Method and system for recovering lithium carbonate from ternary cathode washing water

Abstract

The application discloses a method for recycling lithium carbonate from ternary positive electrode washing water, which comprises the following steps: (1) heavy metal removal: heavy metal flocculation and precipitation; precise filtration; the filtered solution is sent into a precise filtrate tank; the precise filtrate is added with sulfuric acid and then is sent into a pH adjusting tank; (2) lithium recovery: the solution obtained in the previous step is pumped into a pH adjusting tank and is reacted with sodium hydroxide; the solution is filtered through a security filter and then is sent into an ultrafiltration device; the water produced by the ultrafiltration device is sent into a nanofiltration device; the water produced by the nanofiltration device is sequentially sent into a first reverse osmosis concentration device and a second reverse osmosis concentration device. The application has the advantages of saving investment, reducing operation cost, stable and reliable process operation, meeting the discharge requirements of the treated water and lithium carbonate mother liquor, and realizing the recovery of heavy metals, the precipitation of lithium carbonate, the recycling of water and the discharge of the mother liquor meeting the requirements. The application further discloses a system for recycling lithium carbonate from ternary positive electrode washing water.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of industrial wastewater treatment, and particularly relates to a lithium carbonate recovery method and system for ternary positive electrode washing water. BACKGROUND

[0002] The ternary positive electrode washing water mainly contains lithium, nickel, cobalt, manganese and the like, and contains process wastewater and workshop cleaning wastewater generated in the production process of the ternary positive electrode material. SUMMARY

[0003] The main purpose of the application is to provide a lithium carbonate recovery method for ternary positive electrode washing water, so as to solve the technical problems of high cost and low production efficiency in the prior art.

[0004] (1) Heavy metal removal

[0005] The ternary positive electrode washing water sequentially enters a reaction tank and a sedimentation tank after PAM is added, and flocculation and sedimentation of heavy metals are carried out, supernatant overflows to an overflow buffer tank, and heavy metal sediment is discharged from the bottom of the sedimentation tank and pumped to a sludge tank;

[0006] The wastewater in the overflow buffer tank is subjected to suspended matter enrichment, filtration and clarification of wastewater by a precision filtration device, the concentrated water of the precision filtration is sent to the sludge tank, and the filtrate of the precision filtration is sent to a precision filtrate tank;

[0007] The precision filtrate is added with sulfuric acid and then enters a pH adjusting tank, so that carbonate and hydroxyl groups are neutralized and a large amount of carbon dioxide is discharged, the reaction pH is 2.5-3.0, and the reacted wastewater enters a finished liquid tank;

[0008] The sludge in the sludge tank is dewatered by a plate-and-frame filter press, the filtrate obtained by dewatering is sent to an overflow liquid buffer tank, and the filter cake obtained is sent to a leaching device for leaching and recovery of nickel, cobalt and manganese;

[0009] (2) Lithium recovery

[0010] The finished liquid in the heavy metal removal unit finished liquid tank is pumped into a pH readjusting tank and reacts with sodium hydroxide, and the pH after the reaction is controlled to be 6-7;

[0011] The pH readjusting liquid is filtered by a security filter and then sent to an ultrafiltration device, ultrafiltration device produced water is obtained and sent to an ultrafiltration produced water tank, and the concentrated water of the ultrafiltration device is returned to the pH readjusting tank;

[0012] The water produced by the ultrafiltration device is concentrated by the lithium sulfate and sodium sulfate salt in the nanofiltration device, and the concentrated water of the nanofiltration device is sent to a nanofiltration concentrated water tank; the water produced by the nanofiltration device is sent to a nanofiltration water tank;

[0013] The water produced by the nanofiltration device is sequentially concentrated by the first reverse osmosis device and the second reverse osmosis device, the water produced by the first reverse osmosis device is sent to a first reverse osmosis water tank, the concentrated water of the first reverse osmosis device is sent to the ultrafiltration water tank, the first reverse osmosis water in the first reverse osmosis water tank is sent to the second reverse osmosis device, the water produced by the second reverse osmosis device is sent to a reuse water tank, and the concentrated water of the second reverse osmosis device is sent to the nanofiltration water tank;

[0014] The concentrated water of the nanofiltration device is heated to 90 DEG C by steam and sent to a jacketed reactor together with a sodium carbonate solution for mixing reaction and crystal growth, and finally lithium carbonate slurry is obtained.

