Lithium extraction device

Abstract

The utility model provides a lithium extraction device, and belongs to the technical field of lithium extraction devices. The lithium extraction device comprises a bracket, a pressing device and a membrane stack unit group, the pressing device is arranged on the bracket; one end of the membrane stack unit group is connected with the bracket, and the other end is connected with the pressing device; wherein the membrane stack unit group comprises at least two membrane stack units, the membrane stack units are connected in sequence, and any two adjacent membrane stack units are communicated in series through a connecting pipe. According to the lithium extraction device provided by the invention, the plurality of membrane stack units are connected in sequence, and any two adjacent membrane stack units are connected in series through the connecting pipe to form the large lithium extraction device, so that the electrochemical lithium extraction frequency in one cycle process is effectively increased, the electrochemical lithium extraction efficiency is improved, and meanwhile, the lithium extraction efficiency is improved. By arranging the tandem membrane stack unit group, the circulating flow velocity and energy consumption of the solution in the cathode and anode chambers can be greatly reduced in the lithium extraction process, the electrochemical lithium extraction efficiency is improved, and the energy is saved.

Description

Technical Field

[0001] The present application relates to the technical field of lithium extraction devices, and in particular to a lithium extraction device. Background Art

[0002] Lithium and lithium compounds such as lithium chloride, lithium carbonate, lithium hydroxide and organic lithium compounds are widely used in high-energy batteries, aerospace, nuclear power generation and other fields, and are of great significance to the development of my country's national economy. Lithium is the main positive electrode material of high-energy batteries and plays an important strategic role in the development of energy storage materials and clean nuclear energy. With the rapid development of science and technology and the sharp increase in energy demand, energy faces great challenges, and lithium batteries have gradually become the mainstay of the battery industry.

[0003] Salt lake lithium resources account for more than 69% of the world's industrial lithium reserves, and extracting lithium from salt lake brine has become a relatively important means of lithium extraction. The main methods for extracting lithium from brine include evaporation crystallization, precipitation, extraction, adsorption, calcination, membrane separation, electrochemical lithium extraction and other methods. Among them, electrochemical lithium extraction technology, as a new type of lithium separation and extraction technology, has the advantages of being green and environmentally friendly, high lithium extraction efficiency, and good impurity separation effect, and has received more and more attention and research.

[0004] The electrochemical lithium extraction device in the related art includes a plurality of electrochemical deintercalation units, wherein the cathode chambers between the plurality of electrochemical deintercalation units are connected to the cathode chambers, and the anode chambers are connected to the anode chambers, that is, the plurality of electrochemical deintercalation units are in the form of parallel water flow. Thus, on the one hand, when the number of electrochemical deintercalation units is designed to be small, the number of electrochemical lithium extractions in one cycle is small, and there is a problem of low lithium extraction efficiency. On the other hand, when the number of electrochemical deintercalation units is designed to be large, due to the parallel shunting, the sum of the flow rates of each branch is equal to the flow rate of the main trunk. Therefore, the more the number of electrochemical deintercalation units, that is, the more branches, the greater the flow rate of the main trunk, and a circulation pump with a larger working power is required to keep each branch at a preset electrochemical lithium extraction flow rate, which has the problems of large circulation flow rate and high energy consumption.

[0005] In view of this, this application is hereby filed. Utility Model Content

[0006] The purpose of this application is to provide a lithium extraction device to solve or improve the above technical problems.

[0007] This application can be implemented as follows:

[0008] The present application provides a lithium extraction device, comprising:

[0009] Bracket;

[0010] A clamping device is arranged on the bracket;

[0011] A membrane stack unit group, one end of which is connected to the bracket, and the other end of which is connected to the pressing device;

[0012] Wherein, the membrane stack unit group includes at least two membrane stack units, the membrane stack units are connected in sequence, and any two adjacent membrane stack units are connected in series via a connecting pipe.

