Lithium battery slurry recovery equipment and lithium battery slurry recovery method

Abstract

The present invention provides a lithium battery slurry recovery device and a lithium battery slurry recovery method, relating to the technical field of battery material recovery equipment, comprising: a reaction vessel, an oil temperature controller, a stirring mechanism, a vacuum pump, a condenser, and a liquid storage tank; wherein the reaction vessel is also integrated with an oil guide pipe, an oil inlet, and an oil outlet; the oil temperature controller is used to heat the material in the reaction vessel to 240-250 degrees Celsius. The stirring mechanism is arranged in the interior space of the reaction vessel and is used to stir the material in the reaction vessel during the recovery process. The vacuum pump acts on the interior of the reaction vessel to generate negative pressure. The condenser is connected between the reaction vessel and the vacuum pump. The liquid storage tank is connected between the condenser and the vacuum pump. The technical solution of the present application can separate high-purity N-methylpyrrolidone (NMP) and realize the recycling and reuse of N-methylpyrrolidone (NMP).

Description

Technical Field

[0001] The present application relates to the technical field of battery material recycling equipment, and in particular to a lithium battery slurry recycling device and a lithium battery slurry recycling method. Background Art

[0002] New energy is the future direction of development, and batteries are one of the key means of achieving this. Lithium batteries consist of positive and negative electrodes. During the manufacturing process, positive electrode slurry is applied to the positive electrode aluminum foil, and graphite is applied to the negative electrode copper foil. As one of the key raw materials in lithium-ion battery manufacturing, NMP directly impacts the quality of the slurry coating process and environmental protection requirements.

[0003] During the production of positive electrode coating, the positive electrode material and N-methylpyrrolidone (NMP) need to be mixed in a mixing tank. However, after mixing, the unused slurry will stick to the inner surface of the mixing tank, requiring timely cleaning of the mixing tank. The cleaning process involves adding N-methylpyrrolidone (NMP) to the mixing tank again to wash away the residual material on the inner surface of the reaction vessel. However, the N-methylpyrrolidone (NMP) solution after washing will still contain usable powder. Therefore, the cleaned solution is poured out of the reactor and stored in a fixed container. However, how to process the solution, separate the liquid and powder, and reuse them is a key issue facing companies.

[0004] The existing methods for treating cleaning wastewater are mainly the following:

[0005] The first precipitation method uses flocculant precipitation. By adding chemical precipitants, the black NMP solvent can achieve solid-liquid separation, separating the NMP waste liquid and wet slurry. The NMP waste liquid can meet the utilization standards. The slurry can only be burned to turn it into a block of metal material, not into powder. It must be crushed and ball-milled by equipment to become powder. After the NMP in the slurry is burned, it will cause environmental pollution.

[0006] Second, the dry burning method directly burns the metal material inside, and the NMP inside cannot be recovered at all.

[0007] Third, the slurry is filtered out through a filter press to separate part of the NMP in the slurry. The NMP is still black and needs to be reprocessed into NMP waste liquid. The solid filtered out also contains part of NMP, which also needs to be burned to extract the metal material inside.

[0008] The above processes ignore the recovery and utilization of N-methylpyrrolidone (NMP), or the purity of the separated N-methylpyrrolidone (NMP) often cannot meet the use requirements. Summary of the Invention

[0009] The technical problem to be solved by this application is to propose a lithium battery slurry recovery device and a lithium battery slurry recovery method in response to the above-mentioned deficiencies in the prior art.

[0010] A lithium battery slurry recovery device, comprising:

[0011] A reaction container having an internal space for accommodating lithium battery slurry to be recycled; the reaction container is also integrated with an oil guide pipe, and an oil inlet and an oil outlet connected to the oil guide pipe;

[0012] an oil temperature controller connected to the oil inlet and the oil outlet to inject heat transfer oil into the oil inlet and receive the heat transfer oil delivered by the oil outlet; the oil temperature controller is used to heat the material in the reaction vessel to 240-250 degrees Celsius;

[0013] A stirring mechanism is provided in the interior space of the reaction vessel and is used to stir the material in the reaction vessel during the recovery process;

[0014] A vacuum pump acts on the interior of the reaction container to generate negative pressure;

[0015] a condenser connected between the reaction vessel and the vacuum pump;

[0016] A liquid storage tank is connected between the condenser and the vacuum pump.

[0017] In an improved technical solution, the stirring mechanism includes:

[0018] a stirring shaft, transversely and sealedly mounted on the reaction vessel, extending transversely through the interior space of the reaction vessel, with a first end and a second end thereof extending out of the reaction vessel from two sides respectively; the stirring shaft being able to freely rotate relative to the reaction vessel;

[0019] A stirring blade is mounted on the stirring shaft and can rotate synchronously with the stirring shaft to stir the material in the reaction container;

[0020] a first support seat, arranged outside the reaction container, for rotatably supporting the first end of the stirring shaft;

[0021] a second support seat, arranged outside the reaction vessel, for rotatably supporting the second end of the stirring shaft;

[0022] The driving source is arranged outside the reaction container and is connected to the first end of the stirring shaft in a power manner so as to drive the stirring shaft to rotate.

