Lithium extraction equipment by utilizing solid waste leaching and lithium extraction process thereof

Abstract

The invention provides lithium extraction equipment by utilizing solid waste leaching and a lithium extraction process thereof, and relates to the technical field of solid waste treatment, the lithium extraction equipment comprises a base, a heating seat, a driving mechanism and a discharging mechanism; the heating seat is located on the upper surface of the base, the leaching tank is installed in the heating seat, the feeding pipe and the liquid supply pipe are installed on the two sides of the leaching tank in a penetrating mode respectively, the top cover is installed on the top of the leaching tank, and the mounting frame is installed on the top of the top cover through bolts. And the driving mechanism comprises a motor mounted on the upper surface of the mounting frame. According to the scheme, the positive electrode powder obtained from the solid waste battery is used for extracting lithium, reduction and harmlessness of dangerous solid waste are achieved, lithium in the positive electrode powder is recycled through the leaching lithium extraction process, the volume of residual leaching residues is reduced, the content of heavy metal in the residues is greatly reduced, the follow-up treatment difficulty and cost are remarkably reduced, and the method is suitable for industrial production. And secondly, the produced battery-grade lithium carbonate can be used for preparing a lithium battery again, so that efficient recovery and extraction of lithium in the waste positive electrode material are realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of solid waste treatment, and particularly relates to a solid waste leaching lithium extraction equipment and a lithium extraction process thereof. BACKGROUND

[0002] With the rapid development of new energy vehicles and energy storage industries, the amount of scrapped lithium ion batteries increases dramatically. Among them, lithium ion batteries occupy an important market share due to their high safety and long cycle life, but this also means that a large number of retired batteries will be generated. Therefore, the recycling demand of waste lithium batteries is increasingly urgent.

[0003] Solid waste is a solid, semi-solid and gaseous material in a container generated in production, life and other activities that loses its original value or is discarded and abandoned although it has not lost its value. Waste lithium batteries meet this definition. In order to produce environmentally friendly products, recycling and utilization of waste lithium batteries are extremely urgent.

[0004] In the prior art, no industrialized solution has been formed in the field of battery recycling. The traditional leaching method uses concentrated sulfuric acid or hydrochloric acid to dissolve the positive electrode material, which has many problems such as equipment corrosion and heavy metal pollution. Therefore, effective recovery of lithium cannot be achieved.

[0005] Therefore, it is necessary to provide a solid waste leaching lithium extraction equipment and a lithium extraction process thereof to solve the above technical problems. SUMMARY

[0006] The present application provides a solid waste leaching lithium extraction equipment and a lithium extraction process thereof, which solves the problem of equipment corrosion and heavy metal pollution in the related art.

[0007] To solve the above technical problems, the present application provides a waste lithium iron phosphate battery leaching device, which comprises a base, a heating seat, a driving mechanism and a discharging mechanism.

[0008] The heating seat is located on the upper surface of the base, and the heating seat is internally provided with a leaching tank. The leaching tank is provided with an inlet pipe and a liquid supply pipe on both sides in a through manner. The leaching tank is provided with a top cover on the top. The top cover is provided with a mounting bracket on the top through bolts.

[0009] The driving mechanism comprises a motor mounted on the upper surface of the mounting bracket. The output shaft key groove of the motor is connected with a driving rod. The bottom end key groove of the driving rod is connected with a driving gear. A positioning plate is fixedly arranged on the upper surface of the top cover and located on one side of the driving gear. A driven gear is rotatably connected in the positioning plate. An eccentric plate is connected with the key groove at the shaft center of the driven gear. A guide wheel is rotatably connected to the outer wall of the eccentric plate.

[0010] The blanking mechanism comprises a mounting plate fixed to the bottom of the mounting frame, a rotating shaft is rotatably connected inside the mounting plate, a turnover frame is installed on the outer wall of the rotating shaft and located on one side of the mounting plate through bolts, an installation rod is rotatably connected inside the turnover frame, a spray pipe is installed on the outer wall of the installation rod, a reciprocating groove plate is fixed to one end of the rotating shaft and located on the opposite side of the positioning plate and the mounting plate, a spring pipe is sealingly installed at the outlet end of the liquid supply pipe, and a stirring rod is connected to the key groove at the center of the driving gear inside the leaching tank.

