Equipment and method for selectively extracting lithium from ternary lithium battery black powder waste

Abstract

The invention relates to a device and method for selectively extracting lithium from ternary lithium battery black powder waste, the device comprises an acid-resistant ceramic lining reaction kettle, an acid storage tank and a leachate circulation tank, the leachate circulation tank is located below a discharge port of the acid-resistant ceramic lining reaction kettle, a pH meter is arranged on the side face of the acid-resistant ceramic lining reaction kettle, a reaction kettle cover is arranged at the upper end of the acid-resistant ceramic lining reaction kettle, and the acid storage tank is located below the discharge port of the acid-resistant ceramic lining reaction kettle. A motor is fixedly arranged at the upper end of the reaction kettle cover, a stirring paddle is fixed on the motor, the acid storage tank is connected with an acid adding port through a pipeline, and the leachate circulating tank is connected with a circulating liquid feeding port through a pipeline. The method comprises the following steps: mixing the ternary lithium battery black powder waste with graphite; roasting is performed; carrying out leaching reaction; circularly feeding and carrying out leaching reaction; and repeating to obtain a lithium-rich leaching solution. The method is low in process cost, high in safety and free of harmful gas, and selective lithium extraction from the ternary lithium battery black powder waste is efficiently achieved within a short time.

Description

Technical Field

[0001] This invention belongs to the field of waste lithium-ion battery resource recycling technology, specifically relating to a device and method for selectively extracting lithium from ternary lithium battery black powder waste. Background Technology

[0002] Ternary lithium-ion batteries are widely used in new energy vehicle power systems and aerospace due to their advantages such as high energy density, long cycle life, and high safety. However, the average service life of lithium-ion batteries is only 3-5 years, and with the rapid development of the new energy industry, a large-scale retirement wave is imminent. The nickel (6.8-12.1 wt.%), cobalt (5-15 wt.%), and lithium (2-7 wt.%) metal components in ternary lithium-ion battery black powder waste have significant recycling value.

[0003] Existing technologies for recycling ternary lithium battery black powder waste mainly include wet recycling and combined pyrometallurgical-hydrometallurgical processes. Traditional wet recycling processes typically use strong acids to leach out all metal elements, followed by pH-controlled precipitation, solvent extraction separation, and ion exchange to achieve tiered recovery of the metal elements. However, because lithium has similar physicochemical properties to transition metal ions, lithium is lost during co-precipitation or adsorption, resulting in a lithium recovery rate of only 60%–80%. Combined wet-pyrometallurgical processes have seen the emergence of methods for selective lithium extraction through high-temperature roasting pretreatment, such as adding aluminum powder, sulfates, or using hydrogen reduction. However, these methods have drawbacks such as potential safety risks, the generation of harmful gases, or high costs, limiting their industrial application.

[0004] To improve the recovery rate of lithium from ternary lithium battery black powder waste, reduce production costs, and achieve the goals of resource conservation and environmental protection, it is necessary to develop a method and equipment for rapid and preferential lithium extraction from ternary lithium battery black powder waste. Summary of the Invention

[0005] Purpose of the invention

[0006] To address the problems existing in the prior art, this invention provides an apparatus and method for selectively extracting lithium from ternary lithium battery black powder waste, aiming to achieve efficient and highly selective leaching of lithium, while suppressing the enrichment of nickel, cobalt, and manganese in the slag, simplifying the subsequent separation process, and reducing recycling costs.

[0007] Technical solution

[0008] A device for selectively extracting lithium from ternary lithium battery black powder waste includes an acid-resistant ceramic-lined reactor, an acid storage tank, and a leachate circulation tank. The acid-resistant ceramic-lined reactor has a discharge port at its lower end, and a replaceable cotton filter screen is installed at the discharge port. The leachate circulation tank is located below the discharge port. A pH meter is installed on the side of the acid-resistant ceramic-lined reactor, and the probe of the pH meter extends into the interior of the acid-resistant ceramic-lined reactor. A reactor cover is fixedly connected to the upper end of the acid-resistant ceramic-lined reactor. The reactor cover has a solid feed vent, a circulating liquid feed inlet, and an acid addition port. A motor is fixedly installed at the upper end of the reactor cover. The motor's rotating shaft passes through the reactor cover and extends into the interior of the acid-resistant ceramic-lined reactor, where a stirring paddle is fixed. The acid storage tank is connected to the acid addition port through a pipe, and the leachate circulation tank is connected to the circulating liquid feed inlet through a pipe.

[0009] Furthermore, the side wall of the acid-resistant ceramic-lined reactor is provided with an observation window, which includes a fixing steel sleeve, fixing screws and explosion-proof glass. The side wall of the acid-resistant ceramic-lined reactor has an opening, which is covered by explosion-proof glass. The periphery of the explosion-proof glass is covered with a fixing steel sleeve, which is fixedly connected to the side wall of the acid-resistant ceramic-lined reactor by fixing screws, thereby fixing the explosion-proof glass as well.

[0010] Furthermore, valves are provided at the circulating liquid inlet, acid addition port, and outlet.

[0011] Furthermore, the side of the discharge port is provided with an insertion port extending to the other side of the discharge port, and a cotton filter screen is inserted into the insertion port.

[0012] Furthermore, the cotton filter screen has a pore size of 300-350 mesh.

[0013] Furthermore, a first peristaltic pump is installed in the pipeline connecting the acid addition port and the acid storage tank, and a second peristaltic pump is installed in the pipeline connecting the circulating liquid inlet and the leachate circulation tank. The motor is powered by power supply a, the first peristaltic pump is powered by power supply b, and the second peristaltic pump is powered by power supply c.

[0014] Furthermore, the solid feed vent includes a base and a top cover, both of which are hollow structures. The top of the top cover has a through vent hole. The base is fixed to the reactor lid. The upper outer circumference of the base is threadedly connected to the lower inner circumference of the top cover. A spring is vertically connected to the top of the inside of the top cover. A piston is connected to the lower end of the spring. The inside of the base has a structure in which the inner diameter increases uniformly from bottom to top. The circumferential shape of the piston matches the internal structure of the base.

[0015] A method for extracting lithium using the equipment described above for selective lithium extraction from ternary lithium battery black powder waste includes the following steps:

[0016] Step 1: Mix the waste black powder from ternary lithium batteries with graphite, and then ball mill the mixture. The resulting powder is then passed through a 200-mesh sieve.

[0017] Step 2: Calcine the mixed powder in an inert atmosphere. After calcination, take it out and ball mill it. Pass the mixed powder through a 200-mesh sieve to collect the undersize powder. Then pass the mixed powder through a 250-mesh sieve to collect the topsize powder. Control the mixed powder to 200-250 mesh.