[0023] In an improved technical solution, a high-temperature sealing structure is provided between the stirring shaft and the reaction vessel;

[0024] The high temperature sealing structure comprises:

[0025] A sealed cavity mounted on the reaction vessel, the sealed cavity surrounding the periphery of the stirring shaft and provided with an oil inlet hole for injecting lubricating oil and an oil outlet hole for discharging lubricating oil;

[0026] A sealing ring is arranged inside the sealing cavity and around the periphery of the stirring shaft, and the sealing ring includes a static ring and a dynamic ring. The static ring is attached to the sealing cavity to remain stationary, and the dynamic ring is installed on the stirring shaft and rotates with the stirring shaft; a seal is formed between the static ring and the dynamic ring.

[0027] In an improved technical solution, the static ring includes an upper static ring and a lower static ring; the dynamic ring is located between the upper static ring and the lower static ring, and includes an upper dynamic ring adapted to the upper static ring, and a lower dynamic ring adapted to the lower static ring;

[0028] The high-temperature sealing structure further includes a dynamic ring mounting structure for mounting an upper dynamic ring and a lower dynamic ring.

[0029] In an improved technical solution, a cooling channel is arranged circumferentially inside the sealed cavity, and a coolant inlet and a coolant outlet connected to the cooling channel are provided; the positions of the coolant inlet and the coolant outlet are arranged symmetrically relative to the axis of the stirring shaft.

[0030] In an improved technical solution, a filter is further connected between the condenser and the reaction vessel; the filter is arranged on the top of the reaction vessel and communicates with the internal space of the reaction vessel; the air outlet of the filter is connected to the condenser.

[0031] In an improved technical solution, the lithium battery slurry recovery equipment further includes: a nitrogen generator capable of generating nitrogen;

[0032] A first filter and a second filter are arranged on the top of the reaction container; an air outlet of the first filter is connected to the condenser through a first connecting pipe; an air outlet of the second filter is connected to the condenser through a second connecting pipe;

[0033] A first three-way valve is provided on the first connecting pipe, wherein the first interface of the first three-way valve is connected to the first filter, the second interface is connected to the condenser, and the third interface is connected to the nitrogen generator; the first three-way valve has a first working state and a second working state; when the first three-way valve is adjusted to the first working state, the first three-way valve is adjusted so that the first interface is not connected to the second interface, the first interface is connected to the third interface, and the second interface is not connected to the third interface; when the first three-way valve is adjusted to the second working state, the first three-way valve is adjusted so that the first interface is connected to the second interface, the first interface is not connected to the third interface, and the second interface is not connected to the third interface;

[0034] A second three-way valve is provided on the second connecting pipe, wherein the first interface of the second three-way valve is connected to the second filter, the second interface is connected to the condenser, and the third interface is connected to the nitrogen generator; the second three-way valve has a first working state and a second working state; when the second three-way valve is adjusted to the first working state, the second three-way valve is adjusted so that the first interface is not connected to the second interface, the first interface is connected to the third interface, and the second interface is not connected to the third interface; when the second three-way valve is adjusted to the second working state, the second three-way valve is adjusted so that the first interface is connected to the second interface, the first interface is not connected to the third interface, and the second interface is not connected to the third interface;

[0035] When the nitrogen generator is turned on, the first three-way valve cyclically switches between the first working state and the second working state, and the second three-way valve cyclically switches between the first working state and the second working state, and when the first three-way valve is in the first working state, the second three-way valve is in the second working state, and when the first three-way valve is in the second working state, the second three-way valve is in the first working state.

[0036] In an improved technical solution, the top of the reaction container is provided with a feed port, and the middle position of the bottom is provided with a discharge port;

[0037] The stirring blades include a first stirring blade located on the left side of the discharge port and a second stirring blade located on the right side of the discharge port; the first stirring blade and the second stirring blade have opposite deflection directions, and as the first stirring blade rotates, the first stirring blade stirs the material located on the left side of the discharge port and causes the material to move to the right; as the second stirring blade rotates, the second stirring blade stirs the material located on the right side of the discharge port and causes the material to move to the left.

[0038] In an improved technical solution, the vacuum pump is further connected to an exhaust gas treatment device.

[0039] On the other hand, the present application also provides a lithium battery slurry recovery method, which is applied to the above-mentioned lithium battery slurry recovery equipment, comprising the steps of:

[0040] Controlling the vacuum pump to act on the interior of the reaction container to generate negative pressure;

[0041] Control the oil temperature machine to heat the material in the reaction vessel to - degrees Celsius;

[0042] Controlling the stirring mechanism to stir the materials in the reaction container;

[0043] The condenser is controlled to cool the gas evaporated from the reaction vessel so as to condense N-methylpyrrolidone NMP.

[0044] The technical solution provided by this application has the following technical effects: First, it can separate high-purity N-methylpyrrolidone (NMP), enabling the recovery and reuse of N-methylpyrrolidone (NMP). Second, compared to existing technical solutions, the recovery and processing equipment of this application can achieve higher purity, and the recovered N-methylpyrrolidone (NMP) meets the standards for reuse. Third, it causes less pollution to the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is one of the structural schematic diagrams of the lithium battery slurry recovery equipment in the embodiment of the present application.

[0046] Figure 2 This is the second structural diagram of the lithium battery slurry recovery equipment in the embodiment of the present application.

[0047] Figure 3 This is the third structural diagram of the lithium battery slurry recovery equipment in the embodiment of this application.

[0048] Figure 4 This is the fourth structural diagram of the lithium battery slurry recovery equipment in the embodiment of the present application.

[0049] Figure 5 It is a schematic structural diagram of the reaction container in the embodiment of the present application.

[0050] Figure 6 It is a structural schematic diagram of the high-temperature sealing structure in an embodiment of the present application.

