A device for extracting lithium from waste aluminum electrolysis slag and a process for recovering valuable components thereof

Abstract

This invention provides a lithium extraction device and its valuable component recovery process using waste aluminum electrolytic slag, relating to the field of solid waste treatment technology. The device includes a support frame, a water immersion tank, and an injection mechanism. The water immersion tank is located inside the support frame. A top cover is installed on the top of the water immersion tank, and a feed pipe is installed through the top cover. A discharge pipe is installed at the bottom of the water immersion tank. A positioning frame is installed at the center of the top of the top cover, and a motor is installed on the top of the positioning frame. A keyway is connected to the output end of the motor, and a sleeve is slidably installed on the outer wall of the keyway. A mixing frame is fixed at the bottom end of the keyway. This solution uses a reciprocating slider to drive the water injection hose to reciprocate and simultaneously spray deionized water. The deionized water can be evenly distributed throughout the entire leaching tank, continuously replenishing fresh leaching solvent to all areas of the material, eliminating local concentration differences caused by fixed-point water injection, weakening concentration polarization, and effectively improving the dissolution rate of soluble lithium salts in the roasted slag.

Description

Technical Field

[0001] This invention relates to the field of solid waste treatment, and in particular to a lithium extraction device using waste aluminum electrolytic slag and a process for recovering valuable components. Background Technology

[0002] Waste aluminum electrolytic slag is a hazardous solid waste generated during the aluminum electrolysis process. It contains a large amount of soluble fluorides and valuable metals such as lithium, sodium, aluminum, and potassium. It has significant resource recovery value, but stockpiling or landfilling it can easily cause serious environmental pollution. It is classified as hazardous waste in the non-ferrous metal smelting category. It contains toxic and harmful substances such as fluorides and has toxic and hazardous characteristics. It must be collected, transported, and disposed of in accordance with relevant hazardous waste regulations.

[0003] Waste aluminum electrolytic slag is a toxic and hazardous waste containing soluble fluorides, trace heavy metals, lithium salts and other harmful substances. If it is piled up or simply landfilled, rainwater will wash away the toxic ions and allow them to seep into the soil, damaging the soil. Therefore, extracting and recovering valuable materials from this type of hazardous solid waste is the best way to utilize solid waste.

[0004] In existing technologies, traditional water leaching lithium extraction methods can only replenish fresh deionized water in local areas, resulting in significant uneven solid-liquid distribution within the tank. Localized areas with excessive water content form high-lithium-concentration leachate, while the material in the corners and edges of the pipe wall dries out and clumps together. The soluble lithium salts inside the roasted slag particles are encapsulated by the solid phase, making it difficult for them to come into contact with fresh leaching solvent, which severely affects the water leaching effect.

[0005] Therefore, it is necessary to provide a lithium extraction equipment using waste aluminum electrolytic slag and a process for recovering valuable components to solve the above-mentioned technical problems. Summary of the Invention

[0006] This invention provides a lithium extraction device and a process for recovering valuable components using waste aluminum electrolytic slag. It solves the problem in related technologies that deionized water can only be replenished in local areas, and there is obvious uneven solid-liquid distribution in the tank, which affects the water immersion effect.

[0007] To solve the above-mentioned technical problems, the present invention provides a lithium extraction device using waste aluminum electrolytic slag, including a support frame, a water immersion tank and an injection mechanism;

[0008] The water immersion tank is located inside the support. A top cover is installed on the top of the water immersion tank. A feed pipe is installed through the water immersion tank inside the top cover. A discharge pipe is installed at the bottom of the water immersion tank. A positioning frame is installed at the center of the top of the top cover. A motor is installed on the top of the positioning frame. A key rod is connected to the output end of the motor via a keyway. A sleeve is slidably installed on the outer wall of the key rod. A mixing frame is fixed at the bottom end of the key rod. A first gear is fixed on the outer wall of the sleeve.

[0009] The injection mechanism includes a support frame fixed to the inner wall of the water immersion tank. A base plate is fixed to the bottom of the support frame. A drive pulley and a second gear are rotatably connected inside the base plate. A reciprocating screw is connected to the shaft of the drive pulley via a keyway. A slide rod is installed above the reciprocating screw. A slider is threaded to the outer wall of the reciprocating screw. A flexible tube is installed inside the slider.

