Lithium battery slurry wastewater recovery device

Abstract

The utility model discloses a lithium battery slurry waste water recovery device, which comprises a first vacuum concentration component, a second vacuum concentration component, a third vacuum concentration component and a fourth vacuum concentration component, the first condenser is provided with a first condensation inlet, a first gas outlet and a first condensation outlet, and the first condensation inlet is connected with the first recovery outlet; the second vacuum concentration part is provided with a second feeding hole, a second recovery outlet and a second mixed liquid outlet, and the second feeding hole is connected with the first mixed liquid outlet; the second condenser is provided with a second condensation inlet, a second gas outlet and a second condensation outlet, and the second condensation inlet is connected with the second recovery outlet; and the vacuum dryer is provided with a third feed port, a third recovery outlet and a fourth recovery outlet, the third feed port is connected with the second mixed liquid outlet, and the fourth recovery outlet is connected with the second condensation inlet. The lithium salt and NMP (N-Methyl Pyrrolidone) products in the lithium battery slurry can be effectively recycled.

Description

Technical Field

[0001] The utility model relates to the technical field of wastewater recovery equipment, in particular to a lithium battery slurry wastewater recovery device. Background Art

[0002] Lithium batteries are widely used as an energy storage device in electronic devices, new energy batteries, and other fields. With the increase in production, how to effectively recycle and process waste lithium battery slurry has become a research focus for many research institutions and companies at home and abroad.

[0003] Waste lithium battery slurry contains a salty mixed aqueous solution containing 30%-50% N-methylpyrrolidone (NMP). This solution, typically obtained through preliminary filter press pretreatment, contains 20%-30% salty mixed aqueous solution. Many existing technologies for recovering NMP from saline wastewater utilize extractive distillation. While this method effectively recovers NMP, it requires the introduction of an organic extractant, which not only incurs high processing costs but also requires significant resource management for its safe management. Furthermore, the treated wastewater contains high levels of both lithium salts and organic matter, making it difficult to effectively recover the lithium salts. This wastes valuable lithium salts and hinders subsequent wastewater recovery. Utility Model Content

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a lithium battery slurry wastewater recovery device that can effectively recover lithium salts and NMP products in the lithium battery slurry.

[0005] The solution of the utility model to solve its technical problems is:

[0006] A lithium battery slurry wastewater recovery device, comprising:

[0007] a first vacuum concentrating component, provided with a first feed inlet, a first recovery outlet, and a first mixed liquid outlet, wherein the first feed inlet is used to introduce lithium battery slurry, and the first vacuum concentrating component concentrates the lithium battery slurry at a first temperature;

[0008] a first condenser, comprising a first condensation inlet, a first gas outlet, and a first condensation outlet, wherein the first condensation inlet is connected to the first recovery outlet, and the first condensation outlet is used to discharge wastewater;

[0009] a second vacuum concentrating component, provided with a second feed inlet, a second recovery outlet, and a second mixed liquid outlet, wherein the second feed inlet is connected to the first mixed liquid outlet, and the second vacuum concentrating component concentrates the lithium battery slurry at a second temperature, wherein the second temperature is greater than the first temperature;

[0010] a second condenser, provided with a second condensation inlet, a second gas outlet, and a second condensation outlet, wherein the second condensation inlet is connected to the second recovery outlet, and the second condensation outlet is used to flow out the NMP product;

[0011] The vacuum dryer is provided with a third feed inlet, a third recovery outlet and a fourth recovery outlet, wherein the third feed inlet is connected to the second mixed liquid outlet, the third recovery outlet is used to discharge the lithium salt product, and the fourth recovery outlet is connected to the second condensation inlet.

[0012] The present invention has at least the following beneficial effects: the lithium battery slurry is vacuum concentrated and separated to produce wastewater by a first vacuum concentration component, the wastewater is condensed by a first condenser and then recovered in a centralized manner, the NMP concentration in the remaining lithium battery slurry is increased, the NMP solution is vacuum concentrated and separated by a second vacuum concentration component, the NMP solution is condensed by a second condenser to obtain an NMP product for subsequent use, the lithium salt content in the remaining lithium battery slurry is increased, and a pure lithium salt product can be obtained after vacuum drying in a vacuum dryer. The present invention utilizes the different boiling points of water and NMP to achieve separation of wastewater and NMP solution at different temperatures, can recover NMP product without introducing an extractant, and can effectively recover lithium salt product, avoiding waste of lithium salt product. The wastewater obtained after treatment by the lithium battery slurry wastewater recovery device of this embodiment has low NMP and lithium salt content and no organic extractant, which is beneficial for subsequent recovery and treatment of the wastewater.

[0013] In addition, due to the use of the first vacuum concentration component, the second vacuum concentration component and the vacuum dryer, the boiling point can be lowered in a vacuum environment, evaporation concentration can be achieved under low temperature conditions, the concentration efficiency can be improved, and heat loss and energy consumption can be reduced.

[0014] As a further improvement of the above technical solution, the lithium battery slurry wastewater recovery device further includes:

[0015] A vacuum pump, wherein an inlet end of the vacuum pump is connected to the first gas outlet and the second gas outlet respectively.

[0016] With this arrangement, the vacuum pump can evacuate the entire lithium battery slurry wastewater recovery device, reducing the number of vacuum equipment required and improving the utilization rate of the vacuum pump.