[0051] Figure 7 This is a flow chart of the regulation of the first three-way valve and the second three-way valve in an embodiment of the present application.

[0052] Figure 8 This is a flow chart of the lithium battery slurry recovery method in an embodiment of the present application. DETAILED DESCRIPTION

[0053] The following are specific embodiments of the present application and in conjunction with the accompanying drawings, the technical scheme of the present application is further described, but the application is not limited to these embodiments. In the following description, specific details such as specific configurations and components are provided only to help fully understand the embodiments of the present application. Therefore, it should be clear to those skilled in the art that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present application. In addition, for clarity and brevity, the description of known functions and structures has been omitted.

[0054] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0055] It should be noted that existing battery recycling processes include: First, precipitation, which uses flocculants to separate the black NMP solvent into solids and liquids by adding chemical precipitants, separating NMP waste liquid and wet slurry. The NMP waste liquid can meet recycling standards, but the slurry can only be burned to form a bulk metal material, not a powder. It must be crushed and ball-milled to form a powder. The NMP in the slurry is burned after combustion, causing environmental pollution. Second, dry combustion directly burns the metal material, but the NMP in it cannot be recovered at all. Third, the slurry is filtered through a filter press to filter out a portion of the NMP in the slurry. After the NMP is separated, the black NMP still needs to be processed into NMP waste liquid. The solid released by the filter still contains some NMP, which also needs to be burned to extract the metal material. Therefore, the existing battery recycling process has the following shortcomings: First, the recovery of N-methylpyrrolidone NMP is not thorough, and a large amount of N-methylpyrrolidone NMP has not been separated. For example, the technical solution disclosed in Chinese Patent 201911374190.2. Second, the purity of the recovered N-methylpyrrolidone NMP does not meet the use requirements and requires further processing. Third, the solid phase of the positive electrode material needs to be calcined at high temperature, and the N-methylpyrrolidone NMP that is not recovered during the calcination process will cause pollution. In order to solve the above problems in the prior art, the present application provides a lithium battery slurry recovery device, which is described in detail below in conjunction with the accompanying drawings.

[0056] refer to Figures 1 to 6 The present application provides a lithium battery slurry recovery device, which includes at least a reaction container 10, an oil temperature controller 20, a stirring mechanism 80, a vacuum pump 30, a condenser 40, and a liquid storage tank 50.

[0057] The reaction vessel 10 has an internal space 16 for accommodating the lithium battery slurry to be recycled; the reaction vessel 10 is also integrated with an oil pipeline 11, an oil inlet 12 and an oil outlet 13. The oil inlet 12 and the oil outlet 13 are both connected to the oil pipeline 11. Figure 5 The oil guide pipe 11 is integrated into the coating structure layer of the reaction vessel 10 and is arranged in a spiral shape around the circumference of the coating structure, so that the internal space 16 of the reaction vessel 10 can be evenly heated.

[0058] The oil temperature controller 20 is connected to the oil inlet 12 and the oil outlet 13 to inject heat transfer oil into the oil inlet 12 and receive the heat transfer oil from the oil outlet 13. The oil temperature controller 20 is used to heat the material in the reaction vessel 10 to 240-250 degrees Celsius. When the oil temperature controller 20 is in operation, the oil temperature controller outputs heated heat transfer oil, which is injected from the oil inlet 12 of the oil pipe 11, passes through the oil pipe 11, and is discharged from the oil outlet 13 and returned to the oil temperature controller 20. Figure 3 The oil inlet 12 of the oil conduit 11 is located at the bottom of the reaction vessel 10, and the oil outlet 13 is located at the top of the reaction vessel 10. Specifically, the thermal oil output by the oil temperature controller 20 is injected into the oil conduit 11 through the two oil inlets 12 at the bottom of the reaction vessel 10 and discharged from the oil conduit 11 through the two oil outlets 13 at the top, returning to the oil temperature controller 20. In this way, the oil temperature controller 20 uses the thermal oil to circulate and heat the reaction vessel 10. The thermal oil is heated by the heater within the oil temperature controller 20. When the medium temperature detected by the temperature sensor reaches the set value, the heater stops working. When the temperature falls below the set value, the heater starts working, and when the temperature reaches the set value, it stops working again, and this cycle repeats.

[0059] In the present application, the oil temperature controller 20 is used to control the temperature of the reaction vessel 10, and can increase the internal reaction temperature of the reaction vessel to above the boiling point of N-methylpyrrolidone (NMP), thereby enabling the N-methylpyrrolidone (NMP) to be completely evaporated, thereby reducing the residual NMP in the waste, and thus completely separating the N-methylpyrrolidone (NMP) in the waste. The oil temperature controller 20 is used to control the temperature of the reaction vessel 10, and can increase the internal reaction temperature of the reaction vessel to above the boiling point of N-methylpyrrolidone (NMP), thereby enabling the N-methylpyrrolidone (NMP) to be completely evaporated, thereby reducing the residual NMP in the waste, and thus completely separating the N-methylpyrrolidone (NMP) in the waste.

[0060] refer to Figure 4The stirring mechanism 80 is disposed within the interior space 16 of the reaction vessel 10 and is used to stir the material within the reaction vessel 10 during the recovery process. As the oil temperature controller 20 heats the material within the reaction vessel 10 to 240-250 degrees Celsius, the N-methylpyrrolidone (NMP) in the positive electrode waste begins to volatilize. The continuous agitation of the stirring mechanism 80 fully volatilizes the N-methylpyrrolidone (NMP) in the positive electrode waste, ultimately yielding positive electrode material powder for metal element recovery. Simultaneously, the volatilized N-methylpyrrolidone (NMP) is collected and recycled.

