Method and equipment for preparing battery material lithium phosphate from frozen clear liquid

Abstract

The invention provides a method and equipment for preparing battery material lithium phosphate from frozen clear liquid, and relates to the field of preparation of battery material lithium phosphate. The method for preparing the battery material lithium phosphate from the frozen clear liquid comprises the following steps: S1, adding dilute sulphuric acid with a certain concentration into the frozen clear liquid, regulating the pH value to 3.0-4.0, removing carbonate radicals under the conditions that the temperature is 25-40 DEG C and the stirring speed is 200-300rpm, and converting the carbonate radicals into carbon dioxide for escaping to obtain a decarburized liquid; and S2, the obtained decarburized solution and MgH2 (PO4) 2 are subjected to a mixed reaction. According to the method for preparing the battery material lithium phosphate from the frozen clear liquid, carbonate is removed, precipitation formed by Na < + >, K < + > and carbonate is prevented from being mixed into a product, the decarburization liquid and MgH2 (PO4) 2 are subjected to mixed reaction, lithium phosphate precipitation is obtained, under the condition that the PH value is 6-7, Mg < 2 + > does not generate precipitation, the precipitation is subjected to centrifugal washing and calcination in the subsequent process, and the battery material lithium phosphate is obtained. And removing residual trace impurities on the surface to obtain the battery-grade lithium phosphate, thereby reducing impurity ions and improving the purity of the product.

Description

Technical Field

[0001] This invention relates to the field of lithium phosphate preparation for battery materials, and more particularly to a method and apparatus for preparing lithium phosphate for battery materials from a cryogenic solution. Background Technology

[0002] Lithium-ion batteries are widely used in electric vehicles, energy storage systems and other fields, and their demand for key metals such as lithium, cobalt and nickel is growing explosively. Lithium carbonate and lithium phosphate are among the important related materials in the lithium battery field. Among them, the lithium extraction process using spodumene sulfuric acid is one of the mainstream production processes in industry, which mainly includes steps such as roasting, acid leaching, neutralization and freeze desodiuming.

[0003] The supernatant after cryogenic desodiumization is rich in lithium ions (Li). + However, it also contains a large amount of sodium (Na). + ), potassium (K) + Impurities such as sodium carbonate precipitation can lead to a decrease in product purity when lithium carbonate is produced using traditional sodium carbonate precipitation methods. Furthermore, the market added value of lithium carbonate is limited, making it difficult to meet the demand for high-value-added lithium products. In addition, the leaching residue after acid leaching of spodumene mainly consists of SiO2 and Al2O3, which are usually stored or landfilled as industrial solid waste, resulting in not only a waste of resources but also potential environmental risks.

[0004] In recent years, phase change energy storage materials have attracted much attention due to their applications in industrial waste heat recovery and solar thermal storage. Among them, ternary sulfates (such as Na2SO4-K2SO4-MgSO4) have advantages such as adjustable phase change temperature (215~280℃) and high heat storage density (latent heat >185 J / g). However, existing synthesis methods for ternary sulfates mostly use purely chemical raw materials, resulting in high costs and limiting their large-scale application. Therefore, how to efficiently utilize byproducts (such as cryogenic liquid and leaching residue) in the lithium extraction process of spodumene to achieve high-value utilization of lithium resources while reducing the production cost of phase change materials has become an urgent technical problem to be solved in this field.

[0005] Therefore, it is necessary to provide a method and apparatus for preparing lithium phosphate battery material from cryogenic liquid to solve the above-mentioned technical problems. Summary of the Invention

[0006] This invention provides a method for preparing lithium phosphate, a battery material, using a cryogenic solution, which solves the problem that impurity ions easily lead to a decrease in product purity when using the traditional sodium carbonate precipitation method to produce lithium carbonate.

[0007] To solve the above-mentioned technical problems, the present invention provides a method for preparing lithium phosphate battery material from cryogenic liquid, comprising the following steps:

[0008] S1. Add a certain concentration of dilute sulfuric acid to the frozen clear liquid to adjust the pH to 3.0-4.0. Remove carbonate ions and convert them into carbon dioxide under the conditions of 25-40℃ and 200-300rpm to obtain decarbonated liquid.

[0009] S2. The obtained decarbonized liquid is mixed with MgH2(PO4)2 and reacted, and the pH is adjusted to 6-7. The reaction is carried out at 60℃ for 1 hour, and the lithium phosphate and filtrate are obtained by filtration.

[0010] S3. After centrifuging and washing the obtained lithium phosphate precipitate, calcine it at 300°C for 2 hours under a nitrogen atmosphere to obtain battery-grade lithium phosphate.

[0011] Preferably, the following steps are also included:

[0012] S4. Extract the filtrate obtained in step S2 with the extractant trioctylamine-kerosene at a volume ratio of 3:1, and adjust the pH to 1.5-2.5. Mix and extract for 5-8 minutes to separate the organic phase and aqueous phase.

[0013] S5. Add the organic phase to sodium hydroxide solution for back-extraction to obtain back-extraction solution, and return the back-extraction solution to step S2 for recycling.

[0014] S6. The aqueous phase obtained in step S4 is evaporated and crystallized at 100℃ to obtain a ternary sulfate solid.

[0015] S7. The ternary sulfate solid and the spodumene slag dried for 24 hours were mixed in a ball mill at a solid ratio of 1:1.5. After the mixture was homogeneous, it was calcined at 900℃ for 1 hour to obtain the lithium slag-based ternary sulfate composite material.

[0016] Preferably, the ternary sulfate solid in S6 includes sodium sulfate, potassium sulfate, and magnesium sulfate.