[0018] Step 3: Add the mixed powder obtained in Step 2 into the acid-resistant ceramic-lined reactor, inject sulfuric acid solution as the leachate for reaction, and after the reaction stops, open the valve of the discharge port and separate the leachate and leachate residue through a cotton filter screen.

[0019] Step 4: Inject the separated leachate into the leachate circulation tank, and after pressurization, re-enter the acid-resistant ceramic-lined reactor through the circulating liquid inlet. The sulfuric acid in the acid storage tank is pressurized and enters the acid-resistant ceramic-lined reactor through the acid inlet. Add the mixed powder obtained in step 2 through the solid feed vent.

[0020] Step 5: Repeat Step 4 2 to 4 times to obtain lithium-rich leachate.

[0021] Furthermore, in step 1, the amount of graphite added is 12-15 wt.% of the ternary lithium battery black powder waste; in step 2, the calcination temperature is 780-820℃, and the calcination time is 60-80 min; in step 3, the concentration of the injected sulfuric acid solution is 0.08-0.10 mol / L, and the solid-liquid ratio of the calcined powder to the sulfuric acid solution is 1:40-1:50 kg / L.

[0022] Furthermore, in step 3, after the calcined powder and sulfuric acid solution have been fed in, the motor is started, and the stirring paddle is rotated at a speed of 400-500 rpm. The leaching time is 40-60 minutes, and the reaction ends when the pH meter reading is 6-8. The outlet valve is then opened. In step 4, the feed flow rate of the separated leachate is 0.2-0.5 m³ / h. 3 The sulfuric acid feed flow rate is 0.02–0.05 m³ / h. 3 / h.

[0023] Advantages and effects

[0024] This invention relates to an apparatus and method for selectively extracting lithium from ternary lithium battery black powder waste. It innovatively uses graphite as a reducing agent to achieve the directional conversion of the lithium phase in the ternary lithium battery black powder. By adjusting the acidity of the leachate, and utilizing the difference in reaction rates between the converted lithium phase and the nickel-cobalt-manganese phase with low-concentration sulfuric acid, selective extraction of lithium from the ternary lithium battery black powder waste is achieved. Specifically, the graphite reacts with the cathode material in the waste, converting the lithium phase into Li₂O and Li₂CO₃, which react rapidly with sulfuric acid, while the nickel-cobalt-manganese phase is converted into lower-valence oxides (NiO, CoO, MnO) and metallic phases (Ni, Co) that react more slowly with sulfuric acid. During the acidity-controlled leaching process, the lithium phase in the waste rapidly reacts with the sulfuric acid in the leachate and dissolves in the leachate, rapidly consuming the sulfuric acid. The rapid approach of the pH of the leachate inhibits the leaching of the nickel-cobalt-manganese phase in the waste. Compared to traditional hydrometallurgical processes, this invention achieves efficient separation of lithium from nickel, cobalt, and manganese in ternary lithium battery black powder waste while reducing acid consumption in the leaching process, lowering recycling costs, and making the recycling process more environmentally friendly. Compared to some existing pyrometallurgical-hydrometallurgical combined processes, this invention uses graphite as an additive, resulting in lower process costs, higher safety, and no harmful gas generation. It efficiently achieves selective lithium extraction from ternary lithium battery black powder waste in a short time, with lithium leaching rates exceeding 95%, manganese leaching rates below 2.5%, and nickel and cobalt leaching rates both below 1%. Attached Figure Description

[0025] Figure 1 A schematic diagram of a device for selectively extracting lithium from ternary lithium battery black powder waste.

[0026] Figure 2 This is a schematic diagram of the observation window structure;

[0027] Figure 3 This is a schematic diagram of the solid feed vent.

[0028] Figure 4 This is a schematic diagram of the structure at the discharge port and the cotton filter screen.

