Battery-grade lithium carbonate extraction apparatus and method for extracting lithium carbonate from lepidolite

Abstract

This invention provides battery-grade lithium carbonate extraction equipment and a method for extracting lithium carbonate from lepidolite, relating to the field of lithium battery raw material extraction and solid waste resource utilization technology. The equipment includes a leaching tank, a driving mechanism, and an adjustable flow guiding mechanism. The driving mechanism includes a mounting base fixed inside the leaching tank. Four synchronous wheels are rotatably connected to the top of the mounting base, and four auxiliary wheels are rotatably connected to the top of the mounting base on the opposite side of the four synchronous wheels. This design ultimately achieves the following: when the four connecting supports continuously drive the four arc-shaped flow guiding plates inward via sliders, the four arc-shaped flow guiding plates form a cylindrical shape, thus dividing the leaching tank into an inner cylinder and an outer cylinder. When the roasted material falls into the inner cylinder, the powder is instantly captured and forcibly submerged by high turbulence, preventing floating and agglomeration. The radial jet, constrained by the cylinder wall, generates high shear impact, which can quickly break up agglomerates, effectively improving the lithium leaching rate and the preparation efficiency of battery-grade lithium carbonate.

Description

Technical Field

[0001] This invention relates to the field of lithium battery raw material extraction and solid waste resource utilization, and particularly to battery-grade lithium carbonate extraction equipment and methods for extracting lithium carbonate from lepidolite. Background Technology

[0002] As a core component of new energy vehicles and energy storage systems, lithium-ion batteries are experiencing a growing demand for battery-grade lithium carbonate as their cathode material. Extracting lithium carbonate from lepidolite has become a crucial way to ensure lithium resource supply. Regarding solid waste resource utilization, lepidolite typically contains far more aluminum than lithium, and fluorine is also an important chemical raw material. If aluminum can be simultaneously recovered to produce aluminum hydroxide or alumina, and fluorine can be recovered to produce calcium fluoride, near-zero emissions and high-value utilization of solid waste from the lithium extraction process can be achieved.

[0003] In related technologies, the extraction of battery-grade lithium carbonate from lepidolite requires the use of leaching equipment to extract lithium from the roasted material. However, existing extraction equipment suffers from poor flow field uniformity within conventional stirring tanks when processing roasted materials. When the material is directly added to the liquid surface, some powder floats, making it difficult to wet and forming dry powder agglomerates. Existing equipment cannot provide sufficient turbulent shear force to break up these agglomerates and rapidly mix the material, resulting in a low lithium leaching rate. Although some equipment is equipped with fixed guide tubes, their position is inconvenient to adjust according to material characteristics or process stages.

[0004] Therefore, it is necessary to provide battery-grade lithium carbonate extraction equipment to solve the above-mentioned technical problems. Summary of the Invention

[0005] This invention provides a battery-grade lithium carbonate extraction device, which solves the problem that existing equipment cannot provide sufficient turbulent shear force to break up powder agglomerates.

[0006] To solve the above-mentioned technical problems, the battery-grade lithium carbonate extraction equipment provided by the present invention includes a leaching tank, a driving mechanism, and an adjustable flow guiding mechanism;

[0007] The drive mechanism includes a mounting base fixed inside the leaching tank. Four synchronous pulleys are rotatably connected to the top of the mounting base. Four auxiliary pulleys are rotatably connected to the top of the mounting base and to the side opposite to the four synchronous pulleys. A synchronous belt is fitted around the periphery of the four synchronous pulleys and the auxiliary pulleys. Four connecting brackets are fixed to the surface of the synchronous belt. A drive motor for driving the synchronous pulleys to rotate is provided at the bottom left side of the mounting base.

[0008] The adjustable flow guiding mechanism includes a slider slidably connected inside the mounting base. The top of the slider is fixedly connected to the bottom of the connecting bracket. The inner side of the slider and the connecting bracket is vertically rotatably connected to a rotating shaft. An arc-shaped flow guiding plate is fixedly provided at the bottom end of the rotating shaft. Sealing strips are fixedly provided on both the front and back of the arc-shaped flow guiding plate. A first guide plate is fixedly provided on the left side of the arc-shaped flow guiding plate, and a second guide plate is fixedly provided on the right side of the arc-shaped flow guiding plate. The adjustable flow guiding mechanism is arranged in a circular array of four sets.

[0009] Preferably, a swing gear is fixed at the top of the rotating shaft, and two swing tooth plates are fixed on the top of the mounting base and mirrored to the right of the swing gear. When the swing gear moves to the right, it will contact the two swing tooth plates in sequence. The swing gear and the swing tooth plates are arranged in a circular array of four sets.

[0010] Preferably, the first guide plate is tilted upward and the second guide plate is tilted downward. After the four arc-shaped guide plates move to the opposite side to a certain position, they will form a cylindrical shape. At this time, the leaching tank will form two mixing areas: an inner cylinder and an outer cylinder.

[0011] Preferably, the bottom of the mounting base is fixedly provided with a dispensing mechanism, the dispensing mechanism including a sliding seat fixedly provided at the bottom of the mounting base, a sliding bracket slidably connected laterally inside the sliding seat, a guide rod fixedly provided on the right side of the sliding bracket, the peripheral side of the guide rod slidably connected to the inside of the sliding seat, a return spring sleeved on the peripheral side of the guide rod inside the sliding seat, a sealing plate slidably connected longitudinally inside the sliding seat inside the sliding bracket, a drive rod fixedly provided inside the sliding bracket inside the sealing plate, and a trigger bracket fixedly provided at the bottom of the left slider.