[0061] refer to Figure 1 and Figure 2 In the embodiment of the present application, a vacuum pump 30 acts on the interior of the reaction vessel 10 to generate a negative pressure. A condenser 40 is connected between the reaction vessel 10 and the vacuum pump 30. A liquid storage tank 50 is connected between the condenser 40 and the vacuum pump 30. The condenser 40, the liquid storage tank 50, and the vacuum pump 30 are sequentially arranged on the pipeline connected to the reaction vessel 10. Under the action of the vacuum pump 30, N-methylpyrrolidone (NMP) volatilized from the battery positive electrode waste in the reaction vessel 10 enters the pipeline, is cooled by the condenser 40, and then the gas is converted into liquid and is transferred to the liquid storage tank 50.

[0062] Continue to refer Figure 2 In some embodiments of the present application, the vacuum pump 30 is further connected to an exhaust gas treatment device. The exhaust gas treatment device is used to treat excess exhaust gas and reduce pollution emissions.

[0063] refer to Figure 1 and Figure 2 In some embodiments of the present application, a filter 70 is further connected between the condenser 40 and the reaction vessel 10. The filter 70 is disposed on the top of the reaction vessel 10 and communicates with the interior space 16 of the reaction vessel 10. The outlet of the filter 70 is connected to the condenser 40. The filter 70 is used to filter powder impurities. Furthermore, the filter 70 includes a sintered mesh filter element.

[0064] In the embodiment of the present application, the working process of the lithium battery slurry recovery equipment is as follows: first, the NMP black liquor containing N-methylpyrrolidone NMP and rare metals to be processed is added to the reaction container 10, the oil temperature machine 20 is turned on, the oil temperature machine 20 heats the reaction container 10 to 240 degrees Celsius, the vacuum pump 30 is turned on, and the negative pressure of the vacuum pump 30 reaches -0.08 MPa to absorb the N-methylpyrrolidone NMP mixed gas containing powder in the reaction container 10, and the temperature rises to the boiling point of N-methylpyrrolidone NMP to start evaporation, and N- The evaporated gas of N-methylpyrrolidone (NMP) is filtered through a sintered mesh filter to remove powder impurities. The gas is then cooled in a condenser 40 to convert the gas into liquid and enter a liquid storage tank 50. After the N-methylpyrrolidone (NMP) is completely evaporated, the slurry in the reaction vessel 10 becomes a powder containing metal. The N-methylpyrrolidone (NMP) is completely recovered through the condenser 40 and returned to the liquid storage tank 50. During the evaporation and condensation of the N-methylpyrrolidone (NMP), nitrogen is added through a nitrogen device. Nitrogen is an oxygen-free gas, which increases the safety of the equipment and the protection of the materials.

[0065] refer to Figure 4 In one embodiment of the present application, the stirring mechanism 80 includes: a stirring shaft 81, a stirring blade 82, a first support seat 83, a second support seat 84, and a driving source 85. The stirring shaft 81 is horizontally and sealedly mounted on the reaction vessel 10, passing horizontally through the internal space 16 of the reaction vessel 10, and its first end and second end extend out of the reaction vessel 10 from both sides; the stirring shaft 81 can rotate freely relative to the reaction vessel 10. The stirring blade 82 is mounted on the stirring shaft 81 and can rotate synchronously with the stirring shaft 81 to stir the material in the reaction vessel 10. The first support seat 83 is arranged outside the reaction vessel 10 for rotatably supporting the first end of the stirring shaft 81. The second support seat 84 is arranged outside the reaction vessel 10 for rotatably supporting the second end of the stirring shaft 81. The driving source 85 is arranged outside the reaction vessel 10 and is dynamically connected to the first end of the stirring shaft 81 for driving the stirring shaft 81 to rotate.

[0066] Specifically, when the stirring mechanism 80 is working, the driving source 85 first drives the stirring shaft 81 to rotate. The driving source 85 can be an electric device, a hydraulic device, or a pneumatic device, and has an output shaft for outputting power. A coupling can be used to connect the output shaft and the stirring shaft 81. Driven by the driving source 85, the stirring shaft 81 starts to rotate, and the stirring blade 82 also rotates therewith, and begins to stir the material in the reaction vessel 10. The first support seat 83 and the second support seat 84 are respectively arranged on the outside of the stirring shaft 81 reaction vessel 10, and the positions of the two ends of the stirring shaft 81 form a rotating support for the stirring shaft 81 so that the stirring shaft 81 can rotate stably. Under the continuous stirring of the stirring mechanism 80, the N-methylpyrrolidone NMP in the positive electrode waste can be fully volatilized, and the positive electrode material powder is directly obtained at the end.

[0067] refer to Figure 4 , a feed port 14 is provided at the top of the reaction vessel 10, and a discharge port 15 is provided at the middle position of the bottom. The stirring blade 82 includes a first stirring blade 821 located on the left side of the discharge port 15 and a second stirring blade 822 located on the right side of the discharge port 15; the first stirring blade 821 and the second stirring blade 822 are in opposite directions of deflection. As the first stirring blade 821 rotates, the first stirring blade 821 stirs the material located on the left side of the discharge port 15 and causes the material to move to the right; as the second stirring blade 822 rotates, the second stirring blade 822 stirs the material located on the right side of the discharge port 15 and causes the material to move to the left. In this way, as the stirring shaft 81 rotates, the first stirring blade 821 located on the left side of the discharge port 15 and the second stirring blade 822 located on the right side of the discharge port 15 drive the materials on both sides of the discharge port 15 to move toward the middle during the stirring process, so as to facilitate the discharge of the solid powder finally separated.