[0017] As a further improvement of the above technical solution, the first vacuum concentration component includes a first heating chamber, a first separator, a first heat exchanger and a first compressor. The first feed port and the first mixed liquid outlet are arranged in the first heating chamber. The inlet end of the first separator is connected to the first heating chamber, and the outlet end of the first separator is connected to the inlet end of the first heat exchanger. The first heat exchanger is provided with two outlet ends, one of the outlet ends of the first heat exchanger is the first recovery outlet, and the other outlet end of the first heat exchanger is connected to the inlet end of the first compressor. The outlet end of the first compressor is connected to the first heating chamber, and the operating temperature of the first heating chamber is the first temperature.

[0018] With this setup, low-pressure steam is introduced into the first heating chamber. The steam, acting as an energy carrier, cycles back and forth through the closed loop system, releasing and absorbing heat during phase transitions. The released heat is used to heat and evaporate the liquid in the first heating chamber, while the absorbed heat comes from the condensation heat of the secondary steam generated by the evaporation of the liquid. By utilizing both hot and cold energy, low-concentration lithium battery slurry can be concentrated to form a higher-concentration NMP mixture at a relatively low temperature.

[0019] As a further improvement of the above technical solution, the second vacuum concentration component includes a second heating chamber, a second separator, a second heat exchanger and a second compressor. The second feed port and the second mixed liquid outlet are arranged in the second heating chamber. The inlet end of the second separator is connected to the second heating chamber, and the outlet end of the second separator is connected to the inlet end of the second heat exchanger. The second heat exchanger is provided with two outlet ends, one of the outlet ends of the second heat exchanger is the second recovery outlet, and the other outlet end of the second heat exchanger is connected to the inlet end of the second compressor. The outlet end of the second compressor is connected to the second heating chamber, and the operating temperature of the second heating chamber is the second temperature.

[0020] After the lithium battery slurry with low slag content enters the second heating chamber from the second feed port, it is heated to the second temperature and then evaporated and concentrated. The secondary steam generated by evaporation is separated into a recyclable high-concentration NMP solution through the second separator. The slag content of the remaining lithium battery slurry is increased, thereby achieving preliminary separation of the NMP solution and the lithium salt slag.

[0021] As a further improvement to the above technical solution, the second vacuum concentrating unit further includes a propeller blade disposed within the second heating chamber for stirring the material within the second heating chamber. The propeller blade agitates the NMP-slag mixed liquid within the second heating chamber, thereby improving the vacuum evaporation efficiency of the NMP solution and enabling more complete evaporation of the NMP solution, further increasing the slag content of the NMP-slag mixed liquid exiting the second mixed liquid outlet.

[0022] As a further improvement to the above technical solution, the first temperature is in the range of greater than or equal to 60°C and less than or equal to 70°C, and the second temperature is in the range of greater than or equal to 100°C and less than or equal to 120°C. At the first temperature, due to the lowering of the boiling point of water in a vacuum environment, water in the lithium battery slurry can evaporate, thereby increasing the concentration of the lithium battery slurry, and the energy consumption of vacuum evaporation is greatly reduced; vacuum evaporation at the second temperature can substantially achieve the separation of most of the lithium salt slag and the NMP organic liquid, and the energy consumption is greatly reduced.

[0023] As a further improvement of the above technical solution, the lithium battery slurry wastewater recovery device further includes:

[0024] a buffer chamber, wherein an inlet end of the buffer chamber is connected to an outlet of the second mixed liquid;

[0025] An arch breaker, wherein the output end of the arch breaker is arranged in the buffer chamber and located at the bottom of the buffer chamber;

[0026] A screw feeder, wherein the inlet end of the screw feeder is connected to the outlet end of the buffer bin, and the outlet end of the screw feeder is connected to the third feed port.

[0027] After the slag mixture is collected in the buffer bin, it enters the vacuum dryer through a spiral feeder for vacuum drying. The arch breaker can prevent the slag mixture from being blocked in the buffer bin. The spiral feeder can further stir the slag mixture entering the vacuum dryer. The slag mixture spirals into the vacuum dryer under the strong action of the high-speed rotating stirring paddle of the spiral feeder. The slag mixture is affected by impact and shear force and is dispersed. The block material can be quickly crushed. After entering the vacuum dryer, it can be fully contacted with hot air, heated, and dried, thereby improving the vacuum drying efficiency and making the slag mixture dry more completely, and the obtained lithium salt product has higher purity.

[0028] As a further improvement of the above technical solution, the lithium battery slurry wastewater recovery device further includes:

[0029] An exhaust gas treatment component is connected to the outlet end of the vacuum pump.

[0030] The waste gas treatment component is used to treat waste gas. The waste gas extracted by the vacuum pump is treated by the waste gas treatment component, which can prevent the overflow of low-boiling point organic gas and reduce environmental pollution.

[0031] As a further improvement to the above technical solution, multiple vacuum pumps are provided, with their inlet ends interconnected and their outlet ends interconnected. The parallel arrangement of the vacuum pumps can improve vacuuming efficiency, thereby improving the processing efficiency of the lithium battery slurry.

[0032] As a further improvement of the above technical solution, the lithium battery slurry wastewater recovery device further includes:

[0033] A wastewater treatment component is connected to the first condensation outlet.