[0012] Preferably, the inner wall of the leaching tank is provided with a lid, the top of the lid is provided with a hopper, the bottom of the hopper and the bottom of the lid are connected to a discharge pipe, the inside of the sealing plate is provided with a through hole for use with the discharge pipe, the inside of the sealing plate is provided with an inclined groove for use with the drive rod, and the discharge position of the discharge pipe is located inside the inner cylinder formed by the arc-shaped guide plate.

[0013] Preferably, a striking mechanism is fixedly provided at the bottom of the slider. The striking mechanism includes a drive toothed plate fixedly provided at the bottom of the slider. A rotating rod is fixedly provided at the bottom of the mounting base. A drive gear and a drive half gear are fixedly provided on the circumferential side of the rotating rod. The drive toothed plate meshes with the drive gear. A striking bracket is slidably connected in the leaching tank. A spring is sleeved on the circumferential side of the striking bracket and inside the leaching tank. A toothed set is fixedly provided on the front left side of the striking bracket. The toothed set meshes with the drive half gear. The striking mechanism is arranged in a circular array of four sets.

[0014] Preferably, the inside of the vessel lid is vertically rotatably connected to a stirring mechanism, the stirring mechanism including a stirring shaft vertically rotatably connected to the inside of the vessel lid, the circumferential side of the stirring shaft being rotatably connected to the inside of the mounting base, and multiple sets of stirring paddles being fixed on the circumferential side of the stirring shaft and at the bottom of the mounting base, and a stirring motor for driving the stirring shaft to rotate is provided on the top of the vessel lid.

[0015] Preferably, the leaching tank has multiple support legs fixed on its periphery, multiple baffles arranged in a ring array on the inner wall of the leaching tank, multiple protective covers fixed on the top of the mounting base, an inlet pipe connected to the front of the leaching tank, and a discharge pipe connected to the bottom of the leaching tank.

[0016] A method for extracting lithium carbonate from lepidolite includes the following steps:

[0017] Step S1: The lithium mica ore is crushed, ball-milled to <100μm, sieved, and then dried for later use.

[0018] Step S2: Perform two-stage countercurrent leaching. The first stage uses hydrochloric acid, and the second stage uses the leachate from the first stage to continue leaching new ore.

[0019] Step S3: Place the leachate in an evaporation device for evaporation and concentration. During the process, HCl and HF are recovered in gaseous form. After cooling and crystallization, mixed crystals are obtained. The crystals are then processed and dried for later use.

[0020] Step S4: The mixed crystals are heated and calcined, and the released HCl / HF gas is absorbed by alkaline solution;

[0021] Step S5: After roasting, add deionized water, stir and leach at room temperature, and filter to obtain lithium-rich leachate and aluminum-fluorine-containing solid residue.

[0022] Step S6: The aluminum-fluorine residue is heated with sodium hydroxide solution to react aluminum into sodium aluminate and fluorine into sodium fluoride. Carbon dioxide is passed through to precipitate aluminum to obtain aluminum hydroxide. Calcium chloride is added to the remaining liquid to precipitate fluorine to obtain calcium fluoride.

[0023] Step S7: Slowly add sodium hydroxide solution to the lithium-rich leachate obtained in step S5, gradually adjust the pH to precipitate and remove Al, Fe, and Mn, filter, and then add sodium carbonate to adjust the pH and remove Ca.

[0024] Step S8: After the purified solution is concentrated, sodium carbonate is added under heating to react and obtain battery-grade lithium carbonate.

[0025] Compared with related technologies, the battery-grade lithium carbonate extraction equipment provided by this invention has the following advantages:

[0026] The four connecting brackets move inward, and the slider drives the four arc-shaped guide plates to move inward. During the movement, the arc-shaped guide plates rotate through the cooperation of the swing gear and the swing tooth plate, thereby changing the flow field in the leaching tank. The flow field can be flexibly adjusted according to the needs to adapt to different leaching processes of roasted materials.

[0027] When the four connecting supports continuously drive the four arc-shaped guide plates to move inward via the slider, the four arc-shaped guide plates will form a cylindrical shape, thus dividing the leaching tank into two parts: an inner cylinder and an outer cylinder. When the roasted material falls into the inner cylinder, the powder is instantly captured by the high turbulence and forcibly immersed, avoiding floating and agglomeration. The radial jet is constrained by the cylinder wall and generates high shear impact, which can quickly break up agglomerates and effectively improve the lithium leaching rate and the preparation efficiency of battery-grade lithium carbonate. Attached Figure Description

[0028] 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.

[0029] Figure 1 The optimal structural schematic diagram provided for this invention;

[0030] Figure 2 This is a structural schematic diagram of a cross-sectional view of the leaching tank provided by the present invention;

[0031] Figure 3 for Figure 2 The diagram shows a structural schematic of the bottom view of the leaching tank.

[0032] Figure 4 A schematic diagram of the drive mechanism provided by the present invention;

[0033] Figure 5 This is a schematic diagram of the adjustable flow guiding mechanism provided by the present invention;

[0034] Figure 6 The diagram shows the state in which the four arc-shaped guide plates provided by the present invention move to opposite sides and rotate clockwise under the cooperation of the swing gear and the swing tooth plate.

[0035] Figure 7 A schematic diagram showing the state in which four arc-shaped guide plates, provided by the present invention, move to opposite sides to form an inner cylinder;

[0036] Figure 8 This is a schematic diagram of the dispensing mechanism provided by the present invention;

[0037] Figure 9 for Figure 8 The diagram shows the structural schematic of the bottom view of the sliding seat;

[0038] Figure 10 A schematic diagram of the striking mechanism provided by the present invention;

[0039] Figure 11 This is a schematic diagram of the stirring mechanism provided by the present invention;

[0040] Figure 12 This is a schematic diagram of the process flow provided by the present invention.