[0017] The present invention also provides an apparatus for preparing lithium phosphate battery material from cryogenic liquid, and a method for preparing lithium phosphate battery material from the cryogenic liquid, comprising: a support;

[0018] A mixing cylinder, comprising a cylinder body and a cylinder cover, wherein the cylinder cover is detachably installed on the top of the cylinder body, the cylinder body comprising an upper cylinder and a lower cylinder, the upper cylinder being connected to the lower cylinder via a frustum portion, the diameter of the upper cylinder being larger than that of the lower cylinder, and drain pipes being connected to both sides of the lower cylinder.

[0019] A blocking assembly, comprising a blocking plate, a push cylinder, and a valve plate, wherein the blocking plate is installed inside the lower end cylinder, and a water outlet hole is provided in the center of the blocking plate; the valve plate blocks the water outlet hole; the push cylinder is installed in the lower end cylinder, and the valve plate is connected to the output end of the push cylinder;

[0020] A filter cleaning component, comprising a filter cartridge and a rotating component, wherein the filter cartridge is detachably mounted on the valve plate and the side wall of the filter cartridge is in contact with the inner wall of the lower end cylinder, and the rotating component is used to drive the filter cartridge to rotate;

[0021] A stirring device is used to stir and mix the materials in the mixing drum.

[0022] Preferably, the equipment for preparing lithium phosphate battery material from the cryogenic liquid further includes a lifting device, which includes a lifting cylinder and a connecting plate. The lifting cylinder is mounted on the bracket and is arranged adjacent to the mixing cylinder. The connecting plate connects the output end of the lifting cylinder to the cylinder cover.

[0023] Preferably, the stirring device includes a driving device, a stirring tube, and a stirring blade structure. The stirring tube is installed on the cylinder cover, the stirring blade structure is installed on the stirring tube and located inside the mixing cylinder, and the driving device is used to drive the stirring tube to rotate.

[0024] Preferably, the top end of the stirring tube is connected to the water inlet pipe via a rotary connector. The stirring blade structure includes a connecting pipe, a vertical pipe, a driving blade, and multiple nozzles. The connecting pipe is horizontally connected to the stirring tube, and the vertical pipe is vertically connected to the end of the connecting pipe away from the stirring tube. The driving blade is installed on the vertical pipe, and the multiple nozzles are connected to the vertical pipe at intervals and face the wall of the mixing cylinder.

[0025] Preferably, the stirring tube includes a rotating cylinder and a transmission component. The rotating cylinder is rotatably mounted on the cylinder cover. The transmission component includes a transmission tube, a connecting rod, a base, and a square shaft. One end of the transmission tube extends through the cylinder cover into the rotating cylinder and is rotatably connected to the cylinder cover. The base fits against the bottom of the inner wall of the rotating cylinder. The square shaft is connected to the bottom of the base and is inserted into a square hole at the bottom of the rotating cylinder. The top end of the connecting rod is connected to the transmission tube, and the bottom end is vertically slidably connected to the base. A square groove is provided at the bottom end of the square shaft.

[0026] The rotating component is a square rod, which is installed at the bottom center of the filter cartridge and located below the square groove;

[0027] The rotary connector is installed at the top of the rotary cylinder, and the connecting pipe is connected to the rotary cylinder.

[0028] Preferably, the drive device includes a motor, a main gear, and a driven gear. The motor is mounted on the cylinder cover via a mounting bracket. The main gear is mounted on the output end of the motor. The driven gear is mounted on the transmission tube. The main gear meshes with the driven gear.

[0029] Preferably, the nozzle is threaded with a sealing cap.

[0030] Compared with related technologies, the method and equipment for preparing lithium phosphate battery material from cryogenic liquid provided by the present invention have the following beneficial effects:

[0031] This invention provides a method for preparing lithium phosphate battery material from cryogenic liquid, by removing carbonate ions and avoiding Na+ ions. + K + Lithium phosphate precipitate is obtained by reacting with carbonate ions to form a precipitate in the product, and by reacting it with MgH2(PO4)2 in a decarbonation solution. This is achieved under pH conditions of 6-7. 2+ No precipitation will occur. The precipitate will be centrifuged, washed, and calcined to remove trace impurities on the surface, thus obtaining battery-grade lithium phosphate, thereby reducing impurity ions and improving product purity.

[0032] Furthermore, by utilizing byproducts from the lithium extraction process of spodumene, such as cryogenic liquid and leaching residue, lithium slag-based ternary sulfate composite materials can be produced, realizing the high-value utilization of lithium resources while reducing the production cost of phase change materials. Attached Figure Description

[0033] Figure 1 A flowchart illustrating the steps of the method for preparing lithium phosphate battery material from a cryogenic solution provided by the present invention;

[0034] Figure 2 A schematic diagram of the apparatus for preparing lithium phosphate, a battery material, from the cryogenic liquid provided by the present invention;

[0035] Figure 3 A partial cross-sectional view of the apparatus for preparing lithium phosphate, a battery material, from a cryogenic solution provided by the present invention;

[0036] Figure 4 This is a schematic diagram of the structure of the filter cleaning component after the removal of part of the present invention.

[0037] Figure 5 for Figure 3 The enlarged schematic diagram of part A shown below;

[0038] Figure 6 for Figure 3 The enlarged schematic diagram of section B is shown below;

[0039] Figure 7 This is a schematic diagram of the structure of the transmission component provided by the present invention;

[0040] Figure 8 This is a schematic diagram of the threaded connection cap on the nozzle provided by the present invention;

[0041] Figure 9A schematic diagram illustrating the working principle of the apparatus for preparing lithium phosphate battery material from cryogenic liquid provided by the present invention, wherein, Figure 9 Image (a) is a schematic diagram of a stirring device stirring a mixed solution. Figure 9 (b) is a schematic diagram showing the state of the solution discharging the solid precipitate through the outlet hole and filtering it into the filter cartridge. Figure 9 (c) is a schematic diagram of the process of cleaning a solid precipitate by centrifugation;

[0042] Figure 10 for Figure 9 The enlarged schematic diagram of section C is shown.

