Method for extracting lithium from aluminum oxide electrolytic slag and equipment for extracting lithium

Abstract

The invention provides a method for extracting lithium from aluminum oxide electrolytic residues and equipment for extracting lithium, and relates to the field of solid waste recycling. The method for extracting lithium from the aluminum oxide electrolytic slag comprises the following steps: S1, performing crushing and grinding treatment on electrolytic aluminum overhaul slag to obtain electrolytic aluminum overhaul slag particles; s2, the electrolytic aluminum overhaul slag particles and acid liquor are mixed for a reaction, and after the stirring reaction is completed, solid-liquid separation is conducted to obtain leachate; s3, mixing a preset amount of the leachate with a 32% sodium hydroxide solution to form a water phase, and taking P204 and sulfonated kerosene to form an organic phase; according to the method for extracting the lithium from the aluminum oxide electrolytic residues, key operation parameters such as the extraction ratio, the saponification degree and the extraction time are systematically optimized under a p240 system, the loss of the lithium element is further reduced by introducing a washing process, and a set of composite process route integrating extraction, washing, saponification and precipitation is provided.

Description

Technical Field

[0001] This invention relates to the field of solid waste recycling, and in particular to a method and equipment for lithium extraction from alumina electrolytic slag. Background Technology

[0002] During the alumina electrolysis process, alkali metal elements such as Li, K, and Na in the electrolyte gradually accumulate as metallic aluminum is continuously deposited, eventually forming a large amount of alumina electrolysis slag. Against the backdrop of an increasingly prominent global supply-demand imbalance for lithium resources, secondary resource recycling has become an important way to alleviate lithium shortages. Alumina electrolysis slag, as a secondary resource with a high lithium content, has attracted considerable attention for its lithium extraction potential.

[0003] Traditional methods for disposing of alumina electrolytic slag not only face potential environmental risks but also suffer from technical bottlenecks such as high alkali consumption. Solvent extraction, as a core technology for the highly selective separation of lithium from liquid systems, can effectively solve these problems. Studies have shown that the P204 (di(2-ethylhexyl) phosphate) extraction system can achieve efficient separation of lithium from impurity metal ions under strongly acidic conditions with low lithium loss. The resulting lithium-rich raffinate facilitates subsequent lithium enrichment and purification, as well as the production of battery-grade lithium carbonate, which is of great significance for building a sustainable lithium resource circular economy system.

[0004] This invention is based on an extraction system composed of P204 and sulfonated kerosene. It optimizes key operating parameters such as extraction ratio, saponification degree, and extraction time through systematic optimization, and innovatively introduces a washing process to further reduce lithium loss.

[0005] Therefore, it is necessary to provide a method and equipment for lithium extraction from alumina electrolytic slag to solve the above-mentioned technical problems. Summary of the Invention

[0006] This invention provides a method for lithium extraction from alumina electrolytic slag, which solves the problem of lithium loss by optimizing key operating parameters such as extraction ratio, saponification degree, and extraction time, and by introducing a washing process.

[0007] To solve the above-mentioned technical problems, the present invention provides a method for lithium extraction from alumina electrolytic slag, comprising the following steps:

[0008] S1. The electrolytic aluminum overhaul slag is crushed and ground to obtain electrolytic aluminum overhaul slag particles;

[0009] S2. The electrolytic aluminum overhaul slag particles are mixed with acid solution and reacted. After the reaction is completed by stirring, the solid and liquid are separated to obtain leachate.

[0010] S3. Take a preset amount of leachate and 32% sodium hydroxide solution to form an aqueous phase, and take P204 and sulfonated kerosene to form an organic phase. The volume ratio of the organic phase to the aqueous phase in the separatory funnel is (1-3): 1. Extract with 32% sodium hydroxide SD=45% for 12 min, mix evenly and separate to obtain lithium-containing raffinate and extract.

[0011] S4. Add 0.3 mol / L hydrochloric acid solution to the extract in the separatory funnel according to the ratio (2-4):1 and wash 2-3 times to extract lithium. Then separate the extract to obtain organic phase and aqueous phase. Add the aqueous phase to the lithium-containing raffinate in S3.

[0012] S5. Add sodium hydroxide solution to the lithium-containing raffinate to adjust the pH to 10-12, then add sodium carbonate solution. After stirring and reacting, filter, wash and dry to obtain lithium carbonate, the battery material.

[0013] Preferably, the method for extracting lithium from alumina electrolytic slag further includes the following steps:

[0014] S6. The organic phase washed in S4 is added to a high-concentration hydrochloric acid solution, mixed evenly, and then eluted to obtain an aqueous phase containing impurity metals and a strongly acidic organic extractant.

[0015] S7. Add 32% sodium hydroxide to the strongly acidic organic extractant obtained in S6. The solution with SD=45%-55% is reused with the new leachate.

[0016] Preferably, the particle size of the electrolytic aluminum overhaul slag particles in S1 is less than 200 mesh.