[0034] The wastewater treatment component is used to further perform harmless treatment on the wastewater flowing out of the first condensation outlet to prevent the wastewater from polluting the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following is a brief description of the drawings required for describing the embodiments. Obviously, the drawings described are only part of the embodiments of the present invention, not all of them. Those skilled in the art can also derive other design solutions and drawings based on these drawings without inventive effort.

[0036] Figure 1 This is a schematic diagram of the overall layout of the lithium battery slurry wastewater recovery device according to an embodiment of the present utility model;

[0037] Figure 2 This is a schematic diagram of the arrangement of the first vacuum concentration component of the lithium battery slurry wastewater recovery device according to an embodiment of the present utility model;

[0038] Figure 3 This is a schematic diagram of the layout of the second vacuum concentration component of the lithium battery slurry wastewater recovery device according to an embodiment of the present invention;

[0039] Figure 4 This is a schematic diagram of the layout of the vacuum dryer of the lithium battery slurry wastewater recovery device according to an embodiment of the present invention;

[0040] Figure 5 This is a schematic diagram of the layout of the vacuum pump of the lithium battery slurry wastewater recovery device in an embodiment of the present utility model.

[0041] Reference numerals: 100, first vacuum concentration component; 110, first heating chamber; 120, steam heater; 130, first separator; 140, first heat exchanger; 150, first compressor; 160, first feed bin; 170, first feed inlet; 180, first recovery outlet; 190, first mixed liquid outlet; 200, first condenser; 210, wastewater treatment component; 220, first condensation inlet; 230, first condensation outlet; 240, first gas outlet; 300, second vacuum concentration component; 310, second heating chamber; 320, propeller blade; 330, second separator; 340, second heat exchanger; 35 0. Second compressor; 360. Second feed bin; 370. Second feed port; 380. Second recovery outlet; 390. Second mixed liquor outlet; 400. Second condenser; 410. NMP product condensate storage component; 420. Second condensate inlet; 430. Second condensate outlet; 440. Second gas outlet; 500. Vacuum dryer; 510. Lithium salt product storage box; 520. Buffer bin; 530. Arch breaker; 540. Screw feeder; 550. Bag dust collector; 560. Third feed port; 570. Third recovery outlet; 580. Fourth recovery outlet; 600. Vacuum pump; 700. Waste gas treatment component. DETAILED DESCRIPTION

[0042] The following describes in detail embodiments of the present invention, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0043] In the description of the present invention, descriptions of directions, such as up, down, front, back, left, right, etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as a limitation on the present invention.

[0044] In the description of this utility model, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and is not to be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0045] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0046] Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without inventive effort are all within the scope of protection of the present invention. The various technical features of the present invention may be combined interchangeably as long as they do not conflict with each other.

[0047] Reference Figure 1 The embodiment of the present utility model proposes a lithium battery slurry wastewater recovery device, which can effectively recover lithium salts and NMP products in the lithium battery slurry, and does not require the introduction of organic extractants, thereby reducing the treatment cost of the lithium battery slurry wastewater.

[0048] In this embodiment, the lithium battery slurry wastewater recovery device includes a first vacuum concentration component 100, a first condenser 200, a second vacuum concentration component 300, a second condenser 400 and a vacuum dryer 500, and the lithium battery slurry is concentrated and dried under a vacuum environment.

[0049] Reference Figure 2 The first vacuum concentrating unit 100 is provided with a first feed port 170, a first recovery outlet 180, and a first mixed liquid outlet 190. The first feed port 170 is used to introduce lithium battery slurry. After the lithium battery slurry enters the first vacuum concentrating unit 100 through the first feed port 170, it is vacuum-concentrated within the first vacuum concentrating unit 100. The vacuum concentrating temperature of the first vacuum concentrating unit 100 is a first temperature.

[0050] After the lithium battery slurry is vacuum concentrated at the first temperature, a lithium battery slurry with higher wastewater and NMP concentration can be obtained. Figure 2 and Figure 5 The first condenser 200 is provided with a first condensation inlet 220, a first condensation outlet 230, and a first gas outlet 240. The first condensation inlet 220 is connected to the first recovery outlet 180. The wastewater flows to the first condensation inlet 220 through the first recovery outlet 180, and enters the first condenser 200 through the first condensation inlet 220 to be condensed to form wastewater at room temperature. The wastewater flows out of the first condensation outlet 230 of the first condenser 200 for recovery, and the low-boiling-point non-condensable gas leaves the first condenser 200 through the first gas outlet 240.

[0051] Reference Figure 3The second vacuum concentrating unit 300 is provided with a second feed inlet 370, a second recovery outlet 380, and a second mixed liquid outlet 390. The second feed inlet 370 is connected to the first mixed liquid outlet 190 of the first vacuum concentrating unit 100. The lithium battery slurry flowing out of the first mixed liquid outlet 190 enters the second vacuum concentrating unit 300 through the second feed inlet 370 for vacuum concentration. The vacuum concentration temperature of the second vacuum concentrating unit 300 is a second temperature, which is greater than the first temperature.

[0052] It can be understood that the lithium battery slurry with higher concentration is the NMP slag mixed liquid, which enters the second vacuum concentration component 300. After vacuum concentration at the second temperature, the NMP slag mixed liquid with higher slag content and the high-concentration NMP solution can be obtained. The NMP slag mixed liquid flows out from the second mixed liquid outlet 390, and the high-concentration NMP solution flows out from the second recovery outlet 380.

