A lithium extraction device from aluminum electrolysis slag and a lithium extraction co-production of cryolite process thereof

Abstract

The application provides a lithium extraction equipment from electrolytic aluminum slag and a lithium extraction and cryolite co-production process thereof, and relates to the technical field of solid waste treatment. The heating tank is installed on the upper surface of the bottom plate, the extraction tank is installed in the heating tank, the filter tank is installed in the extraction tank, the top cover is sealingly installed on the upper surface of the filter tank, and the inner portion of the top cover is respectively provided with a liquid inlet pipe and a feeding pipe. The conical mixing cylinder and the linkage overturning type mixing plate are adopted, the mixing plate can overturn the flake alkali into the electrolytic aluminum slag, and then the mixing rod mixes and processes the flake alkali and the electrolytic aluminum slag.

Description

Technical Field

[0001] This invention relates to the field of solid waste treatment technology, and in particular to a lithium extraction device from electrolytic aluminum slag and a process for lithium extraction and cryolite production. Background Technology

[0002] China relies on imports for over 80% of its lithium carbonate needs, primarily due to limitations in resources, technology, mining conditions, and economics. This has resulted in a long-term slow industrialization of lithium carbonate in my country, falling far short of the rapidly growing demands of the new energy industry. In aluminum electrolysis production, to improve current efficiency and reduce energy consumption, in addition to aluminum fluoride and cryolite, certain lithium-containing fluoride or chloride salts are typically added to improve electrolyte properties.

[0003] Electrolytic filter residue generates a large amount of solid waste, with electrolytic aluminum waste amounting to 364,600 tons, equivalent to 3,646–9,844 tons of lithium. If this lithium resource is properly recycled and utilized, it will help alleviate the lithium consumption pressure brought by the new energy industry. Therefore, this paper focuses on the efficient recycling of low-grade lithium resources from electrolytic aluminum waste, exploring the optimal process route and parameters to improve product quality and maximize resource value.

[0004] Existing technologies are very limited in the treatment of electrolytic filter residue, especially in the alkalization and acid leaching processes. Traditional technologies often use separate tanks for operation, which is very cumbersome and easily wastes lithium extraction time. Secondly, the caustic soda and electrolytic filter residue need to be mixed during the lithium extraction process. Traditional mixing methods can easily cause fixed-point contact and overheating, which can be dangerous and affect the lithium extraction effect.

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

[0006] This invention provides a lithium extraction device and a process for lithium extraction and cryolite production from electrolytic aluminum slag, which solves the technical problems of cumbersome lithium extraction operations, excessive time, and overheating caused by caustic soda mixing in related technologies.

[0007] To solve the above-mentioned technical problems, the present invention provides a lithium extraction device from electrolytic aluminum slag, comprising a bottom plate, a heating tank, an extraction tank, a filter tank, a top cover, a drive mechanism, a switching mechanism, and a mixing mechanism;

[0008] The heating tank is installed on the upper surface of the base plate, the extraction tank is installed inside the heating tank, the filter tank is installed inside the extraction tank, the top cover is sealed and installed on the upper surface of the filter tank, and the inside of the top cover is respectively equipped with a liquid inlet pipe and a feed pipe;

[0009] The drive mechanism includes a mounting base, a motor, and a drive rod. The mounting base is bolted to the upper surface of the top cover. The motor is mounted on the upper surface of the mounting base. The drive rod is keyway connected to the bottom output shaft of the motor. A sliding sleeve is fitted on the outer wall of the drive rod. A positioning bolt is threaded onto the outer wall of the sliding sleeve. A first half gear is fixed at the bottom of the sliding sleeve, and a second half gear is fixed at the bottom of the first half gear.

[0010] The upper and lower ends of the drive rod are rotatably connected to the mounting base and the top cover;

[0011] The switching mechanism includes a positioning seat, a first gear, and a hollow tube. The positioning seat is bolted to the upper surface of the top cover and located on one side of the mounting seat. The hollow tube is rotatably mounted at the axis of the top cover. The first gear is connected to the outer wall of the hollow tube and the keyway inside the positioning seat.

[0012] The mixing mechanism includes a mixing cylinder, a fixed plate, and a mixing plate. The mixing cylinder is fixed to the inner wall of the filter tank, the fixed plate is fixed to the inner wall of the mixing cylinder, and the mixing plate is rotatably connected to the middle position of the fixed plate. The outer wall of the hollow tube and the inside of the mixing cylinder are connected to a second bevel gear via a keyway. The outer wall of the second bevel gear is meshed with a first bevel gear. A mixing rod is fixed to the outer wall of the hollow tube and below the second bevel gear.