[0017] The present invention also provides an apparatus for lithium extraction from alumina electrolytic slag, the apparatus comprising: an installation platform;

[0018] A mixing cylinder, comprising a cylinder body and a heating jacket, wherein the cylinder body is detachably mounted on the mounting platform and the heating jacket is fitted onto the cylinder body;

[0019] A lifting device, wherein the lifting device is installed on the mounting platform;

[0020] A stirring device, comprising a motor, a stirring shaft, and blades, wherein the motor is mounted at the output end of the lifting device, the stirring shaft is mounted at the output end of the motor, the blades are mounted at the bottom end of the stirring shaft, and mounting holes are provided on the blades;

[0021] The filter element includes a filter plate, a flange, and an assembly. The filter plate is disposed on an annular support inside the cylinder. The flange is disposed on the filter plate. The assembly includes a connecting plate and a convex shaft. The convex shaft is mounted on the filter plate through the connecting plate. The convex shaft is located on the projection of the rotation trajectory of the mounting hole.

[0022] Preferably, the lifting device includes a lifting cylinder, a mounting plate, and a telescopic rod. The lifting cylinder is mounted on the mounting platform, the mounting plate is mounted on the output end of the lifting cylinder, the telescopic rod is mounted on the mounting platform, the telescopic end of the telescopic rod is connected to the mounting plate, and the motor is mounted on the mounting plate.

[0023] Preferably, the mixing cylinder further includes a liquid outlet pipe connected to the bottom end of the cylinder body, and a valve is installed on the liquid outlet pipe.

[0024] Preferably, the mounting platform has a circular hole at its center, the inner wall of the circular hole is connected to multiple embedding grooves, and multiple embedding blocks are installed on the peripheral side of the bottom of the cylinder, the embedding blocks being embedded in the embedding grooves.

[0025] Preferably, the top of the cylinder is threaded with a cap, the inside of the cap is provided with a circular boss, a gap is left between the boss and the inner wall of the cylinder, the bottom of the peripheral side of the boss is provided with a thread, the cap has a strip opening in the middle, and the stirring shaft passes through the strip opening;

[0026] The top of the flange is provided with a threaded surface.

[0027] Preferably, a bracket is installed at the bottom of the mounting plate, and the stirring shaft passes through the bracket and is rotatably connected to the bracket.

[0028] Preferably, the annular support is provided with multiple slots, and the bottom of the filter plate is provided with multiple insert shafts, which are inserted into the slots.

[0029] Compared with related technologies, the lithium extraction method from alumina electrolytic slag provided by this invention has the following beneficial effects:

[0030] This invention provides a method for lithium extraction from alumina electrolytic slag. Under a p240 system, this invention optimizes key operating parameters such as extraction ratio, saponification degree, and extraction time, and introduces a washing process to further reduce lithium loss, proposing a composite process route integrating "extraction-washing-saponification-precipitation". This process provides a green and simple technical route for the efficient recovery of lithium resources from alumina electrolytic slag, offering both environmental and economic benefits. Attached Figure Description

[0031] Figure 1This is a flowchart of the method for lithium extraction from alumina electrolytic slag provided by the present invention.

[0032] Figure 2 The equation for the saponification reaction of sodium hydroxide with p240 (di(2-ethylhexyl) phosphate) in S3 extraction is given.

[0033] Figure 3 This is a schematic diagram of the equipment for lithium extraction from alumina electrolytic slag provided by the present invention;

[0034] Figure 4 This is a schematic diagram of the structure of the lithium extraction equipment from alumina electrolytic slag provided by the present invention after removing the cover and part of the cylindrical shell;

[0035] Figure 5 This is a cross-sectional view of the equipment for lithium extraction from alumina electrolytic slag provided by the present invention.

[0036] Figure 6 A bottom view of the cap provided for this invention;

[0037] Figure 7 for Figure 4 Enlarged diagram of section A in the middle;

[0038] Figure 8 This is a schematic diagram of the assembly of the blade and the cam shaft provided by the present invention, wherein, Figure 8 (a) is a schematic diagram showing the alignment of the mounting hole on the blade with the cam shaft. Figure 8 (b) is a schematic diagram of the assembly hole on the blade and the cam shaft.

[0039] Figure 9 This is a schematic diagram illustrating the state of the filter element separating solid components provided by the present invention, wherein... Figure 9 Image (a) is a schematic diagram of the assembly of the blade and the fittings. Figure 9 (b) is a schematic diagram showing how the lifting device raises the stirring device, which in turn drives the filter element to separate the solid components from the solution.

[0040] Figure 10 This is a schematic diagram of the state in which solid components are removed from the mixing cylinder according to the present invention, wherein, Figure 10 Image (a) is a schematic diagram of the threaded connection between the flange and the boss. Figure 10 (b) is a schematic diagram showing the separation of the filter element from the mixing cylinder caused by the capping.

