A lithium ion battery separator coating waste liquid treatment system

Abstract

The application discloses a lithium ion battery diaphragm coating waste liquid treatment system and belongs to the field of waste liquid treatment. The system comprises a waste liquid storage tank for containing original liquid to be treated; a first water pump connected with a water outlet of the waste liquid storage tank; a vacuum evaporation kettle connected with a water outlet of the first water pump; an organic separation membrane connected with a gas outlet at the top of the vacuum evaporation kettle; a first post-treatment mechanism and a second post-treatment mechanism connected with an output end of the organic separation membrane; and a water separation membrane connected with the gas outlet at the top of the vacuum evaporation kettle and connected in parallel with the organic separation membrane, wherein the output end of the water separation membrane is connected with the first post-treatment mechanism and the second post-treatment mechanism respectively. The system is provided with the organic separation membrane, the distilled water is further treated, the organic matter in the distilled water is separated out, low-COD distilled water is obtained, and the separated organic high-purity solvent with low water content can be recycled.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of waste liquid treatment, and particularly relates to a lithium ion battery diaphragm coating waste liquid treatment system. BACKGROUND

[0002] The lithium battery diaphragm, as an important component of the lithium ion battery, plays a role of separating the positive and negative electrodes, preventing internal short circuit of the battery, allowing the electrolyte ions to pass freely, and completing the electrochemical charging and discharging process. The performance of the lithium battery diaphragm determines the interface structure and internal resistance of the battery, and directly affects the capacity, cycle performance, safety performance and other characteristics of the battery. The diaphragm with excellent performance plays an important role in improving the comprehensive performance of the battery, and is called the "third electrode" of the battery.

[0003] For the lithium battery diaphragm coated with oil, water washing is usually required. After water washing, a certain amount of organic solvent wastewater is generated, and the concentration is about 10% to 30%. The concentration of the wastewater is low, and the wastewater cannot be directly used, and the treatment is difficult. Usually, the solvent recovery manufacturer is invited to treat the wastewater by high-temperature distillation and concentration. However, the treatment method has waste gas emission, and is easy to pollute the environment. Therefore, the waste liquid is usually treated and recovered. The common treatment process is as follows: the low-concentration raw liquid is subjected to vacuum low-temperature evaporation, the concentrated liquid generated is recycled and reused, and the high-COD distillation water generated is treated by COD reduction and then discharged.

[0004] However, the prior art has the following problems: in the vacuum low-temperature evaporation process, as the concentration of the raw liquid gradually increases, the content of the organic matter in the distillation water is higher and higher, and the cumulative concentration of the organic solvent in the distillation water is higher and higher. If the organic matter is not recycled and reused, not only the resources will be wasted, but also the environment will be polluted. Therefore, the present application provides a lithium ion battery diaphragm coating waste liquid treatment system to solve the problems in the background art. SUMMARY

[0005] The present application aims to provide a lithium ion battery diaphragm coating waste liquid treatment system. The organic separation membrane is added to the system to further treat the distillation water, separate the organic matter in the distillation water, obtain low-COD distillation water, and recycle the low-water-content organic high-purity solvent, so as to solve the problems in the background art.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical scheme:

[0007] A lithium ion battery diaphragm coating waste liquid treatment system comprises:

[0008] a waste liquid storage tank for containing raw liquid to be treated;

[0009] a first water pump connected to a water outlet of the waste liquid storage tank;

[0010] a vacuum evaporation kettle connected with the water outlet of the first water pump;

[0011] an organic separation membrane connected with the gas outlet on the top of the vacuum evaporation kettle;

[0012] a first post-treatment mechanism and a second post-treatment mechanism connected with the output end of the organic separation membrane.

[0013] As a further scheme of the present application, the gas outlet on the top of the vacuum evaporation kettle is further connected with a water separation membrane, and the water separation membrane is connected in parallel with the organic separation membrane, and the output end of the water separation membrane is connected with the first post-treatment mechanism and the second post-treatment mechanism respectively.

[0014] As a further scheme of the present application, the water separation membrane and the organic separation membrane are both provided with electromagnetic valves at the input end and the output end.

[0015] As a further scheme of the present application, the input end of the water separation membrane is provided with a second heater.