[0041] Explanation of icon numbers:

[0042] 1. Leaching tank;

[0043] 2. Drive mechanism; 21. Mounting base; 22. Synchronous pulley; 23. Auxiliary pulley; 24. Synchronous belt; 25. Connecting bracket; 26. Drive motor;

[0044] 3. Adjustable flow guiding mechanism; 31. Slider; 32. Rotating shaft; 33. Arc-shaped flow guide plate; 34. Sealing strip; 35. First guide plate; 36. Second guide plate;

[0045] 4. Oscillating gear; 5. Oscillating toothed plate;

[0046] 6. Dispensing mechanism; 61. Sliding seat; 62. Sliding bracket; 63. Guide rod; 64. Return spring; 65. Sealing plate; 66. Drive rod; 67. Trigger bracket;

[0047] 7. Kettle lid; 8. Hopper; 9. Discharge pipe;

[0048] 10. Striking mechanism; 101. Drive toothed plate; 102. Rotating rod; 103. Drive gear; 104. Drive half gear; 105. Striking bracket; 106. Spring; 107. Tooth assembly;

[0049] 11. Stirring mechanism; 111. Stirring shaft; 112. Stirring paddle; 113. Stirring motor;

[0050] 12. Support leg; 13. Baffle; 14. Protective cover; 15. Liquid inlet pipe; 16. Discharge pipe. 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 battery-grade lithium carbonate extraction device.

[0053] First embodiment:

[0054] Please see Figures 1 to 7 Battery-grade lithium carbonate extraction equipment includes a leaching tank 1, a drive mechanism 2, and an adjustable flow guiding mechanism 3;

[0055] The drive mechanism 2 includes a mounting base 21 fixed inside the leaching tank 1. Four synchronous wheels 22 are rotatably connected to the top of the mounting base 21. Four auxiliary wheels 23 are rotatably connected to the top of the mounting base 21 and to the opposite side of the four synchronous wheels 22. A synchronous belt 24 is sleeved on the peripheral side of the four synchronous wheels 22 and the auxiliary wheels 23. Four connecting brackets 25 are fixed on the surface of the synchronous belt 24. A drive motor 26 for driving the synchronous wheels 22 to rotate is provided at the bottom left side of the mounting base 21.

[0056] The adjustable flow guiding mechanism 3 includes a slider 31 slidably connected inside the mounting base 21. The top of the slider 31 is fixedly connected to the bottom of the connecting bracket 25. The inner side of the slider 31 and the connecting bracket 25 is vertically rotatably connected to a rotating shaft 32. An arc-shaped flow guiding plate 33 is fixedly provided at the bottom end of the rotating shaft 32. Sealing strips 34 are fixedly provided on both the front and back of the arc-shaped flow guiding plate 33. A first guide plate 35 is fixedly provided on the left side of the arc-shaped flow guiding plate 33, and a second guide plate 36 is fixedly provided on the right side of the arc-shaped flow guiding plate 33. The adjustable flow guiding mechanism 3 is arranged in a circular array of four sets.

[0057] The top of the rotating shaft 32 is fixed with a swing gear 4, and the top of the mounting base 21 and the right side of the swing gear 4 are fixed with two swing tooth plates 5. When the swing gear 4 moves to the right, it will contact the two swing tooth plates 5 in sequence. The swing gear 4 and the swing tooth plates 5 are arranged in a circular array of four sets.

[0058] The first guide plate 35 is tilted upward, the second guide plate 36 is tilted downward, and the four arc-shaped guide plates 33 move to the opposite side a certain position to form a cylindrical shape. At this time, the leaching tank 1 will form two mixing areas: an inner cylinder and an outer cylinder.

[0059] Preferably, both the first guide plate 35 and the second guide plate 36 have a guiding function. The first guide plate 35 changes its direction to flow upward through the guidance of the inclined surface. When the first guide plate 35 is located on the inner wall of the leaching tank 1, its guiding and accelerating effect can guide the water flow to quickly flush the inner wall of the leaching tank 1, thus preventing the roasted material from continuously adhering to the leaching tank 1.

[0060] The second guide plate 36 has a downward sloping structural feature. When the four arc-shaped guide plates 33 form the inner cylinder, a downward sloping guide surface will be formed below the liquid surface inside. The downward sloping surface also forms a gradually narrowing flow channel. The fluid accelerates at the outlet of the sloping surface and rushes vertically downward into the lower part of the inner cylinder at a high speed. This downward high-speed jet meets the upward or radial flow generated by the stirring paddle 112 and forms a strong convection mixing zone above the stirring paddle 112, which can enhance the turbulence intensity in the upper part of the inner cylinder and improve the mixing effect of the roasted products.

[0061] Please combine Figure 2 Start the drive motor 26. The drive motor 26 rotates and drives the left synchronous pulley 22 to rotate. The rotation of the left synchronous pulley 22 drives the remaining synchronous pulley 22 and multiple auxiliary pulleys 23 to rotate through the synchronous belt 24. The synchronous belt 24 will simultaneously drive the four connecting brackets 25 to move inward during the movement.

[0062] Please combine Figures 5 to 7 When the four connecting brackets 25 move inward, the slider 31 and the rotating shaft 32 will simultaneously drive the four arc-shaped guide plates 33 to move inward. When the four arc-shaped guide plates 33 move inward, they will simultaneously drive the swing gear 4 to move. When the swing gear 4 contacts the left swing tooth plate 5 (taking the left swing gear 4 and the two swing tooth plates 5 as an example), the swing gear 4 will drive the arc-shaped guide plate 33 to rotate clockwise through the rotating shaft 32, thereby changing the angle of the arc-shaped guide plate 33. Similarly, the other arc-shaped guide plates 33 will also rotate clockwise during the movement.