[0041] Numbering on the map:

[0042] 1. Mounting platform; 11. Embedded slot;

[0043] 2. Mixing cylinder; 21. Cylinder body; 22. Liquid outlet pipe; 23. Heating jacket;

[0044] 211. Embedded block; 212. Annular support; 221. Valve;

[0045] 3. Lifting device; 31. Lifting cylinder; 32. Mounting plate; 33. Telescopic rod;

[0046] 321. Bracket;

[0047] 4. Stirring device; 41. Motor; 42. Stirring shaft; 43. Blades; 431. Mounting hole;

[0048] 5. Filter elements; 51. Filter plates; 52. Flanges; 53. Assembly parts;

[0049] 521. Threaded surface; 531. Connecting plate; 532. Protruding shaft;

[0050] 6. Cap; 61. Sealing plate; 62. Boss; 601. Strip opening. Detailed Implementation

[0051] 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.

[0052] This invention provides a method for extracting lithium from alumina electrolytic slag.

[0053] Please refer to the following: Figure 1 and Figure 2 In one embodiment of the present invention, the method for extracting lithium from alumina electrolytic slag includes the following steps:

[0054] S1. The electrolytic aluminum overhaul slag is crushed and ground to obtain electrolytic aluminum overhaul slag particles;

[0055] S2. The electrolytic aluminum overhaul slag particles are mixed with acid solution and reacted. After the reaction is completed by stirring, the solid and liquid are separated to obtain leachate.

[0056] S3. Take a preset amount of leachate and 32% sodium hydroxide solution to form an aqueous phase, and take P204 and sulfonated kerosene to form an organic phase. The volume ratio of the organic phase to the aqueous phase in the separatory funnel is (1-3): 1. Extract with 32% sodium hydroxide SD=45% for 12 min, mix evenly and separate to obtain lithium-containing raffinate and extract.

[0057] S4. Add 0.3 mol / L hydrochloric acid solution to the extract in the separatory funnel according to the ratio (2-4):1 and wash 2-3 times to extract lithium. Then separate the extract to obtain organic phase and aqueous phase. Add the aqueous phase to the lithium-containing raffinate in S3.

[0058] S5. Add sodium hydroxide solution to the lithium-containing raffinate to adjust the pH to 10-12, then add sodium carbonate solution. After stirring and reacting, filter, wash and dry to obtain lithium carbonate, the battery material.

[0059] This invention, based on the p240 system, optimizes key operating parameters such as extraction ratio, saponification degree, and extraction time, and introduces a washing process to further reduce lithium loss. It proposes a composite process route integrating "extraction-washing-saponification-precipitation". This process provides a green and simple technical path for the efficient recovery of lithium resources from alumina electrolytic slag, with both environmental and economic benefits.

[0060] Among them, p240 is di(2-ethylhexyl) phosphate;

[0061] In S2, hydrochloric acid or sulfuric acid is used for acid leaching treatment, with hydrochloric acid concentration of 6–10 mol / L and sulfuric acid concentration of 15–25%, and the reaction temperature is 70–90℃.

[0062] After adding sodium hydroxide solution to S5 and adjusting the pH to 10-12, a precipitate (hydroxides of impurities such as calcium and magnesium) appears. The precipitate should be filtered first.

[0063] As a preferred embodiment, the method for lithium extraction from alumina electrolytic slag further includes the following steps:

[0064] S6. The organic phase washed in S4 is added to a high-concentration hydrochloric acid solution, mixed evenly, and then eluted to obtain an aqueous phase containing impurity metals and a strongly acidic organic extractant.

[0065] S7. Add 32% sodium hydroxide to the strongly acidic organic extractant obtained in S3, and reuse the solution with SD=45%-55% with the new leachate.

[0066] By following the steps described above, the process cost of regenerating the strongly acidic P204 extraction system can be significantly reduced, while the discharge of organic waste liquid can be decreased, thereby improving the economic efficiency and environmental friendliness of the process.

[0067] The particle size of the electrolytic aluminum overhaul slag particles in S1 is less than 200 mesh.

[0068] Specifically, the present invention includes the following embodiments:

[0069] Example 1

[0070] S1. The electrolytic aluminum overhaul slag is crushed and ground to obtain electrolytic aluminum overhaul slag particles;

[0071] S2. The electrolytic aluminum overhaul slag particles are mixed with acid solution and reacted. After the reaction is completed by stirring, the solid and liquid are separated to obtain leachate.

[0072] S3: Take 100 ml of the leachate from the acid leaching stage, 32% sodium hydroxide solution, and organic phase extraction system composed of P204 and sulfonated kerosene. In a separatory funnel, extract for 12 min at a ratio of 1:1 and 32% sodium hydroxide SD (degree of saponification of sodium hydroxide) = 45%. Mix thoroughly and separate to obtain lithium-containing raffinate and extract.

[0073] S4: Add 0.3 mol / L hydrochloric acid solution to the extract in the separatory funnel of step S1 at a ratio of 2:1 and wash 2-3 times to extract lithium. Then separate the extract to obtain an organic phase and an aqueous phase. Add the aqueous phase to the lithium-containing raffinate in S3.

[0074] S5. Add sodium hydroxide solution to the lithium-containing raffinate to adjust the pH to 10-12, then add sodium carbonate solution. Stir at 80-95℃ for 1-3 hours. After the reaction is complete, filter, wash and dry to obtain lithium carbonate battery material.