[0053] Reference Figure 3 and Figure 5 The second condenser 400 is provided with a second condensation inlet 420, a second condensation outlet 430, and a second gas outlet 440. The first condensation inlet 220 is connected to the second recovery outlet 380. The high-concentration NMP solution flows through the second recovery outlet 380 to the second condensation inlet 420, and enters the second condenser 400 through the second condensation inlet 420 for condensation to form NMP product, which flows out from the second condensation outlet 430 for recovery, while the non-condensable gas leaves the condenser from the second gas outlet 440.

[0054] Reference Figure 4 The vacuum dryer 500 is provided with a third feed port 560, a third recovery outlet 570, and a fourth recovery outlet 580. The third feed port 560 is connected to the second mixed liquid outlet 390. The NMP residue mixed liquid flowing out of the second mixed liquid outlet 390 enters the vacuum dryer 500 through the third feed port 560 and is dried under a vacuum environment. After drying, a lithium salt product and an NMP solution separated from each other are obtained. The lithium salt product flows out of the third recovery outlet 570 and is recovered. The fourth recovery outlet 580 is connected to the second condensation inlet 420. The NMP solution obtained after drying flows from the fourth recovery outlet 580 to the second condensation inlet 420 and enters the second condenser 400 through the second condensation inlet 420 for condensation. After the NMP solution is condensed, an NMP product can be obtained. The NMP product flows out of the second condensation outlet 430 and is recovered.

[0055] It can be understood that by using the lithium battery slurry wastewater recovery device of this embodiment, the NMP product can be recovered without introducing an extractant, and the lithium salt product can be effectively recovered to avoid waste of the lithium salt product. The wastewater obtained after treatment by the lithium battery slurry wastewater recovery device of this embodiment has low NMP and lithium salt content, and no organic extractant is present, which is conducive to the subsequent recovery and treatment of the wastewater.

[0056] Since the lithium battery slurry wastewater recovery device of this embodiment adopts a vacuum concentration method, it can lower the boiling point, achieve evaporation concentration under low temperature conditions, improve concentration efficiency, reduce heat loss, and reduce energy consumption.

[0057] It is understandable that the first vacuum concentrating component 100, the second vacuum concentrating component 300 and the vacuum dryer 500 all need to undergo a vacuuming process to achieve low vacuum concentration or drying requirements.

[0058] In this embodiment, referring to Figure 1 and Figure 5 The lithium battery slurry wastewater recovery device also includes a vacuum pump 600, which can perform vacuuming. The first gas outlet 240 of the first condenser 200 and the second gas outlet 440 of the second condenser 400 are respectively connected to the outlet end of the vacuum pump 600.

[0059] With such an arrangement, the vacuum pump 600 can vacuum the entire lithium battery slurry wastewater recovery device, including vacuuming the first condenser 200 and the second condenser 400. It can also vacuum the first vacuum concentration component 100 through the first condenser 200, and vacuum the second vacuum concentration component 300 and the vacuum dryer 500 through the second condenser 400, thereby reducing the setting of vacuum equipment.

[0060] In addition, the vacuum pump 600 can extract the low-boiling-point non-condensable gas remaining from the first condenser 200 and the non-condensable gas remaining from the second condenser 400, which is beneficial for subsequent centralized treatment of the waste gas.

[0061] In some embodiments, reference Figure 2 The first vacuum concentration unit 100 includes a first heating chamber 110, a first separator 130, a first heat exchanger 140, and a first compressor 150. The first feed port 170 and the first mixed liquid outlet 190 are both located in the first heating chamber 110. The inlet of the first separator 130 is connected to the first heating chamber 110, and the outlet of the first separator 130 is connected to the inlet of the first heat exchanger 140. The first heat exchanger 140 has two outlets, one of which is a first recovery outlet 180, and the other is connected to the first heating chamber 110.

[0062] It is understood that a steam heater 120 is provided in the first heating chamber 110. After the vacuum pump 600, the first separator 130, the first heat exchanger 140, the first compressor 150 and the first condenser 200 are turned on, the steam heater 120 in the first heating chamber 110 is turned on, and low-pressure steam is introduced into the first heating chamber 110. Steam is used as an energy-carrying medium to complete the continuous cycle of gaseous, liquid and gaseous states in a closed circulation system, and heat release and heat absorption are achieved during the phase change process. Among them, the released heat energy is used to heat and evaporate the feed liquid in the first heating chamber 110, and the absorbed heat energy comes from the condensation heat of the secondary steam generated by the evaporation of the feed liquid. By utilizing both the hot and cold sides of the energy, it is possible to concentrate the low-concentration lithium battery slurry to form an NMP mixed solution with a higher NMP concentration under low temperature regulation.

[0063] It can be understood that after the low-concentration lithium battery slurry enters the first heating chamber 110 from the first feed port 170, it is heated to the first temperature and then evaporated and concentrated. The secondary steam generated by evaporation passes through the first separator 130 and enters the first heat exchanger 140. After passing through the first heat exchanger 140, part of it enters the first compressor 150 and re-enters the first heating chamber 110 through the first compressor 150, which can further reduce energy consumption.