[0063] Furthermore, as the arc-shaped guide plate 33 and the swing gear 4 continue to move, the swing gear 4 will contact the right swing tooth plate 5 (taking the left swing gear 4 and the two swing tooth plates 5 as an example). Through the cooperation of the swing gear 4 and the swing tooth plate 5, the swing gear 4 will drive the arc-shaped guide plate 33 to rotate counterclockwise through the rotating shaft 32, thereby resetting the arc-shaped guide plate 33.

[0064] Furthermore, as the four connecting brackets 25 drive the slider 31 and the arc-shaped guide plate 33 to continue moving inward, the four arc-shaped guide plates 33 will eventually form a cylindrical shape after contacting each other. This cylindrical shape will be immersed in the tank 1 and divided into an inner cylinder and an outer cylinder.

[0065] Preferably, the stirring mechanism 11 is disposed inside the inner cylinder, and the topmost stirring paddle 112 is disposed inside the inner cylinder formed by the arc-shaped guide plate 33;

[0066] Preferably, in a conventional mixing tank without an inner cylinder, the radial jet generated by the radial flow impeller 112 diffuses freely in the open fluid after leaving the impeller blade. When the inner cylinder is formed, the radial jet of the impeller 112 is confined within the narrow space enclosed by the inner wall of the cylinder. The radial gap between the inner wall of the cylinder and the tip of the impeller blade is very small. The jet has almost no attenuation space before reaching the inner wall and directly impacts the inner wall of the cylinder at a speed close to the tip speed. With the help of the second guide plate 36, it will form a violent turbulence.

[0067] Preferably, when the calcined material is placed into the leaching tank 1, the powder agglomerates are impacted at high speed by the jet and hit the inner wall of the cylinder. They are subjected to strong compression and shearing. At the moment of impact, the internal stress of the agglomerates exceeds its tensile strength, the outer shell breaks, and the internal lithium salt is exposed. After the impact, the fluid deflects downward along the inner wall of the cylinder, forming a high-gradient boundary layer near the wall, which further tears the agglomerates.

[0068] In this embodiment, four connecting brackets 25 move inward, and the slider 31 drives four arc-shaped guide plates 33 to move inward. During the movement, the arc-shaped guide plates 33 rotate through the cooperation of the swing gear 4 and the swing tooth plate 5, thereby changing the flow field in the leaching tank 1. The flow field can be flexibly adjusted according to the requirements to adapt to different leaching processes of roasted materials.

[0069] When the four connecting brackets 25 continuously drive the four arc-shaped guide plates 33 to move inward through the slider 31, the four arc-shaped guide plates 33 will form a cylindrical shape, thereby dividing the leaching tank 1 into two parts: an inner cylinder and an outer cylinder. When the roasted material falls into the inner cylinder, the powder is instantly captured by the high turbulence and forcibly submerged, avoiding floating and agglomeration. The radial jet is constrained by the cylinder wall and generates high shear impact, which can quickly break up the agglomerates and effectively improve the lithium leaching rate and the preparation efficiency of battery-grade lithium carbonate.

[0070] Second embodiment:

[0071] Please see Figures 8 to 10 The bottom of the mounting base 21 is fixedly provided with a dispensing mechanism 6. The dispensing mechanism 6 includes a sliding base 61 fixedly provided at the bottom of the mounting base 21. A sliding bracket 62 is slidably connected to the inside of the sliding base 61. A guide rod 63 is fixedly provided on the right side of the sliding bracket 62. The circumferential side of the guide rod 63 is slidably connected to the inside of the sliding base 61. A return spring 64 is sleeved on the circumferential side of the guide rod 63 and inside the sliding base 61. A sealing plate 65 is slidably connected to the inside of the sliding base 61 and inside the sliding bracket 62. A drive rod 66 is fixedly provided inside the sliding bracket 62 and inside the sealing plate 65. A trigger bracket 67 is fixedly provided at the bottom of the slider 31 on the left side.

[0072] The inner wall of the leaching tank 1 is provided with a lid 7, the top of the lid 7 is provided with a hopper 8, the bottom of the hopper 8 and the bottom of the lid 7 are connected to a discharge pipe 9, the inside of the sealing plate 65 is provided with a through hole that works with the discharge pipe 9, the inside of the sealing plate 65 is provided with an inclined groove that works with the drive rod 66, and the discharge position of the discharge pipe 9 is located inside the inner cylinder formed by the arc-shaped guide plate 33.

[0073] A striking mechanism 10 is fixedly provided at the bottom of the slider 31. The striking mechanism 10 includes a drive toothed plate 101 fixedly provided at the bottom of the slider 31. A rotating rod 102 is fixedly provided at the bottom of the mounting base 21. A drive gear 103 and a drive half gear 104 are fixedly provided on the circumferential side of the rotating rod 102. The drive toothed plate 101 meshes with the drive gear 103. A striking bracket 105 is slidably connected in the leaching tank 1. A spring 106 is sleeved on the circumferential side of the striking bracket 105 and inside the leaching tank 1. A toothed set 107 is fixedly provided on the front left side of the striking bracket 105. The toothed set 107 meshes with the drive half gear 104. The striking mechanism 10 is arranged in a circular array of four sets.

[0074] Preferably, the bottom of the discharge pipe 9 is in contact with the top of the sealing plate 65, and the bottom of the discharge pipe 9 is sealed by the sealing plate 65.