[0015] The lithium carbonate slurry is dehydrated by a centrifuge, and the pure water is washed to obtain lithium carbonate wet solid which is sent to a lithium carbonate wet solid tank; the mother liquor is sent to a mother liquor tank, and the washing water is sent to a washing water tank and then sent back to a lithium carbonate slurry tank.

[0016] The lithium carbonate slurry is dried by a drying machine, and the lithium carbonate powder is sent to a lithium carbonate dry powder tank.

[0017] The lithium carbonate dry powder tank is sent to a packaging machine for bagging, weighing and sealing, and finally lithium carbonate products are obtained.

[0018] The lithium carbonate slurry is dried by a drying machine, and the lithium carbonate powder is sent to a lithium carbonate dry powder tank.

[0019] Further, the SDI of the ultrafiltration water is less than 5.

[0020] Further, the salt concentration in the concentrated water of the nanofiltration device is greater than 120 g / L.

[0021] Further, the conductivity of the water produced by the first reverse osmosis device is less than 200 us / cm.

[0022] Further, the conductivity of the water produced by the first reverse osmosis device is less than 10 us / cm.

[0023] Further, the concentration of the sodium carbonate solution is 300 g / L.

[0024] Further, the concentrated water of the nanofiltration device is heated to 90 DEG C by steam and then sent to a jacketed reactor together with a sodium carbonate solution for mixing for 10 minutes, reaction for 10-30 minutes, and crystal growth for 60-120 minutes, and finally lithium carbonate slurry is obtained.

[0025] Further, the drying machine is a spiral conveyor sent to a disc dryer.

[0026] The ternary positive electrode washing water recovery lithium carbonate system comprises:

[0027] The heavy metal removal unit comprises a raw water collecting tank, a reaction tank and a sedimentation tank connected in sequence, further comprises a slurry tank connected with a slurry discharge outlet of the sedimentation tank, an overflow liquid buffer tank connected with an overflow liquid overflow outlet of the sedimentation tank, a plate-frame filter device connected with the slurry tank, and a precision filter device, a precision filtered liquid tank, a pH adjusting tank and a finished liquid storage tank connected in sequence with the overflow liquid buffer tank, wherein a clear liquid outlet of the plate-frame filter device is connected with the overflow liquid buffer tank, and the pH adjusting tank is connected with a dilute sulfuric acid storage tank.

[0028] The lithium recovery unit comprises a pH readjusting tank, a security filter, an ultrafiltration device, an ultrafiltration device water tank, a nanofiltration device, a nanofiltration device water tank connected with a clear liquid outlet of the nanofiltration device, and further comprises a sodium hydroxide storage tank connected with the pH readjusting tank, and further comprises a nanofiltration device concentrated water tank, a heat exchanger, a jacketed reactor, a centrifuge and a mother liquor storage tank connected in sequence with a concentrated liquid outlet of the nanofiltration device, and further comprises a lithium carbonate storage bin, a dryer and a dust removal device connected in sequence with the centrifuge, and further comprises a sodium carbonate pulping tank connected with a feed inlet of the jacketed reactor, and further comprises a first reverse osmosis concentration device connected in sequence with the nanofiltration device water tank, a first reverse osmosis liquid tank connected with a clear liquid outlet of the first reverse osmosis concentration device, a second reverse osmosis concentration device, and a backwater tank connected with a clear liquid outlet of the second reverse osmosis concentration device, wherein a concentrated outlet of the first reverse osmosis concentration device and a concentrated liquid outlet of the second reverse osmosis concentration device are both connected with the ultrafiltration device water tank.

[0029] Further, the dryer is a spiral conveyor sent to a disc dryer.

[0030] The present application has the advantages of saving investment, reducing operating costs, stable and reliable process operation, meeting the discharge requirements of the treated water and lithium carbonate mother liquor, and achieving the recovery of heavy metals, the precipitation of lithium carbonate products, and the final discharge requirements of the recovered water and mother liquor.

[0031] The present application will be further described below in conjunction with the accompanying drawings and specific embodiments. Additional aspects and advantages of the present application will be partially given in the following description, partially will become apparent from the following description, or will be understood by practicing the present application. BRIEF DESCRIPTION OF DRAWINGS

[0032] The accompanying drawings, which form a part of the present application, are used to assist in the understanding of the present application and the content provided by the accompanying drawings and the related description in the present application can be used to explain the present application, but do not constitute undue limitations on the present application. In the drawings:

[0033] Figure 1The device flow chart of the heavy metal removal system in the application.