[0013] Preferably, the positioning bolt extends to the outer wall of the drive rod, the first half gear and the second half gear are slidably connected to the drive rod, and the first half gear and the second half gear are adapted to the first gear.

[0014] Preferably, the outlet end of the liquid inlet pipe is directly above the mixing plate, one side of the mixing plate is rotatably connected to the inner wall of the mixing cylinder via a bearing, the mixing cylinder has a tapered cross-section, and the shaft of the first bevel gear is connected to the keyway of the mixing plate.

[0015] Preferably, it also includes an extraction mechanism;

[0016] The outer wall of the drive rod and above the sliding sleeve is slidably connected to a first rotating ring, the outer wall of the first rotating ring is rotatably connected to a lifting plate, and the top of the sliding sleeve is fixedly provided with a connecting rod.

[0017] The positioning seat is rotatably connected to a third rotating ring, the keyway inside the third rotating ring is connected to a key rod, the top of the key rod is fixed with a top plate, the outer wall of the key rod is sleeved with a spring, and a second rotating ring is rotatably connected to one side of the lifting plate and above the top plate.

[0018] The extraction mechanism includes a sealed box fixed to the bottom of the hollow tube. Two rotating shafts are rotatably connected inside the sealed box. Extraction plates are bolted to the outside of both rotating shafts. Linkage plates are installed inside the sealed box at the axis of the two rotating shafts. Slots are opened inside the two linkage plates. A switching rod is fixed inside the sealed box at the bottom of the key rod.

[0019] A screw conveyor is installed at the bottom of the filter tank, a discharge pipe is installed at the bottom of the extraction tank, and an auxiliary rod is fixed at the bottom of the sealing box.

[0020] Preferably, the top end of the connecting rod is fixedly connected to the upper surface of the first rotating ring, and the axis of the second rotating ring is connected to the axis keyway of the top plate.

[0021] Preferably, the upper and lower ends of the spring are fixedly connected to the top plate and the third rotating ring, and the key rod is slidably connected to the hollow tube.

[0022] Preferably, it also includes a negative pressure mechanism;

[0023] The negative pressure mechanism includes a third gear rotatably connected to the upper surface of the top cover. The top keyway of the third gear is connected to a first pulley. A rotating rod is rotatably connected to the upper surface of the top cover and located on one side of the third gear. The top keyway of the rotating rod is connected to a second pulley. A belt is fitted on the outer wall of the first pulley and the second pulley. A fan blade is connected to the bottom of the rotating rod and located inside the filter canister via a keyway. An exhaust pipe is fixed on the outer wall of the filter canister and above the fan blade. A second gear is meshed with one side of the third gear.

[0024] Preferably, the second half gear is adapted to the second gear, the hollow tube passes through the axis of the second gear but does not contact the second gear, and the second gear is rotatably connected to the upper surface of the top cover.

[0025] The process for lithium extraction and cryolite co-production includes the following steps:

[0026] S1: Electrolytic aluminum slag, water and caustic soda are reacted at a certain temperature for a period of time in a certain mass ratio, and then filtered to obtain a mixed washing solution of sodium aluminate and sodium hydroxide and filter residue.

[0027] Specifically:

[0028] Electrolytic aluminum slag, water, and caustic soda are reacted in a mass ratio of 1:0.5~5:0.1~5 at a temperature of 25~95 degrees Celsius for 0.2~5 hours, and then filtered to obtain a sodium aluminate / sodium hydroxide mixed washing solution.

[0029] S2: The filter residue, water and concentrated sulfuric acid are leached in an acidic manner in a certain proportion. After reacting at a certain temperature for a period of time, a slurry containing lithium solution is obtained and hydrofluoric acid gas is generated.

[0030] Specifically:

[0031] The filter residue, water, and concentrated sulfuric acid are leached in a ratio of 1:0.5~5:0.1~5 at a temperature of 25~95 degrees Celsius. After 0.2~9 hours of reaction, a lithium solution slurry is obtained and hydrofluoric acid gas is generated. S1 and S2 need to be operated in the filter tank during the operation.

[0032] S3: After liquid-solid separation, the slurry containing the lithium solution is used to obtain a lithium solution and crude cryolite;

[0033] S4: After adjusting the pH of the lithium solution to 11-13, perform liquid-solid separation to obtain a purified lithium solution;

[0034] S5: Remove calcium and magnesium ions from the lithium purification solution using sodium carbonate and ion exchange resin to obtain the lithium purification solution.