[0016] As a further scheme of the present application, the input end of the organic separation membrane is provided with a first heater.

[0017] As a further scheme of the present application, the first post-treatment mechanism specifically comprises a first vacuum condensing tank, the output end of the first vacuum condensing tank is connected with a first vacuum generator, the output end of the first vacuum generator is connected with a first condensing storage tank, the output end of the first condensing storage tank is connected with a fourth water pump and a fifth water pump respectively, and the output end of the fifth water pump is connected with the first vacuum generator.

[0018] As a further scheme of the present application, the second post-treatment mechanism specifically comprises a second vacuum condensing tank, the output end of the second vacuum condensing tank is connected with a second vacuum generator, the output end of the second vacuum generator is connected with a second condensing storage tank, the output end of the second condensing storage tank is connected with a sixth water pump and a seventh water pump respectively, and the output end of the seventh water pump is connected with the second vacuum generator.

[0019] As a further scheme of the present application, the outside of the vacuum evaporation kettle is connected with a first concentration tester, the outside of the first vacuum condensing tank is connected with a second concentration tester, and the outside of the second vacuum condensing tank is connected with a third concentration tester.

[0020] As a further scheme of the present application, a filter is connected between the first water pump and the vacuum evaporation kettle.

[0021] As a further scheme of the present application, the lithium ion battery separator coating waste liquid treatment system further comprises:

[0022] a second water pump connected with the water outlet on the bottom of the vacuum evaporation kettle.

[0023] A concentrated liquid tank connected with the water outlet of the second water pump;

[0024] A third water pump connected with the water outlet of the concentrated liquid tank.

[0025] Compared with the prior art, the present application has the following advantages:

[0026] 1. The distilled water of the original system needs to be treated to reduce COD because of high organic content, and can be discharged only after treatment. In the present application, an organic separation membrane is added to the system, and the organic matter in the distilled water is further separated and treated during evaporation, so that the distilled water can be directly recycled or directly discharged up to the standard. In addition, by adding the water separation membrane and cooperating with the valve switching control, when the organic solvent concentration is high to a certain concentration, the separation and treatment of the distilled water vapor is switched from the organic separation membrane to the water separation membrane, so as to fully exert the separation efficiency of the two separation membrane assemblies for the treatment of distilled water vapor with different concentrations.

[0027] 2. The heater added in the present application can adjust the temperature of the vapor to the most suitable temperature range for the separation of the organic separation membrane or the water separation membrane, thereby improving the separation efficiency of the organic separation membrane or the water separation membrane, and the use effect is more efficient.

[0028] 3. The present application can improve the recovery rate of organic solvent, and the low water content organic high-purity solvent separated from the distilled water can be directly recycled.

[0029] 4. The present application eliminates the COD reduction treatment step of distilled water, and can reduce the water treatment cost.

[0030] 5. The present application installs a concentration tester, an electric control valve on the vacuum evaporation kettle, the first vacuum condenser and the second vacuum condenser, and can automatically control the concentration of each tank in the process. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of a lithium ion battery diaphragm coating waste liquid treatment system;

[0032] Figure 2 It is a structural schematic diagram of the first deformation example of the present application;

[0033] Figure 3 It is a structural schematic diagram of the second deformation example of the present application;

[0034] Figure 4 It is a structural schematic diagram of the third deformation example of the present application;

[0035] Figure 5 It is a structural schematic diagram of the lithium ion battery diaphragm coating waste liquid treatment system in the prior art of the present application.

[0036] In the figure: 1, waste liquid storage tank; 2, first water pump; 3, filter; 4, vacuum evaporation kettle; 5, second water pump; 6, concentrated liquid tank; 7, third water pump; 8, organic separation membrane; 9, first vacuum condensation tank; 10, first vacuum generator; 11, first condensation storage tank; 12, fourth water pump; 13, fifth water pump; 14, second vacuum condensation tank; 15, second condensation storage tank; 16, sixth water pump; 17, seventh water pump; 18, second vacuum generator; 19, water separation membrane; 20, first heater; 21, second heater; 22, first concentration tester; 23, second concentration tester; 24, third concentration tester. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0038] As mentioned in the background of the present application, the inventor has found through research that the existing lithium ion battery separator coating waste liquid treatment process is as follows: low concentration stock solution is vacuum low-temperature evaporated, the concentrated liquid generated is recycled, and the high COD (chemical oxygen demand) distilled water generated is treated to meet the discharge standard after COD reduction, as shown in Figure 5 However, in the vacuum low-temperature evaporation process, as the concentration of the stock solution gradually increases, the content of organic matter in the distilled water becomes higher and higher, resulting in a higher and higher cumulative concentration of organic solvents in the distilled water. If these organic matters are not recycled, not only will resources be wasted, but also environmental pollution will be caused.