[0010] Preferably, the mixing frame is positioned and installed via a stabilizing frame and the inner wall of the water immersion tank, and the sleeve slides about the axis of the top cover.

[0011] Preferably, the first gear and the second gear mesh with each other, and the second gear is keyway connected to the shaft of the drive pulley.

[0012] Preferably, the two ends of the reciprocating screw are rotatably connected to the support frame, the two ends of the slide rod are fixedly connected to the support frame, the slider can slide along the slide rod in the horizontal direction, and the inlet end of the hose extends through the outer wall of the water immersion tank to the outside.

[0013] Preferably, it also includes a distributed mechanism;

[0014] The dispersing mechanism includes a driven pulley rotatably connected to the outer wall of the base plate and located directly below the drive pulley. The outer walls of the drive pulley and the driven pulley are fitted with belts. Inside the support frame and below the driven pulley, a rotating rod is rotatably connected. The outer wall of the rotating rod is fixed with a reciprocating plate and a dispersing plate. An eccentric plate is connected to the shaft center of the driven pulley via a keyway. A guide wheel is rotatably connected to the outer wall of the eccentric plate.

[0015] Preferably, the outer wall of the guide wheel and the inner wall of the reciprocating plate are in contact with each other, and the dispersion plate is located directly below the hose outlet.

[0016] Preferably, it also includes auxiliary mechanisms;

[0017] A ratchet is fixedly installed on the outer wall of the sleeve, a ratchet sleeve is engaged with the outer wall of the ratchet, a cam is fixedly provided on the outer wall of the ratchet sleeve, and a positioning bolt is threadedly connected inside the sleeve.

[0018] The auxiliary mechanism includes a mounting bracket installed on the upper surface of the top cover, an extrusion cylinder installed inside the mounting bracket, a spring piston slidably installed inside the extrusion cylinder, a roller installed at the front end of the spring piston, a supply pipe and an inlet pipe respectively installed on the outer wall of the extrusion cylinder, and an annular spray pipe fixedly installed on the inner wall of the water immersion tank below the respective dispersion mechanism.

[0019] Preferably, the outlet end of the supply pipe and the annular nozzle are interconnected, and the cam is located below the roller.

[0020] The process for recovering valuable components from waste aluminum electrolytic slag includes the following steps:

[0021] S1: Crush, grind, and dry the waste aluminum electrolytic slag for later use;

[0022] S2: The waste aluminum electrolytic slag obtained in S1 is mixed with potassium sulfate in a suitable mass ratio and placed in a roasting furnace for roasting. The insoluble sodium lithium cryolite in the waste aluminum electrolytic slag undergoes an ion exchange reaction with K2SO4 and is converted into soluble lithium sulfate, sodium sulfate and potassium lithium sulfate double salt. At the same time, sodium cryolite is converted into potassium-rich cryolite, realizing the selective conversion of lithium and the stable solidification of fluorine.

[0023] S3: The calcined product obtained in S2 is soaked in water to allow soluble lithium and sodium salts to enter the leachate. The product is then filtered and separated to obtain a leachate containing lithium and sodium and a leachate residue containing potassium-rich cryolite, alumina, and calcium fluoride.

[0024] The process of immersion in water needs to be carried out in a lithium extraction equipment made from waste aluminum electrolytic slag.

[0025] S4: The lithium and sodium leaching solution obtained in S3 is evaporated and concentrated. Sodium carbonate is added to the concentrated solution to generate lithium carbonate precipitate. After filtration, washing and drying, industrial-grade or battery-grade lithium carbonate products are obtained. The precipitate mother liquor mainly contains sodium sulfate, which can be recovered as a by-product by evaporation and crystallization.

[0026] S5: The precipitated mother liquor in S4 is evaporated, concentrated, cooled and crystallized to obtain sodium sulfate by-product. The crystallized mother liquor is returned to the water leaching process in S3 for recycling.

[0027] S6: Grind the leaching residue containing potassium-rich cryolite, alumina, and calcium fluoride obtained in S3, and use gravity separation or centrifugal separation to perform preliminary separation by utilizing the density difference of the three to obtain crude potassium-rich cryolite and a mixture of heavy minerals.

[0028] S7: The potassium-rich cryolite crude product obtained in S6 is slurried, sodium carbonate pH adjuster is added, water glass inhibitor, sodium oleate collector and foaming agent are added in sequence, foam flotation is carried out, foam product is scraped, filtered and dried to obtain potassium-rich cryolite product.