[0068] Specifically, the first stirring blade 821 and the second stirring blade 822 may be spiral blades, and their deflection directions are opposite, so that the directions of the stirring materials are opposite.

[0069] In the embodiment of the present application, the oil temperature controller 20 heats the material in the reaction vessel 10 to 240-250 degrees Celsius. Under this temperature condition, the vacuum pump 30 acts on the interior of the reaction vessel 10 to generate negative pressure, and a stirring mechanism 80 is required to stir the material in the reaction vessel 10. Therefore, a high-temperature sealing structure 86 is provided between the stirring shaft 81 and the reaction vessel 10 to ensure that the stirring shaft 81 can rotate in a sealed manner under high temperature conditions.

[0070] refer to Figure 6In some embodiments of the present application, the high-temperature sealing structure 86 primarily comprises a sealing cavity 861 and a sealing ring. The sealing cavity 861 is mounted on the reaction vessel 10 and surrounds the agitator shaft 81. The sealing cavity 861 is provided with an oil inlet 8611 for injecting lubricating oil and an oil outlet 8612 for discharging lubricating oil. The sealing ring is disposed within the sealing cavity 861 and surrounds the agitator shaft 81. The sealing ring comprises a stationary ring 862 and a dynamic ring 863. The stationary ring 862 is attached to the sealing cavity 861 to remain stationary, while the dynamic ring 863 is mounted on the agitator shaft 81 and rotates therewith. A seal is formed between the stationary ring 862 and the dynamic ring 863.

[0071] During stirring, the stirring shaft 81 rotates, causing the dynamic ring 863 to rotate, while the static ring 862 remains stationary attached to the sealed cavity 861, forming a stable seal between the static ring 862 and the dynamic ring 863. In some embodiments, both the dynamic ring 863 and the static ring 862 are perfluoroether sealing rings. During stirring, lubricating oil enters through the oil inlet 8611 in the sealed cavity 861 and is discharged through the oil outlet 8612.

[0072] Further references Figure 6 In some embodiments of the present application, the stationary ring 862 includes an upper stationary ring 862a and a lower stationary ring 862b; the dynamic ring 863 is located between the upper stationary ring 862a and the lower stationary ring 862b and includes an upper dynamic ring 863a adapted to the upper stationary ring 862a and a lower dynamic ring 863b adapted to the lower stationary ring 862b; the high-temperature sealing structure 86 also includes a dynamic ring mounting structure 864 for mounting the upper dynamic ring 863a and the lower dynamic ring 863b. A seal is formed between the upper stationary ring 862a and the upper dynamic ring 863a, and a seal is formed between the lower stationary ring 862b and the lower dynamic ring 863b. The oil inlet hole 8611 and the oil outlet hole 8612 are both arranged between the upper dynamic ring 863a and the lower dynamic ring 863b. In this way, the lubricating oil entering through the oil inlet hole 8611 can lubricate the sealing parts on both sides.

[0073] Further references Figure 6In some embodiments of the present application, a cooling channel 8613 is arranged circumferentially within the sealed cavity 861. A coolant inlet 8614 and a coolant outlet 8615 are provided, communicating with the cooling channel 8613. The coolant inlet 8614 and the coolant outlet 8615 are symmetrically positioned relative to the axis of the agitator shaft 81. Coolant is injected through the coolant inlet 8614, passes through the cooling channel 8613, and is discharged from the coolant outlet 8615. The cooling channel 8613 is arranged circumferentially within the sealed cavity 861, effectively absorbing heat from the sealed cavity 861, cooling the sealed cavity 861 and thereby lowering the temperature of the entire sealing structure, thereby maintaining good lubrication performance. The symmetrical arrangement of the coolant inlet 8614 and the coolant outlet 8615 relative to the axis of the agitator shaft 81 allows the coolant to evenly cool the sealed cavity 861 and flow more efficiently through the cooling channel 8613, thereby improving cooling efficiency.

[0074] refer to Figure 2 In some embodiments of the present application, a filter 70 is further connected between the condenser 40 and the reaction vessel 10. The filter 70 is in communication with the internal space 16 of the reaction vessel 10; the air outlet of the filter 70 is connected to the condenser 40. A first filter 70a and a second filter 70b are arranged on the top of the reaction vessel 10; the air outlet of the first filter 70a is connected to the condenser 40 via a first connecting pipe 90a; and the air outlet of the second filter 70b is connected to the condenser 40 via a second connecting pipe 90b.

[0075] The filter 70 is used to filter powder impurities. Gas volatilized from the reaction vessel 10 can partially pass through the first filter 70a and the first connecting pipe 90a before entering the condenser 40, and partially pass through the second filter 70b and the second connecting pipe 90b before entering the condenser 40. The first filter 70a and the first connecting pipe 90a form a first filtration channel, and the second filter 70b and the second connecting pipe 90b form a second filtration channel. Gas volatilized from the reaction vessel 10 can enter the condenser 40 through the first and second filtration channels. The first and second filtration channels can operate independently of each other without interfering with each other.