[0039] In order to solve the above-mentioned defects, the present application discloses a lithium ion battery separator coating waste liquid treatment system, which adds an organic separation membrane 8 in the system to further treat the distilled water, separate the organic matter in the distilled water, and obtain low-COD distilled water. At the same time, the separated organic high-purity solvent with low water content can be recycled.

[0040] The present application will be described in detail below in combination with the drawings on how the solutions of the present application solve the above-mentioned technical problems.

[0041] Please refer to Figure 1The embodiment of the present application is a lithium ion battery diaphragm coating waste liquid treatment system, which comprises: a waste liquid storage tank 1 for containing the original liquid to be treated; a first water pump 2 connected with the water outlet of the waste liquid storage tank 1; a vacuum evaporation kettle 4 connected with the water outlet of the first water pump 2; an organic separation membrane 8 connected with the top gas outlet of the vacuum evaporation kettle 4; a first post-treatment mechanism and a second post-treatment mechanism connected with the output end of the organic separation membrane 8. In use, the original liquid to be treated in the waste liquid storage tank 1 is extracted by the first water pump 2 into the vacuum evaporation kettle 4 for vacuum low-temperature evaporation, and then the high-COD distilled water generated is separated by the organic separation membrane 8, so that the organic matter in the distilled water is separated into the first post-treatment mechanism, while the distilled water cannot pass through the organic separation membrane 8 into the second post-treatment mechanism, thereby realizing further treatment of the distilled water, separating the organic matter in the distilled water, and obtaining low-COD distilled water, and the separated organic high-purity solvent with low water content can be recycled.

[0042] In the embodiment, the first post-treatment mechanism specifically comprises: a first vacuum condensing tank 9, the output end of the first vacuum condensing tank 9 is connected with a first vacuum generator 10, the output end of the first vacuum generator 10 is connected with a first condensing storage tank 11, the output end of the first condensing storage tank 11 is respectively connected with a fourth water pump 12 and a fifth water pump 13, and the output end of the fifth water pump 13 is connected with the first vacuum generator 10. When the organic matter in the distilled water is separated into the first vacuum condensing tank 9 of the first post-treatment mechanism, the first vacuum condensing tank 9 performs vacuum condensation on the organic matter, the condensed organic matter enters the first condensing storage tank 11 through the first vacuum generator 10, and the organic matter in the first condensing storage tank 11 can be discharged to an external organic matter collecting tank through the fourth water pump 12. It should be noted that the fifth water pump 13 cooperates with the first vacuum generator 10 to perform vacuum pumping on the first vacuum condensing tank 9 so that the first vacuum condensing tank 9 is in a vacuum state.

[0043] In the embodiment, the second post-treatment mechanism specifically comprises: a second vacuum condensing tank 14, the output end of the second vacuum condensing tank 14 is connected with a second vacuum generator 18, the output end of the second vacuum generator 18 is connected with a second condensing storage tank 15, the output end of the second condensing storage tank 15 is respectively connected with a sixth water pump 16 and a seventh water pump 17, and the output end of the seventh water pump 17 is connected with the second vacuum generator 18. The distilled water that cannot pass through the organic separation membrane 8 still contains a small amount of organic matter, when it enters the second vacuum condensing tank 14, a large amount of water and a small amount of organic matter are condensed out, the organic matter content in the condensed water is very low and can be directly discharged without causing environmental pollution, the condensed water enters the second condensing storage tank 15 through the second vacuum generator 18, and the condensed water in the second condensing storage tank 15 can be directly discharged through the sixth water pump 16, and the seventh water pump 17 cooperates with the second vacuum generator 18 to perform vacuum pumping on the second condensing storage tank 15 so that the second condensing storage tank 15 is in a vacuum state.