[0029] S8: Add the heavy mineral mixture obtained in S7 to dilute hydrochloric acid or dilute sulfuric acid and stir to react. Filter and separate to obtain aluminum-containing leachate and calcium fluoride solid residue.

[0030] S9: Add an alkaline neutralizing agent to the aluminum-containing leachate obtained in S8 to precipitate aluminum ions in the form of aluminum hydroxide. After filtration and washing of the precipitate, calcine to decompose the aluminum hydroxide into aluminum oxide.

[0031] Compared with related technologies, the lithium extraction equipment and its process for recovering valuable components using waste aluminum electrolytic slag provided by this invention have the following beneficial effects:

[0032] The reciprocating slider drives the water injection hose to reciprocate and spray deionized water simultaneously. The deionized water can be evenly distributed throughout the entire leaching tank, continuously replenishing fresh leaching solvent to all areas of the material. This eliminates local concentration differences caused by fixed-point water injection, weakens concentration polarization, effectively increases the leaching rate of soluble lithium salts in the roasted slag, and improves the overall water leaching recovery rate of lithium. Attached Figure Description

[0033] 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.

[0034] Figure 1 The optimal structural schematic diagram provided for this invention;

[0035] Figure 2 for Figure 1 The diagram shows a cross-sectional view of the water immersion tank.

[0036] Figure 3 for Figure 2 The diagram shows a side view of the structure.

[0037] Figure 4 for Figure 2 The diagram shows the connection structure of the key rod, the first gear, the second gear, and the injection mechanism.

[0038] Figure 5 for Figure 4 The enlarged structural diagram at point A is shown below;

[0039] Figure 6 for Figure 4 The enlarged structural diagram at point B is shown below;

[0040] Figure 7 for Figure 4 Detailed structural diagrams of the injection and dispersion mechanisms are shown below;

[0041] Figure 8 A detailed structural diagram of the auxiliary mechanism provided by the present invention;

[0042] Figure 9 The present invention provides a process flow diagram for recovering valuable components from waste aluminum electrolytic slag.

[0043] Explanation of icon numbers:

[0044] 1. Support frame; 2. Water immersion tank; 3. Top cover;

[0045] 4. Feed pipe; 5. Discharge pipe;

[0046] 6. Injection mechanism; 61. Support frame; 62. Base plate; 63. Drive pulley; 64. Reciprocating screw; 65. Slide rod; 66. Slider; 67. Hoses.

[0047] 7. Dispersion mechanism; 71. Driven pulley; 72. Belt; 73. Eccentric plate; 74. Guide wheel; 75. Rotating rod; 76. Reciprocating plate; 77. Dispersion plate.

[0048] 8. Auxiliary mechanism; 81. Mounting bracket; 82. Extrusion cylinder; 83. Spring piston; 84. Roller; 85. Supply pipe; 86. Annular nozzle; 87. Inlet pipe.

[0049] 9. Positioning frame; 10. Motor;

[0050] 11. Key lever; 12. Sleeve; 13. First gear; 14. Second gear; 15. Mixing frame;

[0051] 16. Ratchet, 17. Ratchet sleeve, 18. Cam, 19. Locating bolt. Detailed Implementation

[0052] 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.

[0053] This invention provides a lithium extraction device using waste aluminum electrolytic slag and a process for recovering valuable components.

[0054] First embodiment:

[0055] Please see Figures 1 to 4 , Figure 7 A lithium extraction device using waste aluminum electrolytic slag includes a support frame 1, a water immersion tank 2, and an injection mechanism 6.

[0056] The water immersion tank 2 is located inside the support 1. A top cover 3 is installed on the top of the water immersion tank 2. A feed pipe 4 is installed through the water immersion tank 2 inside the top cover 3. A discharge pipe 5 is installed at the bottom of the water immersion tank 2. A positioning frame 9 is installed at the center of the top of the top cover 3. A motor 10 is installed on the top of the positioning frame 9. A key rod 11 is connected to the output end of the motor 10 via a keyway. A sleeve 12 is slidably installed on the outer wall of the key rod 11. A mixing frame 15 is fixed at the bottom end of the key rod 11. A first gear 13 is fixed on the outer wall of the sleeve 12.

