, The precipitation preparation module includes a neutralization reactor, a hydrofluoric acid high-level tank, and a mold temperature controller; The neutralization reactor is connected to the solution preparation module, the hydrofluoric acid high-level tank and the mold temperature controller, and both the neutralization reactor and the hydrofluoric acid high-level tank are also connected to the tail gas treatment module. The hydrofluoric acid high-level tank is used to contain hydrofluoric acid and allow it to flow into the neutralization reactor. The neutralization reactor is also connected to the purification module. The neutralization reactor is used to contain hydrofluoric acid flowing in from the hydrofluoric acid high-level tank and lithium hydroxide solution flowing in from the solution preparation module, and to make the hydrofluoric acid and lithium hydroxide solution form lithium fluoride precipitate before flowing into the purification module.

5. The high-purity lithium fluoride preparation system according to claim 4, characterized in that, The precipitation preparation module includes a hydrofluoric acid temporary container, which is connected to a hydrofluoric acid high-level tank. The hydrofluoric acid temporary container is used to contain hydrofluoric acid.

6. The high-purity lithium fluoride preparation system according to claim 4, characterized in that, The precipitation preparation module includes a horizontal grinder, which is connected to both the neutralization reactor and the purification module. The horizontal grinding mill is used to grind the lithium fluoride precipitate flowing in from the neutralization reactor and to allow the ground lithium fluoride precipitate to flow into the purification module.

7. The high-purity lithium fluoride preparation system according to claim 1, characterized in that, The purification module includes a filtration device, a filtrate storage tank, and a vacuum buffer tank, with the filtrate storage tank connected to both the filtration device and the vacuum buffer tank. The filtration device is connected to the precipitation preparation module. The filtration device is used to filter the lithium fluoride precipitate flowing in from the precipitation preparation module, so that the filtered lithium fluoride precipitate flows into the filtrate storage tank. The vacuum buffer tank is also connected to the filtrate storage tank and the exhaust gas treatment module. The vacuum buffer tank is used to transport the lithium fluoride precipitate flowing in from the filtrate storage tank to the drying and roasting module.

8. The high-purity lithium fluoride preparation system according to claim 1, characterized in that, The drying and roasting module includes an interconnected drying oven and a high-temperature roasting oven, both of which are connected to the purification module.

9. The high-purity lithium fluoride preparation system according to claim 1, characterized in that, The exhaust gas treatment module includes a vacuum water jet unit, a spray tower, and an induced draft fan. The vacuum water jet unit and the spray tower are both connected to the induced draft fan. The solution preparation module is connected to the induced draft fan and the spray tower. The precipitation preparation module is connected to the vacuum water jet unit, the spray tower, and the induced draft fan. The purification module is connected to the spray tower.

10. The high-purity lithium fluoride preparation system according to claim 9, characterized in that, The exhaust gas treatment module includes a vacuum pump, and the purification module is connected to the spray tower through the vacuum pump.

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