[0044] In the embodiment, a first concentration tester 22 is connected to the outside of the vacuum evaporation kettle 4, a second concentration tester 23 is connected to the outside of the first vacuum condenser 9, and a third concentration tester 24 is connected to the outside of the second vacuum condenser 14. The first concentration tester 22, the second concentration tester 23, and the third concentration tester 24 can be used to monitor the concentration of the organic matter in the vacuum evaporation kettle 4, the first vacuum condenser 9, and the second vacuum condenser 14, respectively. In combination with the electrically controlled valves installed at the input ends of the vacuum evaporation kettle 4, the first vacuum condenser 9, and the second vacuum condenser 14, the concentration of each tank in the process can be automatically controlled.

[0045] In the embodiment, a filter 3 is connected between the first water pump 2 and the vacuum evaporation kettle 4. The filter 3 can filter out solid particles in the raw liquid in advance.

[0046] In the embodiment, the lithium ion battery separator coating waste liquid treatment system further comprises a second water pump 5 connected to the water outlet at the bottom of the vacuum evaporation kettle 4, a concentrated liquid tank 6 connected to the water outlet of the second water pump 5, and a third water pump 7 connected to the water outlet of the concentrated liquid tank 6. The concentrated liquid generated by the vacuum low-temperature evaporation of the vacuum evaporation kettle 4 is sent to the concentrated liquid tank 6 by the second water pump 5 and then to the recycling point for further use by the third water pump 7.

[0047] Variant Example One

[0048] Please refer to Figure 2 In the variant example, a temperature adjustment is added to the above-mentioned embodiment, that is, a first heater 20 is arranged at the input end of the organic separation membrane 8. The first heater 20 can adjust the temperature of the distilled water before it enters the organic separation membrane 8, so that the temperature of the steam is adjusted to the most suitable temperature range for the separation of the organic separation membrane 8, thereby improving the separation efficiency of the organic separation membrane 8.

[0049] Variant Example Two

[0050] Please refer to Figure 3, the water separation membrane 19 is connected to the top gas outlet of the vacuum evaporation kettle 4, and the water separation membrane 19 is connected in parallel with the organic separation membrane 8, the output end of the water separation membrane 19 is connected to the first post-treatment mechanism and the second post-treatment mechanism respectively, and the water separation membrane 19 and the input end and the output end of the organic separation membrane 8 are all provided with electromagnetic valves. As the concentration of organic solvents in distilled water becomes higher and higher, the water separation membrane 19 is further added on the basis of the organic separation membrane 8, and the separation treatment of distilled water vapor is switched from the organic separation membrane 8 to the water separation membrane 19 when the concentration of organic solvents is high to a certain extent, so as to fully exert the separation efficiency of the two kinds of separation membrane assemblies for the treatment of distilled water vapor with different concentrations. It should be noted that the water separation membrane 19 guides the separated water into the second post-treatment mechanism and guides the separated organic matter into the first post-treatment mechanism. In addition, in order to improve the separation efficiency, the staff can use an organic separation membrane assembly formed by combining a plurality of organic separation membranes 8 instead of the original single organic separation membrane 8, and can also use a water separation membrane assembly formed by combining a plurality of water separation membranes 19 instead of the original single water separation membrane 19. In this way, the original liquid needs to pass through a plurality of water separation membranes 19 or organic separation membranes 8 for separation when passing through the water separation membrane assembly or the organic separation membrane assembly, thereby effectively improving the separation effect.

[0051] Variant three

[0052] Please refer to Figure 4 , the water separation membrane 19 is connected to the top gas outlet of the vacuum evaporation kettle 4, and the water separation membrane 19 is connected in parallel with the organic separation membrane 8, the output end of the water separation membrane 19 is connected to the first post-treatment mechanism and the second post-treatment mechanism respectively, and the water separation membrane 19 and the input end and the output end of the organic separation membrane 8 are all provided with electromagnetic valves. As the concentration of organic solvents in distilled water becomes higher and higher, the water separation membrane 19 is further added on the basis of the organic separation membrane 8, and the separation treatment of distilled water vapor is switched from the organic separation membrane 8 to the water separation membrane 19 when the concentration of organic solvents is high to a certain extent, so as to fully exert the separation efficiency of the two kinds of separation membrane assemblies for the treatment of distilled water vapor with different concentrations. It should be noted that the water separation membrane 19 guides the separated water into the second post-treatment mechanism and guides the separated organic matter into the first post-treatment mechanism. In addition, in order to improve the separation efficiency, the staff can use an organic separation membrane assembly formed by combining a plurality of organic separation membranes 8 instead of the original single organic separation membrane 8, and can also use a water separation membrane assembly formed by combining a plurality of water separation membranes 19 instead of the original single water separation membrane 19. In this way, the original liquid needs to pass through a plurality of water separation membranes 19 or organic separation membranes 8 for separation when passing through the water separation membrane assembly or the organic separation membrane assembly, thereby effectively improving the separation effect.