[0075] S6: After washing the organic phase in S4, add a high-concentration hydrochloric acid solution, mix thoroughly, and then elute to obtain an aqueous phase containing impurity metals and a strongly acidic organic extractant.

[0076] S7: Add 32% sodium hydroxide to the p204 strong acid extractant obtained in S6, and reuse the SD=45% solution with the new leachate.

[0077] Example 2

[0078] S1. The electrolytic aluminum overhaul slag is crushed and ground to obtain electrolytic aluminum overhaul slag particles;

[0079] S2. The electrolytic aluminum overhaul slag particles are mixed with acid solution and reacted. After the reaction is completed by stirring, the solid and liquid are separated to obtain leachate.

[0080] S3: Take 100 ml of the leachate from the acid leaching stage, 32% sodium hydroxide solution, and organic phase extraction system composed of P204 and sulfonated kerosene. Extract in a separatory funnel at a ratio of 2:1 and 32% sodium hydroxide SD (degree of saponification of sodium hydroxide) = 50% for 18 min. Mix evenly and separate to obtain lithium-containing raffinate and extract.

[0081] S4: Add 0.5 mol / L hydrochloric acid solution to the extract in the separatory funnel of step S1 at a ratio of 3:1 and wash 2-3 times to extract lithium. Then separate the extract to obtain an organic phase and an aqueous phase. Add the aqueous phase to the lithium-containing raffinate in S3.

[0082] S5. Add sodium hydroxide solution to the lithium-containing raffinate to adjust the pH to 10-12, then add sodium carbonate solution, and stir for 1-3 hours at 80-95℃. After the reaction is complete, filter, wash and dry to obtain lithium carbonate battery material.

[0083] S6: Add a high concentration of hydrochloric acid solution to the organic phase after washing in step S4, mix evenly, and then elute to obtain an aqueous phase containing impurity metals and a strongly acidic organic extractant.

[0084] S7: Add 32% sodium hydroxide to the p204 strong acid extractant obtained in S6, and reuse the SD=50% solution with the new leachate.

[0085] Example 3

[0086] S1. The electrolytic aluminum overhaul slag is crushed and ground to obtain electrolytic aluminum overhaul slag particles;

[0087] S2. The electrolytic aluminum overhaul slag particles are mixed with acid solution and reacted. After the reaction is completed by stirring, the solid and liquid are separated to obtain leachate.

[0088] S3: Take 100 ml of the leaching solution from the acid leaching stage, 32% sodium hydroxide solution, and the organic phase extraction system composed of P204 and sulfonated kerosene. In a separatory funnel, extract for 12 min at a ratio of 3:1 and 32% sodium hydroxide SD (degree of saponification of sodium hydroxide) = 55%. Mix thoroughly and separate to obtain lithium-containing raffinate and extract.

[0089] S4: Add 1 mol / L hydrochloric acid solution to the extract in the separatory funnel of step S1 and wash 2-3 times to extract lithium. Then separate the organic phase and the aqueous phase. Add the aqueous phase to the lithium-containing raffinate in S3.

[0090] S5. Add sodium hydroxide solution to the lithium-containing raffinate to adjust the pH to 10-12, then add sodium carbonate solution. Stir at 80-95℃ for 1-3 hours. After the reaction is complete, filter, wash and dry to obtain lithium carbonate battery material.

[0091] S6: Add a high concentration of hydrochloric acid solution to the organic phase after washing in step S4, mix evenly, and then elute to obtain an aqueous phase containing impurity metals and a strongly acidic organic extractant.

[0092] S7: Add 32% sodium hydroxide to the p204 strong acid extractant obtained in S6, and reuse the SD=55% solution with the new leachate.

[0093] The present invention also provides an apparatus for lithium extraction from alumina electrolytic slag.

[0094] Please refer to the figure. A device for lithium extraction from alumina electrolytic slag, comprising: a mounting platform 1;

[0095] The mixing cylinder 2 includes a cylinder body 21 and a heating sleeve 23. The cylinder body 21 is detachably installed on the mounting platform 1, and the heating sleeve 23 is sleeved and installed on the cylinder body 21.

[0096] Lifting device 3, which is installed on the mounting platform 1;

[0097] A stirring device 4 includes a motor 41, a stirring shaft 42, and blades 43. The motor 41 is installed at the output end of the lifting device 3, the stirring shaft 42 is installed at the output end of the motor 41, and the blades 43 are installed at the bottom end of the stirring shaft 42. The blades 43 are provided with mounting holes 431.

[0098] The filter element 5 includes a filter plate 51, a flange 52, and an assembly 53. The filter plate 51 is disposed on an annular support 212 inside the cylinder 21. The flange 52 is disposed on the filter plate 51. The assembly 53 includes a connecting plate 531 and a convex shaft 532. The convex shaft 532 is mounted on the filter plate 51 through the connecting plate 531. The convex shaft 532 is located on the projection of the rotation trajectory of the mounting hole 431.