[0035] S6: Mix the sodium aluminate / sodium hydroxide mixed washing solution from S1, the hydrofluoric acid gas from S2, and the crude cryolite produced in step S3, and stir at a certain temperature for 10-60 minutes to generate the finished cryolite.

[0036] Compared with related technologies, the lithium extraction equipment and its lithium extraction and cryolite co-production process provided by this invention have the following advantages:

[0037] Compared to traditional designs, this design incorporates a filter tank inside the extraction tank. The electrolytic aluminum slag undergoes alkalization within the filter tank first, separating the sodium aluminate / sodium hydroxide mixed washing solution from the filter residue. Finally, the user can extract the sodium aluminate / sodium hydroxide mixed washing solution and continue acid leaching for lithium extraction within the filter tank. This integrated design allows both steps to be performed within a single filter tank, effectively saving the user's operating time and thus improving lithium extraction efficiency.

[0038] Secondly, during the lithium extraction process, a conical mixing cylinder and a linked tilting mixing plate are used. The mixing plate can tilt the caustic soda flakes into the electrolytic aluminum slag, and then the mixing rod mixes the caustic soda flakes and electrolytic aluminum slag. This design can ensure that the caustic soda flakes can be evenly mixed with the electrolytic aluminum slag, and that the caustic soda flakes can adhere well to the surface of the electrolytic aluminum slag. This also prevents rapid overheating when the caustic soda flakes come into contact with water, making the filter tank work more stably and safely. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0040] Figure 1 The optimal structural schematic diagram provided for this invention;

[0041] Figure 2 for Figure 1 The diagram shows a cross-sectional view of the heating tank and extraction tube.

[0042] Figure 3 for Figure 2 The diagram shows a cross-sectional view of the filter tank.

[0043] Figure 4 for Figure 1 The diagram shows the location distribution of the drive mechanism, switching mechanism, and top cover.

[0044] Figure 5 for Figure 4 The diagram shows a detailed connection structure of the drive mechanism and the switching mechanism.

[0045] Figure 6 for Figure 3 The diagram shows the structure of the mixing mechanism.

[0046] Figure 7 for Figure 4 The schematic diagram shows the cross-sectional structure of the first gear, the second gear, and the hollow tube.

[0047] Figure 8 This is a schematic diagram of the hollow tube and extraction mechanism structure shown in this invention;

[0048] Figure 9 for Figure 8 The enlarged structural diagram at point A is shown below;

[0049] Figure 10 for Figure 9 The diagram shows a detailed structural schematic of the extraction mechanism.

[0050] Figure 11 This is a detailed structural diagram of the negative pressure mechanism shown in this invention.

[0051] Explanation of icon numbers:

[0052] 1. Base plate; 2. Heating tank; 3. Extraction tank; 4. Filter tank;

[0053] 5. Drive mechanism; 51. Mounting base; 52. Motor; 53. Drive rod; 54. Sliding sleeve; 55. Positioning bolt; 56. First half gear; 57. Second half gear; 58. Connecting rod; 59. Lifting plate; 510. First rotating ring; 511. Second rotating ring.

[0054] 6. Switching mechanism; 61. Positioning seat; 62. Third rotating ring; 63. Key rod; 64. Spring; 65. Top plate; 66. Hollow tube; 67. First gear; 68. Second gear.

[0055] 7. Extraction mechanism; 71. Sealed box; 72. Rotating shaft; 73. Linkage plate; 74. Extraction plate; 75. Groove; 76. Switching rod;

[0056] 8. Mixing mechanism; 81. Mixing cylinder; 82. Fixed plate; 83. Mixing plate; 84. First bevel gear; 85. Second bevel gear; 86. Mixing rod;

[0057] 9. Negative pressure mechanism; 91. Third gear; 92. First pulley; 93. Second pulley; 94. Belt; 95. Rotating rod; 96. Fan blade;

[0058] 10. Liquid inlet pipe, 11. Feed inlet pipe, 12. Exhaust pipe, 13. Screw conveyor, 14. Discharge pipe, 15. Auxiliary rod, 16. Top cover.

[0059] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0060] 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.

[0061] This invention provides a lithium extraction device from electrolytic aluminum slag and a process for lithium extraction and cryolite production.

[0062] First embodiment:

[0063] Please see Figures 1 to 6 A lithium extraction device from electrolytic aluminum slag includes a bottom plate 1, a heating tank 2, an extraction tank 3, a filter tank 4, a top cover 16, a drive mechanism 5, a switching mechanism 6, and a mixing mechanism 8.