[0011] Preferably, the driving gear is rotatably connected to the center of the top cover through a bearing, and the top end of the stirring rod is rotatably connected to the center of the top cover.

[0012] Preferably, the driving gear and the driven gear are in meshing relationship with each other, and the outer wall of the guide wheel and the inner groove wall of the reciprocating groove plate are in contact with each other.

[0013] Preferably, the outlet end of the spring pipe is sealingly installed at the inlet end of the spray pipe, and the outlet end of the spray pipe is directly above the stirring rod.

[0014] Preferably, a side plate is installed on the outer wall of the mounting plate through bolts, a first gear is fixed to the outer wall of the side plate, and a second gear is connected to the key groove inside the turnover frame at the top of the installation rod.

[0015] Preferably, the first gear and the second gear are in meshing relationship with each other, the rotating shaft penetrates the inside of the side plate and the center of the first gear, and the rotating shaft does not contact the side plate and the first gear.

[0016] Preferably, it further comprises an auxiliary mechanism.

[0017] The auxiliary mechanism comprises a fixed ring fixed to the inner wall of the leaching tank, two lug plates are installed on the top of the fixed ring, a key rod is fixed to the bottom end of the stirring rod, a bottom plate is fixed to the bottom end of the key rod, a sliding plate is slidingly connected to the outer wall of the key rod and located above the bottom plate, four inclined plates and two rollers are fixedly installed on the outer wall of the sliding plate, and a return spring is sleeved on the outer wall of the key rod.

[0018] Preferably, the two rollers are in contact with the upper surface of the fixed ring, and the upper and lower ends of the return spring are fixedly connected with the sliding plate and the bottom plate.

[0019] The solid waste leaching lithium extraction process comprises the following steps:

[0020] S1: After the waste battery is disassembled, the positive plate is crushed, screened, and the iron impurities are removed by magnetic separation, and the binder is removed by calcining at 500 DEG C for 2 hours;

[0021] S2: The positive electrode powder is mixed with a reducing agent, the reducing agent is selected from ascorbic acid or glucose, the mass ratio is 1:0.3, and the mixture is heated to 300 DEG C under nitrogen protection for 1 hour;

[0022] Chemical reaction: 2LiCoO2+C6H8O6→Li2O+2CoO+H2O+C6H6O6

[0023] S3: A mixed leaching solution of 0.5 mol / L ammonium sulfate and 0.1 mol / L disodium ethylenediaminetetraacetate is prepared, and leaching is carried out at 80 DEG C for 2 hours under stirring at a liquid-solid ratio of 10:1; the mixed leaching solution of ammonium sulfate and disodium ethylenediaminetetraacetate is pumped into the spray pipe in the feeding mechanism through the liquid supply pipe and sprayed into the leaching tank to mix with the positive electrode powder for leaching;

[0024] Chemical reaction: Li2O+(NH4)2SO4→2Li + +SO4 2− +2NH3↑+H2O

[0025] CoO+EDTA 4− →[Co(EDTA)] 2−

[0026] S4: The leaching solution is centrifuged, and sodium sulfide is added to the filtrate to a concentration of 0.05 mol / L to precipitate residual heavy metals;

[0027] S5: Saturated sodium carbonate solution is added to the purified solution to pH=12, and battery-grade lithium carbonate is obtained after centrifugal drying, reaction: Co 2+ +S 2− →CoS↓.