[0064] It is understood that under the steam heating and high vacuum suction of the first separator 130, the water and secondary steam in the low-concentration lithium battery slurry enter the first separator 130 at a relatively fast rate. Under the high vacuum conditions, the water is evaporated by the principle of water boiling point depression, which can also prevent other substances in the lithium battery slurry from being destroyed, and is more conducive to the subsequent recycling of lithium salt products and NMP products. It is understandable that due to the evaporation of water in the original low-concentration lithium battery slurry, the concentration of the lithium battery slurry increases.

[0065] In some embodiments, reference Figure 3 The second vacuum concentrator 300 includes a second heating chamber 310, a second separator 330, a second heat exchanger 340, and a second compressor 350. The second feed inlet 370 and the second mixed liquid outlet 390 in the second vacuum concentrator 300 are both located in the second heating chamber 310. The second heating chamber 310 serves as the primary heating device for the feed liquid and operates at the second temperature. The inlet of the second separator 330 is connected to the second heating chamber 310, and the outlet of the second separator 330 is connected to the inlet of the second heat exchanger 340. The second heat exchanger 340 has two outlets. One of the outlets of the second heat exchanger 340 serves as a second recovery outlet 380, through which the high-concentration NMP solution flows. The other outlet of the second heat exchanger 340 is connected to the inlet of the second compressor 350, and the outlet of the second compressor 350 is connected to the second heating chamber 310.

[0066] It can be understood that a heating component is provided in the second heating chamber 310, which can raise the temperature inside the heating chamber to a second temperature. The second vacuum concentration component 300 applies the principle of vacuum evaporation to further concentrate and evaporate the high-concentration lithium battery slurry, wherein the second temperature is the evaporation temperature of the NMP solution. The NMP solution evaporates at the second temperature, and the remaining evaporation is a slag mixed liquid with a higher slag content, thereby realizing the preliminary separation of the lithium salt slag and the NMP solution.

[0067] It can be understood that after the lithium battery slurry with low slag content enters the second heating chamber 310 from the second feed port 370, it is heated to the second temperature and then evaporated and concentrated. The secondary steam generated by evaporation passes through the second separator 330 and enters the second heat exchanger 340. After passing through the second heat exchanger 340, part of it enters the second compressor 350 and re-enters the second heating chamber 310 through the second compressor 350, which can further reduce energy consumption.

[0068] It is understood that under the steam heating and the high vacuum suction of the second separator 330, the NMP solution in the lithium battery slurry with low slag content enters the second separator 330 at a relatively fast rate. Under low pressure conditions, the NMP solution is evaporated by utilizing the principle of lowering the boiling point of the NMP solution, thereby achieving a preliminary separation of the NMP solution from the lithium salt slag, which is more conducive to the subsequent recycling of the lithium salt product and the NMP product. It is understandable that since the NMP solution in the lithium battery slurry entering the second heating chamber 310 is evaporated, the NMP mixed liquid with slag flowing out of the second mixed liquid outlet 390 has a higher slag content.

[0069] In some embodiments, the second vacuum concentration component 300 further includes a propeller blade 320, which is disposed in the second heating chamber 310 and can stir the NMP mixed liquid with slag in the second heating chamber 310 to improve the evaporation efficiency of the NMP solution, and can also allow the NMP solution to evaporate more thoroughly, further increasing the slag content of the NMP mixed liquid with slag flowing out of the second mixed liquid outlet 390.

[0070] In some embodiments, the first temperature is within a range of 60°C to 70°C. At this temperature, due to the lower boiling point of water in a vacuum environment, water in the lithium battery slurry can evaporate, thereby increasing the concentration of the lithium battery slurry. Vacuum concentration of the lithium battery slurry at room temperature can reduce the amount of NMP wastewater to be processed by 80%. Furthermore, since the vacuum concentration temperature is only 60°C-70°C, the energy consumption is only 30% of that of traditional multi-stage coupled distillation equipment, significantly reducing the energy consumption of lithium battery slurry processing and reducing resource waste.

[0071] In some embodiments, the second temperature is within a range of greater than or equal to 100°C and less than or equal to 120°C. At this temperature, the boiling point of the NMP solution decreases under vacuum, causing it to evaporate, thereby increasing the slag content of the lithium battery slurry and achieving a preliminary separation of the NMP solution from the lithium salt slag. Vacuum concentration within this temperature range can substantially separate the lithium salt slag from the NMP organic liquid, resulting in a 70% NMP solution and a slag-containing mixed solution with approximately 50% slag. Using the second vacuum concentrator 300 for vacuum concentration consumes only 40% of the energy required for evaporation using a conventional evaporator.

[0072] Reference Figure 4 In some embodiments, the lithium battery slurry wastewater recovery device further includes a buffer bin 520, a breaker 530, and a screw feeder 540. The inlet of the buffer bin 520 is connected to the second mixed liquid outlet 390. The residue-containing mixed liquid, after vacuum concentration by the second vacuum concentrating component 300, flows out of the second heating chamber 310 through the second mixed liquid outlet 390 and enters the buffer bin 520. The output end of the breaker 530 is disposed within the buffer bin 520 and at the bottom of the buffer bin 520. As a silo clearing device, it can clear the outlet of the buffer bin 520 to prevent the residue-containing mixed liquid from clogging in the buffer bin 520. The inlet of the screw feeder 540 is connected to the outlet of the buffer bin 520, while the outlet of the screw feeder 540 is connected to the third feed port 560. After the residue-containing mixed liquid is collected in the buffer bin 520, it passes through the screw feeder 540 and enters the vacuum dryer 500 for vacuum drying to obtain a usable lithium salt product.