[0029] Explanation of reference numerals in the attached drawings: 1. Acid-resistant ceramic-lined reactor; 2. Stirring paddle; 3. Motor; 4. Observation window; 5. Solid feed vent; 6. Circulating liquid feed; 7. Acid inlet; 8. Discharge outlet; 9. Cotton filter screen; 10. Bracket; 11. pH meter; 12. Valve; 13. Acid storage tank; 14. Flow meter; 15. First peristaltic pump; 16. Leachate circulation tank; 17. Motor bracket; 18. Reactor cover; 19. Power supply a; 20. Power supply b; 21. Power supply c; 22. Fixing steel sleeve; 23. Fixing screw; 24. Explosion-proof glass; 25. Base; 26. Top cover; 27. Spring; 28. Piston; 29. ​​Vent hole; 30. Second peristaltic pump. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail with reference to the accompanying drawings, embodiments, and comparative examples. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0031] like Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, an apparatus for selectively extracting lithium from ternary lithium battery black powder waste includes an acid-resistant ceramic-lined reactor 1, an acid storage tank 13, and a leachate circulation tank 16. The acid-resistant ceramic-lined reactor 1 is supported by a bracket 10. The interior of the acid-resistant ceramic-lined reactor 1 is lined with an acid-resistant ceramic to prevent corrosion of the reactor body by the leachate. The lower end of the acid-resistant ceramic-lined reactor 1 is provided with a discharge port 8. The side of the discharge port 8 is provided with an insertion port extending to the other side of the discharge port 8. A cotton filter screen 9 is inserted into the insertion port. The pore size of the cotton filter screen 9 is 300-350 mesh. When the pores of the cotton filter screen 9 are clogged, the valve of the discharge port 8 can be closed first, and then the old cotton filter screen 9 can be removed and replaced with a new cotton filter screen 9. The leachate circulation tank 16 is located below the discharge port 8. A pH meter 11 is installed on the side of the acid-resistant ceramic-lined reactor 1, with the probe of the pH meter 11 extending into the interior of the acid-resistant ceramic-lined reactor 1. The pH meter 11 is preferably an industrial pH meter with an accuracy of two decimal places. The reading of the pH meter 11 can be used to determine the reaction progress. After calcination, the lithium phase in the waste reacts with the sulfuric acid in the leachate, causing the pH of the leachate to rise. The upper end of the acid-resistant ceramic-lined reactor 1 is fixedly connected to the reactor lid 18, preferably by a clamp or by a threaded connection, for easy disassembly and cleaning of the interior. The reactor lid 18 is provided with a solid feed vent 5, a circulating liquid feed 6, and an acid addition port 7. The solid feed vent 5, circulating liquid feed 6, and acid addition port 7 are all provided with the following functions: There is a distance between the liquid inlet 6 and the acid inlet 7 to prevent the materials from mixing and reacting prematurely during the material addition process, which would affect the element separation effect. A motor 3 is fixedly installed on the upper end of the reactor cover 18. The motor 3 is supported and fixed on the reactor cover 18 by the motor bracket 17. The rotating shaft of the motor 3 passes through the reactor cover 18 and extends into the interior of the acid-resistant ceramic-lined reactor 1, where a stirring paddle 2 is fixed. The rotation of the stirring paddle 2 can prevent the solid powder from agglomerating during the leaching process, which would affect the element separation effect. The rotating shaft of the motor 3 and the surface of the stirring paddle 2 are coated with an acid-resistant corrosion-resistant coating. The acid storage tank 13 is equipped with a flow meter 14. The acid storage tank 13 is connected to the acid inlet 7 through a pipe. The leaching liquid circulation tank 16 is connected to the circulating liquid inlet 6 through a pipe. A first peristaltic pump 15 is installed in the pipeline connecting the acid inlet 7 and the acid storage tank 13, and a second peristaltic pump 30 is installed in the pipeline connecting the circulating liquid inlet 6 and the leachate circulation tank 16. The motor 3 is powered by power supply a19, the first peristaltic pump 15 is powered by power supply b20, and the second peristaltic pump 30 is powered by power supply c21. Valves 12 are installed in the circulating liquid inlet 6, the acid inlet 7, and the outlet 8. An observation window 4 is provided on the side wall of the acid-resistant ceramic-lined reactor 1. The observation window 4 includes a fixing steel sleeve 22, fixing screws 23, and explosion-proof glass 24. An opening is provided on the side wall of the acid-resistant ceramic-lined reactor 1, and the opening is covered by explosion-proof glass 24. The fixing steel sleeve 22 is covered around the explosion-proof glass 24. The fixing steel sleeve 22 is fixedly connected to the side wall of the acid-resistant ceramic-lined reactor 1 by fixing screws 23, thereby fixing the explosion-proof glass 24 as well.The observation window 4 is located on the side of the acid-resistant ceramic-lined reactor 1 for observation. This prevents the liquid level from becoming too high during leaching, which could cause the slurry to come into contact with the solid feed vent 5, the circulating liquid feed 6, and the acid addition port 7, resulting in blockage. It also allows observation of the stirring status of the stirring paddle 2. The solid feed vent 5 includes a base 25 and a top cover 26. Both the base 25 and the top cover 26 are hollow structures. The top of the top cover 26 has a through vent 29. The base 25 is threaded onto the reactor cover 18. The upper outer circumference of the base 25 is threadedly connected to the lower inner circumference of the top cover 26. A spring 27 is vertically connected to the top of the inside of the top cover 26. A piston 28 is connected to the lower end of the spring 27. The interior of the base 25 has a structure where the inner diameter increases uniformly from bottom to top. The circumferential shape of the piston 28 matches the internal structure of the base 25. By adjusting the screw depth of the top cover 26, the tension of the internal spring 27 can be adjusted, thereby regulating the pressure exerted by the piston 28 on the inside of the base 25. Since the acid-resistant ceramic-lined reactor 1 only has a solid feed vent 5 to vent air outwards during internal reactions, the screw depth of the top cover 26 of the solid feed vent 5 and the base 25 can control the reaction pressure inside the acid-resistant ceramic-lined reactor 1. When no reaction occurs inside the acid-resistant ceramic-lined reactor 1, and solid materials need to be added, the top cover 26 is unscrewed, and the top cover 26, along with the spring 27 and piston 28, is removed to the side. The solid materials can then be poured into the base 25, allowing them to enter the acid-resistant ceramic-lined reactor 1.

[0032] A method for extracting lithium using the equipment described above for selective lithium extraction from ternary lithium battery black powder waste includes the following steps:

[0033] Step 1: Mix the ternary lithium battery black powder waste with graphite. The amount of graphite added is 12-15 wt.% of the ternary lithium battery black powder waste. Use a ball mill to ball mill the mixture and pass the ball-milled powder through a 200-mesh sieve.

[0034] Step 2: The mixed powder is calcined in an inert atmosphere at a temperature of 780–820°C for 60–80 minutes. Under the action of graphite and high temperature, the layered structure of the ternary lithium battery black powder waste is destroyed, and the lithium phase in the waste is transformed into soluble Li₂O and Li₂CO₃. The nickel, cobalt, and manganese phases undergo a reduction reaction with graphite, changing from a high valence state to a low valence state, which is beneficial for subsequent recycling. After calcination, the powder is taken out and ball-milled. The mixed powder is passed through a 200-mesh sieve to collect the undersize material, and then through a 250-mesh sieve to collect the oversize material. The mixed powder is controlled at 200–250 mesh. The undersize material of the 250-mesh sieve is not used because its contact area with the leachate is relatively increased compared to the 200–250 mesh sieve. The reaction rate of the nickel, cobalt, and manganese phases in the waste with sulfuric acid in the leachate increases, consuming sulfuric acid in the leachate, resulting in an increase in the nickel, cobalt, and manganese leaching rate and a decrease in the selective lithium extraction effect. The reason why powder is not used for feeding through a 200-mesh sieve is that its particle size is too large, the contact area with the leachate is small, and the reaction rate is relatively slow compared to 200-250 mesh. The lithium phase in the waste cannot fully react with the sulfuric acid in the leachate, so rapid lithium extraction cannot be achieved. This is because lithium and nickel, cobalt, and manganese react with sulfuric acid in the leachate at the same time, but the reaction rates are different. The reaction rate of lithium is slower, the leaching time is increased, which leads to an increase in the reaction time of nickel, cobalt, and manganese with sulfuric acid, and the selective lithium extraction effect is reduced.

[0035] Step 3: Add the mixed powder obtained in Step 2 to the acid-resistant ceramic-lined reactor 1, and inject sulfuric acid solution as the leaching solution for the reaction. The concentration of the injected sulfuric acid solution is 0.08-0.10 mol / L, and the solid-liquid ratio of the calcined powder to the sulfuric acid solution is 1:40-1:50 kg / L. After the calcined powder and sulfuric acid solution are fed, start the motor 3 and rotate the stirring paddle 2. The speed of the stirring paddle 2 is 400-500 rpm, and the leaching time is 40-60 min. When the pH meter 11 reads 6-8, the reaction ends. After the reaction stops, open the valve 12 of the discharge port 8; separate the leaching solution and leaching residue through the cotton filter screen 9.