[0028] Compared with the related art, the equipment for leaching lithium from solid waste and the lithium extraction process provided by the present application have the following beneficial effects:

[0029] The positive electrode powder obtained from the solid waste battery is used for lithium extraction, realizing hazardous solid waste reduction and harmless treatment, reducing environmental disposal pressure, and through the leaching lithium extraction process, lithium in the positive electrode powder is recovered, the volume of the remaining leaching residue is reduced, and the content of heavy metals in the residue is greatly reduced, significantly reducing the subsequent disposal difficulty and cost, and secondly, the battery-grade lithium carbonate obtained can be used to prepare lithium batteries again, realizing efficient recovery and extraction of lithium from waste positive electrode materials;

[0030] Compared with the ordinary feeding mode, the vertical overturning can increase the contact area of the leaching solution and the positive electrode powder particles, accelerate the dissolution reaction of lithium in the positive electrode material lattice, and effectively improve the lithium leaching rate. BRIEF DESCRIPTION OF DRAWINGS

[0031] 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.

[0032] Figure 1 The optimal structural schematic diagram provided for this invention;

[0033] Figure 2 for Figure 1 The diagram shows a cross-sectional view of the leaching tank and its top cover.

[0034] Figure 3 for Figure 2 The enlarged structural diagram at point A is shown below;

[0035] Figure 4 for Figure 2 The diagram shown is a top-down view of the structure.

[0036] Figure 5 Detailed structural diagrams of the drive mechanism and the feeding mechanism provided by the present invention;

[0037] Figure 6 for Figure 5 The diagram shows a side view of the structure.

[0038] Figure 7 for Figure 5 The diagram shows the rotating working state of the drive mechanism.

[0039] Figure 8 for Figure 7 The enlarged structural diagram at point B is shown below;

[0040] Figure 9 A schematic diagram illustrating the working state of the material feeding mechanism driven by the rotating drive mechanism provided by the present invention.

[0041] Figure 10 A detailed structural diagram of the auxiliary mechanism provided by the present invention;

[0042] Figure 11 for Figure 10 The diagram shows the working state of the auxiliary mechanism driven by the rotating stirring rod.

[0043] Explanation of icon numbers:

[0044] 1. Base;

[0045] 2. Heating base; 3. Leaching tank; 4. Top cover;

[0046] 5. Mounting bracket;

[0047] 6, drive mechanism; 61, motor; 62, drive rod; 63, drive gear; 64, positioning plate; 65, driven gear; 66, eccentric plate; 67, guide wheel;

[0048] 7, blanking mechanism; 71, mounting plate; 72, spring tube; 73, side plate; 74, rotating shaft; 75, reciprocating groove plate; 76, turnover frame; 77, first gear; 78, mounting rod; 79, second gear; 710, spray pipe;

[0049] 8, auxiliary mechanism; 81, fixed ring; 82, protruding plate; 83, key rod; 84, bottom plate; 85, sliding plate; 86, return spring; 87, inclined plate; 88, roller;

[0050] 9, feed pipe; 10, liquid supply pipe; 11, stirring rod. DETAILED DESCRIPTION

[0051] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0052] The present application provides a kind of equipment for extracting lithium from solid waste and its lithium extraction process.

[0053] First embodiment:

[0054] Please refer to Figures 1 to 8 A waste lithium iron phosphate battery leaching device, comprising a base 1, a heating seat 2, a drive mechanism 6 and a blanking mechanism 7;

[0055] The heating seat 2 is located on the upper surface of the base 1, the heating seat 2 is internally provided with a leaching tank 3, the leaching tank 3 is provided with a feed pipe 9 and a liquid supply pipe 10 on both sides respectively, the leaching tank 3 is provided with a top cover 4 on the top, and the top cover 4 is provided with a mounting bracket 5 on the top through bolts;

[0056] The drive mechanism 6 comprises a motor 61 mounted on the upper surface of the mounting bracket 5, the output shaft key groove of the motor 61 is connected with a drive rod 62, the bottom end key groove of the drive rod 62 is connected with a drive gear 63, a positioning plate 64 is fixedly arranged on the upper surface of the top cover 4 and located on one side of the drive gear 63, a driven gear 65 is rotatably connected in the positioning plate 64, an eccentric plate 66 is connected with the key groove at the shaft center of the driven gear 65, and a guide wheel 67 is rotatably connected with the outer wall of the eccentric plate 66;