[0099] The equipment for lithium extraction from alumina electrolytic slag proposed in this invention is mainly used for the acid leaching reaction in S2 or the reaction to generate lithium carbonate in S5; and is mainly used in small-scale reaction scenarios such as laboratories.

[0100] In use, the raw materials to be reacted are added into the cylinder 21, and then the lifting device 3 lowers the stirring device 4 so that the stirring blade 43 extends into the cylinder 21, is immersed in the reaction solution, and is positioned above the assembly 53. The motor 41 drives the stirring shaft 42 to rotate the stirring blade 43 to stir the mixed solution. The heating jacket 23 can be used to heat the cylinder 21 to reach the reaction temperature.

[0101] After the reaction is complete, the solid precipitate is located above the filter element 5. The lifting device 3 continues to lower the stirring device 4, so that the blade 43 descends until the mounting hole 431 on it is flush with the height of the convex shaft 532. At this time, the motor 41 drives the stirring shaft 42 to rotate at a preset angle, so that the mounting hole 431 can be fitted onto the convex shaft 532. Figure 8 (a) and Figure 8 (b)

[0102] Then, the lifting device 3 lifts the stirring device 4, which drives the filter element 5 to move upward and out of the solution. The filter element 5 quickly separates the solid precipitate in the solution from the solution, thus quickly achieving solid-liquid separation.

[0103] The filter plate 51 includes a perforated plate and a filter screen, with the filter screen covering the perforated plate. The components in the filter element 5 are made of acid-resistant materials or are treated to be acid-resistant.

[0104] In this embodiment, there are preferably no fewer than two mounting parts 53. In this embodiment, there are two, arranged clockwise or counterclockwise with the stirring shaft 42 as the center. The convex shaft 532 has an arc, which facilitates assembly with the mounting holes 431 on the rotating blades 43. There are two blades 43, which are symmetrically installed on the stirring shaft 42.

[0105] One end of the convex shaft 532 is threaded and threaded to the connecting plate 531. Thus, the filter screen can be assembled by making a corresponding hole in the connecting plate 531.

[0106] The heating jacket 23 includes a jacket body, an inlet pipe, an outlet pipe, a partition, and a water circulation system (not shown). The jacket body is fitted and fixed on the cylinder 21. The inlet pipe and the outlet pipe are installed alternately on the jacket body, and the partition is installed inside the jacket body to separate the inlet pipe and the outlet pipe. The output end of the water circulation system is connected to the inlet pipe, and the input end is connected to the outlet pipe. The water circulation system is used to input hot water or cold water into the jacket body.

[0107] After mixing, the two blades 43 are located between the two assemblies 53, and the distance between the two assemblies 53 and the two blades 43 is the same.

[0108] Preferably, a groove is provided at the bottom of the convex shaft 532. When the blade 43 is sleeved on the convex shaft 532 through the mounting hole 431, the blade 43 can be inserted into the groove when the lifting device 3 lifts the stirring device 4, thereby improving the stability of the lifting filter element 5.

[0109] Please see Figure 3 In this embodiment, the lifting device 3 includes a lifting cylinder 31, a mounting plate 32, and a telescopic rod 33. The lifting cylinder 31 is mounted on the mounting platform 1, the mounting plate 32 is mounted on the output end of the lifting cylinder 31, the telescopic rod 33 is mounted on the mounting platform 1, the telescopic end of the telescopic rod 33 is connected to the mounting plate 32, and the motor 41 is mounted on the mounting plate 32.

[0110] When it is necessary to raise or lower the stirring device 4, the lifting cylinder 31 raises or lowers the mounting plate 32, and the mounting plate 32 drives the stirring device 4 to rise or fall, thereby achieving the raising or lowering of the stirring device 4.

[0111] The telescopic rod 33 includes a mounting cylinder and a positioning rod. The mounting cylinder is installed on the mounting platform 1, and one end of the positioning rod is located inside the mounting cylinder, while the other end passes through the mounting cylinder and is connected to the mounting plate 32. The number of telescopic rods 33 is preferably multiple, and in this embodiment, there are four, arranged around the lifting cylinder 31.

[0112] The lifting cylinder 31 can be a pneumatic cylinder, a hydraulic cylinder, or an electric push cylinder.

[0113] In other embodiments, belt lifting devices, chain lifting devices, etc., may also be used.

[0114] Please see Figure 5 In this embodiment, the mixing cylinder 2 further includes a liquid outlet pipe 22, which is connected to the bottom end of the cylinder body 21, and a valve 221 is installed on the liquid outlet pipe 22.

[0115] By setting the outlet pipe 22, after the solid precipitate in the mixed solution is separated, the mixing cylinder 2 can be removed from the mounting platform 1, and then the valve 221 can be opened to stably discharge the solution in the cylinder 21 into the designated container through the outlet pipe 22.

[0116] The connection between the cylinder 21 and the outlet pipe 22 is conical to facilitate the outflow of the solution.