[0075] Please combine Figure 8 and Figure 9 When the left slider 31 moves to the right, it will simultaneously drive the trigger bracket 67 to move to the right. After the trigger bracket 67 moves to the right and contacts the sliding bracket 62, it will push the sliding bracket 62 to move to the right and cause the return spring 64 to contract. The sliding bracket 62 moves to the right, which in turn drives the drive rod 66 to move to the right. Under the action of the inclined groove in the sealing plate 65, the sealing plate 65 will slide backward in the sliding seat 61. When the four arc-shaped guide plates 33 form a cylindrical shape, the through hole position of the sealing plate 65 will coincide with the bottom of the discharge pipe 9. The roasted material in the hopper 8 will fall into the leaching tank 1 through the discharge pipe 9.

[0076] Furthermore, when the slider 31 drives the left arc-shaped guide plate 33 to reset, under the elastic force of the reset spring 64, the sliding bracket 62 will drive the drive rod 66 to move to the left. With the cooperation of the inclined groove in the sealing plate 65, the sealing plate 65 will be driven forward to reset and reseal the discharge pipe 9.

[0077] Please combine Figure 10When the slider 31 continuously drives the arc-shaped guide plate 33 to move to the left, the slider 31 will simultaneously drive the drive tooth plate 101 to move to the left. When the drive tooth plate 101 contacts the drive gear 103 and continues to move, it will drive the drive gear 103, the rotating rod 102 and the drive half gear 104 to rotate. The rotation of the drive half gear 104 will then drive the striking bracket 105 to move to the left through the tooth assembly 107, causing the spring 106 to contract. When the tooth assembly 107 continues to move to the left and separates from the drive half gear 104, under the expansion force of the spring 106, the striking bracket 105 will move to the right and strike the arc-shaped guide plate 33, causing the roasted material remaining on the surface of the arc-shaped guide plate 33 to fall into the deionized water.

[0078] In this embodiment, when the left slider 31 drives the trigger bracket 67 and the arc-shaped guide plate 33 to move to the right, the trigger bracket 67 will push the sliding bracket 62 to the right. With the cooperation of the drive rod 66, the sealing plate 65 moves backward. When the four arc-shaped guide plates 33 form a cylindrical shape, the through hole of the sealing plate 65 will coincide with the bottom of the discharge pipe 9, thereby feeding the roasted material. Only when the four sets of arc-shaped guide plates 33 are completely closed and form a regular inner cylinder partition structure, the through hole of the sealing plate 65 will be aligned with the discharge pipe 9, and the material will fall automatically. When the guide plate is not in place, the discharge pipe 9 will always be blocked by the sealing plate 65, preventing premature feeding and random feeding, and ensuring that the material is accurately fed into the central area of ​​the inner cylinder surrounded by the arc-shaped plates, and will not scatter into the outer cylinder or the corner of the tank wall.

[0079] During the resetting process of the arc-shaped guide plate 33, through the cooperation of the drive tooth plate 101, drive gear 103, drive half gear 104 and tooth assembly 107, under the action of spring 106, the striking bracket 105 will strike the arc-shaped guide plate 33 to the right, and the vibration will shake the roasted powder attached and bonded to the plate surface into the leachate, thus preventing the material from adhering to the plate surface and forming a crust.

[0080] Third embodiment:

[0081] Please see Figure 1 and Figure 11 The inside of the vessel lid 7 is vertically rotatably connected to a stirring mechanism 11. The stirring mechanism 11 includes a stirring shaft 111 vertically rotatably connected to the inside of the vessel lid 7. The circumferential side of the stirring shaft 111 is rotatably connected to the inside of the mounting base 21. Multiple sets of stirring paddles 112 are fixed on the circumferential side of the stirring shaft 111 and at the bottom of the mounting base 21. The top of the vessel lid 7 is provided with a stirring motor 113 for driving the stirring shaft 111 to rotate.

[0082] The leaching tank 1 has multiple support legs 12 fixed on its periphery, and multiple baffles 13 are arranged in a ring array on the inner wall of the leaching tank 1. Multiple protective covers 14 are fixed on the top of the mounting base 21. The front side of the leaching tank 1 is connected to a liquid inlet pipe 15, and the bottom of the leaching tank 1 is connected to a discharge pipe 16.

[0083] Preferably, the top stirring paddle 112 and the bottom stirring paddle 112 are arranged in opposite directions. When the top stirring paddle 112 rotates, it will push the liquid downwards, and when the top stirring paddle 112 rotates, it will spread the liquid at the bottom to the top and around.

[0084] Please combine Figure 11 After the roasted material is placed into the leaching tank 1, the stirring motor 113 is started. The stirring motor 113 rotates and drives the stirring shaft 111 to rotate. The rotation of the stirring shaft 111 in turn drives multiple sets of stirring paddles 112 to rotate, thereby mixing and leaching the roasted material with deionized water.

[0085] In this embodiment, the top stirring paddle 112 presses down the liquid flow and the bottom stirring paddle 112 pushes the flow upward, forming a large longitudinal circulation flow field in the tank from top to bottom and from bottom to top. This can prevent the material from becoming locally static and stratified, and keep the roasted material suspended in the leachate. It will not sink to the bottom quickly and will maintain full contact between the solid and liquid.

[0086] In another application, the battery-grade lithium carbonate extraction equipment can also be used for the dispersion of nanomaterials and carbon materials, such as graphene, carbon nanotubes, and nano-silica, in aqueous or oily media to deagglomerate. Radial jet impact on the cylinder wall can generate extreme shear stress, which can peel off sheets or tube bundles. The concentration gradient between the inner and outer cylinders assists in the rapid adsorption of the dispersant. The knocking vibration prevents the nanoparticles from adhering to the container wall, thus obtaining a uniform and stable dispersion.