[0013] In an optional embodiment, the membrane stack unit includes a water distribution plate at the water inlet end, at least two sub-membrane units and a water distribution plate at the water outlet end;

[0014] Each of the sub-membrane units comprises a first separator, a cathode plate, a second separator, an anion membrane, a third separator, an anode plate and a fourth separator arranged in sequence;

[0015] The sub-membrane units are arranged in sequence in the order that the fourth partition in the previous sub-membrane unit corresponds to the first partition in the next sub-membrane unit; and in two adjacent sub-membrane units, the fourth partition of the previous sub-membrane unit and the first partition in the next sub-membrane unit are separated by the separately arranged anion membrane; the water distribution plate at the water inlet end is connected to the outer side of the first partition of the first sub-membrane unit, and the water distribution plate at the water outlet end is connected to the outer side of the fourth partition of the last sub-membrane unit, so that the brine to be treated flows in from the water distribution plate at the water inlet end and flows out from the water distribution plate at the water outlet end after being treated by each sub-membrane unit in sequence.

[0016] In an optional embodiment, the membrane stack unit further includes an anode-side water inlet pipe and a cathode-side water inlet pipe;

[0017] The water inlet end water distribution plate is provided with a first anode side water inlet hole and a first cathode side water inlet hole; the first anode side water inlet hole is connected to the anode side water inlet pipe, and the first cathode side water inlet hole is connected to the cathode side water inlet pipe.

[0018] In an optional embodiment, the membrane stack unit further includes an anode side water outlet pipe and a cathode side water outlet pipe;

[0019] The water outlet distribution plate is provided with a first anode side water outlet hole and a first cathode side water outlet hole; the first anode side water outlet hole is connected to the anode side water outlet pipe, and the first cathode side water outlet hole is connected to the cathode side water outlet pipe.

[0020] In an optional embodiment, the first partition plate, the second partition plate, the third partition plate, and the fourth partition plate all include a frame and a water distribution network, and the frame is arranged on the periphery of the water distribution network;

[0021] The frame is provided with a second cathode side water inlet hole, a second anode side water inlet hole, a second cathode side water outlet hole, and a second anode side water outlet hole; the frames of the first partition and the second partition located on both sides of the cathode plate are also provided with a cathode side water inlet channel and a cathode side water outlet channel; the frames of the third partition and the fourth partition located on both sides of the anode plate are also provided with an anode side water inlet channel and an anode side water outlet channel.

[0022] In an optional embodiment, the frame is made of rubber or silicone.

[0023] In an optional embodiment, the anode plate and the cathode plate both include a metal mesh electrode piece and a metal outer frame arranged on the periphery of the metal mesh electrode piece;

[0024] The metal outer frame is provided with a third anode side water inlet hole, a third cathode side water inlet hole, a third anode side water outlet hole and a third cathode side water outlet hole.

[0025] In an optional embodiment, the metal outer frame is further provided with a pole ear, and the pole ear is provided with a wiring port for connecting to a power source.

[0026] In an optional embodiment, the water distribution plate at the water inlet end and the water distribution plate at the water outlet end are both provided with support ears, and the support ears are connected to the bracket.

[0027] In an optional embodiment, the lithium extraction device further comprises a crossbeam, which is disposed on the bracket and is used for supporting the membrane stack unit.

[0028] The beneficial effects of this application include:

[0029] The present application forms a large-scale lithium extraction device by connecting the membrane stack units in sequence, and connecting any two adjacent membrane stack units in series through a connecting pipe, which effectively increases the number of electrochemical lithium extractions in a cycle, thereby improving the efficiency of electrochemical lithium extraction. At the same time, by setting up a series-connected membrane stack unit group, the circulation flow rate and energy consumption of the anode and cathode chamber solutions can be greatly reduced during the lithium extraction process, thereby improving the efficiency of electrochemical lithium extraction and saving energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 A schematic diagram of the structure of the membrane stack unit provided in this application;

[0032] Figure 2 for Figure 1 Structural diagram of the water distribution plate at the middle water inlet end;

[0033] Figure 3 for Figure 1 Structural diagram of the water distribution plate at the middle water outlet end;

[0034] Figure 4 for Figure 1 A schematic diagram of the structure of the first baffle and the second baffle;

[0035] Figure 5 for Figure 1 A schematic diagram of the structure of the third partition and the fourth partition;

[0036] Figure 6 for Figure 1 Schematic diagram of the structure of the cathode plate;

[0037] Figure 7 for Figure 1 Schematic diagram of the structure of the anode plate;

[0038] Figure 8 This is a schematic diagram of the structure of the lithium extraction device provided in this application.