[0036] Step 4: The separated leachate is injected into the leachate circulation tank 16, and after pressurization, it re-enters the acid-resistant ceramic-lined reactor 1 through the circulating liquid inlet 6. Sulfuric acid in the acid storage tank 13 is pressurized and enters the acid-resistant ceramic-lined reactor 1 through the acid inlet 7. The mixed powder obtained in step 2 is added through the solid feed vent 5. The feed flow rate of the separated leachate is 0.2–0.5 m³ / h. 3 The sulfuric acid feed flow rate is 0.02–0.05 m³ / h. 3 / h; Step 5: Repeat "Step 4" 2 to 4 times to obtain lithium-rich leachate.

[0037] The present invention will be further illustrated below through specific experimental examples:

[0038] Example 1

[0039] Step 1: Grind the ternary lithium battery black powder waste with graphite using a ball mill for 40-60 minutes and mix them evenly. The size of the mixed powder should be controlled at 200-250 mesh.

[0040] Step 2: Calcine the mixed powder in a reducing atmosphere, and after calcination, take it out and grind it into powder with the powder size controlled at 200-250 mesh.

[0041] Step 3: Add the powder obtained in Step 2 into an acid-resistant ceramic-lined reactor, inject sulfuric acid solution as the leachate for reaction, and after the reaction stops, separate the leachate and leachate residue through a cotton filter screen.

[0042] Step 4: Inject the leachate obtained in Step 3 into the leachate circulation tank, and after being transferred by the peristaltic pump, it enters the acid-resistant ceramic-lined reactor, where it is mixed with the concentrated sulfuric acid injected through the acid addition port to obtain the leachate. Add the powder obtained in Step 2 to the solid feed vent port for reaction.

[0043] Step 5: Repeat step 4 2-4 times to obtain lithium-rich leachate.

[0044] In step 1, the amount of graphite added is 12 wt.% of the ternary lithium battery waste.

[0045] In step 2, the roasting temperature is 800℃ and the roasting time is 60min.

[0046] In step 3, the sulfuric acid concentration is 0.10 mol / L, the solid-liquid ratio of the calcined powder to the sulfuric acid solution is 1:50 kg / L, the stirring speed is 400-500 rpm, and the leaching time is 60 min.

[0047] In this embodiment, the leaching rates of lithium, nickel, cobalt, and manganese were 97.54%, 0.97%, 0.53%, and 2.03%, respectively.

[0048] Example 2

[0049] Step 1: Grind the ternary lithium battery black powder waste with graphite using a ball mill for 40-60 minutes and mix them evenly. The size of the mixed powder should be controlled at 200-250 mesh.

[0050] Step 2: Calcine the mixed powder in a reducing atmosphere, and after calcination, take it out and grind it into powder with the powder size controlled at 200-250 mesh.

[0051] Step 3: Add the powder obtained in Step 2 into an acid-resistant ceramic-lined reactor, inject sulfuric acid solution as the leachate for reaction, and after the reaction stops, separate the leachate and leachate residue through a cotton filter screen.

[0052] Step 4: Inject the leachate obtained in Step 3 into the leachate circulation tank, and after being transferred by the peristaltic pump, it enters the acid-resistant ceramic-lined reactor, where it is mixed with the concentrated sulfuric acid injected through the acid addition port to obtain the leachate. Add the powder obtained in Step 2 to the solid feed vent port for reaction.

[0053] Step 5: Repeat step 4 2-4 times to obtain lithium-rich leachate.

[0054] In step 1, the amount of graphite added is 15 wt.% of the ternary lithium battery waste.

[0055] In step 2, the roasting temperature is 820℃ and the roasting time is 60min.

[0056] In step 3, the sulfuric acid concentration is 0.08 mol / L, the solid-liquid ratio of the calcined powder to the sulfuric acid solution is 1:50 kg / L, the stirring speed is 400-500 rpm, and the leaching time is 40 min.

[0057] In this embodiment, the leaching rates of lithium, nickel, cobalt, and manganese were 96.14%, 0.85%, 0.47%, and 1.54%, respectively.

[0058] Example 3

[0059] Step 1: Grind the ternary lithium battery black powder waste with graphite using a ball mill for 40-60 minutes and mix them evenly. The size of the mixed powder should be controlled at 200-250 mesh.

[0060] Step 2: Calcine the mixed powder in a reducing atmosphere, and after calcination, take it out and grind it into powder with the powder size controlled at 200-250 mesh.

[0061] Step 3: Add the powder obtained in Step 2 into an acid-resistant ceramic-lined reactor, inject sulfuric acid solution as the leachate for reaction, and after the reaction stops, separate the leachate and leachate residue through a cotton filter screen.

[0062] Step 4: Inject the leachate obtained in Step 3 into the leachate circulation tank, and after being transferred by the peristaltic pump, it enters the acid-resistant ceramic-lined reactor, where it is mixed with the concentrated sulfuric acid injected through the acid addition port to obtain the leachate. Add the powder obtained in Step 2 to the solid feed vent port for reaction.

[0063] Step 5: Repeat step 4 2-4 times to obtain lithium-rich leachate.

[0064] In step 1, the amount of graphite added is 12 wt.% of the ternary lithium battery waste.

[0065] In step 2, the roasting temperature is 780℃ and the roasting time is 80min.

[0066] In step 3, the sulfuric acid concentration is 0.10 mol / L, the solid-liquid ratio of the calcined powder to the sulfuric acid solution is 1:40 kg / L, the stirring speed is 400-500 rpm, and the leaching time is 60 min.

[0067] In this embodiment, the leaching rates of lithium, nickel, cobalt, and manganese were 97.03%, 0.92%, 0.51%, and 1.89%, respectively.

[0068] Comparative Example 1

[0069] Step 1: Grind the ternary lithium battery black powder waste with graphite using a ball mill for 40-60 minutes and mix them evenly. The size of the mixed powder should be controlled at 200-250 mesh.

[0070] Step 2: Calcine the mixed powder in a reducing atmosphere, and after calcination, take it out and grind it into powder with the powder size controlled at 200-250 mesh.

[0071] Step 3: Add the powder obtained in Step 2 into an acid-resistant ceramic-lined reactor, inject sulfuric acid solution as the leachate for reaction, and after the reaction stops, separate the leachate and leachate residue through a cotton filter screen.

[0072] Step 4: Inject the leachate obtained in Step 3 into the leachate circulation tank, and after being transferred by the peristaltic pump, it enters the acid-resistant ceramic-lined reactor, where it is mixed with the concentrated sulfuric acid injected through the acid addition port to obtain the leachate. Add the powder obtained in Step 2 to the solid feed vent port for reaction.

[0073] Step 5: Repeat step 4 2-4 times to obtain lithium-rich leachate.

[0074] In step 1, the amount of graphite added is 6 wt.% of the ternary lithium battery waste.

[0075] In step 2, the roasting temperature is 800℃ and the roasting time is 60min.