[0064] The heating tank 2 is installed on the upper surface of the base plate 1, the extraction tank 3 is installed inside the heating tank 2, the filter tank 4 is installed inside the extraction tank 3, the top cover 16 is sealed and installed on the upper surface of the filter tank 4, and the liquid inlet pipe 10 and the feed pipe 11 are respectively installed inside the top cover 16;

[0065] The drive mechanism 5 includes a mounting base 51, a motor 52, and a drive rod 53. The mounting base 51 is bolted to the upper surface of the top cover 16. The motor 52 is mounted on the upper surface of the mounting base 51. The drive rod 53 is keyway connected to the bottom output shaft of the motor 52. A sliding sleeve 54 is sleeved on the outer wall of the drive rod 53. A positioning bolt 55 is threaded onto the outer wall of the sliding sleeve 54. A first half gear 56 is fixed at the bottom of the sliding sleeve 54. A second half gear 57 is fixed at the bottom of the first half gear 56.

[0066] The upper and lower ends of the drive rod 53 are rotatably connected to the mounting base 51 and the top cover 16.

[0067] The switching mechanism 6 includes a positioning seat 61, a first gear 67, and a hollow tube 66. The positioning seat 61 is bolted to the upper surface of the top cover 16 and is located on one side of the mounting base 51. The hollow tube 66 is rotatably mounted at the axis of the top cover 16. The first gear 67 is connected to the keyway of the outer wall of the hollow tube 66 and inside the positioning seat 61.

[0068] Preferably, the motor 52 can be a three-phase asynchronous motor.

[0069] Please see Figure 4 and Figure 5 The starter motor 52 can control the drive rod 53 to rotate clockwise or counterclockwise.

[0070] When the drive rod 53 rotates, it will drive the sliding sleeve 54, the first half gear 56 and the second half gear 57 to rotate synchronously. First, when the tooth surface of the second half gear 57 rotates to the tooth surface of the first gear 67, the second half gear 57 will rotate and mesh to control the rotation of the first gear 67. When the toothless surface of the second half gear 57 rotates to the first gear 67, the second half gear 57 will not mesh to drive the first gear 67. At this time, the tooth surface of the first half gear 56 will rotate and mesh to control the rotation of the first gear 67. Therefore, whether the drive rod 53 rotates clockwise or counterclockwise, the first half gear 56 and the second half gear 57 will mesh to intermittently control the rotation of the first gear 67.

[0071] The mixing mechanism 8 includes a mixing cylinder 81, a fixing plate 82, and a mixing plate 83. The mixing cylinder 81 is fixed to the inner wall of the filter tank 4, the fixing plate 82 is fixed to the inner wall of the mixing cylinder 81, and the mixing plate 83 is rotatably connected to the middle position of the fixing plate 82. The outer wall of the hollow tube 66 and the inside of the mixing cylinder 81 are connected to a second bevel gear 85 via a keyway. The outer wall of the second bevel gear 85 is meshed with a first bevel gear 84. The outer wall of the hollow tube 66 and the area below the second bevel gear 85 are fixed to a mixing rod 86.

[0072] Please see Figure 5 and Figure 6 When the first gear 67 rotates, the first gear 67 will rotate and drive the hollow tube 66 to rotate at the center position of the top cover 16. Secondly, during the rotation of the hollow tube 66, the second bevel gear 85 and the mixing rod 86 will rotate synchronously. During the rotation of the second bevel gear 85, it meshes with the first bevel gear 84 to drive the mixing plate 83 to rotate within the fixed plate 82.

[0073] The positioning bolt 55 extends to the outer wall of the drive rod 53. The first half gear 56 and the second half gear 57 are slidably connected to the drive rod 53. The first half gear 56 and the second half gear 57 are adapted to the first gear 67.

[0074] The outlet end of the liquid inlet pipe 10 is directly above the mixing plate 83. One side of the mixing plate 83 is rotatably connected to the inner wall of the mixing cylinder 81 through a bearing. The mixing cylinder 81 has a tapered cross-section. The axis of the first bevel gear 84 is connected to the keyway of the mixing plate 83.

[0075] The working principle of this embodiment:

[0076] S1: Mix electrolytic aluminum slag, water and caustic soda flakes in filter tank 4 at a mass ratio of 1:0.5~5:0.1~5. Electrolytic filter slag needs to be fed into mixing cylinder 81 through feed pipe 11, and caustic soda flakes and water need to be fed into mixing cylinder 81 through liquid inlet pipe 10. The order of feeding is caustic soda flakes first and then water.