[0039] Icons: 10-membrane stack unit; 11-first baffle; 12-cathode plate; 13-second baffle; 14-anion membrane; 15-third baffle; 16-anode plate; 17-fourth baffle; 21-water distribution plate at water inlet end; 22-water distribution plate at water outlet end; 31-anode side water inlet pipe; 32-cathode side water inlet pipe; 33-anode side water outlet pipe; 34-cathode side water outlet pipe; 41-first anode side water inlet hole; 42-first cathode side water inlet hole; 43-first anode side water outlet hole; 44-first cathode side water outlet hole; 45-second cathode side water inlet hole; 46-second anode side water inlet hole; 47-second cathode side water outlet hole; 48-first Second anode side water outlet; 51-frame; 52-water distribution network; 53-cathode side water inlet flow channel; 54-cathode side water outlet flow channel; 55-anode side water inlet flow channel; 56-anode side water outlet flow channel; 61-metal mesh electrode; 62-metal outer frame; 63-coating material; 64-pole ear; 65-wiring port; 66-third anode side water inlet hole; 67-third cathode side water inlet hole; 68-third anode side water outlet hole; 69-third cathode side water outlet hole; 71-support ear; 80-bracket; 90-clamping device; 91-left end plate; 92-right end plate; 93-upper frame plate; 94-lower frame plate; 95-crossbeam; 96-screw. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0041] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0042] In addition, the terms "horizontal" and "vertical" do not mean that the components must be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0043] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0044] It should be noted that the electrochemical lithium extraction device in the related art includes a plurality of electrochemical deintercalation units, and the cathode chambers between the plurality of electrochemical deintercalation units are connected to the cathode chambers, and the anode chambers are connected to the anode chambers, that is, the plurality of electrochemical deintercalation units are in the form of parallel water flow. In this way, on the one hand, when the number of electrochemical deintercalation units is designed to be small, the number of electrochemical lithium extractions in one cycle is small, and there is a problem of low lithium extraction efficiency. On the other hand, when the number of electrochemical deintercalation units is designed to be large, due to the parallel shunting, the sum of the flow rates of each branch is equal to the flow rate of the main trunk. Therefore, the more the number of electrochemical deintercalation units, that is, the more branches, the greater the flow rate of the main trunk, and a circulation pump with a larger working power is required to keep each branch at a preset electrochemical lithium extraction flow rate, which has the problems of large circulation flow rate and high energy consumption.

[0045] In view of this, please refer to Figure 8 This embodiment provides a lithium extraction device, which includes a bracket 80, a pressing device 90 and a membrane stack unit group.

[0046] The clamping device 90 is disposed on the bracket 80, one end of the membrane stack unit group is connected to the bracket 80, and the other end is connected to the clamping device 90. The membrane stack unit group includes at least two membrane stack units 10, which are connected in sequence, and any two adjacent membrane stack units 10 are connected in series through a connecting pipe.

[0047] The lithium extraction device provided in the embodiment of the present application forms a large lithium extraction device by connecting the membrane stack units 10 in sequence, and connecting any two adjacent membrane stack units 10 in series through a connecting pipe, which effectively increases the number of electrochemical lithium extraction in a cycle, thereby improving the efficiency of electrochemical lithium extraction. At the same time, by setting a series-connected membrane stack unit group, in any two adjacent membrane stack units, each sub-membrane unit of the previous membrane stack unit 10 is connected in series with each sub-membrane unit of the next membrane stack unit 10, so that the flow rate of any two adjacent membrane stack units 10 is equal, that is, the circulation flow rate of the lithium extraction device will not increase with the increase in the number of membrane stack units 10. Compared with the parallel connection between each sub-membrane unit and each sub-membrane unit in the related art, the series connection can greatly reduce the circulation flow rate of the anode and cathode chamber solution during the lithium extraction process, save the power consumption of the circulation pump, improve the efficiency of electrochemical lithium extraction, and save energy. In addition, the modularization of the membrane stack unit 10 is conducive to overhaul and maintenance, and can save production space to a certain extent and reduce equipment manufacturing costs.

[0048] Exemplarily, the pressing device 90 may be a push rod.