[0117] Please see Figure 5 In this embodiment, a circular hole is provided in the center of the mounting platform 1, and a plurality of embedding grooves 11 are connected to the inner wall of the circular hole. A plurality of embedding blocks 211 are installed on the peripheral side of the bottom of the cylinder 21, and the embedding blocks 211 are embedded in the embedding grooves 11.

[0118] By opening a circular hole in the center of the mounting platform 1, when the mixing cylinder 2 is installed on the mounting platform 1, the liquid outlet pipe 22 is located in the circular hole, and the embedding block 211 is located in the embedding groove 11, which limits the mixing cylinder 2 in the axial direction, making it more stable during stirring and mixing. The installation operation of the mixing cylinder 2 and the mounting platform 1 is simple and convenient.

[0119] In other embodiments, multiple straight shafts can be provided on the mounting platform 1, and embedding grooves 11 can be opened on the straight shafts. When the embedding block 211 on the mixing cylinder 2 is embedded in the embedding groove 11, the liquid outlet pipe 22 will not interact with the mounting platform 1, thereby realizing the installation of the mixing cylinder 2.

[0120] Please see Figure 3 , Figure 5 and Figure 6 The top of the cylinder 21 is threadedly connected to a cover 6. The cover 6 has a circular boss 62 inside. There is a gap between the boss 62 and the inner wall of the cylinder 21. The bottom of the peripheral side of the boss 62 is threaded. The cover 6 has a strip-shaped opening 601 in the middle. The stirring shaft 42 passes through the strip-shaped opening 601.

[0121] The top of the flange 52 is provided with a threaded surface 521.

[0122] By setting the cap 6 to be threadedly connected to the mixing cylinder 2, the solution can be prevented from splashing out during stirring;

[0123] After the solution reaction is complete, once the blades 43 and the cam shaft 532 in the stirring device 4 are assembled, the lifting device 3 moves the stirring device 4 upward. The blades 43, through the cam shaft 532, move the filter element 5 upward as well. The filter plate 51 pulls the solids in the solution upward, so that the solids are located on the filter plate 51. After the filter plate 51 separates from the solution, as... Figure 9 In step (b), when the flange 52 moves upward to abut against the threaded bottom of the boss 62, the motor 41 drives the blade 43 to rotate via the stirring shaft 42. The blade drives the filter element 5 to rotate via the convex shaft 532 and the connecting plate 531, thus connecting the flange 52 in the filter element 5 to the boss 62 via the thread. Figure 10 In the middle (a), during this process, the lifting device 3 adaptively raises the stirring device 4, at which time a collection container is formed between the filter element 5 and the cover 6 to collect and store the solid filter material;

[0124] And the motor 41 continues to rotate, so that the threaded surface 521 on the flange 52 and the thread at the bottom of the boss 62 are fully engaged and the threaded connection is terminated. That is, the threaded surface 521 is now above the thread at the bottom of the boss 62. At this time, the blade 43 is aligned with the strip opening 601. The lifting device 3 lifts the stirring device 4 and continues to lift the filter element 5 through the convex shaft 532, so that the solid material on the filter plate 51 and the boss 62 are squeezed, thereby forming a pressure filtration function, so that the liquid contained in the solid material is quickly filtered through the filter plate 51 and falls into the cylinder 21. At this time, the blade enters the strip opening 601.

[0125] After the solution has fully penetrated into the cylinder 21, the motor 41 drives the stirring shaft 42 to rotate again. At this time, the blades 43 drive the cover 6 to rotate through the strip-shaped opening 601, so that the cover 6 is unscrewed from the cylinder 21. At the same time, the lifting device 3 adaptively lifts the stirring device 4. After the cover 6 is separated from the cylinder 21, the lifting device 3 lifts the filter element 5 and the cover 6 to separate them from the cylinder 21, thus realizing the function of taking out the solid material separately from the cylinder 21.

[0126] Thus, the stirring device 4, in conjunction with the lifting device 3, is used to stir and mix the mixed solution in one state, and to separate the solid components from the solution after the reaction is completed in another state. In yet another state, the filter element 5 and the cap 6 are assembled to form a collection container, and the cap 6 is separated from the cylinder 21, so that the solid components can be taken out of the cylinder 21 separately. In this process, the solid components can also be pressure filtered, so that the solution contained in the solid components is quickly squeezed out.

[0127] The solid material can then be removed by separating the cap 6 from the filter element 5 by thread.

[0128] Among them, the distance between the two assemblies 53 is less than or equal to the width of the slot 601;

[0129] In this process, the motor 41 drives the stirring shaft 42 to rotate an integer number of revolutions each time. When the lifting device 3 drives the filter element 5 through the stirring device 4 to make its flange 52 abut against the thread at the bottom of the boss 62, the blade 43 and the fitting 53 align with the strip opening 601, so that the blade 43 and the fitting 53 can then extend into the strip opening 601.