[0057] The feeding mechanism 7 includes a mounting plate 71 fixed to the bottom of the mounting frame 5. A rotating shaft 74 is rotatably connected inside the mounting plate 71. A tilting frame 76 is bolted to the outer wall of the rotating shaft 74 and located on one side of the mounting plate 71. A mounting rod 78 is rotatably connected inside the tilting frame 76. A spray pipe 710 is installed on the outer wall of the mounting rod 78. A reciprocating groove plate 75 is fixed at one end of the rotating shaft 74 and located on the opposite side of the positioning plate 64 and the mounting plate 71. A spring tube 72 is sealed at the outlet end of the liquid supply pipe 10. A stirring rod 11 is keyway connected inside the leaching tank 3 and located at the axis of the drive gear 63.

[0058] The drive gear 63 is rotatably connected to the top cover 4 at the center via a bearing, and the top end of the stirring rod 11 is rotatably connected to the top cover 4 at the center.

[0059] The driving gear 63 and the driven gear 65 mesh with each other, and the outer wall of the guide wheel 67 and the inner wall of the reciprocating groove plate 75 are in contact with each other.

[0060] The outlet end of the spring tube 72 and the inlet end of the nozzle 710 are sealed together, with the outlet end of the nozzle 710 directly above the stirring rod 11.

[0061] Please see Figures 2 to 4 During the leaching process, the calcined positive electrode powder obtained from the waste batteries needs to be fed into the leaching tank 3 through the feed pipe 9, while the liquid supply pipe 10 mainly transports the mixed leaching solution of ammonium sulfate and disodium ethylenediaminetetraacetate to the leaching tank 3.

[0062] Please see Figures 5 to 8 During leaching, the user starts the motor 61, controls the drive rod 62 to control the drive gear 63 to rotate. When the drive gear 63 rotates, it meshes with the driven gear 65 to rotate. The rotation of the driven gear 65 drives the eccentric plate 66 to rotate eccentrically on the positioning plate 64. When the eccentric plate 66 rotates, it drives the guide wheel 67 to be forcefully controlled to reciprocate the tank plate 75. Through the continuous eccentric rotation of the guide wheel 67, the reciprocating tank plate 75 is adaptively moved within the reciprocating tank plate 75, thereby controlling the bottom control shaft 74 of the reciprocating tank plate 75 to reciprocate and rotate back and forth in the vertical direction about the positioning plate 64. During the rotation, the rotating frame 76 and the mounting rod 78 are simultaneously driven to reciprocate and rotate, ultimately realizing that the nozzle 710 reciprocates and rotates along the vertical direction to spray the mixed leachate into the leaching tank 3.

[0063] Understandably: the positioning plate 64 positions the eccentric plate 66 and the driven gear 65 on the top cover 4, thereby ensuring that the driven gear 65 and the eccentric plate 66 can rotate stably;

[0064] Secondly, motor 61 can be a three-phase asynchronous motor, and the control drive rod 62 can achieve forward and reverse rotation.

[0065] This embodiment:

[0066] The jet stream of the vertically flipping nozzle 710 has high kinetic energy, which can directly impact the positive electrode powder bed in the leaching tank 3, breaking the powder agglomeration. At the same time, the flipping design can evenly spray the leaching solution onto the positive electrode powder. Compared with the ordinary feeding method, the vertical flipping can increase the contact area between the leaching solution and the positive electrode powder particles, accelerate the lithium dissolution reaction in the positive electrode material lattice, and effectively improve the lithium leaching rate.

[0067] Secondly, lithium is extracted from the cathode powder obtained from solid waste batteries, thereby reducing and rendering harmless hazardous solid waste and reducing environmental disposal pressure. Through the leaching lithium extraction process, lithium in the cathode powder is recovered, the volume of the remaining leaching residue is reduced, and the heavy metal content in the residue is significantly reduced, significantly reducing the difficulty and cost of subsequent disposal. Furthermore, the battery-grade lithium carbonate obtained can be used to re-prepare lithium batteries.

[0068] Second embodiment:

[0069] Please refer to 7 to Figure 9 The mounting plate 71 has a side plate 73 bolted to its outer wall. A first gear 77 is fixed to the outer wall of the side plate 73. A second gear 79 is connected to the top of the mounting rod 78 and inside the flipping frame 76 via a keyway.