[0049] In some embodiments, the bracket 80 includes a left end plate 91 and a right end plate 92 opposite to each other, and an upper frame plate 93 and a lower frame plate 94 are connected between the left end plate 91 and the right end plate 92. The right end plate 92 is provided with a movable push rod, and the water distribution plate 21 at the water inlet end of the membrane stack unit 10 located at the leftmost end is fixed to the left end plate 91 by a screw 96, and the water distribution plate 22 at the water outlet end of the membrane stack unit 10 located at the rightmost end is connected to one end of the push rod, and the other end of the push rod is connected to the right end plate 92. In this way, the movable push rod is used to tighten the membrane stack unit group (such as fixing and pressing all membrane stack units 10) and to disassemble the membrane stack unit group after loosening.

[0050] Please refer to Figure 1 In some embodiments, the membrane stack unit 10 includes a water distribution plate 21 at the water inlet end, at least two sub-membrane units and a water distribution plate 22 at the water outlet end.

[0051] Each sub-membrane unit includes a first separator 11, a cathode plate 12, a second separator 13, an anion membrane 14, a third separator 15, an anode plate 16 and a fourth separator 17 which are arranged in sequence.

[0052] The sub-membrane unit is arranged in the order that the fourth baffle 17 in the previous sub-membrane unit corresponds to the first baffle 11 in the next sub-membrane unit, that is, referring to Figure 1 In the orientation, each sub-membrane unit is sequentially provided with a first separator 11, a cathode plate 12, a second separator 13, an anion membrane 14, a third separator 15, an anode plate 16 and a fourth separator 17 from left to right. Moreover, in two adjacent sub-membrane units, the fourth separator 17 of the previous sub-membrane unit is separated from the first separator 11 of the next sub-membrane unit by an additional anion membrane 14.

[0053] The water inlet end water distribution plate 21 is connected to the outer side of the first partition plate 11 of the first sub-membrane unit (i.e. Figure 1 The outlet water distribution plate 22 is connected to the outer side of the fourth partition plate 17 of the last sub-membrane unit (i.e. Figure 1 The brine and the conductive liquid to be treated flow into the water distribution plate 21 at the water inlet end and flow out from the water distribution plate 22 at the water outlet end after being processed by each sub-membrane unit in turn. In this way, each membrane stack unit 10 can perform electrochemical lithium extraction on the brine to be treated for multiple times during one cycle, thereby improving the efficiency of electrochemical lithium extraction.

[0054] It can be understood that any two adjacent membrane stack units 10 are separated by the water distribution plate 22 at the water outlet end of the previous membrane stack unit 10 and the water distribution plate 21 at the water inlet end of the subsequent membrane stack unit 10, and the water distribution plate 22 at the water outlet end of the previous membrane stack unit 10 is connected in series with the water distribution plate 21 at the water inlet end of the subsequent membrane stack unit 10 through a connecting pipe, so that each sub-membrane unit of the previous membrane stack unit 10 is connected in series with each sub-membrane unit of the subsequent membrane stack unit 10, so that the flow rate of any two adjacent membrane stack units 10 is equal, that is, the circulation flow rate of the lithium extraction device will not increase with the increase in the number of membrane stack units 10. Compared with the parallel connection between each sub-membrane unit and each sub-membrane unit in the related art, the series connection can greatly reduce the circulation flow rate of the anode and cathode chamber solutions during the lithium extraction process, save the power consumption of the circulation pump, improve the electrochemical lithium extraction efficiency, and save energy.

[0055] Please combine again Figure 2 and Figure 3 In this embodiment, the membrane stack unit 10 further includes an anode side water inlet pipe 31 , a cathode side water inlet pipe 32 , an anode side water outlet pipe 33 and a cathode side water outlet pipe 34 .

[0056] Correspondingly, the water inlet end water distribution plate 21 is provided with a first anode side water inlet hole 41 and a first cathode side water inlet hole 42 ; the first anode side water inlet hole 41 is connected to the anode side water inlet pipe 31 , and the first cathode side water inlet hole 42 is connected to the cathode side water inlet pipe 32 .