[0130] Among them, the strip-shaped opening 601 is designed to penetrate the cover 6, so that the cover 6 can be separated from the stirring device 4 later;

[0131] Furthermore, sealing plates 61 are installed on both sides of the sealing cover 6 and the stirring shaft 42. The sealing plates 61 are made of rubber and are only installed on one side of the sealing cover 6. Thus, in the normal state, the sealing plates 61 adhere to the sealing cover 6 through elastic potential energy, blocking the strip opening 601. When the stirring device 4 separates from the sealing cover 6, the subsequent blades 43 can push the sealing plates 61 to separate them from the strip opening 601. After the blades 43 separate from the strip opening 601, the sealing plates 61 adhere to the sealing cover 6 again through elastic potential energy.

[0132] Please see Figure 3 In a preferred embodiment, a bracket 321 is mounted on the bottom of the mounting plate 32, and the stirring shaft 42 passes through the bracket 321 and is rotatably connected to the bracket 321.

[0133] By setting up bracket 321, the stirring shaft 42 is rotatably connected to the bracket 321. Thus, when the stirring device 4 is lifted on the lifting device 3 and the filter element 5 and the boss 62 act to filter solid materials, when the stirring shaft 42 is subjected to a vertical force, the force can be applied to the bracket 321, avoiding direct application to the output shaft of the motor 41.

[0134] The stirring shaft 42 passes through the support 321, and circular disks are provided on the stirring shaft 42 above and below the support 321 to form a rotating connection.

[0135] Alternatively, a rotating structure such as a bearing can be used to achieve a rotating connection between the stirring shaft 42 and the support 321.

[0136] Preferably, the annular support 212 has multiple slots, and the bottom of the filter plate 51 is equipped with multiple insert shafts, which are inserted into the slots.

[0137] By setting a shaft at the bottom of the filter plate 51, when the filter element 5 is placed inside the cylinder 21, the shaft at the bottom of the filter plate 51 is inserted into the slot of the annular support 212, thereby improving the stability of the assembly of the filter element 5 and the annular support 212.

[0138] The working principle of the lithium extraction equipment from alumina electrolytic slag provided by this invention is as follows:

[0139] In use, the raw materials to be reacted are added into the cylinder 21, and then the lifting device 3 lowers the stirring device 4 so that the stirring blade 43 extends into the cylinder 21, is immersed in the reaction solution, and is positioned above the assembly 53. The motor 41 drives the stirring shaft 42 to rotate the stirring blade 43 to stir the mixed solution. The heating jacket 23 can be used to heat the cylinder 21 to reach the reaction temperature.

[0140] After the reaction is complete, the solid precipitate is located above the filter element 5. The lifting device 3 continues to lower the stirring device 4, so that the blade 43 descends until the mounting hole 431 on it is flush with the height of the convex shaft 532. At this time, the motor 41 drives the stirring shaft 42 to rotate at a preset angle, so that the mounting hole 431 can be fitted onto the convex shaft 532. Figure 8 (a) and Figure 8 (b)

[0141] Then, the lifting device 3 raises the stirring device 4, causing the filter element 5 to move upwards and out of the solution. The filter element 5 quickly separates the solid precipitate in the solution from the solution, thus rapidly achieving solid-liquid separation. Figure 9 In step (b), when the flange 52 moves upward to abut against the threaded bottom of the boss 62, the motor 41 drives the blade 43 to rotate via the stirring shaft 42. The blade drives the filter element 5 to rotate via the convex shaft 532 and the connecting plate 531, thus connecting the flange 52 in the filter element 5 to the boss 62 via the thread. Figure 10 In the middle (a), during this process, the lifting device 3 adaptively raises the stirring device 4, at which time a collection container is formed between the filter element 5 and the cover 6 to collect and store the solid filter material;

[0142] And the motor 41 continues to rotate, so that the threaded surface 521 on the flange 52 and the thread at the bottom of the boss 62 are fully engaged and the threaded connection is terminated. That is, the threaded surface 521 is now above the thread at the bottom of the boss 62. At this time, the blade 43 is aligned with the strip opening 601. The lifting device 3 lifts the stirring device 4 and continues to lift the filter element 5 through the convex shaft 532, so that the solid material on the filter plate 51 and the boss 62 are squeezed, thereby forming a pressure filtration function, so that the liquid contained in the solid material is quickly filtered through the filter plate 51 and falls into the cylinder 21. At this time, the blade enters the strip opening 601.

[0143] After the solution has fully penetrated into the cylinder 21, the motor 41 drives the stirring shaft 42 to rotate again. At this time, the blades 43 drive the cover 6 to rotate through the strip-shaped opening 601, so that the cover 6 is unscrewed from the cylinder 21. At the same time, the lifting device 3 adaptively lifts the stirring device 4. After the cover 6 is separated from the cylinder 21, the lifting device 3 lifts the filter element 5 and the cover 6 to separate them from the cylinder 21, thus realizing the function of taking out the solid material separately from the cylinder 21.

[0144] Thus, the stirring device 4, in conjunction with the lifting device 3, is used to stir and mix the mixed solution in one state, and to separate the solid components from the solution after the reaction is completed in another state. In yet another state, the filter element 5 and the cap 6 are assembled to form a collection container, and the cap 6 is separated from the cylinder 21, so that the solid components can be taken out of the cylinder 21 separately. In this process, the solid components can also be pressure filtered, so that the solution contained in the solid components is quickly squeezed out.