[0057] The injection mechanism 6 includes a support frame 61 fixed to the inner wall of the water immersion tank 2. A base plate 62 is fixed to the bottom of the support frame 61. A drive pulley 63 and a second gear 14 are rotatably connected inside the base plate 62. A reciprocating screw 64 is connected to the shaft of the drive pulley 63 via a keyway. A slide rod 65 is installed above the reciprocating screw 64. A slider 66 is threadedly connected to the outer wall of the reciprocating screw 64. A flexible hose 67 is installed inside the slider 66.

[0058] The mixing frame 15 is positioned and installed by a stabilizing frame and the inner wall of the water immersion tank 2, and the sleeve 12 slides about the axis of the top cover 3.

[0059] The first gear 13 and the second gear 14 mesh with each other, and the second gear 14 is keyway connected to the shaft of the drive pulley 63.

[0060] The two ends of the reciprocating screw 64 are rotatably connected to the support frame 61, the two ends of the slide rod 65 are fixedly connected to the support frame 61, the slider 66 can slide along the slide rod 65 in the horizontal direction, and the inlet end of the hose 67 extends through the outer wall of the water immersion tank 2 to the outside.

[0061] Please see Figures 1 to 3 The waste aluminum electrolytic slag roasting material needs to enter the water immersion tank 2 through the feed pipe 4. After being treated by water immersion in the water immersion tank 2, the slurry is discharged to the subsequent separation equipment through the discharge pipe 5.

[0062] Please see Figure 4 During water immersion, the user needs to start the motor 10 and control the lever 11 to drive the mixing rack 15 to rotate. The rotation of the mixing rack 15 will fully mix the deionized water and calcined products inside to achieve water immersion.

[0063] During the rotation of the key rod 11, it drives the sleeve 12 to control the first gear 13 to mesh and transmit the rotation of the second gear 14.

[0064] Please see Figure 7 When the second gear 14 rotates, it can drive the drive pulley 63 to control the reciprocating screw 64 to rotate. When the reciprocating screw 64 rotates, it controls the slider 66 to move reciprocally along the horizontal direction of the slide bar 65. During the movement, it drives the hose 67 to move reciprocally, so that deionized water can be reciprocally injected into the water immersion tank 2.

[0065] In one application scenario, the lithium extraction equipment using waste aluminum electrolytic slag can be used to extract lithium from the crushed black powder of retired power lithium batteries.

[0066] When extracting lithium from the crushed black powder of retired power lithium batteries, the crushed black powder of retired power lithium batteries is fed into the water immersion tank 2 through the feed pipe 4 to participate in the water immersion lithium extraction. The specific feeding and lithium extraction are as described above.

[0067] In another application, the lithium extraction equipment using waste aluminum electrolytic slag can also be used for water leaching extraction of lithium from tailings of lithium battery recycling processes and filter residue of lithium precipitation mother liquor.

[0068] This embodiment:

[0069] The reciprocating slider 66 drives the water injection hose 67 to reciprocate and spray deionized water simultaneously. The deionized water can be evenly distributed throughout the entire leaching tank 2, continuously replenishing fresh leaching solvent to all areas of the material, eliminating local concentration differences caused by fixed-point water injection, weakening concentration polarization, effectively improving the dissolution rate of soluble lithium salts in the roasted residue, and increasing the overall water leaching recovery rate of lithium elements. The dynamic change of the spray position allows fresh deionized water to gradually wet all roasted materials in the tank, which can effectively inhibit the agglomeration and clumping of dry materials, prevent lithium salts from being wrapped and retained by solid particles, stabilize the lithium ion concentration of the leachate, ensure the stable production of subsequent evaporation concentration and sodium carbonate lithium precipitation processes, and improve the consistency of lithium carbonate finished product quality.

[0070] This recycling process fully utilizes the resources of waste aluminum electrolytic slag. The raw hazardous waste is converted into industrial products such as lithium carbonate, potassium-rich cryolite, alumina, sodium sulfate, and calcium fluoride through processes such as roasting, water leaching, lithium precipitation, gravity flotation, acid leaching, and calcination. There is no waste hazardous residue that needs to be disposed of in landfills for a long time, which greatly reduces the total amount of hazardous waste generated, saves the land occupation of hazardous waste landfills, and completely avoids the long-term environmental hazards of hazardous waste landfill seepage damage and leachate leakage that pollutes soil and groundwater.