[0043] Numbering on the map:

[0044] 1. Bracket;

[0045] 2. Mixing drum; 21. Drum body; 22. Drum cover; 23. Heating assembly;

[0046] 211. Upper end cylinder; 212. Lower end cylinder; 201. Drain pipe; 202. Valve;

[0047] 3. Stirring device; 31. Drive device; 32. Rotating drum; 33. Transmission component; 34. Stirring blade structure;

[0048] 311. Motor; 312. Main gear; 313. Driven gear; 321. Square hole;

[0049] 331. Transmission tube; 332. Connecting rod; 333. Chassis; 334. Insert tube; 335. Square shaft; 336. Elastic element; 330. Square groove;

[0050] 341. Connecting pipe; 342. Vertical pipe; 343. Nozzle; 344. Drive blade;

[0051] 4. Lifting device; 41. Lifting cylinder; 42. Connecting plate; 43. Telescopic rod;

[0052] 5. Sealing assembly; 51. Sealing plate; 52. Push cylinder; 53. Valve plate;

[0053] 6. Filter cleaning components; 61. Filter cartridge; 62. Rotating components; 63. Rotating shaft;

[0054] 7. Rotary connector;

[0055] 8. Water inlet pipe;

[0056] 9. Capping. Detailed Implementation

[0057] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0058] This invention provides a method for preparing lithium phosphate, a battery material, from a cryogenic solution.

[0059] Please refer to the following: Figure 1 In one embodiment of the present invention, the method for preparing lithium phosphate battery material from the cryogenic liquid includes the following steps:

[0060] S1. Add a certain concentration of dilute sulfuric acid to the frozen clear liquid to adjust the pH to 3.0-4.0. Remove carbonate ions and convert them into carbon dioxide under the conditions of 25-40℃ and 200-300rpm to obtain decarbonated liquid.

[0061] S2. The obtained decarbonized liquid is mixed with MgH2(PO4)2 and reacted, and the pH is adjusted to 6-7. The reaction is carried out at 60℃ for 1 hour, and the lithium phosphate and filtrate are obtained by filtration.

[0062] S3. After centrifuging and washing the obtained lithium phosphate precipitate, calcine it at 300°C for 2 hours under a nitrogen atmosphere to obtain battery-grade lithium phosphate.

[0063] Among them, the cryogenic supernatant is the lithium-containing supernatant obtained after the "cryogenic desodiuming" step in the lithium extraction process of spodumene sulfuric acid method;

[0064] By removing carbonate (CO3) 2- ), avoid Na + K + Lithium phosphate precipitate is obtained by reacting with carbonate ions to form a precipitate in the product, and by reacting it with MgH2(PO4)2 in a decarbonation solution. This is achieved under pH conditions of 6-7. 2+ No precipitation will occur. The precipitate will be centrifuged, washed, and calcined to remove trace impurities on the surface, thus obtaining battery-grade lithium phosphate, thereby reducing impurity ions and improving product purity.

[0065] The decarbonized liquid reacts with MgH2(PO4)2 at a molar ratio of 1:0.525.

[0066] In this embodiment, the method for preparing lithium phosphate battery material from cryogenic liquid further includes the following steps:

[0067] S4. Extract the filtrate obtained in step S2 with the extractant trioctylamine-kerosene at a volume ratio of 3:1, and adjust the pH to 1.5-2.5. Mix and extract for 5-8 minutes to separate the organic phase and aqueous phase.

[0068] S5. Add the organic phase to sodium hydroxide solution for back-extraction to obtain back-extraction solution, and return the back-extraction solution to step S2 for recycling.

[0069] S6. The aqueous phase obtained in step S4 is evaporated and crystallized at 100℃ to obtain a ternary sulfate solid.

[0070] S7. The ternary sulfate solid and the spodumene slag dried for 24 hours were mixed in a ball mill at a solid ratio of 1:1.5. After the mixture was homogeneous, it was calcined at 900℃ for 1 hour to obtain the lithium slag-based ternary sulfate composite material.

[0071] By utilizing byproducts from the lithium extraction process of spodumene, such as cryogenic liquid and leaching residue, lithium slag-based ternary sulfate composite materials can be produced, realizing the high-value utilization of lithium resources while reducing the production cost of phase change materials.

[0072] The volume ratio of the extractant trioctylamine to kerosene is 1:4.

[0073] The ternary sulfate solid in S6 includes sodium sulfate, potassium sulfate, and magnesium sulfate.

[0074] The present invention also provides an apparatus for preparing lithium phosphate, a battery material, using cryogenic liquid.

[0075] Please see Figure 2 and Figure 3 An apparatus for preparing lithium phosphate battery material from cryogenic liquid, and a method for preparing lithium phosphate battery material from the cryogenic liquid, comprising: a support 1;

[0076] A mixing cylinder 2 includes a cylinder body 21 and a cylinder cover 22. The cylinder cover 22 is detachably installed on the top of the cylinder body 21. The cylinder body 21 includes an upper cylinder 211 and a lower cylinder 212. The upper cylinder 211 is connected to the lower cylinder 212 through a frustum. The diameter of the upper cylinder 211 is larger than that of the lower cylinder 212. Both sides of the lower cylinder 212 are connected to drain pipes 201.