[0076] Furthermore, the lithium battery slurry recovery equipment further includes a nitrogen generator 60 capable of generating nitrogen. The nitrogen generator 60 can be used to backflush the first filter 70a and the second filter 70b to blow away dust on the first filter 70a and the second filter 70b.

[0077] Continue to refer Figure 2A first three-way valve 91 is provided on the first connecting pipe 90a, wherein a first interface of the first three-way valve 91 is connected to the first filter 70a, a second interface is connected to the condenser 40, and a third interface is connected to the nitrogen generator 60; the first three-way valve 91 has a first working state and a second working state; when the first three-way valve 91 is adjusted to the first working state, the first three-way valve 91 is adjusted so that the first interface is not connected to the second interface, the first interface is connected to the third interface, and the second interface is not connected to the third interface; when the first three-way valve 91 is adjusted to the second working state, the first three-way valve 91 is adjusted so that the first interface is connected to the second interface, the first interface is not connected to the third interface, and the second interface is not connected to the third interface.

[0078] When the first three-way valve 91 is adjusted to the first operating state, the first interface is connected to the third interface, the first filter 70a is connected to the nitrogen generator 60, and the first interface is disconnected from the second interface, so that the first filter channel is closed and the nitrogen generator 60 can blow air back to the first filter 70a to remove dust accumulated on the first filter 70a. When the first three-way valve 91 is adjusted to the second operating state, the first interface is connected to the second interface, the first filter channel operates normally, and the volatilized gas in the reaction vessel 10 passes through the first filter 70a, enters the first three-way valve 91 from the first interface, and exits the first three-way valve 91 from the second interface, and then enters the condenser 40.

[0079] Continue to refer Figure 2 A second three-way valve 92 is provided on the second connecting pipe 90b, the first interface of the second three-way valve 92 is connected to the second filter 70b, the second interface is connected to the condenser 40, and the third interface is connected to the nitrogen generator 60; the second three-way valve 92 has a first working state and a second working state; when the second three-way valve 92 is adjusted to the first working state, the second three-way valve 92 is adjusted so that the first interface and the second interface are not connected, the first interface and the third interface are connected, and the second interface and the third interface are not connected; when the second three-way valve 92 is adjusted to the second working state, the second three-way valve 92 is adjusted so that the first interface and the second interface are connected, the first interface and the third interface are not connected, and the second interface and the third interface are not connected.

[0080] When the second three-way valve 92 is adjusted to the first operating state, the first interface is connected to the third interface, the second filter 70b is connected to the nitrogen generator 60, and the first interface is disconnected from the second interface, closing the second filter channel. The nitrogen generator 60 can blow air back to the second filter 70b to remove dust accumulated on the second filter 70b. When the second three-way valve 92 is adjusted to the second operating state, the first interface is connected to the second interface, the second filter channel operates normally, and the volatilized gas in the reaction vessel 10 passes through the second filter 70b, enters the second three-way valve 92 from the first interface, exits the second three-way valve 92 from the second interface, and then enters the condenser 40.

[0081] When the nitrogen generator 60 is turned on, the first three-way valve 91 cyclically switches between the first working state and the second working state, and the second three-way valve 92 cyclically switches between the first working state and the second working state. When the first three-way valve 91 is in the first working state, the second three-way valve 92 is in the second working state, and when the first three-way valve 91 is in the second working state, the second three-way valve 92 is in the first working state.

[0082] Specific reference Figure 7 , Figure 7 This is a flow chart of adjusting the first three-way valve and the second three-way valve in an embodiment of the present application, including step 701 and step 702. After the nitrogen generator 60 is turned on, step 701 and step 702 are executed.

[0083] Step 701: Adjust the first three-way valve to a first working state; and adjust the second three-way valve to a second working state.

[0084] Step 702: Adjust the first three-way valve to the second working state; and adjust the second three-way valve to the first working state.

[0085] Step 701 and step 702 are executed in a loop, and the first filter 70a and the second filter 70b are back-blown in a loop in sequence. Specifically, in step 701, the first three-way valve is adjusted to the first operating state, the second three-way valve is adjusted to the second operating state, and the nitrogen generator 60 performs reverse blowing on the first filter 70a, while the second filter channel works normally, outputting the gas volatilized in the waste material. In step 702, the first three-way valve is adjusted to the second operating state, the second three-way valve is adjusted to the first operating state, and the nitrogen generator 60 performs reverse blowing on the second filter 70b to blow off the dust accumulated on the second filter 70b, while the first filter channel works normally, outputting the gas volatilized in the waste material. In this way, the nitrogen generator 60 can cyclically blow the first filter 70a and the second filter 70b in the opposite direction to blow off the dust accumulated on the first filter 70a and the second filter 70b, and the equipment can work normally during the back-blowing process, discharging the gas volatilized in the waste material.

[0086] refer to Figure 8 The present application also provides a lithium battery slurry recovery method, which is applied to the above-mentioned lithium battery slurry recovery equipment and includes the following steps:

[0087] Step 801: Control the vacuum pump 30 to act on the interior of the reaction container 10 to generate negative pressure.

[0088] Step 802: Control the oil temperature controller 20 to heat the material in the reaction vessel 10 to 240-250 degrees Celsius.

[0089] Step 803 : Control the stirring mechanism 80 to stir the material in the reaction container 10 .

[0090] Step 804 : Control the condenser 40 to cool the gas evaporated from the reaction container 10 so as to condense N-methylpyrrolidone NMP.