[0071] Second embodiment:

[0072] Please refer to Figure 4 , Figure 5 and Figure 7 It also includes decentralized institutions 7;

[0073] The dispersing mechanism 7 includes a driven pulley 71 rotatably connected to the outer wall of the base plate 62 and located directly below the drive pulley 63. A belt 72 is sleeved on the outer wall of the drive pulley 63 and the driven pulley 71. A rotating rod 75 is rotatably connected inside the support frame 61 and below the driven pulley 71. A reciprocating plate 76 and a dispersing plate 77 are fixed on the outer wall of the rotating rod 75. An eccentric plate 73 is connected to the axis of the driven pulley 71 via a keyway. A guide wheel 74 is rotatably connected to the outer wall of the eccentric plate 73.

[0074] The outer wall of the guide wheel 74 and the inner wall of the reciprocating plate 76 are in contact with each other, and the dispersion plate 77 is located directly below the outlet of the hose 67.

[0075] Please see Figure 4 , Figure 5 and Figure 7In the first embodiment, when the drive pulley 63 rotates, the synchronous transmission belt 72 drives the driven pulley 71 to control the rotation of the eccentric plate 73. The eccentric plate 73 drives the guide wheel 74 to rotate in a circle and control the reciprocating plate 76 to reciprocate and flip. At the same time, the reciprocating plate 76 drives the rotating rod 75 to control the dispersing plate 77 to move back and forth under the hose 67. The deionized water injected through the hose 67 will enter the reciprocating dispersing plate 77 and be dispersed before being injected into the water immersion tank 2.

[0076] This embodiment:

[0077] Water from the reciprocating moving hose 67 falls to the simultaneously reciprocating dispersing plate 77 below. The concentrated columnar water flow impacts the dispersing plate 77 and is dispersed into a thin water curtain and fine water mist, significantly increasing the contact area between deionized water and the roasted hazardous waste residue. This weakens the concentration polarization phenomenon in the water leaching system, promotes the full dissolution of soluble lithium salts in the material, and improves the water leaching extraction rate of lithium from hazardous solid waste. The reciprocating rotation of the dispersing plate 77 can dynamically change the coverage area of ​​the falling water curtain. Combined with the reciprocating movement of the water injection hose 67 above, it forms a double-layer dynamic water distribution structure, eliminating the phenomenon of local water shortage and dry material clumping in the water leaching tank 2.

[0078] Third embodiment:

[0079] Please see Figure 4 , Figure 6 , Figures 8 to 8 It also includes auxiliary mechanisms 8;

[0080] A ratchet 16 is fixedly installed on the outer wall of the sleeve 12. A ratchet sleeve 17 is meshed with the outer wall of the ratchet 16. A cam 18 is fixedly provided on the outer wall of the ratchet sleeve 17. A positioning bolt 19 is threadedly connected inside the sleeve 12.

[0081] The auxiliary mechanism 8 includes a mounting bracket 81 installed on the upper surface of the top cover 3. An extrusion cylinder 82 is installed inside the mounting bracket 81. A spring piston 83 is slidably installed inside the extrusion cylinder 82. A roller 84 is installed at the front end of the spring piston 83. A supply pipe 85 and an inlet pipe 87 are respectively installed on the outer wall of the extrusion cylinder 82. An annular spray pipe 86 is fixedly installed on the inner wall of the water immersion tank 2 and below the dispersing mechanism 7.

[0082] The outlet end of the supply pipe 85 is connected to the annular nozzle 86, and the cam 18 is located below the roller 84.

[0083] Please see Figure 4 and Figure 6 In the first embodiment, since the cam 18 is located below the auxiliary mechanism 8 and the first gear 13 and the second gear 14 are engaged, the auxiliary mechanism 8 will not be activated when the mixing frame 15 rotates during the operation of the first embodiment.

[0084] Please see Figure 8 After the first and second embodiments are completed, the user needs to loosen the positioning bolt 19 and the sliding sleeve 12 to rise so that the cam 18 enters the outer wall of the roller 84. At this time, the first gear 13 also rises and the second gear 14 separates. At this time, the mixing frame 15 will not drive the injection mechanism 6 and the dispersion mechanism 7 to work, whether it rotates clockwise or counterclockwise.