[0034] Figure 2 The device flow chart of the lithium recovery system in the application. DETAILED DESCRIPTION

[0035] The application will be apparent from the following description in conjunction with the drawings. Those skilled in the art can implement the application based on the description. Before the application is described in conjunction with the drawings, it should be particularly pointed out that:

[0036] The technical solutions and technical features provided in each part of the application including the following description can be combined with each other without conflict.

[0037] In addition, the embodiments of the application involved in the following description are generally only embodiments of part of the application, not all embodiments. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments in the application without creative labor should belong to the scope of protection of the application.

[0038] Regarding the terms and units in the application. The terms "include", "have" and any variations thereof in the description and claims of the application and related parts are intended to cover non-exclusive inclusion.

[0039] As shown in Figure 1 and Figure 2 The lithium carbonate recovery method from ternary positive electrode washing water includes the following steps:

[0040] (1) Heavy metal removal

[0041] The ternary positive electrode washing water enters the reaction tank and the sedimentation tank in sequence after adding PAM to carry out heavy metal flocculation and sedimentation, respectively. The supernatant overflows to the overflow buffer tank, and the heavy metal sediment is discharged from the bottom of the sedimentation tank and transported to the sludge tank by a pump;

[0042] The wastewater in the overflow buffer tank is subjected to suspended matter enrichment, filtered and clarified wastewater by a precision filtration device. The concentrated water of the precision filtration is sent to the sludge tank, and the filtrate of the precision filtration is sent to the precision filtrate tank;

[0043] The precision filtrate is added with sulfuric acid and then enters the pH adjusting tank to neutralize carbonate and hydroxide and discharge a large amount of carbon dioxide. The reaction pH is 2.5-3.0. The reacted wastewater enters the finished liquid tank;

[0044] The sludge in the sludge tank is dewatered by a plate and frame filter press. The filtrate obtained by dewatering is sent to the overflow liquid buffer tank, and the filter cake obtained is sent to the leaching device for leaching and recovery of nickel, cobalt and manganese;

[0045] The sulfuric acid is 3% sulfuric acid.

[0046] (2) Lithium recovery

[0047] The finished liquid in the finished liquid tank of the heavy metal removal unit is pumped into a pH adjustment tank and reacts with a sodium hydroxide solution, and the pH after the reaction is controlled at 6-7;

[0048] The pH adjustment liquid is filtered through a security filter and then sent to an ultrafiltration device to obtain ultrafiltration device product water, which is sent to an ultrafiltration product water tank, and the concentrated water of the ultrafiltration device is returned to the pH adjustment tank.

[0049] The ultrafiltration device product water is concentrated with lithium sulfate and sodium sulfate salt through a nanofiltration device, the nanofiltration device concentrated water is sent to a nanofiltration device concentrated water tank, and the nanofiltration device product water is sent to a nanofiltration product water tank.

[0050] The nanofiltration device product water is sequentially concentrated through a first reverse osmosis concentration device and a second reverse osmosis concentration device, the first reverse osmosis concentration device product water is sent to a first reverse osmosis product water tank, the first reverse osmosis concentration device concentrated water is sent to the ultrafiltration product water tank, the first reverse osmosis product water in the first reverse osmosis product water tank enters the second reverse osmosis concentration device, the second reverse osmosis concentration device product water is sent to a reuse water tank, and the second reverse osmosis concentrated water is sent to the nanofiltration product water tank.

[0051] The nanofiltration device concentrated water is heated to 90°C by steam and sent to a jacketed reactor together with a sodium carbonate solution for mixing reaction and crystal growth, and finally lithium carbonate slurry is obtained.

[0052] The lithium carbonate slurry is dehydrated by a centrifuge and washed with pure water to obtain lithium carbonate wet solid, which is sent to a lithium carbonate wet solid storage bin; the mother liquor is sent to a mother liquor tank, and the washing water is sent to a washing water tank and then back to a lithium carbonate slurry preparation tank.

[0053] The lithium carbonate slurry is dried by a drying machine, and the lithium carbonate powder is sent to a lithium carbonate dry powder storage bin.

[0054] The lithium carbonate dry powder storage bin is sent to packaging for bagging, weighing, and sealing, and finally lithium carbonate products are obtained.

[0055] The lithium carbonate slurry is dried by a drying machine, and the lithium carbonate powder is sent to a lithium carbonate dry powder storage bin.