[0077] The sealing assembly 5 includes a sealing plate 51, a push cylinder 52, and a valve plate 53. The sealing plate 51 is installed inside the lower end cylinder 212, and a water outlet hole is opened in the center of the sealing plate 51. The valve plate 53 blocks the water outlet hole. The push cylinder 52 is installed in the lower end cylinder 212, and the valve plate 53 is connected to the output end of the push cylinder 52.

[0078] The filter cleaning component 6 includes a filter cartridge 61 and a rotating component 62. The filter cartridge 61 is detachably mounted on the valve plate 53, and the side wall of the filter cartridge 61 is in contact with the inner wall of the lower end cylinder 212. The rotating component 62 is used to drive the filter cartridge 61 to rotate.

[0079] A stirring device 3 is used to stir and mix the materials in the mixing cylinder 2.

[0080] In this example, the equipment used for preparing lithium phosphate battery material from cryogenic liquid is mainly used in steps S2 and S3, and this equipment is mainly used in laboratories, etc.

[0081] In this embodiment, a heating assembly 23 is provided outside the mixing cylinder 2. The heating assembly 23 includes two heating sleeves and two electric heating devices (not shown in the figure). The two heating sleeves are respectively fitted outside the upper cylinder 211 and the lower cylinder 212. Each heating sleeve is provided with an electric heating device. The heating rod of the electric heating device is located inside the heating sleeve. Each heating sleeve is provided with a water inlet pipe. The water inlet pipe is threaded with a cap. Clean water is added into the heating sleeve through the heating pipe, and then the clean water is heated by the electric heating device, thereby heating the mixing cylinder 2 so that it can meet the reaction temperature.

[0082] During operation, the decarbonization liquid and MgH2(PO4)2 are added to the mixing cylinder 2, and the reaction is carried out by the stirring device 3. After the reaction is completed, the push cylinder 52 pushes the valve plate 53 upward, and the valve plate 53 moves the filter cylinder 61 upward. At this time, a gap is left between the valve plate 53 and the sealing plate 51, and the top of the filter cylinder 61 is flush with the top of the lower cylinder 212. Figure 9 In (b), after the reaction, the solution is discharged through the filter cartridge 61 through the water outlet on the sealing plate 51, and finally discharged into the preset container through the drain pipe 201. The solid precipitate is filtered in the filter cartridge 61.

[0083] After all the solution has been discharged, the push cylinder 52 continues to lift the valve plate 53, causing the filter cartridge 61 to move upwards and be positioned inside the upper end cylinder 211. Figure 9 In the middle (c), at this time, there is a gap between the filter cartridge 61 and the inner wall of the upper end cylinder 211. The rotating part 62 rotates the filter cartridge 61, and the centrifugal force causes the solid precipitate inside the filter cartridge 61 to adhere to the cylinder wall of the filter cartridge 61. Then, cleaning liquid can be sprayed onto the inner wall of the filter cartridge 61 to rinse the solid precipitate on the inner wall of the filter cartridge 61, remove the impurities on the surface of the solid precipitate, and achieve the cleaning work of the precipitate. The cleaning liquid is finally discharged through the drain pipe 201.

[0084] After cleaning is complete, filter cartridge 61 is removed to discharge the precipitated material (lithium phosphate).

[0085] This equipment can be used to achieve stirring and reaction of materials, solid-liquid separation of products, and centrifugal cleaning of solid materials.

[0086] Among them, such as Figure 3 and Figure 4 As an optional embodiment, the top of the valve plate 53 is provided with a cylindrical groove, and the bottom of the filter cartridge 61 is provided with a rotating shaft 63. The rotating shaft 63 is inserted into the cylindrical groove, thereby satisfying the detachable connection between the filter cartridge 61 and the valve plate 53, and at the same time satisfying the requirement that the filter cartridge 61 can rotate relative to the valve plate 53.

[0087] As another alternative to this embodiment, a connecting sleeve can be provided at the bottom of the filter cartridge 61, and a connecting column can be installed on the top of the valve plate 53. The cylindrical sleeve is fitted onto the connecting column to form a detachable connection.

[0088] In a preferred embodiment, the number of drain pipes 201 is two, such as... Figure 3 Each drain pipe 201 is connected to a valve 202. When the reaction is complete, the valve 202 on one drain pipe 201 is opened to drain the filtrate. When cleaning, the valve 202 is closed and the other valve 202 is opened to drain the cleaning solution. Separate drainage facilitates the configuration of collection containers. Each collection container can be connected to the corresponding valve 202 via a pipe to guide the flow of the solution.

[0089] Please see Figure 2 As a preferred embodiment, the equipment for preparing lithium phosphate battery material from cryogenic liquid further includes a lifting device 4. The lifting device 4 includes a lifting cylinder 41 and a connecting plate 42. The lifting cylinder 41 is installed on the bracket 1 and is arranged adjacent to the mixing cylinder 2. The connecting plate 42 connects the output end of the lifting cylinder 41 to the cylinder cover 22.

[0090] The lifting device 4 is set to easily lift the cylinder cover 22, thereby adjusting the height of the stirring device 3, which makes it easy to add reaction raw materials into the mixing cylinder 2 and to easily remove the filter cylinder 61.

[0091] Furthermore, the height of the stirring device 3 can be flexibly set, and the height of the stirring device 3 can be adjusted during the reaction process, so that mixing and stirring can be carried out at different depths of the solution, thereby improving the reaction rate; and the stirring device 3 can be moved out of the mixing cylinder 2, making it easier to clean the stirring device 3, etc.