[0085] At this time, the user needs to activate the key lever 11 to drive the mixing frame 15 to rotate counterclockwise. When rotating counterclockwise, the ratchet 16 rotates counterclockwise in the ratchet sleeve 17. In this state, only the mixing frame 15 can rotate and work, while the auxiliary mechanism 8 remains stopped.

[0086] After the material is discharged from the water immersion tank 2, the user needs to start the key lever 11 to rotate clockwise. When rotating clockwise, the ratchet 16 drives the ratchet sleeve 17 to control the cam 18 to rotate and squeeze the control roller 84 to drive the spring piston 83 to pressurize the cleaning liquid in the extrusion cylinder 82 and push it through the supply pipe 85 to the annular spray pipe 86 to clean the inner wall of the water immersion tank 2 downwards.

[0087] This embodiment:

[0088] After the leaching process is completed, a pressurized high-pressure water channel is installed along the walls of the two leaching tanks. The high-pressure water flow directly impacts the inner wall of the tank, and the impact force of the high-pressure water can quickly peel off the lithium- and fluorine-containing hazardous waste sludge adhering to the tank wall. There is no need for personnel to enter the restricted leaching tank for manual cleaning. The high-pressure flushing water flow can cover the entire tank wall and the corners and dead corners of the tank bottom, removing the hardened and compacted sludge that is difficult to remove by manual cleaning and low-pressure spraying. This ensures that the inner wall of the leaching tank is clean and free of sludge residue, and avoids residual sludge occupying the effective reaction volume inside the tank.

[0089] The process for recovering valuable components from waste aluminum electrolytic slag includes the following steps:

[0090] S1: Crush and grind the waste aluminum electrolytic slag to a particle size of less than 180μm, and dry it for later use;

[0091] S2: The waste aluminum electrolytic slag obtained in S1 is mixed with potassium sulfate in a suitable mass ratio and placed in a roasting furnace. It is roasted at 550-700℃ for 30-90 minutes. During the roasting process, the insoluble sodium lithium cryolite in the waste aluminum electrolytic slag undergoes an ion exchange reaction with K2SO4 and is converted into soluble lithium sulfate, sodium sulfate and potassium lithium sulfate double salt. At the same time, sodium cryolite is converted into potassium-rich cryolite, realizing the selective conversion of lithium and the stable solidification of fluorine.

[0092] S3: The calcined product obtained in S2 is leached in water for 10 to 30 minutes at a liquid-to-solid ratio of 3:1 to 8:1 (mL / g) and a temperature of 20 to 60°C, so that soluble lithium salts and sodium salts enter the leachate. The leachate is then filtered and separated to obtain a leachate containing lithium and sodium and a leachate residue containing potassium-rich cryolite, alumina, and calcium fluoride.

[0093] The process of immersion in water needs to be carried out in a lithium extraction equipment made from waste aluminum electrolytic slag.

[0094] S4: The lithium- and sodium-containing leachate obtained in S3 is evaporated and concentrated to enrich the lithium concentration to 25-28 g / L. Sodium carbonate is added to the concentrate and reacted at 90-95°C for 1-3 hours to generate lithium carbonate precipitate. The precipitate is filtered, washed, and dried to obtain industrial-grade or battery-grade lithium carbonate products. The precipitate mother liquor mainly contains sodium sulfate, which can be recovered as a byproduct by evaporation and crystallization.

[0095] S5: The precipitated mother liquor in S4 is evaporated, concentrated, cooled and crystallized to obtain sodium sulfate by-product. The crystallized mother liquor is returned to the water leaching process in S3 for recycling.

[0096] S6: The leaching residue containing potassium-rich cryolite, alumina, and calcium fluoride obtained in S3 is ground to a particle size of less than 75μm. Gravity separation or centrifugal separation is used to preliminarily separate the three by utilizing their density differences to obtain crude potassium-rich cryolite and a mixture of heavy minerals.

[0097] S7: The potassium-rich cryolite crude product obtained in S6 is slurryed, sodium carbonate pH adjuster is added to adjust the pH of the slurry to 7.5-8.5, water glass inhibitor, sodium oleate collector and frother are added in sequence, froth flotation is carried out, the froth product is scraped off, filtered and dried to obtain potassium-rich cryolite product with a purity >90%.