[0076] In step 3, the sulfuric acid concentration is 0.10 mol / L, the solid-liquid ratio of the calcined powder to the sulfuric acid solution is 1:50 kg / L, the stirring speed is 400-500 rpm, and the leaching time is 60 min.

[0077] In this embodiment, the leaching rates of lithium, nickel, cobalt, and manganese were 74.61%, 4.12%, 2.18%, and 8.45%, respectively.

[0078] Comparative Example 2

[0079] Step 1: Grind the ternary lithium battery black powder waste with graphite using a ball mill for 40-60 minutes and mix them evenly. The size of the mixed powder should be controlled at 200-250 mesh.

[0080] Step 2: Calcine the mixed powder in a reducing atmosphere, and after calcination, take it out and grind it into powder with the powder size controlled at 200-250 mesh.

[0081] Step 3: Add the powder obtained in Step 2 into an acid-resistant ceramic-lined reactor, inject sulfuric acid solution as the leachate for reaction, and after the reaction stops, separate the leachate and leachate residue through a cotton filter screen.

[0082] Step 4: Inject the leachate obtained in Step 3 into the leachate circulation tank, and after being transferred by the peristaltic pump, it enters the acid-resistant ceramic-lined reactor, where it is mixed with the concentrated sulfuric acid injected through the acid addition port to obtain the leachate. Add the powder obtained in Step 2 to the solid feed vent port for reaction.

[0083] Step 5: Repeat step 4 2-4 times to obtain lithium-rich leachate.

[0084] In step 1, the amount of graphite added is 9 wt.% of the ternary lithium battery waste.

[0085] In step 2, the roasting temperature is 800℃ and the roasting time is 60min.

[0086] In step 3, the sulfuric acid concentration is 0.10 mol / L, the solid-liquid ratio of the calcined powder to the sulfuric acid solution is 1:50 kg / L, the stirring speed is 400-500 rpm, and the leaching time is 60 min.

[0087] In this embodiment, the leaching rates of lithium, nickel, cobalt, and manganese were 90.66%, 1.43%, 1.04%, and 3.43%, respectively.

[0088] Comparative Example 3

[0089] Step 1: Grind the ternary lithium battery black powder waste with graphite using a ball mill for 40-60 minutes and mix them evenly. The size of the mixed powder should be controlled at 200-250 mesh.

[0090] Step 2: Calcine the mixed powder in a reducing atmosphere, and after calcination, take it out and grind it into powder with the powder size controlled at 200-250 mesh.

[0091] Step 3: Add the powder obtained in Step 2 into an acid-resistant ceramic-lined reactor, inject sulfuric acid solution as the leachate for reaction, and after the reaction stops, separate the leachate and leachate residue through a cotton filter screen.

[0092] Step 4: Inject the leachate obtained in Step 3 into the leachate circulation tank, and after being transferred by the peristaltic pump, it enters the acid-resistant ceramic-lined reactor, where it is mixed with the concentrated sulfuric acid injected through the acid addition port to obtain the leachate. Add the powder obtained in Step 2 to the solid feed vent port for reaction.

[0093] Step 5: Repeat step 4 2-4 times to obtain lithium-rich leachate.

[0094] In step 1, the amount of graphite added is 12 wt.% of the ternary lithium battery waste.

[0095] In step 2, the roasting temperature is 600℃ and the roasting time is 60min.

[0096] In step 3, the sulfuric acid concentration is 0.10 mol / L, the solid-liquid ratio of the calcined powder to the sulfuric acid solution is 1:50 kg / L, the stirring speed is 400-500 rpm, and the leaching time is 60 min.

[0097] In this embodiment, the leaching rates of lithium, nickel, cobalt, and manganese were 75.41%, 3.24%, 1.94%, and 7.42%, respectively.

[0098] Comparative Example 4

[0099] Step 1: Grind the ternary lithium battery black powder waste with graphite using a ball mill for 40-60 minutes and mix them evenly. The size of the mixed powder should be controlled at 200-250 mesh.

[0100] Step 2: Calcine the mixed powder in a reducing atmosphere, and after calcination, take it out and grind it into powder with the powder size controlled at 200-250 mesh.

[0101] Step 3: Add the powder obtained in Step 2 into an acid-resistant ceramic-lined reactor, inject sulfuric acid solution as the leachate for reaction, and after the reaction stops, separate the leachate and leachate residue through a cotton filter screen.

[0102] Step 4: Inject the leachate obtained in Step 3 into the leachate circulation tank, and after being transferred by the peristaltic pump, it enters the acid-resistant ceramic-lined reactor, where it is mixed with the concentrated sulfuric acid injected through the acid addition port to obtain the leachate. Add the powder obtained in Step 2 to the solid feed vent port for reaction.

[0103] Step 5: Repeat step 4 2-4 times to obtain lithium-rich leachate.

[0104] In step 1, the amount of graphite added is 12 wt.% of the ternary lithium battery waste.

[0105] In step 2, the roasting temperature is 700℃ and the roasting time is 60min.

[0106] In step 3, the sulfuric acid concentration is 0.10 mol / L, the solid-liquid ratio of the calcined powder to the sulfuric acid solution is 1:50 kg / L, the stirring speed is 400-500 rpm, and the leaching time is 60 min.

[0107] In this embodiment, the leaching rates of lithium, nickel, cobalt, and manganese were 87.92%, 1.97%, 1.03%, and 5.34%, respectively.

[0108] Comparative Example 5

[0109] Step 1: Grind the ternary lithium battery black powder waste with graphite using a ball mill for 40-60 minutes and mix them evenly. The size of the mixed powder should be controlled at 200-250 mesh.

[0110] Step 2: Calcine the mixed powder in a reducing atmosphere, and after calcination, take it out and grind it into powder with the powder size controlled at 200-250 mesh.

[0111] Step 3: Add the powder obtained in Step 2 into an acid-resistant ceramic-lined reactor, inject sulfuric acid solution as the leachate for reaction, and after the reaction stops, separate the leachate and leachate residue through a cotton filter screen.

[0112] Step 4: Inject the leachate obtained in Step 3 into the leachate circulation tank, and after being transferred by the peristaltic pump, it enters the acid-resistant ceramic-lined reactor, where it is mixed with the concentrated sulfuric acid injected through the acid addition port to obtain the leachate. Add the powder obtained in Step 2 to the solid feed vent port for reaction.

[0113] Step 5: Repeat step 4 2-4 times to obtain lithium-rich leachate.

[0114] In step 1, the amount of graphite added is 12 wt.% of the ternary lithium battery waste.

[0115] In step 2, the roasting temperature is 800℃ and the roasting time is 20min.