[0092] In this embodiment, the lifting device 4 also includes a plurality of telescopic rods 43, which are symmetrically located on both sides of the lifting cylinder 41 and mounted on the bracket 1. The top of the telescopic rods 43 are connected to the connecting plate 42, so that when the lifting cylinder 41 drives the cylinder cover 22 to rise and fall through the connecting plate 42, the connecting plate 42 can be limited in the horizontal direction.

[0093] The telescopic rod 43 includes a positioning cylinder and a positioning rod. The positioning cylinder is installed on the connecting plate 42, the positioning rod is installed on the bracket 1, and the positioning cylinder is sleeved on the positioning rod.

[0094] Among them, the lifting cylinder 41 and the push cylinder 52 can be pneumatic cylinders, hydraulic cylinders, or electric push rods.

[0095] When the lifting device 4 is not installed, the stirring end of the stirring device 3 is located inside the upper cylinder 211, so as not to affect the filter cylinder 61 from moving up into the upper cylinder 211.

[0096] Please see Figure 3 In this embodiment, the stirring device 3 includes a driving device 31, a stirring tube, and a stirring blade structure 34. The stirring tube is installed on the cylinder cover 22, and the stirring blade structure 34 is installed on the stirring tube and located inside the mixing cylinder 2. The driving device 31 is used to drive the stirring tube to rotate.

[0097] During operation, the drive device 31 drives the stirring tube to rotate, thereby driving the stirring blade structure 34 to rotate, thus achieving stirring and mixing of the solution.

[0098] Please refer to it again. Figure 3 In other embodiments, the top end of the stirring tube is connected to the water inlet pipe 8 via a rotating connector 7. The stirring blade structure 34 includes a connecting pipe 341, a vertical pipe 342, a driving blade 344, and multiple nozzles 343. The connecting pipe 341 is horizontally connected to the stirring tube, the vertical pipe 342 is vertically connected to the end of the connecting pipe 341 away from the stirring tube, the driving blade 344 is installed on the vertical pipe 342, and the multiple nozzles 343 are spaced apart from each other on the vertical pipe 342 and face the wall of the mixing cylinder 2.

[0099] In this embodiment, the water inlet pipe 8 is connected to the output end of the water pump, and the input end of the water pump is connected to the water source.

[0100] When it is necessary to clean the sediment inside the filter cartridge 61, after the filter cartridge 61 is moved upwards, it is fitted onto the stirring blade structure 34, as follows. Figure 9 In section (c), a gap is left between the nozzle 343 and the inner wall of the filter cartridge 61, so that the material can adhere to the inner wall of the filter cartridge 61 under the action of centrifugation. The water pump puts the cleaning water into the stirring tube through the water inlet pipe 8, and then sprays it out to the side wall of the filter cartridge 61 through the connecting pipe 341, the vertical pipe 342 and the nozzle 343 in sequence. This allows the cleaning liquid to act directly on the solid precipitate attached to the side wall of the filter cartridge 61. The liquid is discharged from the filter cartridge 61 after sedimentation. The cleaning liquid can directly carry away the impurities on the sediment, improving the cleaning effect.

[0101] The number of stirring blade structures 34 is one or more. In this embodiment, there are two stirring blade structures 34, which are symmetrically arranged on the stirring tube.

[0102] By installing a drive blade 344 on the vertical pipe 342, the contact area with the solution is increased, thereby ensuring that the solution flows quickly during stirring.

[0103] Nozzle 343 is a fan-shaped nozzle to ensure the spraying area, and the liquid sprayed from adjacent nozzles 343 has an overlapping portion.

[0104] As an optional embodiment, the stirring tube is a straight tube with a sealed bottom end, the connecting tube 341 is connected to the straight tube, and the rotary connector 7 is connected to the bottom end of the straight tube.

[0105] The rotating component 62 is a rotary motor, which is installed inside the valve plate 53. Its output shaft is connected to a prism shaft, and a slot is provided at the bottom of the corresponding rotating shaft 63. The prism shaft is inserted into the slot, and the rotary motor drives the rotating shaft 63 to rotate through the prism shaft and the slot, thereby driving the filter cartridge 61 to rotate. The rotary motor is equipped with a waterproof shell.

[0106] Please see Figures 4 to 6 In a preferred embodiment, the stirring tube includes a rotating cylinder 32 and a transmission component 33. The rotating cylinder 32 is rotatably mounted on the cylinder cover 22. The transmission component 33 includes a transmission tube 331, a connecting rod 332, a base 333, and a square shaft 335. One end of the transmission tube 331 extends through the cylinder cover 22 into the rotating cylinder 32 and is rotatably connected to the cylinder cover 22. The base 333 fits against the bottom of the inner wall of the rotating cylinder 32. The square shaft 335 is connected to the bottom of the base 333 and is inserted into a square hole 321 at the bottom of the rotating cylinder 32. The top end of the connecting rod 332 is connected to the transmission tube 331, and the bottom end is vertically slidably connected to the base 333. A square groove 330 is provided at the bottom end of the square shaft 335.

[0107] The rotating component 62 is a square rod, which is installed at the bottom center of the filter cartridge 61 and located below the square groove 330.

[0108] The rotary connector 7 is installed at the top of the rotary cylinder 32, and the connecting pipe 341 is connected to the rotary cylinder 32.

[0109] In this embodiment, the maximum diameter of the square shaft 335 is smaller than the maximum diameter of the square hole 321.