[0070] The first gear 77 and the second gear 79 mesh with each other, and the rotating shaft 74 passes through the interior of the side plate 73 and the axis of the first gear 77, and the rotating shaft 74 does not contact the side plate 73 and the first gear 77.

[0071] Please see Figures 7 to 9 In the first embodiment, the rotating shaft 74 can drive the tilting frame 76 and the mounting rod 78 to reciprocate. Then, when the tilting frame 76 reciprocates, the mounting rod 78 and the second gear 79 inside the reciprocating transmission reciprocate along the axis of the rotating shaft 74. Therefore, the second gear 79 reciprocates about the first gear 77 during the tilting process. Since the first gear 77 is in a fixed state and the second gear 79 is in a rotating state, the second gear 79 can synchronously drive the mounting rod 78 to form a rotational motion along the tooth surface of the first gear 77 under the influence of the reciprocating motion, thereby controlling the rotational motion of the nozzle 710.

[0072] Understandably, since the nozzle 710 and the liquid supply pipe 10 are connected by a spring tube 72, the spring tube 72 will be pulled to extend when the nozzle 710 is flipped or rotated, and the spring tube 72 will automatically return to its original position when it is reset. Therefore, there will be no interference from the movement.

[0073] Secondly, the first gear 77 and the side plate 73 are fixedly installed, so they will not interfere with the rotation of the shaft 74 in the rotating state.

[0074] This embodiment:

[0075] During the process of controlling the rotation of the nozzle 710 by the flipping frame 76, the nozzle 710 rotates simultaneously, achieving no dead corner coverage inside the leaching tank 3 and eliminating local dry areas and concentration gradients. However, if the nozzle 710 is rotated as a whole, the spray direction of the nozzle 710 is relatively fixed, which can easily form dry areas not covered by the leaching liquid in the corners and powder accumulation areas inside the tank. This results in the cathode powder in these areas not being able to react fully, and the lithium leaching rate has local shortcomings.

[0076] The rotation and flipping of the nozzle 710 form a dual motion coupling. The rotation of the nozzle 710 allows the leachate to be sprayed in a spiral or fan shape to various areas inside the tank. Combined with the vertical flipping of the nozzle 710, it achieves three-dimensional enveloping spraying of the material inside the tank, completely eliminating dry areas. Secondly, the rotational spraying can quickly disperse local high-concentration or low-concentration liquid phase areas, maintaining the ion concentration and pH value of the leaching system in various parts of the tank in a consistent manner, avoiding the inhibition of lithium dissolution or the occurrence of impurity co-precipitation due to local concentration imbalance.

[0077] The leaching liquid jet from the rotating nozzle 710 has radial impact force, which can directly impact the agglomerated particles of the cathode powder, especially the loose and porous powder after calcination, breaking them down into smaller particles, exposing more lithium reaction sites, accelerating the dissolution of lithium from the crystal lattice, and the turbulent flow field formed by the rotating spray can produce a continuous shearing effect on the particle surface, reducing the boundary layer thickness, allowing for faster contact with impurity metal ions on the particle surface, and improving chelation efficiency.

[0078] Third embodiment:

[0079] Please see Figure 10 and Figure 11 It also includes auxiliary mechanisms 8;

[0080] The auxiliary mechanism 8 includes a fixing ring 81 fixed to the inner wall of the leaching tank 3. Two protruding plates 82 are installed on the top of the fixing ring 81. A key rod 83 is fixed to the bottom end of the stirring rod 11. A base plate 84 is fixed to the bottom end of the key rod 83. A sliding plate 85 is slidably connected to the outer wall of the key rod 83 and above the base plate 84. Four inclined plates 87 and two rollers 88 are fixedly installed on the outer wall of the sliding plate 85. A return spring 86 is sleeved on the outer wall of the key rod 83.

[0081] The two rollers 88 are in contact with the upper surface of the fixed ring 81, and the upper and lower ends of the return spring 86 are fixedly connected to the slide plate 85 and the base plate 84.