[0073] It can be understood that the spiral feeder 540 can further stir the mixed liquid with residue entering the vacuum dryer 500. The mixed liquid with residue spirally enters the vacuum dryer 500 under the strong action of the high-speed rotating stirring paddle of the spiral feeder 540. The mixed liquid with residue is affected by the impact and shear force and is dispersed. The block material can be quickly crushed. After entering the vacuum dryer 500, it can be fully contacted with the hot air, heated, and dried, thereby improving the vacuum drying efficiency, and allowing the mixed liquid with residue to be dried more completely, and the obtained lithium salt product has a higher purity.

[0074] In this embodiment, the vacuum dryer 500 can further dry and separate the NMP-slag mixture containing 50% slag at a processing temperature of 120-140°C, resulting in an NMP-free lithium salt product. The lithium battery slurry wastewater recovery device also includes a lithium salt product storage tank 510, which is located at the third recovery outlet 570. The lithium salt product obtained after drying in the vacuum dryer 500 enters the lithium salt product storage tank 510 from the third recovery outlet 570 for storage for subsequent use.

[0075] It can be understood that after drying in the vacuum dryer 500, the NMP solution separated from the lithium salt product flows into the second condenser 400 through the fourth recovery outlet 580, and is condensed in the second condenser 400 together with the NMP solution flowing out of the second recovery outlet 380 of the second vacuum concentration component 300, to obtain a usable NMP product after condensation.

[0076] In some embodiments, the lithium battery slurry wastewater recovery device also includes a bag dust collector 550, which is arranged between the fourth recovery outlet 580 of the vacuum dryer 500 and the second condensation inlet 420 of the second condenser 400. The bag dust collector 550 can remove dust and filter the NMP solution dried by the vacuum dryer 500, which is more conducive to obtaining a cleaner NMP product, reducing subsequent processing steps for the NMP product, and avoiding blockage and damage to the second condenser 400.

[0077] In some embodiments, the lithium battery slurry wastewater recovery device further includes an NMP product condensation storage component 410, which is disposed at the second condensation outlet 430 of the second condenser 400 and can collect the outflowing NMP product for subsequent centralized processing and utilization of the NMP product.

[0078] It is understood that a small amount of low-boiling-point organic gas may be present in the gas flowing out of the first gas outlet 240 and the second gas outlet 440, and these low-boiling-point organic gases are extracted under the action of the vacuum pump 600. In some embodiments, the lithium battery slurry wastewater recovery device further includes an exhaust gas treatment component 700. It is understood that the exhaust gas treatment component 700 is used to treat exhaust gas, which is connected to the outlet end of the vacuum pump 600. The exhaust gas extracted by the vacuum pump 600 is treated by the exhaust gas treatment component 700, which can prevent the low-boiling-point organic gas from overflowing and reduce environmental pollution.

[0079] In this embodiment, the exhaust gas treatment component 700 includes a water spray system and an activated carbon adsorption system. The water spray system applies a mist to the exhaust gas extracted by the vacuum pump 600, removing pollutants from the exhaust gas through the cooling and sedimentation effects of the mist. The activated carbon adsorption system uses activated carbon to adsorb organic gases in the exhaust gas. This, combined with the water spray system, provides a dual safeguard, further preventing the escape of low-boiling-point organic gases.

[0080] Reference Figure 5In some embodiments, multiple vacuum pumps 600 are provided, and the inlet ends and outlet ends of the multiple vacuum pumps 600 are interconnected, that is, the multiple vacuum pumps 600 are arranged in parallel. This arrangement can improve the efficiency of vacuuming and ensure that both the first vacuum concentrating unit 100 and the second vacuum concentrating unit 300 are in a vacuum state. The first separator 130 provides high vacuum suction to the first heating chamber 110, and the second separator 330 provides high vacuum suction to the second heating chamber 310. The concentrated material and secondary steam enter the first separator 130 or the second separator 330 at a relatively high speed, and are quickly separated into gas and liquid.

[0081] Reference Figure 1 and Figure 2 In some embodiments, the lithium battery slurry wastewater recovery device further includes a wastewater treatment component 210, which is connected to the first condensation outlet 230. It can be understood that the wastewater treatment component 210 is used to further harmlessly treat the wastewater flowing out of the first condensation outlet 230 to prevent the wastewater from polluting the environment.

[0082] Reference Figure 2 and Figure 3 In some embodiments, the lithium battery slurry wastewater recovery device further includes a first feed bin 160 and a second feed bin 360, both of which are used to cache materials. The outlet end of the first feed bin 160 is connected to the first feed port 170. During operation, the lithium battery slurry is added from the inlet end of the first feed bin 160 to the first feed bin 160, and the lithium battery slurry can be evenly added to the first vacuum concentration component 100 for vacuum concentration. The inlet end of the second feed bin 360 is connected to the first mixed liquid outlet 190, and the outlet end of the second feed bin 360 is connected to the second feed port 370 of the second vacuum concentration component 300. After the lithium battery slurry flowing out of the first vacuum concentration component 100 is concentrated in the second feed bin 360, it is evenly added to the second vacuum concentration component 300 through the second feed bin 360 for vacuum concentration.