[0145] 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's 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 extracting lithium from alumina electrolytic slag, characterized in that, Includes the following steps: S1. The electrolytic aluminum overhaul slag is crushed and ground to obtain electrolytic aluminum overhaul slag particles; S2. The electrolytic aluminum overhaul slag particles are mixed with acid solution and reacted. After the reaction is completed by stirring, the solid and liquid are separated to obtain leachate. S3. Take a preset amount of leachate and 32% sodium hydroxide solution to form an aqueous phase, and take P204 and sulfonated kerosene to form an organic phase. The volume ratio of the organic phase to the aqueous phase in the separatory funnel is (1-3):

1. Extract with 32% sodium hydroxide SD=45% for 12 min, mix evenly and separate to obtain lithium-containing raffinate and extract. S4. Add 0.3 mol / L hydrochloric acid solution to the extract in the separatory funnel according to the ratio (2-4):1 and wash 2-3 times to extract lithium. Then separate the extract to obtain organic phase and aqueous phase. Add the aqueous phase to the lithium-containing raffinate in S3. S5. Add sodium hydroxide solution to the lithium-containing raffinate to adjust the pH to 10-12, then add sodium carbonate solution. After stirring and reacting, filter, wash and dry to obtain lithium carbonate, the battery material.

2. The method for lithium extraction from alumina electrolytic slag according to claim 1, characterized in that, The method for extracting lithium from alumina electrolytic slag further includes the following steps: S6. The organic phase washed in S4 is added to a high-concentration hydrochloric acid solution, mixed evenly, and then eluted to obtain an aqueous phase containing impurity metals and a strongly acidic organic extractant. S7. Add 32% sodium hydroxide to the strongly acidic organic extractant obtained in S6. The solution with SD=45%-55% is reused with the new leachate.

3. The method for lithium extraction from alumina electrolytic slag according to claim 1, characterized in that, The particle size of the electrolytic aluminum overhaul slag particles in S1 is less than 200 mesh.

4. A device for lithium extraction from alumina electrolytic slag, characterized in that, The equipment for lithium extraction from alumina electrolytic slag as described in any one of claims 1-3 includes: a mounting platform; A mixing cylinder, comprising a cylinder body and a heating jacket, wherein the cylinder body is detachably mounted on the mounting platform and the heating jacket is fitted onto the cylinder body; A lifting device, wherein the lifting device is installed on the mounting platform; A stirring device, comprising a motor, a stirring shaft, and blades, wherein the motor is mounted at the output end of the lifting device, the stirring shaft is mounted at the output end of the motor, the blades are mounted at the bottom end of the stirring shaft, and mounting holes are provided on the blades; The filter element includes a filter plate, a flange, and an assembly. The filter plate is disposed on an annular support inside the cylinder. The flange is disposed on the filter plate. The assembly includes a connecting plate and a convex shaft. The convex shaft is mounted on the filter plate through the connecting plate. The convex shaft is located on the projection of the rotation trajectory of the mounting hole.

5. The equipment for lithium extraction from alumina electrolytic slag according to claim 4, characterized in that, The lifting device includes a lifting cylinder, a mounting plate, and a telescopic rod. The lifting cylinder is mounted on the mounting platform, the mounting plate is mounted on the output end of the lifting cylinder, the telescopic rod is mounted on the mounting platform, the telescopic end of the telescopic rod is connected to the mounting plate, and the motor is mounted on the mounting plate.

6. The equipment for lithium extraction from alumina electrolytic slag according to claim 4, characterized in that, The mixing cylinder also includes a liquid outlet pipe, which is connected to the bottom end of the cylinder body, and a valve is installed on the liquid outlet pipe.

7. The equipment for lithium extraction from alumina electrolytic slag according to claim 4, characterized in that, The mounting platform has a circular hole at its center, and the inner wall of the circular hole is connected to multiple embedding grooves. Multiple embedding blocks are installed on the circumferential side of the bottom of the cylinder, and the embedding blocks are embedded in the embedding grooves.

8. The equipment for lithium extraction from alumina electrolytic slag according to claim 4, characterized in that, The top of the cylinder is threaded with a cap, and the inside of the cap is provided with a circular boss. There is a gap between the boss and the inner wall of the cylinder. The bottom of the peripheral side of the boss is provided with threads. The cap has a strip-shaped opening in the middle, and the stirring shaft passes through the strip-shaped opening. The top of the flange is provided with a threaded surface.

9. The equipment for lithium extraction from alumina electrolytic slag according to claim 8, characterized in that, A bracket is installed at the bottom of the mounting plate, and the stirring shaft passes through the bracket and is rotatably connected to the bracket.

10. The equipment for lithium extraction from alumina electrolytic slag according to claim 4, characterized in that, The annular support has multiple slots, and the bottom of the filter plate has multiple insert shafts that are inserted into the slots.

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