[0082] Please see Figure 10 and Figure 11In the operation of the first and second embodiments, the stirring rod 11 is driven by the drive gear 63 to rotate and stir the positive electrode powder and leaching liquid in the leaching tank 3. Therefore, it can drive the key rod 83, the slide plate 85, the inclined plate 87 and the roller 88 to rotate. When the roller 88 rotates on the upper surface of the fixed ring 81, the inclined plate 87 is in a horizontal position and does not move. The sinking positive electrode powder will fall into the inclined surface of the inclined plate 87. The inclined plate rotates to generate an oblique motion and pushes the positive electrode powder upward.

[0083] As the roller 88 continues to rotate to the position of the convex plate 82, the roller 88 rises. When it rises, it drives the slide plate 85 to control the inclined plate 87 to move upward. When it moves upward, it forms a secondary upward thrust that disturbs the overall flow field inside the leaching tank 3.

[0084] This embodiment:

[0085] The stratification problem of insufficient powder suspension at the top and bottom of the leaching tank is addressed by the large positive electrode powder particles settling under gravity, forming a static powder layer at the bottom of the tank, which makes it difficult for the leachate to penetrate, resulting in a low local lithium leaching rate. Meanwhile, the powder at the top is excessively washed away by the leachate, leading to a rapid decrease in the concentration of chelating agent. By using equidistant inclined plates 87 to form an angle with the horizontal plane, the rotation generates a directional thrust on the powder at the corresponding height, pushing the large powder particles deposited at the bottom of the tank upward, breaking the gravity settling trend, and avoiding the formation of local dead zones.

[0086] Secondly, when the roller 88 rotates to the position of the convex plate 82, it can control the inclined plate 87 to move mechanically upward. The thrust of the inclined plate 87 forms a superposition effect, which drives the powder in the tank to form an overall circulating flow field from bottom to top, so that the coarse and fine particles are evenly dispersed in the leachate.

[0087] The inclined plate 87 propels the powder from bottom to top in two stages, while the leaching liquid sprayed by the rotating nozzle 710 diffuses in a spiral shape from top to bottom. The two form a counter-current contact mode. This convection method greatly increases the contact frequency and contact area between the solid and liquid phases. Compared with unidirectional flow mixing, it increases the number of effective collisions between the positive electrode powder particles and the leaching liquid.

[0088] The lithium extraction process using solid waste leaching includes the following steps:

[0089] S1: After dismantling the waste battery, the positive electrode sheet is crushed, screened and magnetically separated to remove iron impurities, and then roasted at 500℃ for 2 hours to remove the binder.

[0090] S2: Mix the positive electrode powder and the reducing agent, which can be ascorbic acid or glucose, at a mass ratio of 1:0.3, heat to 300℃ under nitrogen protection, and keep warm for 1 hour;

[0091] Chemical reaction: 2LiCoO2 + C6H8O6 → Li2O + 2CoO + H2O + C6H6O6

[0092] S3: Prepare a mixed leaching solution of 0.5 mol / L ammonium sulfate and 0.1 mol / L disodium ethylenediaminetetraacetate. The solution is leached at 80°C with stirring for 2 hours at a liquid-to-solid ratio of 10:1. The stirring leaching should be carried out in leaching tank 3. The mixed leaching solution of ammonium sulfate and disodium ethylenediaminetetraacetate is pumped into the spray nozzle 710 in the feeding mechanism 7 through the liquid supply pipe 10 and sprayed into leaching tank 3 to mix with the positive electrode powder for leaching.

[0093] Chemical reaction: Li₂O + (NH₄)₂SO₄ → 2Li + +SO4 2− +2NH3↑+H2O

[0094] CoO+EDTA 4− →[Co(EDTA)] 2−

[0095] S4: Centrifuge the leachate, add sodium sulfide to the filtrate to a concentration of 0.05 mol / L to precipitate residual heavy metals;

[0096] S5: Add saturated sodium carbonate solution to the purified solution until pH=12, centrifuge and dry to obtain battery-grade lithium carbonate. Reaction: Co 2+ +S 2− →CoS↓.