[0077] The user starts the motor 52 and controls the drive rod 53 to drive the first half gear 56 and the second half gear 57 to rotate. During the rotation, the first half gear 56 and the second half gear 57 intermittently control the first gear 67 to control the hollow tube 66 to rotate. During the rotation, the mixing rod 86 rotates on the electrolytic aluminum slag, while the mixing plate 83 rotates to mix the caustic soda flakes into the electrolytic aluminum slag.

[0078] S2: Start heating tank 2 to heat extraction tank 3, control the temperature to 25~95 degrees, react for 0.2~5 hours and then filter to obtain sodium aluminate / sodium hydroxide mixed washing solution and filter residue. Discharge the sodium aluminate / sodium hydroxide mixed washing solution in extraction tank 3 through discharge pipe 14, and leave the filter residue in filter tank 4.

[0079] S3: Finally, in the filter residue inside filter tank 4, water and concentrated sulfuric acid are leached in a ratio of 1:0.5~5:0.1~5 at a temperature of 25~95 degrees Celsius. After reacting for 0.2~9 hours, a lithium solution slurry is obtained and hydrofluoric acid gas is generated.

[0080] S4: Finally, the lithium solution in the extraction tank 3 is discharged through the discharge pipe 14, and the screw conveyor 13 is started to drive the filter residue in the filter tank 4 to be discharged.

[0081] This embodiment

[0082] Compared to traditional designs, this design incorporates a filter tank 4 inside the extraction tank 3. The electrolytic aluminum slag undergoes alkalization within the filter tank 4 first, separating the sodium aluminate / sodium hydroxide mixed washing solution from the filter residue. Finally, the user can extract the sodium aluminate / sodium hydroxide mixed washing solution and continue acid leaching for lithium extraction within the filter tank 4. This integrated design allows both steps to be performed within a single filter tank 4, effectively saving the user's operating time and thus improving lithium extraction efficiency.

[0083] Secondly, during the lithium extraction process, a conical mixing cylinder 81 and a linkage flipping mixing plate 83 are used. The mixing plate 83 can flip the caustic soda flakes into the electrolytic aluminum slag. Then, the mixing rod 86 mixes the caustic soda flakes and the electrolytic aluminum slag. This design can ensure that the caustic soda flakes can be evenly mixed with the electrolytic aluminum slag, and that the caustic soda flakes can adhere well to the surface of the electrolytic aluminum slag. This also prevents rapid overheating when the caustic soda flakes come into contact with water, making the operation of the filter tank 4 more stable and safe.

[0084] Second embodiment:

[0085] Please see Figure 5 , Figures 7 to 10 It also includes extraction mechanism 7;

[0086] The outer wall of the drive rod 53 and above the sliding sleeve 54 is slidably connected to a first rotating ring 510, and the outer wall of the first rotating ring 510 is rotatably connected to a lifting plate 59. The top of the sliding sleeve 54 is fixedly provided with a connecting rod 58.

[0087] The positioning seat 61 is rotatably connected to a third rotating ring 62. The keyway inside the third rotating ring 62 is connected to a key rod 63. The top end of the key rod 63 is fixed with a top plate 65. The outer wall of the key rod 63 is fitted with a spring 64. The lifting plate 59 is rotatably connected to a second rotating ring 511 on one side and above the top plate 65.

[0088] The extraction mechanism 7 includes a sealed box 71 fixed to the bottom end of the hollow tube 66. Two rotating shafts 72 are rotatably connected inside the sealed box 71. Extraction plates 74 are bolted to the outside of each of the two rotating shafts 72. Linkage plates 73 are installed inside the sealed box 71 at the axis of each of the two rotating shafts 72. Slots 75 are opened inside each of the two linkage plates 73. A switching rod 76 is fixed inside the sealed box 71 at the bottom end of the key rod 63.

[0089] A screw conveyor 13 is installed at the bottom of the filter tank 4, a discharge pipe 14 is installed at the bottom of the extraction tank 3, and an auxiliary rod 15 is fixed at the bottom of the sealing box 71.

[0090] Please see Figure 5 In the first embodiment, during operation, the user can slide the sliding sleeve 54 downward to make the first half gear 56 and the second half gear 57 slide downward. When the second half gear 57 moves downward, the second half gear 57 will mesh with the second gear 68, and the first half gear 56 will move to the position of the initial second half gear 57.

[0091] Please see Figure 5 and Figure 6 As the sliding sleeve 54 moves downward, it synchronously drives the connecting rod 58 to control the first rotating ring 510 and the lifting plate 59 to move downward. As the lifting plate 59 moves downward, the second rotating ring 511 will control the top plate 65 to compress the spring 64. As the top plate 65 moves downward, it will control the key rod 63 to move downward along the vertical direction of the hollow tube 66.