[0116] In step 3, the sulfuric acid concentration is 0.10 mol / L, the solid-liquid ratio of the calcined powder to the sulfuric acid solution is 1:50 kg / L, the stirring speed is 400-500 rpm, and the leaching time is 60 min.

[0117] In this embodiment, the leaching rates of lithium, nickel, cobalt, and manganese were 94.66%, 1.55%, 0.86%, and 3.22%, respectively.

[0118] Comparative Example 6

[0119] Step 1: Grind the ternary lithium battery black powder waste with graphite using a ball mill for 40-60 minutes and mix them evenly. The size of the mixed powder should be controlled at 200-250 mesh.

[0120] Step 2: Calcine the mixed powder in a reducing atmosphere, and after calcination, take it out and grind it into powder with the powder size controlled at 200-250 mesh.

[0121] Step 3: Add the powder obtained in Step 2 into an acid-resistant ceramic-lined reactor, inject sulfuric acid solution as the leachate for reaction, and after the reaction stops, separate the leachate and leachate residue through a cotton filter screen.

[0122] Step 4: Inject the leachate obtained in Step 3 into the leachate circulation tank, and after being transferred by the peristaltic pump, it enters the acid-resistant ceramic-lined reactor, where it is mixed with the concentrated sulfuric acid injected through the acid addition port to obtain the leachate. Add the powder obtained in Step 2 to the solid feed vent port for reaction.

[0123] Step 5: Repeat step 4 2-4 times to obtain lithium-rich leachate.

[0124] In step 1, the amount of graphite added is 12 wt.% of the ternary lithium battery waste.

[0125] In step 2, the roasting temperature is 800℃ and the roasting time is 60min.

[0126] In step 3, the sulfuric acid concentration is 0.05 mol / L, the solid-liquid ratio of the calcined powder to the sulfuric acid solution is 1:50 kg / L, the stirring speed is 400-500 rpm, and the leaching time is 60 min.

[0127] In this embodiment, the leaching rates of lithium, nickel, cobalt, and manganese were 74.66%, 0.55%, 0.26%, and 0.89%, respectively.

[0128] Comparative Example 7

[0129] Step 1: Grind the ternary lithium battery black powder waste with graphite using a ball mill for 40-60 minutes and mix them evenly. The size of the mixed powder should be controlled at 200-250 mesh.

[0130] Step 2: Calcine the mixed powder in a reducing atmosphere, and after calcination, take it out and grind it into powder with the powder size controlled at 200-250 mesh.

[0131] Step 3: Add the powder obtained in Step 2 into an acid-resistant ceramic-lined reactor, inject sulfuric acid solution as the leachate for reaction, and after the reaction stops, separate the leachate and leachate residue through a cotton filter screen.

[0132] Step 4: Inject the leachate obtained in Step 3 into the leachate circulation tank, and after being transferred by the peristaltic pump, it enters the acid-resistant ceramic-lined reactor, where it is mixed with the concentrated sulfuric acid injected through the acid addition port to obtain the leachate. Add the powder obtained in Step 2 to the solid feed vent port for reaction.

[0133] Step 5: Repeat step 4 2-4 times to obtain lithium-rich leachate.

[0134] In step 1, the amount of graphite added is 12 wt.% of the ternary lithium battery waste.

[0135] In step 2, the roasting temperature is 800℃ and the roasting time is 60min.

[0136] In step 3, the sulfuric acid concentration is 0.20 mol / L, the solid-liquid ratio of the calcined powder to the sulfuric acid solution is 1:50 kg / L, the stirring speed is 400-500 rpm, and the leaching time is 60 min.

[0137] In this embodiment, the leaching rates of lithium, nickel, cobalt, and manganese were 99.64%, 6.94%, 5.53%, and 15.14%, respectively.

[0138] Comparative Example 8

[0139] Step 1: Grind the ternary lithium battery black powder waste with graphite using a ball mill for 40-60 minutes and mix them evenly. The size of the mixed powder should be controlled at 200-250 mesh.

[0140] Step 2: Calcine the mixed powder in a reducing atmosphere, and after calcination, take it out and grind it into powder with the powder size controlled at 200-250 mesh.

[0141] Step 3: Add the powder obtained in Step 2 into an acid-resistant ceramic-lined reactor, inject sulfuric acid solution as the leachate for reaction, and after the reaction stops, separate the leachate and leachate residue through a cotton filter screen.

[0142] Step 4: Inject the leachate obtained in Step 3 into the leachate circulation tank, and after being transferred by the peristaltic pump, it enters the acid-resistant ceramic-lined reactor, where it is mixed with the concentrated sulfuric acid injected through the acid addition port to obtain the leachate. Add the powder obtained in Step 2 to the solid feed vent port for reaction.

[0143] Step 5: Repeat step 4 2-4 times to obtain lithium-rich leachate.

[0144] In step 1, the amount of graphite added is 12 wt.% of the ternary lithium battery waste.

[0145] In step 2, the roasting temperature is 800℃ and the roasting time is 60min.

[0146] In step 3, the sulfuric acid concentration is 0.10 mol / L, the solid-liquid ratio of the calcined powder to the sulfuric acid solution is 1:25 kg / L, the stirring speed is 400-500 rpm, and the leaching time is 60 min.

[0147] In this embodiment, the leaching rates of lithium, nickel, cobalt, and manganese were 73.74%, 0.42%, 0.21%, and 0.78%, respectively.

[0148] Comparative Example 9

[0149] Step 1: Grind the ternary lithium battery black powder waste with graphite using a ball mill for 40-60 minutes and mix them evenly. The size of the mixed powder should be controlled at 200-250 mesh.

[0150] Step 2: Calcine the mixed powder in a reducing atmosphere, and after calcination, take it out and grind it into powder with the powder size controlled at 200-250 mesh.

[0151] Step 3: Add the powder obtained in Step 2 into an acid-resistant ceramic-lined reactor, inject sulfuric acid solution as the leachate for reaction, and after the reaction stops, separate the leachate and leachate residue through a cotton filter screen.

[0152] Step 4: Inject the leachate obtained in Step 3 into the leachate circulation tank, and after being transferred by the peristaltic pump, it enters the acid-resistant ceramic-lined reactor, where it is mixed with the concentrated sulfuric acid injected through the acid addition port to obtain the leachate. Add the powder obtained in Step 2 to the solid feed vent port for reaction.

[0153] Step 5: Repeat step 4 2-4 times to obtain lithium-rich leachate.

[0154] In step 1, the amount of graphite added is 12 wt.% of the ternary lithium battery waste.

[0155] In step 2, the roasting temperature is 800℃ and the roasting time is 60min.