[0087] The present invention also provides a method for extracting lithium carbonate from lepidolite.

[0088] Please see Figure 12 A method for extracting lithium carbonate from lepidolite includes the following steps:

[0089] Step S1: The lithium mica ore is crushed, ball-milled to <100μm, sieved, and then dried for later use.

[0090] Step S2: Perform two-stage countercurrent leaching. The first stage uses hydrochloric acid, and the second stage uses the leachate from the first stage to continue leaching new ore.

[0091] Step S3: Place the leachate in an evaporation device for evaporation and concentration. During the process, HCl and HF are recovered in gaseous form. After cooling and crystallization, mixed crystals are obtained. The crystals are then processed and dried for later use.

[0092] Step S4: The mixed crystals are heated and calcined, and the released HCl / HF gas is absorbed by alkaline solution;

[0093] Step S5: After roasting, add deionized water, stir and leach at room temperature, and filter to obtain lithium-rich leachate and aluminum-fluorine-containing solid residue.

[0094] Step S6: The aluminum-fluorine residue is heated with sodium hydroxide solution to react aluminum into sodium aluminate and fluorine into sodium fluoride. Carbon dioxide is passed through to precipitate aluminum to obtain aluminum hydroxide. Calcium chloride is added to the remaining liquid to precipitate fluorine to obtain calcium fluoride.

[0095] Step S7: Slowly add sodium hydroxide solution to the lithium-rich leachate obtained in step S5, gradually adjust the pH to precipitate and remove Al, Fe, and Mn, filter, and then add sodium carbonate to adjust the pH and remove Ca.

[0096] Step S8: After the purified solution is concentrated, sodium carbonate is added under heating to react and obtain battery-grade lithium carbonate;

[0097] Preferably, in step S1, the lithium mica ore is coarsely crushed by a jaw crusher, then ground in a ball mill until the particle size is less than 100μm, sieved, and dried at 105℃±5℃ to constant weight, and stored for later use.

[0098] Preferably, in step S2, a two-stage countercurrent leaching is performed. In the first stage, 6.21 mol / L hydrochloric acid is used with a liquid-to-solid ratio of 3:1, and the leaching is carried out at a constant temperature of 108°C with stirring for 8 hours. In the second stage, the leaching solution from the first stage is used to continue leaching new ore. Through the two-stage countercurrent method, the lithium leaching rate can reach 95.7%, and the aluminum and fluorine leaching rates can reach 80.0% and 71.0%, respectively. After leaching, vacuum filtration is performed to obtain lithium-rich leaching solution and siliceous residue.

[0099] Preferably, in step S3, the leachate is placed in an evaporation apparatus, heated to boiling, and continuously evaporated to 15% of its original volume. HCl and HF generated during the process are recovered in gaseous form. After evaporation, the solution is cooled to 0°C and allowed to crystallize for 12 hours to obtain mixed crystals containing Al, K, Li, and F (main components are KCl, AlCl3·6H2O, and K2NaAl3F). 12 (etc.), the crystals are separated by centrifugation, washed with deionized water, and then dried for later use;

[0100] Preferably, in step S4, the obtained mixed crystals are placed in an air atmosphere and heated to 350°C at 5°C / min, and calcined at a constant temperature for 30 minutes. During the calcination process, AlCl3·6H2O is partially converted into polyaluminum chloride and aluminum hydroxy fluoride, and HCl and HF gases are released. These gases are recovered by an alkaline absorption system. The calcination product is a multiphase mixture containing PAC, AlF3, KAlF4 and a small amount of unconverted chlorides.

[0101] Preferably, in step S5, after roasting, deionized water is added to the material at a liquid-to-solid ratio of 5:1, and the mixture is stirred and leached at room temperature. The mixture is then filtered to obtain a lithium-rich leachate and a solid residue containing aluminum and fluorine, thus achieving the initial separation of lithium and aluminum and fluorine.

[0102] Preferably, in step S6, aluminum fluoride residue is mixed with 6 mol / L NaOH solution at a liquid-solid ratio of 4:1 and stirred at 90°C for 2 hours. Aluminum enters the solution as NaAl(OH)4, while fluorine partially dissolves as NaF. CO2 gas is then introduced into the alkali-dissolved solution until the pH reaches 10.5, causing aluminum to precipitate as Al(OH)3. The precipitate is then filtered to obtain aluminum hydroxide, which can be further calcined to alumina. The mother liquor after aluminum separation via carbonation is added to the alkali-dissolved solution, with the CaCl2 solution controlled at a Ca / F molar ratio of 1.05. The mixture is reacted at room temperature for 1 hour to generate CaF2 precipitate, which is then filtered, washed, and dried to obtain calcium fluoride, thus achieving the resource recovery of fluorine.

[0103] Preferably, in step S7, 2 mol / L NaOH solution is slowly added to the obtained lithium-rich solution, and the pH is gradually adjusted to around 5.2 to precipitate and remove Al and Fe. Then, Mn is precipitated and removed in the pH range of 8-9. After filtration, sodium carbonate is added to adjust the pH to 10.5-11 to remove Ca.

[0104] Preferably, in step S8, the neutralized and impurity-removed solution is evaporated and concentrated to a Li concentration of 25-28 g / L, heated to 90°C, and then mixed with CO3 at a concentration of Li:CO3. 2- A sodium carbonate solution was slowly added at a molar ratio of 1:0.525, and the reaction was carried out under constant temperature and stirring for 1 hour. Li was then produced. 2 After washing the CO3 precipitate with hot water, vacuum filtering, and drying at 120°C for 4 hours, battery-grade lithium carbonate product with a purity ≥99.5% is obtained.