[0056] The sodium hydroxide solution is 32% sodium hydroxide solution.

[0057] The SDI of the ultrafiltration product water is less than 5.

[0058] The salt concentration in the nanofiltration device concentrated water is greater than 120 g / L.

[0059] The conductivity of the first reverse osmosis concentration device product water is less than 200 us / cm.

[0060] The water conductivity of the first reverse osmosis concentration device is less than 10 us / cm.

[0061] The concentration of the sodium carbonate solution is 300 g / L.

[0062] The concentrated water of the nanofiltration device is heated to 90 DEG C by steam heating, and then is sent into a jacketed reactor together with the sodium carbonate solution to mix for 10 minutes, react for 10-30 minutes, and crystallize for 60-120 minutes, so as to finally obtain lithium carbonate slurry.

[0063] The drying machine is a spiral conveyor sent to a disc dryer.

[0064] The ternary positive electrode washing water recovery lithium carbonate system comprises:

[0065] The heavy metal removal unit comprises a raw water collecting tank, a reaction tank and a sedimentation tank connected in sequence, further comprises a slurry tank connected with a slurry discharge outlet of the sedimentation tank, an overflow liquid buffer tank connected with an overflow liquid overflow outlet of the sedimentation tank, a plate and frame filter device connected with the slurry tank, and a precision filter device, a precision filtered liquid tank, a pH adjusting tank and a finished liquid storage tank connected in sequence with the overflow liquid buffer tank, wherein the clear liquid outlet of the plate and frame filter device is connected with the overflow liquid buffer tank, and the pH adjusting tank is connected with a dilute sulfuric acid storage tank.

[0066] The lithium recovery unit comprises a pH readjusting tank, a security filter, an ultrafiltration device, an ultrafiltration device water tank, a nanofiltration device, a nanofiltration device water tank connected with a clear liquid outlet of the nanofiltration device, a sodium hydroxide storage tank connected with the pH readjusting tank, a nanofiltration device concentrated liquid outlet connected with a nanofiltration device concentrated water tank, a heat exchanger, a jacketed reactor, a centrifuge and a mother liquor storage tank connected in sequence, a lithium carbonate storage bin, a drying machine and a dust removal device connected in sequence with the centrifuge, a sodium carbonate pulping tank connected with a washing water outlet of the jacketed reactor, the sodium carbonate pulping tank connected with a feed inlet of the jacketed reactor, a first reverse osmosis concentration device connected with the nanofiltration device water tank in sequence, a first reverse osmosis liquid tank connected with a clear liquid outlet of the first reverse osmosis concentration device, a second reverse osmosis concentration device, and a backwater tank connected with a clear liquid outlet of the second reverse osmosis concentration device, wherein the concentration outlet of the first reverse osmosis concentration device and the concentrated liquid outlet of the second reverse osmosis concentration device are both connected with the ultrafiltration device water tank.

[0067] The drying machine is a spiral conveyor sent to a disc dryer.

[0068] The present application is further described below by specific experimental parameters of the present application:

[0069] The water quality table obtained by the heavy metal removal system in the present application is shown in Table 1 below:

[0070] Table 1

[0071]

[0072] The water quality of the lithium recovery system in the present application is shown in Table 2 below:

[0073] Table 2

[0074]

[0075]

[0076] The water quality of the influent of the present application is shown in Table 3 below

[0077] Table 3

[0078] Detection item Water quantity SS Ni Co Mn Unit m 3 / d]]> mg / L mg / L mg / L mg / L Value 80.00 ＜10 2.58 0.25 0.29 Detection item Na Li SO4 2- ]] TDS PH Unit mg / L mg / L mg / L mg / L mg / L Value 158.00 3352.00 29.40 3542.52 12.09

[0079] The water quality of the effluent of the second reverse osmosis concentration device in the present application is shown in Table 4 below

[0080] Table 4

[0081] Detection item pH Temperature Conductivity Unit of measurement Dimensionless ℃ us / cm Detection value 6～9 Normal temperature ＜10

[0082] The lithium carbonate produced by the present application is about 800 kg / d (taking the lithium content as 2362 mg / L), with a purity of ≥ 99% and a water content of < 0.3%. It meets the Li2CO3 requirements in “Lithium Carbonate GB / T 11075-2013”.

[0083] The mud produced by the present application is about 80 kg / d, with a water content of 65-70%.