[0092] Please see Figure 8 and Figure 9 During the descent, the key lever 63 controls the switching lever 76 to descend in tandem. During the descent, the switching lever 76 is subjected to force on the two slots 75. When the slots 75 are subjected to force, the inclined linkage plate 73 is flipped to control the rotating shaft 72 to rotate within the sealing box 71, thereby controlling the extraction plate 74 to switch from the inclined direction to the horizontal direction.

[0093] The top end of the connecting rod 58 is fixedly connected to the upper surface of the first rotating ring 510, and the axis of the second rotating ring 511 is connected to the axis keyway of the top plate 65.

[0094] The upper and lower ends of the spring 64 are fixedly connected to the top plate 65 and the third rotating ring 62, and the key rod 63 is slidably connected to the hollow tube 66.

[0095] Preferably, the horizontal cross-section of the switching rod 76 is Z-shaped, and the switching rod 76 passes through the interior of the two slots 75.

[0096] The working principle of this embodiment:

[0097] S1: During the operation of the first embodiment, when the user is in the acid immersion operation, he / she needs to first rotate and loosen the positioning bolt 55, slide the sliding sleeve 54 so that the first half gear 56 and the second half gear 57 move downward, and the second half gear 57 meshes with the second gear 68. At this time, only the first half gear 56 can mesh to control the rotation of the first gear 67.

[0098] S2: During the downward movement of the sliding sleeve 54, the lifting plate 59 moves downward in conjunction with the control lever 63. The lever 63 can control the switching lever 76 to control the corresponding extraction plate 74 to switch from the tilted state to the horizontal state.

[0099] S3: When the user starts the motor 52, the first half gear 56 can be controlled to mesh with the first gear 67 to rotate. The first gear 67 will drive the hollow tube 66 to rotate. When the hollow tube 66 rotates, it will synchronously drive the key rod 63 to rotate, and finally realize the rotation of the extraction plate 74 to perform acid leaching and lithium extraction in the filter tank 4.

[0100] Understandably, since the first rotating ring 510 and the lifting plate 59 rotate, the process of lifting the sliding sleeve 54 will not affect the drive rod 53's control of the rotation of the first rotating ring 510, the connecting rod 58 and the sliding sleeve 54. Furthermore, the second rotating ring 511, the third rotating ring 62 are rotatably connected to the lifting plate 59 and the positioning seat 61. Therefore, the key rod 63 will not affect the first gear 67's control of the key rod 63 and the hollow tube 66's rotation during the descent process.

[0101] This embodiment

[0102] Compared to traditional designs, in this case, during the acid leaching lithium extraction process, the user can slide the first half gear 56 and the second half gear 57 downwards. The second half gear 57 disengages from the first gear 67, and only the first half gear 56 engages with the first gear 67. Under the same rotational speed, the motor 52 can adjust the speed of the first gear 67 by changing the switching meshing tooth surface, ensuring that the pause time is longer when the first gear 67 rotates intermittently. This design can ensure the safety of the acid leaching process and avoid boiling in the filter tank 4.

[0103] Secondly, during the downward switching process, the key lever 63 will move downward in conjunction with the control, which can change the angle of the extraction plate 74. In the first embodiment, since the extraction plate 74 is designed to be inclined, this can ensure that the contact surface of the extraction plate 74 can maximize contact with the electrolytic aluminum slag, thus ensuring sufficient secondary alkali mixing.

[0104] During the acid leaching process, the extraction plate 74 can be switched to a horizontal position. This minimizes the contact area between the extraction plate 74 and the filter residue when the plate rotates during acid leaching. This ensures that the rotational resistance is minimized while still achieving mixing and stirring, allowing the filter residue to be mixed in a more stable state.

[0105] Third embodiment:

[0106] Please see Figure 5 , Figure 7 and Figure 11 It also includes a negative pressure mechanism 9;

[0107] The negative pressure mechanism 9 includes a third gear 91 rotatably connected to the upper surface of the top cover 16. The top keyway of the third gear 91 is connected to a first pulley 92. A rotating rod 95 is rotatably connected to the upper surface of the top cover 16 and located on one side of the third gear 91. The top keyway of the rotating rod 95 is connected to a second pulley 93. A belt 94 is fitted on the outer wall of the first pulley 92 and the second pulley 93. A fan blade 96 is connected to the bottom end of the rotating rod 95 and located inside the filter canister 4. An exhaust pipe 12 is fixed on the outer wall of the filter canister 4 and above the fan blade 96. A second gear 68 is meshed with one side of the third gear 91.