[0083] Take the treatment of 4000kg lithium battery slurry containing 10% NMP and 0.2% salt as an example, refer to Figures 1 to 5 The arrow in the figure indicates the direction of material flow. The specific process of recycling and treating the lithium battery slurry wastewater using the lithium battery slurry wastewater recycling device of this embodiment is as follows:

[0084] First, a canned motor pump was used to uniformly add 4,000 kg of lithium battery slurry containing 10% NMP and 0.2% salt to the first vacuum concentrator 100 at a flow rate of 500 kg / min through the first feed hopper 160. The first feed port 170 was closed, and nitrogen was purged through the first vacuum concentrator 100 for 5 minutes, reducing the oxygen content in the first vacuum concentrator 100 to below 2%. The vacuum pump 600, exhaust gas treatment unit 700, first separator 130, first heat exchanger 140, first compressor 150, and first condenser 200 were then sequentially started. Once these devices were operational, the vacuum level was maintained at an absolute pressure of approximately 1-2 kPa. Finally, the steam heater 120 in the first heating chamber 110 was activated, and 0.1 MPa low-pressure steam was introduced into the chamber to raise the temperature of the lithium battery slurry to 60°C. The slurry was then vacuum-concentrated at room temperature for 2 hours. When the NMP concentration in the lithium battery slurry reaches 70%, heating is stopped. At this point, an estimated 600 kg of 70% NMP-containing residue mixture and 3,400 kg of wastewater containing 0.1% NMP are produced. The residue content of the residue mixture is approximately 14%. During vacuum concentration using the first vacuum concentrator 100, approximately 2 tons of 0.1 MPa low-pressure steam are consumed.

[0085] The first vacuum concentration unit 100 evaporates the 0.1% NMP wastewater, which is cooled to about 35°C by the first condenser 200 and then sent to the wastewater treatment unit 210 for biochemical treatment. Finally, qualified wastewater is obtained, and the chemical oxygen demand (COD) in the wastewater is less than 20 ppm.

[0086] Ten minutes before the end of the room-temperature vacuum concentration in the first vacuum concentrator 100, nitrogen was activated to purge the second vacuum concentrator 300 for five minutes, reducing the oxygen content in the second vacuum concentrator 300 to below 2%. The 600 kg 70% NMP residue-containing mixed solution obtained from the vacuum concentration in the first vacuum concentrator 100 was introduced into the second vacuum concentrator 300 through the second feed bin 360. The second separator 330, second heat exchanger 340, second compressor 350, and second condenser 400 were sequentially activated, while the vacuum pump 600 and exhaust gas treatment unit 700 remained on. Once these devices were operational, the vacuum level was maintained at approximately 1-2 kPa absolute. Finally, the heating element of the second heating chamber 310 was activated, and 0.3 MPa low-pressure steam was introduced into the chamber. The 600 kg 70% NMP residue-containing mixed solution obtained from the first vacuum concentrator 100 was heated to 100°C and subjected to medium-temperature vacuum concentration for two hours. Heating is stopped when the solid mass in the slag-containing mixed liquid decreases to approximately 80 kg. At this point, the expected yield is 80 kg of slag-containing mixed liquid and 520 kg of a product containing 70% NMP solution, with the slag-containing mixed liquid containing approximately 50% slag. During vacuum concentration using the second vacuum concentrating unit 300, approximately 300 kg of 0.3 MPa low-pressure steam is consumed.

[0087] Ten minutes before the second vacuum concentrator 300's medium-temperature vacuum concentration is completed, nitrogen is activated to purge the vacuum dryer 500 for five minutes, reducing the oxygen content in the vacuum dryer 500 to below 2%. The 80 kg of residue-containing mixed liquid obtained after concentration in the second vacuum concentrator 300 is conveyed via the buffer 520 and screw feeder 540 into the vacuum dryer 500. The bag filter 550, second condenser 400, vacuum pump 600, and exhaust gas treatment unit 700 are activated. After the above equipment is started and operates normally, the vacuum degree is maintained at an absolute pressure of about 1-2KPa, and finally 0.8MPa low-pressure steam is introduced to heat the 600kg slag mixed liquid obtained in the previous process to a temperature range of 120℃-140℃, and the slag mixed liquid is dried in the vacuum dryer 500 for about 2 hours. When the solid mass in the slag mixed liquid is reduced to about 40kg and the mass is constant and does not decrease, the heating is stopped. The solid obtained is a lithium salt product, which is sent to the lithium salt product storage box 510 for storage through a water-cooled spiral.

[0088] The dried and evaporated NMP solution is filtered through bag filter 550 and then merged with the NMP solution obtained in second vacuum concentration unit 300. The two solutions flow together into second condenser 400, where they are condensed to obtain NMP product, which is then stored in NMP product condensation storage unit 410. The non-condensable gas obtained after condensation in second condenser 400 and first condenser 200 is then sent to exhaust gas treatment unit 700 for further treatment, ultimately producing exhaust gas that meets emission standards.

[0089] The embodiment of the utility model fully utilizes the different boiling points of water and NMP, and couples the use of room temperature and medium temperature vacuum concentration to reduce the wastewater treatment volume by 80%. The energy consumption of the overall process is only 35% of that of conventional distillation. At the same time, the vacuum dryer 500 is coupled to recover the lithium salt in the wastewater to obtain a pure lithium salt product, thereby improving the economic benefits of lithium battery slurry treatment.