[0084] The mother liquor discharged by the present application is 13.2 m 3 / d of water, and the indicators meet the RBMC#2 industrial wastewater indirect discharge standard.

[0085] The recovery benefits of the present application are shown in Table 5 below

[0086] Table 5

[0087]

[0088] Table 6 is the technical parameters of the precision filtration device in the present application:

[0089] Table 6

[0090] Serial number Item Technical parameter Remark Remark 1 Equipment quantity 1 Set 2 Inlet water quantity 3.51 m 3 / h]]> Designed according to 24h / d 3 Water production quantity 3.33 m 3 / h]]> Designed according to 24h / d 4 Recovery rate 95.00％ 5 Control mode Full-automatic operation 6 Filter quantity 3 Table 7 Filter specification Ф900*H3350 8 Filter core specification Ф40*1000 9 Designed water production flux 291.61 L / m2·H 10 Membrane element quantity 91 branches / set, a total of 1 set 11 Connecting pipeline material UPVC

[0091] Table 7 is the technical parameters of the ultrafiltration device in the present application:

[0092] Table 7

[0093]

[0094] Table 8 is the technical parameter of the nanofiltration device in the application

[0095] Table 8

[0096]

[0097] Table 9 is the technical parameter of the first reverse osmosis filtration device in the application

[0098] Table 9

[0099]

[0100] Table 10 is the technical parameter of the second reverse osmosis filtration device in the application

[0101] Table 10

[0102]

[0103] The advantage of the application compared with the prior art is that investment is saved, operation cost is reduced, process operation is stable and reliable, the produced water and lithium carbonate mother liquor after treatment meet the discharge requirements, and the recovery of heavy metals is also realized, the lithium carbonate product is obtained by precipitation, the recovered water and the mother liquor finally meet the discharge requirements.

[0104] The above related contents of the application have been described. The person skilled in the art can realize the application based on the description. Based on the above contents of the application, all other embodiments obtained by the person skilled in the art without creative labor should belong to the protection scope of the application.

Claims

1. A method for recovering lithium carbonate from ternary cathode washing water, characterized in that, Includes the following steps: (1) Heavy metal removal After adding PAM, the ternary cathode wash water enters the reaction tank and sedimentation tank in sequence for heavy metal flocculation and sedimentation. The supernatant overflows to the overflow buffer tank, and the heavy metal precipitate is discharged from the bottom of the sedimentation tank and pumped to the mud tank. The wastewater in the overflow buffer tank is filtered through a precision filtration device to enrich suspended solids and clarify the wastewater. The concentrated water from the precision filtration is sent to the mud tank, and the filtrate from the precision filtration is sent to the precision filtrate tank. The filtrate from the precision filtration process is then introduced into a pH adjuster after the addition of sulfuric acid. This neutralizes the carbonate and hydroxide ions and removes a large amount of carbon dioxide. The reaction pH is 2.5-3.

0. The wastewater after the reaction is then sent to the finished liquid storage tank. The sludge in the mud tank is dewatered by a plate and frame filter press. The filtrate obtained from the dewatering is sent to the overflow buffer tank, and the resulting filter cake is sent to the leaching unit for leaching and recovery of nickel, cobalt and manganese. (2) Lithium recovery The wastewater in the liquid storage tank is pumped into the pH adjustment tank to react with sodium hydroxide solution. The pH after the reaction is controlled at 6-7. The pH adjustment solution is filtered through a security filter and then sent to an ultrafiltration unit. The ultrafiltration unit's permeate is sent to the ultrafiltration permeate tank, while the ultrafiltration unit's concentrate is returned to the pH adjustment tank. The permeate from the ultrafiltration unit is concentrated with lithium sulfate and sodium sulfate by the nanofiltration unit. The concentrate from the nanofiltration unit is sent to the concentrate tank of the nanofiltration unit, and the permeate from the nanofiltration unit is sent to the permeate tank of the nanofiltration unit. The nanofiltration unit's permeate water sequentially passes through a first reverse osmosis concentration unit and a second reverse osmosis concentration unit. The permeate water from the first reverse osmosis concentration unit is sent to a first reverse osmosis permeate tank. The concentrate from the first reverse osmosis concentration unit is sent to an ultrafiltration permeate tank. The first reverse osmosis permeate water in the first reverse osmosis permeate tank enters the second reverse osmosis concentration unit. The permeate water from the second reverse osmosis concentration unit is sent to a reclaimed water tank. The second reverse osmosis concentrate is sent to a nanofiltration permeate tank. The concentrated water from the nanofiltration unit is heated to 90°C by steam and fed into a jacketed reactor along with a sodium carbonate solution for mixing and crystal growth, ultimately yielding a lithium carbonate slurry. The lithium carbonate slurry is dehydrated by centrifugation and washed with pure water to obtain wet solid lithium carbonate, which enters the lithium carbonate silo; the mother liquor enters the mother liquor storage tank, the wash water enters the wash water storage tank, and the wash water is sent back to the sodium carbonate slurry tank. Lithium carbonate wet solid is dried using a dryer to obtain lithium carbonate dry powder; Lithium carbonate dry powder is fed into a packaging machine for bagging, weighing, and sealing to finally obtain lithium carbonate products.