[0110] When the stirring device 3 is in the stirring state, the square shaft 335 is inserted into the square hole 321. When the driving device 31 drives the transmission tube 331 to rotate, the transmission tube 331 drives the chassis 333 to rotate through the connecting rod 332. The chassis 333 drives the rotating cylinder 32 to rotate through the square shaft 335 and the square hole 321. The rotating cylinder 32 drives the stirring blade structure 34 to rotate to achieve the stirring function.

[0111] After stirring is complete, the lifting device 4 raises the cylinder cover 22, causing the stirring device 3 to move upwards, so that the stirring blade structure 34 moves upwards to the upper cylinder 211, as shown. Figure 9 In step (b), the push cylinder 52 lifts the valve plate 53, causing the filter cartridge 61 to lift, so that the rotating part 62 (square rod) in the middle of the filter cartridge 61 is inserted into the square groove 330 at the bottom of the square shaft 335. At the same time, the base plate 333 is lifted, so that the square shaft 335 at the bottom of the base plate 333 moves out of the square hole 321 at the bottom of the rotating cartridge 32. Figure 10 ;

[0112] When the subsequent drive device 31 drives the transmission tube 331 to rotate again, it drives the rotating component 62 (square rod) to rotate in sequence through the connecting rod 332, the chassis 333, and the square shaft 335, thereby driving the filter cartridge 61 to rotate. At this time, the transmission component 33 will not drive the rotating cylinder 32 to rotate. After the cleaning liquid enters the rotating cylinder 32 through the transmission tube 331, it continues to enter the connecting tube 341 and is sprayed out through the nozzle 343.

[0113] Since the rotating cylinder 32 is not rotating at this time, the stirring blade structure 34 is not rotating, while the filter cylinder 61 is rotating. Thus, the cleaning liquid sprayed from the nozzle 343 can sequentially interact with the solid precipitates on the inner wall of the filter cylinder 61 to clean them.

[0114] Thus, the stirring device 3 can perform the function of mixing and stirring in one state, and can be used to drive the rotation of the filter cartridge 61 in another state. At the same time, the rotating cylinder 32 and the stirring blade structure 34 can spray out cleaning to centrifuge and clean the solid sediment without rotating. This is achieved when the valve plate 53 is lifted on the push cylinder 52 and the filter cartridge 61 is driven into the upper cylinder 211, so that the filter cartridge 61 can switch from the function of filtering to the function of cleaning filter media.

[0115] Subsequently, the push cylinder 52 lowers the valve plate 53 to block the water outlet, the filter cartridge 61 moves down accordingly, and the rotating part 62 (square rod) separates from the square shaft 335.

[0116] The chassis 333 descends under gravity, causing the square shaft 335 at the bottom to re-insert into the square hole 321.

[0117] The drive device 31 rotates an integer number of revolutions each time, so that when the transmission tube 331 stops each time, the square shaft 335 and the square hole 321 can be aligned again, and the rotating part 62 (square rod) and the square groove 330 are aligned.

[0118] The top of the square rod is preferably pyramidal to avoid residual solid sedimentation.

[0119] In one embodiment, a plurality of tubes 334 are installed on the top of the chassis 333. The bottom end of the connecting rod 332 is inserted into the tube 334 and abuts against the chassis 333 to form a vertical sliding connection. Thus, the chassis 333 can slide vertically relative to the connecting rod 332, and the connecting rod 332 can drive the chassis 333 to rotate through the tubes 334.

[0120] In this embodiment, an elastic element 336 is provided inside the insertion tube 334 to connect the connecting rod 332 and the chassis 333. The elastic element 336 can assist the chassis 333 to move down, so that the square shaft 335 can be inserted into the square hole 321 again.

[0121] The elastic element 336 can be an elastic component such as a spring or a leaf spring.

[0122] In another embodiment, a cylindrical hole can be opened at the bottom of the connecting rod 332, and a sliding rod can be installed at the top of the chassis 333. The sliding rod is inserted into the cylindrical hole to achieve a vertical sliding connection.

[0123] The circumferential side of the chassis 333 is attached to the inner wall of the rotating cylinder 32, so that the cleaning fluid can enter the connecting pipe 341 better and finally be sprayed out by the nozzle 343.

[0124] Please see Figure 5 In this embodiment, the drive device 31 includes a motor 311, a main gear 312 and a driven gear 313. The motor 311 is mounted on the cylinder cover 22 by a mounting bracket. The main gear 312 is mounted on the output end of the motor 311. The driven gear 313 is mounted on the transmission tube 331. The main gear 312 meshes with the driven gear 313.

[0125] During operation, the motor 311 drives the driven gear 313 to rotate via the main gear 312, thereby driving the transmission tube 331 to rotate.

[0126] In other embodiments, the main gear 312 and the driven gear 313 can be replaced by two bevel gears respectively installed on the transmission tube 331 and the output shaft of the motor 311, and the two bevel gears mesh. In this case, the motor 311 is horizontally installed on the cylinder cover 22.

[0127] Please see Figure 8 The nozzle 343 is threaded with a cap 9.

[0128] By threading a cap 9 onto the nozzle 343, the solution and precipitates can be prevented from entering the nozzle 343 during the mixing reaction of the mixture by the stirring device 3.

[0129] When cleaning the sediment, the lifting device 4 raises the cylinder cover 22, which in turn moves the stirring device 3 upwards, and then the staff can remove the cap 9.

[0130] The nozzle 343 has an external thread on its surface and the cap 9 has an internal thread on its inner wall to achieve a threaded connection. A sealing gasket is provided on the inner wall of the cap 9. When the threaded connection is completed, the sealing gasket abuts against the nozzle of the nozzle 343.