[0098] S8: Add the heavy mineral mixture obtained in S7 to dilute hydrochloric acid or dilute sulfuric acid with a concentration of 10%-20% and a liquid-solid ratio of 4:1-8:1 (mL / g). Stir and react at 60-90℃ for 30-60 minutes, filter and separate to obtain aluminum-containing leachate and calcium fluoride solid residue.

[0099] S9: Add an alkaline neutralizing agent to the aluminum-containing leachate obtained in S8, adjust the pH to 6.5-7.5, so that aluminum ions precipitate in the form of aluminum hydroxide. Filter and wash the precipitate, and calcine it at 800-1000℃ for 2-4 hours to decompose the aluminum hydroxide into aluminum oxide.

[0100] Please refer to the reference again. Figures 1 to 9 The working principle of the lithium extraction equipment and its valuable component recovery process using waste aluminum electrolytic slag provided by this invention is as follows:

[0101] Step S1: The waste aluminum electrolytic slag roasting material needs to enter the water immersion tank 2 through the feed pipe 4. Start the motor 10 to control the key rod 11 to drive the mixing frame 15 to rotate. The rotation of the mixing frame 15 fully mixes the deionized water and roasting product inside to achieve water immersion. During the rotation of the key rod 11, it drives the sleeve 12 to control the first gear 13 to mesh and drive the second gear 14 to rotate. When the second gear 14 rotates, it can drive the drive pulley 63 to control the reciprocating screw 64 to rotate. When the reciprocating screw 64 rotates, it controls the slider 66 to move back and forth along the horizontal direction of the slide rod 65. During the movement, it drives the hose 67 to move back and forth. Therefore, the deionized water can be reciprocated and injected into the water immersion tank 2.

[0102] Step S2: When the drive pulley 63 rotates, the synchronous transmission belt 72 drives the driven pulley 71 to control the rotation of the eccentric plate 73. The eccentric plate 73 drives the guide wheel 74 to rotate in a circle and control the reciprocating plate 76 to reciprocate and flip. At the same time, the reciprocating plate 76 drives the rotating rod 75 to control the dispersing plate 77 to move back and forth under the hose 67. The deionized water injected through the hose 67 will enter the reciprocating dispersing plate 77, disperse, and then be injected into the water immersion tank 2.

[0103] 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. An apparatus for extracting lithium from spent aluminum electrolysis residue, characterized by, Includes a support frame, a water immersion tank, and an injection mechanism; The water immersion tank is located inside the support. A top cover is installed on the top of the water immersion tank. A feed pipe is installed through the water immersion tank inside the top cover. A discharge pipe is installed at the bottom of the water immersion tank. A positioning frame is installed at the center of the top of the top cover. A motor is installed on the top of the positioning frame. A key rod is connected to the output end of the motor via a keyway. A sleeve is slidably installed on the outer wall of the key rod. A mixing frame is fixed at the bottom end of the key rod. A first gear is fixed on the outer wall of the sleeve. The injection mechanism includes a support frame fixed to the inner wall of the water immersion tank. A base plate is fixed to the bottom of the support frame. A drive pulley and a second gear are rotatably connected inside the base plate. A reciprocating screw is connected to the shaft of the drive pulley via a keyway. A slide rod is installed above the reciprocating screw. A slider is threaded to the outer wall of the reciprocating screw. A flexible tube is installed inside the slider.

2. The equipment for extracting lithium from waste aluminum electrolysis residue according to claim 1, characterized in that, The mixing frame is positioned and installed via a stabilizing frame and the inner wall of the water immersion tank, and the sleeve slides about the axis of the top cover.

3. The equipment for extracting lithium from waste aluminum electrolysis slag according to claim 1, characterized in that, The first gear and the second gear mesh with each other, and the second gear is connected to the shaft of the drive pulley via a keyway.

4. The equipment for extracting lithium from waste aluminum electrolysis slag according to claim 1, characterized in that, The two ends of the reciprocating screw are rotatably connected to the support frame, the two ends of the slide rod are fixedly connected to the support frame, the slider can slide along the horizontal direction of the slide rod, and the inlet end of the hose extends through the outer wall of the water immersion tank to the outside.