[0108] The second half gear 57 is adapted to the second gear 68. The hollow tube 66 passes through the axis of the second gear 68 but does not contact the second gear 68. The second gear 68 is rotatably connected to the upper surface of the top cover 16.

[0109] Please see Figure 5 and Figure 11 In the second embodiment, when the second half gear 57 meshes with the second gear 68, starting the motor 52 can control the first half gear 56 to mesh with the first gear 67 and rotate, and control the second half gear 57 to mesh with the second gear 68.

[0110] When the second gear 68 rotates, it can control the rotation of the third gear 91. The third gear 91 controls the rotation of the first pulley 92, and the transmission control belt 94 controls the rotation of the second pulley 93. During the rotation of the second pulley 93, it can transmit the control rod 95 to drive the fan blade 96 to rotate.

[0111] Understandable: Combination Figure 7 It can be seen that the hollow tube 66 is not connected to the second gear 68, so the rotation of the hollow tube 66 will not affect the operation of the second gear 68. Secondly, the shaft of the second gear 68 adopts a hollow design and can be rotatably connected to the upper surface of the top cover 16 through a bearing.

[0112] This embodiment

[0113] When the second embodiment is in operation, during the process of the user switching the speed of the first gear 67, the second half gear 57 will mesh with the second gear 68. In this way, during the acid leaching process, the second half gear 57 will mesh to control the rotation of the second gear 68.

[0114] The second gear 68 drives the fan blade 96 to rotate inside the filter tank 4. During the rotation of the fan blade 96, a slight negative pressure is formed in the internal space. At this time, the hydrofluoric acid gas generated during the acid leaching process will move upward and enter the slight negative pressure environment, which can help the exhaust pipe 12 to quickly discharge the hydrofluoric acid gas. The discharged hydrofluoric acid gas can help prepare cryolite.

[0115] Fourth embodiment:

[0116] The process for lithium extraction and cryolite co-production includes the following steps:

[0117] S1: Electrolytic aluminum slag, water and caustic soda are reacted at a certain temperature for a period of time in a certain mass ratio, and then filtered to obtain a mixed washing solution of sodium aluminate and sodium hydroxide and filter residue.

[0118] Specifically:

[0119] Electrolytic aluminum slag, water, and caustic soda are reacted in a mass ratio of 1:0.5~5:0.1~5 at a temperature of 25~95 degrees Celsius for 0.2~5 hours, and then filtered to obtain a sodium aluminate / sodium hydroxide mixed washing solution.

[0120] S2: The filter residue, water and concentrated sulfuric acid are leached in an acidic manner in a certain proportion. After reacting at a certain temperature for a period of time, a slurry containing lithium solution is obtained and hydrofluoric acid gas is generated.

[0121] Specifically:

[0122] The filter residue, water, and concentrated sulfuric acid are leached in a ratio of 1:0.5~5:0.1~5 at a temperature of 25~95 degrees Celsius. After 0.2~9 hours of reaction, a lithium solution slurry is obtained and hydrofluoric acid gas is generated. S1 and S2 need to be completed in filter tank 4 during the operation.

[0123] S3: After liquid-solid separation, the slurry containing the lithium solution is used to obtain a lithium solution and crude cryolite;

[0124] S4: After adjusting the pH of the lithium solution to 11-13, perform liquid-solid separation to obtain a purified lithium solution;

[0125] S5: Remove calcium and magnesium ions from the lithium purification solution using sodium carbonate and ion exchange resin to obtain the lithium purification solution.

[0126] S6: Mix the sodium aluminate / sodium hydroxide mixed washing solution from S1, the hydrofluoric acid gas from S2, and the crude cryolite produced in step S3, and stir at a certain temperature for 10-60 minutes to generate the finished cryolite.

[0127] In summary, this application obtains lithium brine by alkaline washing, acid leaching, and impurity removal of electrolytic aluminum slag. The lithium sulfate brine can be used as a raw material for producing lithium carbonate, lithium hydroxide, and lithium chloride through traditional processes. At the same time, lithium is extracted from lithium-containing electrolytic aluminum slag and cryolite is produced. This approach can effectively extract lithium from electrolytic aluminum slag while obtaining cryolite byproducts, thereby maximizing comprehensive utilization and improving lithium utilization rate.