[0131] Preferably, a positioning ring can be provided at the top of the outer wall of the rotating cylinder 32, and a positioning pin (not shown) can be threaded through and threaded onto the cylinder cover 22. When the sediment is centrifuged and cleaned, the positioning pin is inserted into the positioning ring to limit the axial movement of the rotating cylinder 32, preventing the rotating cylinder 32 from rotating during the spraying of cleaning liquid, so that it can work more stably.

[0132] The working principle of the equipment for preparing lithium phosphate battery material using cryogenic liquid provided by this invention is as follows:

[0133] During operation, the decarbonization liquid and MgH2(PO4)2 are added to the mixing cylinder 2, and the reaction is carried out by the stirring device 3. After the reaction is completed, the push cylinder 52 pushes the valve plate 53 upward, and the valve plate 53 moves the filter cylinder 61 upward. At this time, a gap is left between the valve plate 53 and the sealing plate 51, and the top of the filter cylinder 61 is flush with the top of the lower cylinder 212. Figure 9 In (b), after the reaction, the solution is discharged through the filter cartridge 61 through the water outlet on the sealing plate 51, and finally discharged into the preset container through the drain pipe 201. The solid precipitate is filtered in the filter cartridge 61.

[0134] After all the solution has been discharged, the push cylinder 52 continues to lift the valve plate 53, causing the filter cartridge 61 to move upwards and be positioned inside the upper end cylinder 211. Figure 9 In the middle (c), at this time, there is a gap between the filter cartridge 61 and the inner wall of the upper end cylinder 211. The rotating part 62 rotates the filter cartridge 61, and the centrifugal force causes the solid precipitate inside the filter cartridge 61 to adhere to the cylinder wall of the filter cartridge 61. Then, cleaning liquid can be sprayed onto the inner wall of the filter cartridge 61 to rinse the solid precipitate on the inner wall of the filter cartridge 61, remove the impurities on the surface of the solid precipitate, and achieve the cleaning work of the precipitate. The cleaning liquid is finally discharged through the drain pipe 201.

[0135] After cleaning is complete, filter cartridge 61 is removed to discharge the precipitated material (lithium phosphate).

[0136] When it is necessary to clean the sediment inside the filter cartridge 61, the filter cartridge 61 is moved upwards and fitted onto the stirring blade structure 34, such as... Figure 9In section (c), a gap is left between the nozzle 343 and the inner wall of the filter cartridge 61, so that the material can adhere to the inner wall of the filter cartridge 61 under the action of centrifugation. The water pump puts the cleaning water into the stirring tube through the water inlet pipe 8, and then sprays it out to the side wall of the filter cartridge 61 through the connecting pipe 341, the vertical pipe 342 and the nozzle 343 in sequence. This allows the cleaning liquid to act directly on the solid precipitate attached to the side wall of the filter cartridge 61. The liquid is discharged from the filter cartridge 61 after sedimentation. The cleaning liquid can directly carry away the impurities on the precipitate and improve the cleaning effect.

[0137] Specifically, when the stirring device 3 is in the stirring state, the square shaft 335 is inserted into the square hole 321. When the driving device 31 drives the transmission tube 331 to rotate, the transmission tube 331 drives the chassis 333 to rotate through the connecting rod 332. The chassis 333 drives the rotating cylinder 32 to rotate through the square shaft 335 and the square hole 321. The rotating cylinder 32 drives the stirring blade structure 34 to rotate to achieve the stirring function.

[0138] After stirring is complete, the lifting device 4 raises the cylinder cover 22, causing the stirring device 3 to move upwards, so that the stirring blade structure 34 moves upwards to the upper cylinder 211, as shown. Figure 9 In step (b), the push cylinder 52 lifts the valve plate 53, which in turn lifts the filter cylinder 61, so that the rotating part 62 (square rod) in the middle of the filter cylinder 61 is inserted into the square groove 330 at the bottom of the square shaft 335. At the same time, the base plate 333 is lifted, so that the square shaft 335 at the bottom of the base plate 333 moves out of the square hole 321 at the bottom of the rotating cylinder 32, and the filter cylinder 61 is fitted onto the stirring blade structure 34.

[0139] When the subsequent drive device 31 drives the transmission tube 331 to rotate again, it drives the rotating component 62 (square rod) to rotate in sequence through the connecting rod 332, the chassis 333, and the square shaft 335, thereby driving the filter cartridge 61 to rotate. At this time, the transmission component 33 will not drive the rotating cylinder 32 to rotate. After the cleaning liquid enters the rotating cylinder 32 through the transmission tube 331, it continues to enter the connecting tube 341 and is sprayed out through the nozzle 343.

[0140] Since the rotating cylinder 32 is not rotating at this time, the stirring blade structure 34 is not rotating, while the filter cylinder 61 is rotating. Thus, the cleaning liquid sprayed from the nozzle 343 can sequentially interact with the solid precipitates on the inner wall of the filter cylinder 61 to clean them.

[0141] Thus, the stirring device 3 can perform the function of mixing and stirring in one state, and can be used to drive the rotation of the filter cartridge 61 in another state. At the same time, the rotating cylinder 32 and the stirring blade structure 34 can spray out cleaning to centrifuge and clean the solid sediment without rotating. This is achieved when the valve plate 53 is lifted on the push cylinder 52 and the filter cartridge 61 is driven into the upper cylinder 211, so that the filter cartridge 61 can switch from the function of filtering to the function of cleaning filter media.

[0142] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for preparing lithium phosphate, a battery material, from a cryogenic liquid, characterized in that, Includes the following steps: S1. Add a certain concentration of dilute sulfuric acid to the frozen clear liquid to adjust the pH to 3.0-4.