5. The equipment for extracting lithium from waste aluminum electrolysis slag according to claim 1, characterized in that, It also includes decentralized institutions; The dispersing mechanism includes a driven pulley rotatably connected to the outer wall of the base plate and located directly below the drive pulley. The outer walls of the drive pulley and the driven pulley are fitted with belts. Inside the support frame and below the driven pulley, a rotating rod is rotatably connected. The outer wall of the rotating rod is fixed with a reciprocating plate and a dispersing plate. An eccentric plate is connected to the shaft center of the driven pulley via a keyway. A guide wheel is rotatably connected to the outer wall of the eccentric plate.

6. The equipment for extracting lithium from waste aluminum electrolysis slag according to claim 5, characterized in that, The outer wall of the guide wheel and the inner wall of the reciprocating plate are in contact with each other, and the dispersion plate is located directly below the hose outlet.

7. The equipment for extracting lithium from waste aluminum electrolysis slag according to claim 1, characterized in that, It also includes auxiliary mechanisms; A ratchet is fixedly installed on the outer wall of the sleeve, a ratchet sleeve is engaged with the outer wall of the ratchet, a cam is fixedly provided on the outer wall of the ratchet sleeve, and a positioning bolt is threadedly connected inside the sleeve. The auxiliary mechanism includes a mounting bracket installed on the upper surface of the top cover, an extrusion cylinder installed inside the mounting bracket, a spring piston slidably installed inside the extrusion cylinder, a roller installed at the front end of the spring piston, a supply pipe and an inlet pipe respectively installed on the outer wall of the extrusion cylinder, and an annular spray pipe fixedly installed on the inner wall of the water immersion tank below the respective dispersion mechanism.

8. The equipment for extracting lithium from waste aluminum electrolysis slag according to claim 7, characterized in that, The outlet end of the supply pipe is connected to the annular nozzle, and the cam is located below the roller.

9. Process for the recovery of valuable components with spent aluminum electrolysis slag, characterized by, Includes the following steps: S1: Crush, grind, and dry the waste aluminum electrolytic slag for later use; S2: The waste aluminum electrolytic slag obtained in S1 is mixed with potassium sulfate in a suitable mass ratio and placed in a roasting furnace for roasting. The insoluble sodium lithium cryolite in the waste aluminum electrolytic slag undergoes an ion exchange reaction with K2SO4 and is converted into soluble lithium sulfate, sodium sulfate and potassium lithium sulfate double salt. At the same time, sodium cryolite is converted into potassium-rich cryolite, realizing the selective conversion of lithium and the stable solidification of fluorine. S3: The calcined product obtained in S2 is soaked in water to allow soluble lithium and sodium salts to enter the leachate. The product is then filtered and separated to obtain a leachate containing lithium and sodium and a leachate residue containing potassium-rich cryolite, alumina, and calcium fluoride. The water immersion process must be carried out in the lithium extraction equipment for waste aluminum electrolytic slag as described in any one of claims 1-8; S4: The lithium and sodium leaching solution obtained in S3 is evaporated and concentrated. Sodium carbonate is added to the concentrated solution to generate lithium carbonate precipitate. After filtration, washing and drying, industrial-grade or battery-grade lithium carbonate products are obtained. The precipitate mother liquor mainly contains sodium sulfate, which can be recovered as a by-product by evaporation and crystallization. S5: The precipitated mother liquor in S4 is evaporated, concentrated, cooled and crystallized to obtain sodium sulfate by-product. The crystallized mother liquor is returned to the water leaching process in S3 for recycling. S6: Grind the leaching residue containing potassium-rich cryolite, alumina, and calcium fluoride obtained in S3, and use gravity separation or centrifugal separation to perform preliminary separation by utilizing the density difference of the three to obtain crude potassium-rich cryolite and a mixture of heavy minerals. S7: The potassium-rich cryolite crude product obtained in S6 is slurried, sodium carbonate pH adjuster is added, water glass inhibitor, sodium oleate collector and foaming agent are added in sequence, foam flotation is carried out, foam product is scraped, filtered and dried to obtain potassium-rich cryolite product. S8: Add the heavy mineral mixture obtained in S7 to dilute hydrochloric acid or dilute sulfuric acid and stir to react. Filter and separate to obtain aluminum-containing leachate and calcium fluoride solid residue. S9: Add an alkaline neutralizing agent to the aluminum-containing leachate obtained in S8 to precipitate aluminum ions as aluminum hydroxide. After filtration and washing of the precipitate, calcine to decompose the aluminum hydroxide into aluminum oxide.

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