[0090] The above specifically describes the preferred embodiments of the present invention, but the invention is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A lithium battery slurry wastewater recovery device, characterized in that: include: A first vacuum concentrating component (100) is provided with a first feed port (170), a first recovery outlet (180), and a first mixed liquid outlet (190), wherein the first feed port (170) is used to introduce lithium battery slurry, and the first vacuum concentrating component (100) concentrates the lithium battery slurry at a first temperature; A first condenser (200) is provided with a first condensation inlet (220), a first gas outlet (240), and a first condensation outlet (230), wherein the first condensation inlet (220) is connected to the first recovery outlet (180), and the first condensation outlet (230) is used to discharge wastewater; A second vacuum concentrating component (300) is provided with a second feed port (370), a second recovery outlet (380), and a second mixed liquid outlet (390), wherein the second feed port (370) is connected to the first mixed liquid outlet (190), and the second vacuum concentrating component (300) concentrates the lithium battery slurry at a second temperature, wherein the second temperature is greater than the first temperature; a second condenser (400) having a second condensation inlet (420), a second gas outlet (440), and a second condensation outlet (430), wherein the second condensation inlet (420) is connected to the second recovery outlet (380), and the second condensation outlet (430) is used to discharge the NMP product; The vacuum dryer (500) is provided with a third feed inlet (560), a third recovery outlet (570), and a fourth recovery outlet (580), wherein the third feed inlet (560) is connected to the second mixed liquid outlet (390), the third recovery outlet (570) is used to discharge the lithium salt product, and the fourth recovery outlet (580) is connected to the second condensation inlet (420).

2. The lithium battery slurry wastewater recovery device according to claim 1, characterized in that: The lithium battery slurry wastewater recovery device also includes: A vacuum pump (600), wherein an inlet end of the vacuum pump (600) is connected to the first gas outlet (240) and the second gas outlet (440) respectively.

3. The lithium battery slurry wastewater recovery device according to claim 1, characterized in that: The first vacuum concentration component (100) includes a first heating chamber (110), a first separator (130), a first heat exchanger (140) and a first compressor (150). The first feed port (170) and the first mixed liquid outlet (190) are provided in the first heating chamber (110). The inlet end of the first separator (130) is connected to the first heating chamber (110), and the outlet end of the first separator (130) is connected to the inlet end of the first heat exchanger (140). The first heat exchanger (140) is provided with two outlet ends, one of which is the first recovery outlet (180). The other outlet end of the first heat exchanger (140) is connected to the inlet end of the first compressor (150). The outlet end of the first compressor (150) is connected to the first heating chamber (110). The operating temperature of the first heating chamber (110) is the first temperature.

4. The lithium battery slurry wastewater recovery device according to claim 1, characterized in that: The second vacuum concentration component (300) includes a second heating chamber (310), a second separator (330), a second heat exchanger (340) and a second compressor (350). The second feed port (370) and the second mixed liquid outlet (390) are provided in the second heating chamber (310). The inlet end of the second separator (330) is connected to the second heating chamber (310), and the outlet end of the second separator (330) is connected to the inlet end of the second heat exchanger (340). The second heat exchanger (340) is provided with two outlet ends, one of which is the second recovery outlet (380). The other outlet end of the second heat exchanger (340) is connected to the inlet end of the second compressor (350). The outlet end of the second compressor (350) is connected to the second heating chamber (310). The operating temperature of the second heating chamber (310) is the second temperature.

5. The lithium battery slurry wastewater recovery device according to claim 4, characterized in that: The second vacuum concentration component (300) further includes a propeller blade (320), wherein the propeller blade (320) is disposed in the second heating chamber (310), and the propeller blade (320) is used to stir the material in the second heating chamber (310).

6. The lithium battery slurry wastewater recovery device according to claim 1, characterized in that: The first temperature has a value range of greater than or equal to 60° C. and less than or equal to 70° C., and the second temperature has a value range of greater than or equal to 100° C. and less than or equal to 120° C.

7. The lithium battery slurry wastewater recovery device according to claim 1, characterized in that: The lithium battery slurry wastewater recovery device also includes: a buffer chamber (520), wherein an inlet end of the buffer chamber (520) is connected to the second mixed liquid outlet (390); An arch breaker (530), wherein an output end of the arch breaker (530) is arranged in the buffer chamber (520) and is located at the bottom of the buffer chamber (520); A screw feeder (540), wherein the inlet end of the screw feeder (540) is connected to the outlet end of the buffer bin (520), and the outlet end of the screw feeder (540) is connected to the third feed port (560).

8. The lithium battery slurry wastewater recovery device according to claim 2, characterized in that: The lithium battery slurry wastewater recovery device also includes: An exhaust gas treatment component (700) is connected to the outlet end of the vacuum pump (600).

9. The lithium battery slurry wastewater recovery device according to claim 2, characterized in that: A plurality of the vacuum pumps (600) are provided, the inlet ends of the plurality of vacuum pumps (600) are connected to each other, and the outlet ends of the plurality of vacuum pumps (600) are connected to each other.

10. The lithium battery slurry wastewater recovery device according to claim 1, characterized in that: The lithium battery slurry wastewater recovery device also includes: A wastewater treatment component (210) is connected to the first condensation outlet (230).

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