[0105] In this embodiment, for the extraction of battery-grade lithium carbonate, efficient lithium leaching and high purification of lithium-rich liquid are achieved through two-stage countercurrent leaching and stepwise impurity removal. Combined with controllable crystallization and washing and drying processes, battery-grade lithium carbonate products that meet the requirements of cathode materials can be stably obtained, and it has excellent adaptability to processing complex lithium mica ores with high aluminum and high fluorine. In terms of solid waste resource utilization, the process converts the aluminum and fluorine components discarded in the traditional lithium extraction process into aluminum hydroxide and calcium fluoride products, respectively. At the same time, the fluorine-containing gases released in the evaporation and roasting processes are effectively absorbed and recovered to avoid harmful emissions. The recycling of the leachate reduces the generation of waste liquid, and finally only a small amount of harmless silicon residue is produced, realizing the high-value utilization of valuable elements such as aluminum and fluorine and near-zero emissions of solid waste in the process.

[0106] Please refer to the reference again. Figures 1 to 11 The working principle of the battery-grade lithium carbonate extraction equipment provided by this invention is as follows:

[0107] Step S1: When leaching the roasted material, start the stirring motor 113. The stirring motor 113 rotates and drives the stirring shaft 111 to rotate. The rotation of the stirring shaft 111 drives multiple sets of stirring paddles 112 to rotate, and mixes the roasted material with deionized water.

[0108] Step S2: Start the drive motor 26. The drive motor 26 rotates and drives the left synchronous pulley 22 to rotate. The rotation of the left synchronous pulley 22 drives the remaining synchronous pulley 22 and multiple auxiliary pulleys 23 to rotate through the synchronous belt 24. The synchronous belt 24 will simultaneously drive the four connecting brackets 25 to move inward during the movement.

[0109] In step S3, when the four connecting brackets 25 move inward, the slider 31 and the rotating shaft 32 will simultaneously drive the four arc-shaped guide plates 33 to move inward. When the four arc-shaped guide plates 33 move inward, they will simultaneously drive the swing gear 4 to move. When the swing gear 4 contacts the left swing tooth plate 5 (taking the left swing gear 4 and the two swing tooth plates 5 as an example), the swing gear 4 will drive the arc-shaped guide plate 33 to rotate clockwise through the rotating shaft 32, thereby changing the angle of the arc-shaped guide plate 33. Similarly, the other arc-shaped guide plates 33 will also rotate clockwise during the movement.

[0110] As the arc-shaped guide plate 33 and the swing gear 4 continue to move, the swing gear 4 will contact the right swing tooth plate 5 (taking the left swing gear 4 and the two swing tooth plates 5 as an example). Through the cooperation of the swing gear 4 and the swing tooth plate 5, the swing gear 4 will drive the arc-shaped guide plate 33 to rotate counterclockwise through the rotating shaft 32, thereby resetting the arc-shaped guide plate 33.

[0111] When the four connecting brackets 25 drive the slider 31 and the arc-shaped guide plate 33 to continue moving inward, after the four arc-shaped guide plates 33 come into contact with each other, they will eventually form a cylindrical shape. The cylindrical shape will be immersed in the tank 1 and divided into an inner cylinder and an outer cylinder.

[0112] In step S4, when the left slider 31 moves to the right, it will simultaneously drive the trigger bracket 67 to move to the right. After the trigger bracket 67 moves to the right and contacts the sliding bracket 62, it will push the sliding bracket 62 to move to the right and cause the reset spring 64 to contract. The sliding bracket 62 moves to the right, which in turn drives the drive rod 66 to move to the right. Under the action of the inclined groove in the sealing plate 65, the sealing plate 65 will slide backward in the sliding seat 61. When the four arc-shaped guide plates 33 form a cylindrical shape, the through hole position of the sealing plate 65 will coincide with the bottom of the discharge pipe 9. The roasted material in the hopper 8 will fall into the leaching tank 1 through the discharge pipe 9.

[0113] In step S5, when the slider 31 continuously drives the arc-shaped guide plate 33 to move to the left, the slider 31 will simultaneously drive the drive tooth plate 101 to move to the left. When the drive tooth plate 101 contacts the drive gear 103 and continues to move, it will drive the drive gear 103, the rotating rod 102 and the drive half gear 104 to rotate. The rotation of the drive half gear 104 will then drive the striking bracket 105 to move to the left through the tooth assembly 107, causing the spring 106 to contract. When the tooth assembly 107 continues to move to the left and separates from the drive half gear 104, under the expansion force of the spring 106, the striking bracket 105 will move to the right and strike the arc-shaped guide plate 33, causing the roasted material remaining on the surface of the arc-shaped guide plate 33 to fall into the deionized water.

[0114] 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. Battery-grade lithium carbonate extraction equipment, characterized in that, Includes leaching tank, drive mechanism, and adjustable flow guiding mechanism; The drive mechanism includes a mounting base fixed inside the leaching tank. Four synchronous pulleys are rotatably connected to the top of the mounting base. Four auxiliary pulleys are rotatably connected to the top of the mounting base and to the side opposite to the four synchronous pulleys. A synchronous belt is fitted around the periphery of the four synchronous pulleys and the auxiliary pulleys. Four connecting brackets are fixed to the surface of the synchronous belt. A drive motor for driving the synchronous pulleys to rotate is provided at the bottom left side of the mounting base. The adjustable flow guiding mechanism includes a slider slidably connected inside the mounting base. The top of the slider is fixedly connected to the bottom of the connecting bracket. The inner side of the slider and the connecting bracket is vertically rotatably connected to a rotating shaft. An arc-shaped flow guiding plate is fixedly provided at the bottom end of the rotating shaft. Sealing strips are fixedly provided on both the front and back of the arc-shaped flow guiding plate. A first guide plate is fixedly provided on the left side of the arc-shaped flow guiding plate, and a second guide plate is fixedly provided on the right side of the arc-shaped flow guiding plate. The adjustable flow guiding mechanism is arranged in a circular array of four sets.