[0128] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made under the concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A lithium extraction device from electrolytic aluminum slag, characterized in that, Includes a base plate, heating tank, extraction tank, filter tank, top cover, drive mechanism, switching mechanism, and mixing mechanism; The heating tank is installed on the upper surface of the base plate, the extraction tank is installed inside the heating tank, the filter tank is installed inside the extraction tank, the top cover is sealed and installed on the upper surface of the filter tank, and the inside of the top cover is respectively equipped with a liquid inlet pipe and a feed pipe; The drive mechanism includes a mounting base, a motor, and a drive rod. The mounting base is bolted to the upper surface of the top cover. The motor is mounted on the upper surface of the mounting base. The drive rod is keyway connected to the bottom output shaft of the motor. A sliding sleeve is fitted on the outer wall of the drive rod. A positioning bolt is threaded onto the outer wall of the sliding sleeve. A first half gear is fixed at the bottom of the sliding sleeve, and a second half gear is fixed at the bottom of the first half gear. The upper and lower ends of the drive rod are rotatably connected to the mounting base and the top cover; The switching mechanism includes a positioning seat, a first gear, and a hollow tube. The positioning seat is bolted to the upper surface of the top cover and located on one side of the mounting seat. The hollow tube is rotatably mounted at the axis of the top cover. The first gear is connected to the outer wall of the hollow tube and the keyway inside the positioning seat. The mixing mechanism includes a mixing cylinder, a fixed plate, and a mixing plate. The mixing cylinder is fixed to the inner wall of the filter tank, the fixed plate is fixed to the inner wall of the mixing cylinder, and the mixing plate is rotatably connected to the middle position of the fixed plate. The outer wall of the hollow tube and the inside of the mixing cylinder are connected to a second bevel gear via a keyway. The outer wall of the second bevel gear is meshed with a first bevel gear. A mixing rod is fixed to the outer wall of the hollow tube and below the second bevel gear. It also includes extraction facilities; The outer wall of the drive rod and above the sliding sleeve is slidably connected to a first rotating ring, the outer wall of the first rotating ring is rotatably connected to a lifting plate, and the top of the sliding sleeve is fixedly provided with a connecting rod. The positioning seat is rotatably connected to a third rotating ring, the keyway inside the third rotating ring is connected to a key rod, the top of the key rod is fixed with a top plate, the outer wall of the key rod is sleeved with a spring, and a second rotating ring is rotatably connected to one side of the lifting plate and above the top plate. The extraction mechanism includes a sealed box fixed to the bottom of the hollow tube. Two rotating shafts are rotatably connected inside the sealed box. Extraction plates are bolted to the outside of both rotating shafts. Linkage plates are installed inside the sealed box at the axis of the two rotating shafts. Slots are opened inside the two linkage plates. A switching rod is fixed inside the sealed box at the bottom of the key rod. A screw conveyor is installed at the bottom of the filter tank, a discharge pipe is installed at the bottom of the extraction tank, and an auxiliary rod is fixed at the bottom of the sealing box; It also includes a negative pressure mechanism; The negative pressure mechanism includes a third gear rotatably connected to the upper surface of the top cover. The top keyway of the third gear is connected to a first pulley. A rotating rod is rotatably connected to the upper surface of the top cover and located on one side of the third gear. The top keyway of the rotating rod is connected to a second pulley. A belt is fitted on the outer wall of the first pulley and the second pulley. A fan blade is connected to the bottom of the rotating rod and located inside the filter canister via a keyway. An exhaust pipe is fixed on the outer wall of the filter canister and above the fan blade. A second gear is meshed with one side of the third gear.

2. The lithium extraction equipment from electrolytic aluminum slag according to claim 1, characterized in that, The positioning bolt extends to the outer wall of the drive rod, and the first half gear and the second half gear are slidably connected to the drive rod. The first half gear and the second half gear are adapted to the first gear.

3. The lithium extraction equipment from electrolytic aluminum slag according to claim 1, characterized in that, The outlet end of the liquid inlet pipe is directly above the mixing plate. One side of the mixing plate is rotatably connected to the inner wall of the mixing cylinder via a bearing. The mixing cylinder has a tapered cross-section. The shaft of the first bevel gear is connected to the keyway of the mixing plate.

4. The lithium extraction equipment from electrolytic aluminum slag according to claim 1, characterized in that, The top end of the connecting rod is fixedly connected to the upper surface of the first rotating ring, and the axis of the second rotating ring is connected to the axis keyway of the top plate.

5. The lithium extraction equipment from electrolytic aluminum slag according to claim 1, characterized in that, The upper and lower ends of the spring are fixedly connected to the top plate and the third rotating ring, and the key rod is slidably connected to the hollow tube.

6. The lithium extraction equipment from electrolytic aluminum slag according to claim 1, characterized in that, The second half gear is adapted to the second gear, the hollow tube passes through the axis of the second gear but does not contact the second gear, and the second gear is rotatably connected to the upper surface of the top cover.

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