[0091] The above steps are not strictly executed in chronological order and can be executed according to actual conditions. Figure 8The sequence of steps shown is merely exemplary. Specifically, the working process of the lithium battery slurry recovery equipment is as follows: First, the NMP black liquor containing N-methylpyrrolidone (NMP) and rare metals to be processed is added to the reaction vessel 10, the oil temperature controller 20 is turned on, and the oil temperature controller 20 heats the reaction vessel 10 to 240 degrees Celsius, and the vacuum pump 30 is turned on, and the negative pressure of the vacuum pump 30 reaches -0.08 MPa to absorb the N-methylpyrrolidone (NMP) mixed gas containing powder in the reaction vessel 10. The temperature rises to the boiling point of N-methylpyrrolidone (NMP) and begins to evaporate, and N-methylpyrrolidone (NMP) is removed. The evaporated gas of NMP is filtered through a sintered mesh filter to remove powder impurities, and then cooled in a condenser 40 to convert the gas into liquid and transfer it to a liquid storage tank 50. After the N-methylpyrrolidone NMP is completely evaporated, the slurry in the reaction vessel 10 becomes a powder containing metal. The N-methylpyrrolidone NMP is completely recovered into the liquid storage tank 50 through the condenser 40. During the evaporation and condensation of the N-methylpyrrolidone NMP, nitrogen is added through a nitrogen device. The nitrogen is an oxygen-free gas, which increases the safety of the equipment and the protection of the materials.

[0092] The following is a comparative analysis of existing battery recycling processes and the technical solutions of this application. First, the precipitation method uses flocculant precipitation. By adding a chemical precipitant, the black NMP solvent achieves solid-liquid separation, separating the NMP waste liquid and the wet slurry. While the NMP waste liquid meets the recycling standards, the slurry can only be burned to convert it into a bulk metal material, not a powder. It must be crushed and ball-milled to convert it into a powder. The NMP in the slurry, after combustion, pollutes the environment. This separation process does not completely separate NMP from N-methylpyrrolidone (NMP) and poses certain environmental risks. Second, the dry combustion method directly burns the metal material, but the NMP contained in it cannot be recovered at all. Third, the slurry is filtered through a filter press to filter out a portion of the NMP in the slurry. After the NMP is separated, the NMP remains black and needs to be reprocessed into NMP waste liquid. The solids released by the filter press also contain some NMP, which also needs to be burned to extract the metal material. Therefore, the existing battery recycling process has the following disadvantages: First, the recovery of N-methylpyrrolidone NMP is not thorough, and a large amount of N-methylpyrrolidone NMP has not been separated. For example, the technical solution disclosed in Chinese Patent 201911374190.2. Second, the purity of the recovered N-methylpyrrolidone NMP does not meet the use requirements and requires further processing. Third, the solid phase of the positive electrode material needs to be calcined at high temperature, and the N-methylpyrrolidone NMP that is not recovered during the calcination process will cause pollution. The present application provides a lithium battery slurry recovery device that can separate high-purity N-methylpyrrolidone NMP and realize the recycling and reuse of N-methylpyrrolidone NMP. Second, compared with the existing technical solutions, the recycling and processing equipment of the present application can achieve higher purity, and the recovered N-methylpyrrolidone NMP can meet the reuse standards. Third, there is less pollution to the environment.

[0093] In the above embodiments of the present application, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0094] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0095] The specific embodiments described herein are merely illustrative of the spirit of the present application. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present application or exceeding the scope defined by the appended claims.

Claims

1. A lithium battery slurry recovery device, characterized in that: include: A reaction container (10) having an internal space (16) for accommodating lithium battery slurry to be recycled; the reaction container (10) is further integrated with an oil guide pipe (11), and an oil inlet (12) and an oil outlet (13) in communication with the oil guide pipe (11); an oil temperature controller (20) connected to the oil inlet (12) and the oil outlet (13) to inject heat transfer oil into the oil inlet (12) and receive the heat transfer oil delivered from the oil outlet (13); the oil temperature controller (20) is used to heat the material in the reaction container (10) to 240-250 degrees Celsius; a stirring mechanism (80), disposed in the inner space (16) of the reaction container (10), for stirring the material in the reaction container (10) during the recovery process; A vacuum pump (30) acts on the interior of the reaction container (10) to generate negative pressure; a condenser (40), connected between the reaction vessel (10) and the vacuum pump (30); a liquid storage tank (50), connected between the condenser (40) and the vacuum pump (30); A filter (70) is further connected between the condenser (40) and the reaction container (10); the filter (70) is arranged on the top of the reaction container (10) and communicates with the internal space (16) of the reaction container (10); an air outlet of the filter (70) is connected to the condenser (40); The lithium battery slurry recovery equipment further includes: a nitrogen generator (60) capable of generating nitrogen; A first filter (70a) and a second filter (70b) are arranged on the top of the reaction container (10); an air outlet of the first filter (70a) is connected to the condenser (40) via a first connecting pipe (90a); and an air outlet of the second filter (70b) is connected to the condenser (40) via a second connecting pipe (90b). A first three-way valve (91) is provided on the first connecting pipe (90a), wherein a first interface of the first three-way valve (91) is connected to the first filter (70a), a second interface is connected to the condenser (40), and a third interface is connected to the nitrogen generator (60); the first three-way valve (91) has a first working state and a second working state; when the first three-way valve (91) is adjusted to the first working state, the first three-way valve (91) is adjusted so that the first interface is not connected to the second interface, the first interface is connected to the third interface, and the second interface is not connected to the third interface; when the first three-way valve (91) is adjusted to the second working state, the first three-way valve (91) is adjusted so that the first interface is connected to the second interface, the first interface is not connected to the third interface, and the second interface is not connected to the third interface; A second three-way valve (92) is provided on the second connecting pipe (90b); a first interface of the second three-way valve (92) is connected to the second filter (70b), a second interface is connected to the condenser (40), and a third interface is connected to the nitrogen generator (60); the second three-way valve (92) has a first working state and a second working state; when the second three-way valve (92) is adjusted to the first working state, the second three-way valve (92) is adjusted so that the first interface is not connected to the second interface, the first interface is connected to the third interface, and the second interface is not connected to the third interface; when the second three-way valve (92) is adjusted to the second working state, the second three-way valve (92) is adjusted so that the first interface is connected to the second interface, the first interface is not connected to the third interface, and the second interface is not connected to the third interface; When the nitrogen generator (60) is turned on, the first three-way valve (91) is cyclically switched between the first working state and the second working state, and the second three-way valve (92) is cyclically switched between the first working state and the second working state, and when the first three-way valve (91) is in the first working state, the second three-way valve (92) is in the second working state, and when the first three-way valve (91) is in the second working state, the second three-way valve (92) is in the first working state.