2. The battery-grade lithium carbonate extraction equipment according to claim 1, characterized in that, A swing gear is fixed at the top of the rotating shaft, and two swing tooth plates are fixed on the top of the mounting base and on the right side of the swing gear. When the swing gear moves to the right, it will contact the two swing tooth plates in sequence. The swing gear and the swing tooth plates are arranged in a circular array of four sets.

3. The battery-grade lithium carbonate extraction equipment according to claim 1, characterized in that, The first guide plate is tilted upwards, and the second guide plate is tilted downwards. After the four arc-shaped guide plates move to the opposite side to a certain position, they will form a cylindrical shape. At this time, the leaching tank will form two mixing areas: an inner cylinder and an outer cylinder.

4. The battery-grade lithium carbonate extraction equipment according to claim 1, characterized in that, The bottom of the mounting base is fixedly provided with a dispensing mechanism. The dispensing mechanism includes a sliding base fixedly provided at the bottom of the mounting base. A sliding bracket is slidably connected to the inside of the sliding base. A guide rod is fixedly provided on the right side of the sliding bracket. The circumferential side of the guide rod is slidably connected to the inside of the sliding base. A return spring is sleeved on the circumferential side of the guide rod inside the sliding base. A sealing plate is slidably connected to the inside of the sliding base inside the sliding bracket. A drive rod is fixedly provided inside the sliding bracket inside the sealing plate. A trigger bracket is fixedly provided at the bottom of the slider on the left side.

5. The battery-grade lithium carbonate extraction equipment according to claim 4, characterized in that, The leaching tank has a lid on its inner wall, a hopper on the top of the lid, and a discharge pipe at the bottom of the hopper and at the bottom of the lid. The sealing plate has a through hole for use with the discharge pipe, and an inclined groove for use with the drive rod. The discharge point of the discharge pipe is located inside the inner cylinder formed by the arc-shaped guide plate.

6. The battery-grade lithium carbonate extraction equipment according to claim 1, characterized in that, The bottom of the slider is fixedly provided with a striking mechanism, which includes a drive toothed plate fixedly provided at the bottom of the slider. The bottom of the mounting base is fixedly provided with a rotating rod. The circumferential side of the rotating rod is fixedly provided with a drive gear and a drive half gear. The drive toothed plate meshes with the drive gear. A striking bracket is slidably connected in the leaching tank. A spring is sleeved on the circumferential side of the striking bracket and inside the leaching tank. A toothed set is fixedly provided on the front left side of the striking bracket. The toothed set meshes with the drive half gear. The striking mechanism is arranged in a circular array of four sets.

7. The battery-grade lithium carbonate extraction equipment according to claim 5, characterized in that, The inside of the vessel lid is vertically rotatably connected to a stirring mechanism. The stirring mechanism includes a stirring shaft vertically rotatably connected to the inside of the vessel lid. The circumferential side of the stirring shaft is rotatably connected to the inside of the mounting base. Multiple sets of stirring paddles are fixed on the circumferential side of the stirring shaft and at the bottom of the mounting base. A stirring motor for driving the stirring shaft to rotate is provided on the top of the vessel lid.

8. The battery-grade lithium carbonate extraction equipment according to claim 1, characterized in that, The leaching tank has multiple support legs fixed on its periphery, and multiple baffles are arranged in a ring array on the inner wall of the leaching tank. Multiple protective covers are fixed on the top of the mounting base. The front side of the leaching tank is connected to a liquid inlet pipe, and the bottom of the leaching tank is connected to a discharge pipe.

9. A method for extracting lithium carbonate from lepidolite, characterized in that, Includes the following steps: Step S1: The lithium mica ore is crushed, ball-milled to <100μm, sieved, and then dried for later use. Step S2: Perform two-stage countercurrent leaching. The first stage uses hydrochloric acid, and the second stage uses the leachate from the first stage to continue leaching new ore. Step S3: Place the leachate in an evaporation device for evaporation and concentration. During the process, HCl and HF are recovered in gaseous form. After cooling and crystallization, mixed crystals are obtained. The crystals are then processed and dried for later use. Step S4: The mixed crystals are heated and calcined, and the released HCl / HF gas is absorbed by alkaline solution; Step S5: After roasting, deionized water is added to the material, and the mixture is stirred and leached at room temperature. The leaching is then filtered to obtain a lithium-rich leachate and a solid residue containing aluminum and fluorine. The leaching process must be completed in the battery-grade lithium carbonate extraction equipment as described in any one of claims 1-8. Step S6: The aluminum-fluorine residue is heated with sodium hydroxide solution to react aluminum into sodium aluminate and fluorine into sodium fluoride. Carbon dioxide is passed through to precipitate aluminum to obtain aluminum hydroxide. Calcium chloride is added to the remaining liquid to precipitate fluorine to obtain calcium fluoride. Step S7: Slowly add sodium hydroxide solution to the lithium-rich leachate obtained in step S5, gradually adjust the pH to precipitate and remove Al, Fe, and Mn, filter, and then add sodium carbonate to adjust the pH and remove Ca. Step S8: After the purified solution is concentrated, sodium carbonate is added under heating to react and obtain battery-grade lithium carbonate.

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