0. Under the conditions of 25-40℃ and 200-300rpm, remove carbonate ions and convert them into carbon dioxide to escape, thus obtaining a decarbonated liquid. S2. The obtained decarbonized liquid is mixed with MgH2(PO4)2 and reacted, and the pH is adjusted to 6-7. The reaction is carried out at 60℃ for 1 hour, and the lithium phosphate and filtrate are obtained by filtration. S3. After centrifuging and washing the obtained lithium phosphate precipitate, calcine it at 300°C for 2 hours under a nitrogen atmosphere to obtain battery-grade lithium phosphate.

2. The method for preparing lithium phosphate battery material from cryogenic liquid according to claim 1, characterized in that, It also includes the following steps: S4. Extract the filtrate obtained in step S2 with the extractant trioctylamine-kerosene at a volume ratio of 3:1, and adjust the pH to 1.5-2.

5. Mix and extract for 5-8 minutes to separate the organic phase and aqueous phase. S5. Add the organic phase to sodium hydroxide solution for back-extraction to obtain back-extraction solution, and return the back-extraction solution to step S2 for recycling. S6. The aqueous phase obtained in step S4 is evaporated and crystallized at 100℃ to obtain a ternary sulfate solid. S7. The ternary sulfate solid and the spodumene slag dried for 24 hours were mixed in a ball mill at a solid ratio of 1:1.

5. After the mixture was homogeneous, it was calcined at 900℃ for 1 hour to obtain the lithium slag-based ternary sulfate composite material.

3. The method for preparing lithium phosphate battery material from cryogenic liquid according to claim 2, characterized in that, The ternary sulfate solid in S6 includes sodium sulfate, potassium sulfate, and magnesium sulfate.

4. An apparatus for preparing lithium phosphate battery material from cryogenic liquid, characterized in that, A method for preparing lithium phosphate battery material from the cryo-cleansing solution as described in any one of claims 1-3, comprising: a support; A mixing cylinder, comprising a cylinder body and a cylinder cover, wherein the cylinder cover is detachably installed on the top of the cylinder body, the cylinder body comprising an upper cylinder and a lower cylinder, the upper cylinder being connected to the lower cylinder via a frustum portion, the diameter of the upper cylinder being larger than that of the lower cylinder, and drain pipes being connected to both sides of the lower cylinder. A blocking assembly, comprising a blocking plate, a push cylinder, and a valve plate, wherein the blocking plate is installed inside the lower end cylinder, and a water outlet hole is provided in the center of the blocking plate; the valve plate blocks the water outlet hole; the push cylinder is installed in the lower end cylinder, and the valve plate is connected to the output end of the push cylinder; A filter cleaning component, comprising a filter cartridge and a rotating component, wherein the filter cartridge is detachably mounted on the valve plate and the side wall of the filter cartridge is in contact with the inner wall of the lower end cylinder, and the rotating component is used to drive the filter cartridge to rotate; A stirring device is used to stir and mix the materials in the mixing drum.

5. The apparatus for preparing lithium phosphate battery material from cryogenic liquid according to claim 4, characterized in that, The equipment for preparing lithium phosphate battery material from cryogenic liquid also includes a lifting device, which includes a lifting cylinder and a connecting plate. The lifting cylinder is installed on the bracket and is arranged adjacent to the mixing cylinder. The connecting plate connects the output end of the lifting cylinder to the cylinder cover.

6. The apparatus for preparing lithium phosphate battery material from cryogenic liquid according to claim 4, characterized in that, The stirring device includes a driving device, a stirring tube, and a stirring blade structure. The stirring tube is installed on the cylinder cover, and the stirring blade structure is installed on the stirring tube and located inside the mixing cylinder. The driving device is used to drive the stirring tube to rotate.

7. The apparatus for preparing lithium phosphate battery material from cryogenic liquid according to claim 6, characterized in that, The top of the stirring tube is connected to the water inlet pipe via a rotating connector. The stirring blade structure includes a connecting pipe, a vertical pipe, a driving blade, and multiple nozzles. The connecting pipe is horizontally connected to the stirring tube, and the vertical pipe is vertically connected to the end of the connecting pipe away from the stirring tube. The driving blade is installed on the vertical pipe, and the multiple nozzles are connected to the vertical pipe at intervals and face the wall of the mixing cylinder.

8. The apparatus for preparing lithium phosphate battery material from cryogenic liquid according to claim 7, characterized in that, The stirring tube includes a rotating cylinder and a transmission component. The rotating cylinder is rotatably mounted on the cylinder cover. The transmission component includes a transmission tube, a connecting rod, a base, and a square shaft. One end of the transmission tube extends through the cylinder cover into the rotating cylinder and is rotatably connected to the cylinder cover. The base fits against the bottom of the inner wall of the rotating cylinder. The square shaft is connected to the bottom of the base and is inserted into a square hole at the bottom of the rotating cylinder. The top end of the connecting rod is connected to the transmission tube, and the bottom end is vertically slidably connected to the base. A square groove is provided at the bottom end of the square shaft. The rotating component is a square rod, which is installed at the bottom center of the filter cartridge and located below the square groove; The rotary connector is installed at the top of the rotary cylinder, and the connecting pipe is connected to the rotary cylinder.

9. The apparatus for preparing lithium phosphate battery material from cryogenic liquid according to claim 8, characterized in that, The drive device includes a motor, a main gear, and a driven gear. The motor is mounted on the cylinder cover via a mounting bracket. The main gear is mounted on the output end of the motor. The driven gear is mounted on the transmission tube. The main gear meshes with the driven gear.

10. The apparatus for preparing lithium phosphate battery material from cryogenic liquid according to claim 7, characterized in that, The nozzle is threaded with a sealing cap.

Images