2. The lithium battery slurry recovery equipment according to claim 1, characterized in that: The stirring mechanism (80) comprises: a stirring shaft (81) which is transversely and sealedly mounted on the reaction vessel (10), laterally passing through the interior space (16) of the reaction vessel (10), with a first end and a second end thereof extending out of the reaction vessel (10) from both sides; the stirring shaft (81) is capable of freely rotating relative to the reaction vessel (10); A stirring blade (82) is mounted on the stirring shaft (81) and is capable of rotating synchronously with the stirring shaft (81) to stir the material in the reaction container (10); A first support seat (83) is arranged outside the reaction container (10) and is used to rotatably support the first end of the stirring shaft (81); A second support base (84) is arranged outside the reaction vessel (10) and is used to rotatably support the second end of the stirring shaft (81); The driving source (85) is arranged outside the reaction container (10) and is connected to the first end of the stirring shaft (81) in a power manner so as to drive the stirring shaft (81) to rotate.

3. The lithium battery slurry recovery equipment according to claim 2, characterized in that: A high-temperature sealing structure (86) is provided between the stirring shaft (81) and the reaction container (10); The high-temperature sealing structure (86) includes: a sealed cavity (861) mounted on the reaction vessel (10), the sealed cavity (861) surrounding the periphery of the stirring shaft (81) and provided with an oil inlet hole (8611) for injecting lubricating oil and an oil outlet hole (8612) for discharging lubricating oil; A sealing ring is arranged inside the sealing cavity (861) and around the periphery of the stirring shaft (81), the sealing ring comprising a stationary ring (862) and a dynamic ring (863), the stationary ring (862) being attached to the sealing cavity (861) to remain stationary, and the dynamic ring (863) being mounted on the stirring shaft (81) and rotating along with the stirring shaft (81); a seal is formed between the stationary ring (862) and the dynamic ring (863).

4. The lithium battery slurry recovery equipment according to claim 3, characterized in that: The static ring (862) includes an upper static ring (862a) and a lower static ring (862b); the dynamic ring (863) is located between the upper static ring (862a) and the lower static ring (862b), and includes an upper dynamic ring (863a) adapted to the upper static ring (862a), and a lower dynamic ring (863b) adapted to the lower static ring (862b); The high-temperature sealing structure (86) further comprises a dynamic ring mounting structure (864) for mounting an upper dynamic ring (863a) and a lower dynamic ring (863b).

5. The lithium battery slurry recovery equipment according to claim 3, characterized in that: A cooling channel (8613) is arranged circumferentially inside the sealed cavity (861), and a cooling liquid inlet (8614) and a cooling liquid outlet (8615) are provided that are in communication with the cooling channel (8613); the positions of the cooling liquid inlet (8614) and the cooling liquid outlet (8615) are arranged symmetrically with respect to the axis of the stirring shaft (81).

6. The lithium battery slurry recovery equipment according to claim 2, characterized in that: The reaction container (10) is provided with a feed port (14) at the top and a discharge port (15) at the middle of the bottom; The stirring blade (82) includes a first stirring blade (821) located on the left side of the discharge port (15) and a second stirring blade (822) located on the right side of the discharge port (15); the first stirring blade (821) and the second stirring blade (822) are deflected in opposite directions. As the first stirring blade (821) rotates, the first stirring blade (821) stirs the material located on the left side of the discharge port (15) and causes the material to move to the right; as the second stirring blade (822) rotates, the second stirring blade (822) stirs the material located on the right side of the discharge port (15) and causes the material to move to the left.

7. The lithium battery slurry recovery equipment according to claim 1, characterized in that: The vacuum pump (30) is also connected to an exhaust gas treatment device.

8. A lithium battery slurry recovery method, characterized in that: The lithium battery slurry recovery method is applied to the lithium battery slurry recovery equipment according to any one of claims 1 to 7, comprising the steps of: Controlling the vacuum pump (30) to act on the interior of the reaction container (10) to generate negative pressure; Controlling the oil temperature machine (20) to heat the material in the reaction vessel (10) to 240-250 degrees Celsius; controlling the stirring mechanism (80) to stir the material in the reaction container (10); The condenser (40) is controlled to cool the gas evaporated from the reaction vessel (10) so as to condense N-methylpyrrolidone NMP.

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