[0156] In step 3, the sulfuric acid concentration is 0.10 mol / L, the solid-liquid ratio of the calcined powder to the sulfuric acid solution is 1:75 kg / L, the stirring speed is 400-500 rpm, and the leaching time is 60 min.

[0157] In this embodiment, the leaching rates of lithium, nickel, cobalt, and manganese were 99.26%, 3.09%, 2.77%, and 8.15%, respectively.

[0158] Comparative Example 10

[0159] Step 1: Grind the ternary lithium battery black powder waste with graphite using a ball mill for 40-60 minutes and mix them evenly. The size of the mixed powder should be controlled at 200-250 mesh.

[0160] Step 2: Calcine the mixed powder in a reducing atmosphere, and after calcination, take it out and grind it into powder with the powder size controlled at 200-250 mesh.

[0161] Step 3: Add the powder obtained in Step 2 into an acid-resistant ceramic-lined reactor, inject sulfuric acid solution as the leachate for reaction, and after the reaction stops, separate the leachate and leachate residue through a cotton filter screen.

[0162] Step 4: Inject the leachate obtained in Step 3 into the leachate circulation tank, and after being transferred by the peristaltic pump, it enters the acid-resistant ceramic-lined reactor, where it is mixed with the concentrated sulfuric acid injected through the acid addition port to obtain the leachate. Add the powder obtained in Step 2 to the solid feed vent port for reaction.

[0163] Step 5: Repeat step 4 2-4 times to obtain lithium-rich leachate.

[0164] In step 1, the amount of graphite added is 12 wt.% of the ternary lithium battery waste.

[0165] In step 2, the roasting temperature is 800℃ and the roasting time is 60min.

[0166] In step 3, the sulfuric acid concentration is 0.10 mol / L, the solid-liquid ratio of the calcined powder to the sulfuric acid solution is 1:50 kg / L, the stirring speed is 400-500 rpm, and the leaching time is 20 min.

[0167] In this embodiment, the leaching rates of lithium, nickel, cobalt, and manganese were 92.64%, 0.89%, 0.54%, and 1.94%, respectively.

[0168] Comparative Example 11

[0169] Step 1: Grind the ternary lithium battery black powder waste with graphite using a ball mill for 40-60 minutes and mix them evenly. The size of the mixed powder should be controlled at 200-250 mesh.

[0170] Step 2: Calcine the mixed powder in a reducing atmosphere, and after calcination, take it out and grind it into powder with the powder size controlled at 200-250 mesh.

[0171] Step 3: Add the powder obtained in Step 2 into an acid-resistant ceramic-lined reactor, inject sulfuric acid solution as the leachate for reaction, and after the reaction stops, separate the leachate and leachate residue through a cotton filter screen.

[0172] Step 4: Inject the leachate obtained in Step 3 into the leachate circulation tank, and after being transferred by the peristaltic pump, it enters the acid-resistant ceramic-lined reactor, where it is mixed with the concentrated sulfuric acid injected through the acid addition port to obtain the leachate. Add the powder obtained in Step 2 to the solid feed vent port for reaction.

[0173] Step 5: Repeat step 4 2-4 times to obtain lithium-rich leachate.

[0174] In step 1, the amount of graphite added is 12 wt.% of the ternary lithium battery waste.

[0175] In step 2, the roasting temperature is 800℃ and the roasting time is 60min.

[0176] In step 3, the sulfuric acid concentration is 0.10 mol / L, the solid-liquid ratio of the calcined powder to the sulfuric acid solution is 1:50 kg / L, the stirring speed is 400-500 rpm, and the leaching time is 80 min.

[0177] In this embodiment, the leaching rates of lithium, nickel, cobalt, and manganese were 97.58%, 0.96%, 0.57%, and 2.07%, respectively.

[0178] The main component contents of the ternary lithium battery black powder waste used in the above examples are shown in Table 1.

[0179]

[0180] Table 1

[0181] The leaching rates of Li, Ni, Co, and Mn under various influencing factors for the above embodiments and comparative examples are shown in Table 2.

[0182] Table 2

[0183]

[0184]

[0185]

[0186] As can be seen from the above embodiments, comparative examples, and the data in Table 1:

[0187] (1) Through Examples 1-3, the data in Table 2 can be seen intuitively: the process of the present invention can effectively separate lithium elements from nickel, cobalt and manganese elements in ternary lithium battery waste by leaching under the limited graphite addition amount, calcination temperature, calcination time, sulfuric acid concentration, leaching solid-liquid ratio and leaching time.

[0188] (2) Through comparative examples 1-2, the data in Table 1 show that when the amount of graphite added does not meet the standard specified in this invention, it is not possible to effectively separate lithium elements from nickel, cobalt and manganese elements in ternary lithium battery waste.

[0189] (3) Through comparative examples 3-4, the data in Table 1 show that when the roasting temperature does not reach the standard specified in this invention, lithium, nickel, cobalt and manganese elements in ternary lithium battery waste cannot be effectively separated.

[0190] (4) According to the data in Table 1 of Comparative Example 5, it can be seen that when the roasting time does not meet the standard specified in this invention, lithium, nickel, cobalt and manganese elements in ternary lithium battery waste cannot be effectively separated.

[0191] (5) Through comparative examples 6-7, the data in Table 1 show that when the concentration of sulfuric acid used does not meet the standard defined by the present invention, it is not possible to effectively separate lithium elements from nickel, cobalt and manganese elements in ternary lithium battery waste; when the concentration of sulfuric acid used is greater than the standard defined by the present invention, the leaching rate of nickel, cobalt and manganese elements in ternary lithium battery waste increases.

[0192] (6) Through comparative examples 8-9, the data in Table 1 show that when the leaching solid-liquid ratio does not meet the standard defined by this invention, lithium and nickel, cobalt and manganese elements in ternary lithium battery waste cannot be effectively separated; when the leaching liquid-solid ratio is greater than the standard defined by this invention, the leaching rate of nickel, cobalt and manganese elements in ternary lithium battery waste increases.

[0193] (7) Through comparative examples 10-11, the data in Table 1 show that when the leaching time does not meet the standard defined by the present invention, lithium elements in ternary lithium battery waste cannot be effectively separated from nickel, cobalt and manganese elements; when the leaching time is greater than the standard defined by the present invention, the separation effect of lithium elements in ternary lithium battery waste from nickel, cobalt and manganese elements is not further enhanced.