[0097] This process:

[0098] Acid-free leaching system: By combining reduction pretreatment with the synergistic effect of ammonium salts, the use of strong acids is avoided;

[0099] Selective lithium extraction: EDTA preferentially complexes transition metals, resulting in lithium leaching selectivity >99%;

[0100] Closed-loop process: The leachate can be recycled, and the byproduct NH3 can be recovered to prepare ammonium salts.

[0101] Please refer to the reference again. Figures 1 to 11 The working principle of the lithium extraction equipment and process using solid waste leaching provided by this invention is as follows:

[0102] Step S1: The calcined positive electrode powder obtained from the waste batteries is fed into the leaching tank 3 through the feed pipe 9, while the liquid supply pipe 10 mainly transports the mixed leaching solution of ammonium sulfate and disodium ethylenediaminetetraacetate to the leaching tank 3.

[0103] Step S2: Start the motor 61 to control the drive rod 62 to control the drive gear 63 to rotate. When the drive gear 63 rotates, it meshes with the driven gear 65 to rotate. The driven gear 65 rotates and drives the eccentric plate 66 to rotate eccentrically on the positioning plate 64. When the eccentric plate 66 rotates, it drives the guide wheel 67 to be forcefully controlled to control the reciprocating tank plate 75. Through the continuous eccentric rotation of the guide wheel 67, the reciprocating tank plate 75 is adaptively moved within the reciprocating tank plate 75, thereby controlling the bottom control shaft 74 of the reciprocating tank plate 75 to reciprocate back and forth in the vertical direction about the positioning plate 64. During the flipping process, the flipping frame 76 and the mounting rod 78 are simultaneously driven to reciprocate back and forth, and finally the nozzle 710 is flipped back and forth in the vertical direction to spray the mixed leaching liquid into the leaching tank 3. The stirring rod 11 rotates to mix and stir the positive electrode powder and the leaching liquid to leach and extract lithium.

[0104] Step S3: The stirring rod 11 is driven by the drive gear 63 to rotate and stir the positive electrode powder and leaching liquid in the leaching tank 3. Therefore, it can drive the key rod 83, slide plate 85, inclined plate 87 and roller 88 to rotate. When the roller 88 rotates on the upper surface of the fixed ring 81, the inclined plate 87 is in a horizontal position and does not move. The sinking positive electrode powder will fall into the inclined surface of the inclined plate 87. The inclined plate rotates to generate an oblique motion and pushes the positive electrode powder upward.

[0105] As the roller 88 continues to rotate to the position of the convex plate 82, the roller 88 rises. When it rises, it drives the slide plate 85 to control the inclined plate 87 to move upward. When it moves upward, it forms a secondary upward thrust that disturbs the overall flow field inside the leaching tank 3.

[0106] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made under the concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A leaching device for waste lithium iron phosphate batteries, characterized in that, Includes a base, heating seat, drive mechanism, and feeding mechanism; The heating base is located on the upper surface of the base. A leaching tank is installed inside the heating base. A feed pipe and a liquid supply pipe are respectively installed through the two sides of the leaching tank. A top cover is installed on the top of the leaching tank. A mounting bracket is installed on the top of the top cover by bolts. The drive mechanism includes a motor mounted on the upper surface of the mounting bracket. The output shaft of the motor is connected to a drive rod via a keyway. The bottom end of the drive rod is connected to a drive gear via a keyway. A positioning plate is fixed on the upper surface of the top cover and located on one side of the drive gear. A driven gear is rotatably connected inside the positioning plate. An eccentric plate is connected to the shaft center of the driven gear via a keyway. A guide wheel is rotatably connected to the outer wall of the eccentric plate. The feeding mechanism includes a mounting plate fixed to the bottom of the mounting frame. A rotating shaft is rotatably connected inside the mounting plate. A tilting frame is bolted to the outer wall of the rotating shaft and located on one side of the mounting plate. A mounting rod is rotatably connected inside the tilting frame. A spray pipe is mounted on the outer wall of the mounting rod. A reciprocating groove plate is fixed at one end of the rotating shaft and located on the opposite side of the positioning plate and the mounting plate. A spring tube is sealed at the outlet end of the liquid supply pipe. A stirring rod is keyway connected inside the leaching tank and located at the center of the drive gear shaft.