[0053] The application adds organic separation membrane 8 in the system, further separates the organic matter in distilled water in the evaporation process, and the distilled water can be directly recycled or directly discharged up to the standard. In addition, through the added water separation membrane 19, cooperating with the valve switching control, when the organic solvent concentration is high to a certain concentration, the separation treatment of distilled water vapor is switched from the organic separation membrane 8 to the water separation membrane 19, so as to fully exert the separation efficiency of the two kinds of separation membrane assemblies for the treatment of distilled water vapor with different concentrations. Through the added heater, the vapor temperature can be adjusted to the most suitable temperature range for the separation of the organic separation membrane 8 or the water separation membrane 19, so as to improve the separation efficiency of the organic separation membrane 8 or the water separation membrane 19, and the use effect is more efficient. The application can improve the organic solvent recovery rate, and the low water content organic high-purity solvent separated from the distilled water can be directly recycled. In addition, the application eliminates the distilled water COD reduction treatment step, and can reduce the water treatment cost. The application installs a concentration tester, an electric control valve on the vacuum evaporation kettle 4, the first vacuum condenser 9 and the second vacuum condenser 14, and can automatically control the concentration of each tank body in the process.

[0054] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

[0055] The above is only the preferred specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A lithium ion battery separator coating effluent treatment system characterized by, include: Waste liquid storage tanks used to hold the raw liquid to be treated; A first water pump is connected to the outlet of the waste liquid storage tank; A vacuum evaporator connected to the outlet of the first water pump; An organic separation membrane connected to the gas outlet at the top of the vacuum evaporator; A first post-processing mechanism and a second post-processing mechanism are connected to the output end of the organic separation membrane; The top outlet of the vacuum evaporator is also connected to a water separation membrane, and the water separation membrane is connected in parallel with the organic separation membrane. The output end of the water separation membrane is connected to the first post-processing mechanism and the second post-processing mechanism respectively. Both the water separation membrane and the organic separation membrane are equipped with solenoid valves at their input and output ends. A second heater is provided at the input end of the water separation membrane; The organic separation membrane is equipped with a first heater at its input end; The first post-processing mechanism specifically includes: a first vacuum condenser, the output end of the first vacuum condenser is connected to a first vacuum generator, and the output end of the first vacuum generator is connected to a first condensation tank, the output end of the first condensation tank is respectively connected to a fourth water pump and a fifth water pump, and the output end of the fifth water pump is connected to the first vacuum generator.

2. The system for treating lithium ion battery separator coating waste solution according to claim 1, wherein, The second post-processing mechanism specifically includes: a second vacuum condenser, the output end of which is connected to a second vacuum generator, and the output end of which is connected to a second condensation tank, the output ends of which are respectively connected to a sixth water pump and a seventh water pump, and the output end of the seventh water pump is connected to the second vacuum generator.

3. The system for treating lithium ion battery separator coating waste solution according to claim 2, wherein, The vacuum evaporator is externally connected to a first concentration meter, the first vacuum condenser is externally connected to a second concentration meter, and the second vacuum condenser is externally connected to a third concentration meter.

4. The system for treating lithium ion battery separator coating waste solution of claim 1, wherein, A filter is connected between the first water pump and the vacuum evaporator.

5. The system for treating lithium ion battery separator coating waste solution of claim 1, wherein, The lithium-ion battery separator coating waste liquid treatment system also includes: A second water pump is connected to the water outlet at the bottom of the vacuum evaporator; A concentrate tank connected to the outlet of the second water pump; A third water pump connected to the outlet of the concentrate tank.

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