[0194] In summary, the leaching method proposed in this invention optimizes the process flow for selective lithium extraction from ternary lithium battery black powder waste, improving element separation efficiency. The leaching method of this invention utilizes high-temperature graphite activation of the ternary lithium battery black powder waste, altering the phase structure of the cathode material. By disrupting the stable layered structure of the ternary cathode material, the lithium phase is converted into compounds that rapidly dissolve in low-concentration sulfuric acid solution, while transition metal elements (nickel, cobalt, manganese) are converted into low-valence oxides that are not easily soluble in low-concentration sulfuric acid solution, achieving rapid and selective leaching of lithium from the ternary lithium battery black powder waste. Furthermore, compared to traditional processes, reduced sulfuric acid consumption and equipment corrosion are also advantages of this invention. Therefore, the leaching method proposed in this invention has good application value and prospects in the field of ternary lithium battery recycling technology.

[0195] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all embodiments here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A device for selectively extracting lithium from ternary lithium battery black powder waste, characterized in that: The reactor includes an acid-resistant ceramic-lined reactor (1), an acid storage tank (13), and a leachate circulation tank (16). The lower end of the acid-resistant ceramic-lined reactor (1) has a discharge port (8), and a replaceable cotton filter screen (9) is installed at the discharge port (8). The leachate circulation tank (16) is located below the discharge port (8). A pH meter (11) is installed on the side of the acid-resistant ceramic-lined reactor (1), and the probe of the pH meter (11) extends into the interior of the acid-resistant ceramic-lined reactor (1). The upper end is fixedly connected to the reactor lid (18), which is provided with a solid feed vent (5), a circulating liquid feed inlet (6) and an acid inlet (7). The upper end of the reactor lid (18) is fixedly provided with a motor (3). The rotating shaft of the motor (3) passes through the reactor lid (18) and extends into the interior of the acid-resistant ceramic-lined reactor (1) and is fixed with a stirring paddle (2). The acid storage tank (13) is connected to the acid inlet (7) through a pipe, and the leachate circulation tank (16) is connected to the circulating liquid feed inlet (6) through a pipe.

2. The apparatus for selectively extracting lithium from ternary lithium battery black powder waste according to claim 1, characterized in that: The side wall of the acid-resistant ceramic-lined reactor (1) is provided with an observation window (4). The observation window (4) includes a fixing steel sleeve (22), fixing screws (23) and explosion-proof glass (24). The side wall of the acid-resistant ceramic-lined reactor (1) has an opening, which is covered by explosion-proof glass (24). The periphery of the explosion-proof glass (24) is covered by the fixing steel sleeve (22). The fixing steel sleeve (22) is fixedly connected to the side wall of the acid-resistant ceramic-lined reactor (1) by fixing screws (23), thereby fixing the explosion-proof glass (24).

3. The apparatus for selectively extracting lithium from ternary lithium battery black powder waste according to claim 1, characterized in that: The circulating liquid inlet (6), acid inlet (7) and outlet (8) are all equipped with valves (12).

4. The apparatus for selectively extracting lithium from ternary lithium battery black powder waste according to claim 3, characterized in that: The side of the discharge port (8) is provided with an insertion port that extends to the other side of the discharge port (8), and a cotton filter screen (9) is inserted into the insertion port.

5. The apparatus for selectively extracting lithium from ternary lithium battery black powder waste according to claim 4, characterized in that: The cotton filter screen (9) has a pore size of 300-350 mesh.

6. The apparatus for selectively extracting lithium from ternary lithium battery black powder waste according to claim 1, characterized in that: The pipe connecting the acid inlet (7) and the acid storage tank (13) is equipped with a first peristaltic pump (15), and the pipe connecting the circulating liquid inlet (6) and the leachate circulation tank (16) is equipped with a second peristaltic pump (30). The motor (3) is powered by power supply a (19), the first peristaltic pump (15) is powered by power supply b (20), and the second peristaltic pump (30) is powered by power supply c (21).

7. The apparatus for selectively extracting lithium from ternary lithium battery black powder waste according to claim 1, characterized in that: The solid feed vent (5) includes a base (25) and a top cover (26). Both the base (25) and the top cover (26) are hollow structures. The top of the top cover (26) is provided with a through vent (29). The base (25) is fixed on the reactor lid (18). The upper outer periphery of the base (25) is threadedly connected to the lower inner periphery of the top cover (26). A spring (27) is vertically connected to the top of the inside of the top cover (26). A piston (28) is connected to the lower end of the spring (27). The inside of the base (25) is a structure in which the inner diameter increases uniformly from bottom to top. The circumferential shape of the piston (28) matches the internal structure of the base (25).

8. A method for extracting lithium using the equipment for selective lithium extraction from ternary lithium battery black powder waste as described in claim 1, characterized in that: Includes the following steps: Step 1: Mix the waste black powder from ternary lithium batteries with graphite, and then ball mill the mixture. The resulting powder is then passed through a 200-mesh sieve. Step 2: Calcine the mixed powder in an inert atmosphere. After calcination, take it out and ball mill it. Pass the mixed powder through a 200-mesh sieve to collect the unfilled material. Then pass the mixed powder through a 250-mesh sieve to collect the top material. Control the mixed powder to 200~250 mesh. Step 3: Add the mixed powder obtained in step 2 into the acid-resistant ceramic-lined reactor (1), inject sulfuric acid solution as leachate for reaction, and after the reaction stops, open the valve (12) of the discharge port (8) and separate the leachate and leachate residue through the cotton filter screen (9); Step 4: The separated leachate is injected into the leachate circulation tank (16), and after being pressurized, it re-enters the acid-resistant ceramic-lined reactor (1) through the circulating liquid inlet (6). The sulfuric acid in the acid storage tank (13) is pressurized and enters the acid-resistant ceramic-lined reactor (1) through the acid inlet (7). The mixed powder obtained in step 2 is added through the solid feed vent (5). Step 5: Repeat "Step 4" 2 to 4 times to obtain lithium-rich leachate.

9. The method according to claim 8, characterized in that: In step 1, the amount of graphite added is 12-15 wt.% of the ternary lithium battery black powder waste; in step 2, the calcination temperature is 780-820℃ and the calcination time is 60-80 min; in step 3, the concentration of the injected sulfuric acid solution is 0.08-0.10 mol / L and the solid-liquid ratio of the calcined powder to the sulfuric acid solution is 1:40-1:50 kg / L.

10. The method according to claim 8, characterized in that: In step 3, after the calcined powder and sulfuric acid solution are fed, the motor (3) is started, and the stirring paddle (2) is rotated. The stirring paddle (2) rotates at 400-500 rpm, the leaching time is 40-60 min, and the reaction ends when the pH meter (11) reads 6-8. Then the valve (12) of the outlet (8) is opened. In step 4, the feed flow rate of the separated leachate is 0.2-0.5 m³ / h. 3 The sulfuric acid feed flow rate is 0.02–0.05 m³ / h. 3 / h.

Images