2. The leaching device for waste lithium iron phosphate batteries according to claim 1, characterized in that, The drive gear is rotatably connected to the top cover shaft via a bearing, and the top of the stirring rod is rotatably connected to the top cover shaft.

3. The leaching device for waste lithium iron phosphate batteries according to claim 1, characterized in that, The driving gear and the driven gear mesh with each other, and the outer wall of the guide wheel and the inner wall of the reciprocating groove plate are in contact with each other.

4. The leaching device for waste lithium iron phosphate batteries according to claim 1, characterized in that, The outlet end of the spring tube and the inlet end of the nozzle are sealed together, with the outlet end of the nozzle facing directly above the stirring rod.

5. The leaching device for waste lithium iron phosphate batteries according to claim 1, characterized in that, The mounting plate has a side plate installed on its outer wall by bolts. A first gear is fixed on the outer wall of the side plate. A second gear is connected to the top of the mounting rod and inside the flipping frame via a keyway.

6. The leaching device for waste lithium iron phosphate batteries according to claim 5, characterized in that, The first gear and the second gear mesh with each other, and the shaft passes through the interior of the side plate and the axis of the first gear, but the shaft does not contact the side plate or the first gear.

7. The leaching device for waste lithium iron phosphate batteries according to claim 1, characterized in that, It also includes auxiliary mechanisms; The auxiliary mechanism includes a fixing ring fixed to the inner wall of the leaching tank. Two protruding plates are installed on the top of the fixing ring. A key rod is fixed to the bottom end of the stirring rod. A base plate is fixed to the bottom end of the key rod. A sliding plate is slidably connected to the outer wall of the key rod above the base plate. Four inclined plates and two rollers are fixedly installed on the outer wall of the sliding plate. A return spring is sleeved on the outer wall of the key rod.

8. The leaching device for waste lithium iron phosphate batteries according to claim 7, characterized in that, The two rollers are in contact with the upper surface of the fixed ring, and the upper and lower ends of the return spring are fixedly connected to the slide plate and the base plate.

9. A lithium extraction process using solid waste leaching, characterized in that, The lithium extraction process using solid waste leaching includes a waste lithium iron phosphate battery leaching device as described in any one of claims 1-8, comprising the following steps: S1: After dismantling the waste battery, the positive electrode sheet is crushed, screened and magnetically separated to remove iron impurities, and then roasted at 500℃ for 2 hours to remove the binder. S2: Mix the positive electrode powder and the reducing agent, which can be ascorbic acid or glucose, at a mass ratio of 1:0.3, heat to 300℃ under nitrogen protection, and keep warm for 1 hour; Chemical reaction: 2LiCoO2 + C6H8O6 → Li2O + 2CoO + H2O + C6H6O6 S3: Prepare a mixed leaching solution of 0.5 mol / L ammonium sulfate and 0.1 mol / L disodium ethylenediaminetetraacetate. At a liquid-solid ratio of 10:1, stir and leach for 2 hours at 80°C. The stirring leaching should be carried out in the leaching tank. The mixed leaching solution of ammonium sulfate and disodium ethylenediaminetetraacetate is pumped into the nozzle of the feeding mechanism through the liquid supply pipe and sprayed into the leaching tank to mix with the positive electrode powder for leaching. Chemical reaction: Li₂O + (NH₄)₂SO₄ → 2Li + +SO4 2− +2NH3↑+H2O CoO+EDTA 4− →[Co(EDTA)] 2− S4: Centrifuge the leachate, add sodium sulfide to the filtrate to a concentration of 0.05 mol / L to precipitate residual heavy metals; S5: Add saturated sodium carbonate solution to the purified solution until pH=12, centrifuge and dry to obtain battery-grade lithium carbonate. Reaction: Co 2 + +S 2− →CoS↓.

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