2. The method for recovering lithium carbonate from ternary cathode washing water as described in claim 1, characterized in that, The SDI of the ultrafiltration permeate is <5.

3. The method for recovering lithium carbonate from ternary cathode washing water as described in claim 1, characterized in that, The salt concentration in the concentrate from the nanofiltration device is >120 g / L.

4. The method for recovering lithium carbonate from ternary cathode washing water as described in claim 1, characterized in that, The conductivity of the product water from the first reverse osmosis concentration unit is <200 μS / cm.

5. The method for recovering lithium carbonate from ternary cathode washing water as described in claim 1, characterized in that, The conductivity of the product water from the first reverse osmosis concentration unit is <10 μS / cm.

6. The method for recovering lithium carbonate from ternary cathode washing water as described in claim 1, characterized in that, The concentration of the sodium carbonate solution is 300 g / L.

7. The method for recovering lithium carbonate from ternary cathode washing water as described in claim 1, characterized in that, The concentrated water from the nanofiltration unit is heated to 90°C by steam and then fed together with the sodium carbonate solution into a jacketed reactor for mixing for 10 minutes, reaction for 10-30 minutes, and crystal growth for 60-120 minutes, ultimately yielding lithium carbonate slurry.

8. The method for recovering lithium carbonate from ternary cathode washing water as described in claim 1, characterized in that, The dryer is a disc dryer.

9. A system for recovering lithium carbonate from ternary cathode washing water, characterized in that, A method for recovering lithium carbonate from ternary cathode washing water as described in any one of claims 1-8, comprising: The heavy metal removal unit includes a raw water collection tank, a reaction tank, and a sedimentation tank connected in sequence. It also includes a mud tank connected to the mud discharge outlet of the sedimentation tank, an overflow buffer tank connected to the supernatant overflow outlet of the sedimentation tank, a plate and frame filter press connected to the mud tank, and a precision filter device, a precision filtrate tank, a pH adjuster, and a finished liquid storage tank connected in sequence to the overflow buffer tank. The clear liquid outlet of the plate and frame filter press is connected to the overflow buffer tank, and the pH adjuster is connected to a dilute sulfuric acid storage tank. The lithium recovery unit includes a pH adjustment tank, a security filter, an ultrafiltration unit, an ultrafiltration permeate tank, a nanofiltration unit, and a nanofiltration permeate tank connected in sequence to the finished liquid storage tank. It also includes a sodium hydroxide storage tank connected to the pH adjustment tank, a nanofiltration permeate tank, a heat exchanger, a jacketed reactor, a centrifuge, and a mother liquor storage tank connected in sequence to the nanofiltration permeate outlet, a lithium carbonate silo, a dryer, and a dust removal device connected in sequence to the centrifuge, a sodium carbonate slurry tank connected to the wash water storage tank outlet, and the sodium carbonate slurry tank connected to the inlet of the jacketed reactor. Furthermore, it includes a first reverse osmosis concentration unit connected in sequence to the nanofiltration permeate tank, a first reverse osmosis permeate tank connected to the clear liquid outlet of the first reverse osmosis concentration unit, a second reverse osmosis concentration unit, and a reclaimed water tank connected to the clear liquid outlet of the second reverse osmosis concentration unit. The concentrated liquid outlet of the first reverse osmosis concentration unit is connected to the ultrafiltration permeate tank, and the concentrated liquid outlet of the second reverse osmosis concentration unit is connected to the nanofiltration permeate tank.

10. The system for recovering lithium carbonate from ternary cathode washing water as described in claim 9, characterized in that, The dryer is a disc dryer.

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