[0057] Thus, the conductive liquid can flow into the anode chamber formed by the third partition 15, the anode plate 16, and the fourth partition 17 through the anode side water inlet pipe 31 and the first anode side water inlet hole 41 in sequence, and at the same time, the brine to be treated can flow into the cathode chamber formed by the first partition 11, the cathode plate 12, and the second partition 13 through the cathode side water inlet pipe 32 and the first cathode side water inlet hole 42 in sequence. In this process, the cathode plate 12 in the cathode chamber adsorbs lithium in the brine to be treated under the action of electric energy, the anode plate 16 in the anode chamber desorbs lithium under the action of electric energy, and the chloride ions in the brine to be treated in the cathode chamber enter the anode chamber through the anion membrane 14 to ensure the occurrence of electrochemical reaction.

[0058] The outlet water distribution plate 22 is provided with a first anode side water outlet hole 43 and a first cathode side water outlet hole 44 ; the first anode side water outlet hole 43 is connected to the anode side water outlet pipe 33 , and the first cathode side water outlet hole 44 is connected to the cathode side water outlet pipe 34 .

[0059] As a result, the conductive liquid in the anode chamber can be discharged in sequence through the first anode side water outlet hole 43 and the anode side water outlet pipe 33 and enter the anode chamber of the subsequent membrane stack unit 10. At the same time, the brine to be treated in the cathode chamber can be discharged in sequence through the first cathode side water outlet hole 44 and the cathode side water outlet pipe 34 and enter the cathode chamber of the subsequent membrane stack unit 10, so that the cathode chamber of the subsequent membrane stack unit 10 can further adsorb lithium in the brine to be treated, and the anode chamber of the subsequent membrane stack unit 10 can further desorb lithium.

[0060] By providing the water distribution plate 21 at the water inlet and the water distribution plate 22 at the water outlet, the inflow of the brine to be treated and the conductive liquid, as well as the discharge of the lithium-rich liquid or the lithium-poor liquid after lithium extraction can be achieved.

[0061] For reference, the number of the first anode side water inlet hole 41, the first cathode side water inlet hole 42, the first anode side water outlet hole 43 and the first cathode side water outlet hole 44 can be multiple, and the multiple first cathode side water inlet holes 42 and the multiple first anode side water inlet holes 41 are staggered and spaced on the water inlet end water distribution plate 21. The multiple first anode side water outlet holes 43 and the multiple first cathode side water outlet holes 44 are staggered and spaced on the water outlet end water distribution plate 22. All the first anode side water inlet holes 41 are connected to the anode side water inlet pipe 31, all the first cathode side water inlet holes 42 are connected to the cathode side water inlet pipe 32, all the first anode side water outlet holes 43 are connected to the anode side water outlet pipe 33, and all the first cathode side water outlet holes 44 are connected to the cathode side water outlet pipe 34.

[0062] In some embodiments, the first anode side water inlet hole 41 and the first cathode side water inlet hole 42 can be arranged at the lower part of the water distribution plate 21 at the water inlet end, and the first anode side water outlet hole 43 and the first cathode side water outlet hole 44 can be arranged relatively at the upper part of the water distribution plate 22 at the water outlet end.

[0063] In other embodiments, the first anode side water inlet hole 41 and the first cathode side water inlet hole 42 can be arranged on the upper part of the water distribution plate 21 at the water inlet end, and the first anode side water outlet hole 43 and the first cathode side water outlet hole 44 can be relatively arranged on the lower part of the water distribution plate 22 at the water outlet end.

[0064] For reference, the materials of the water inlet distribution plate 21 and the water outlet distribution plate 22 can be PVC, UPVC or PP, etc. In some optional embodiments, the materials of the water inlet distribution plate 21 and the water outlet distribution plate 22 are both PVC.

[0065] Please combine again Figure 4 and Figure 5 In this embodiment, the first partition 11 , the second partition 13 , the third partition 15 , and the fourth partition 17 all include a frame 51 and a water distribution network 52 , and the frame 51 is arranged on the outer periphery of the water distribution network 52 .

[0066] For reference, the frame 51 used for the first partition 11, the second partition 13, the third partition 15, and the fourth partition 17 can be exemplarily but not limitatively made of rubber or silicone material, so that the first partition 11, the second partition 13, the third partition 15, and the fourth partition 17 themselves have the function of sealing and preventing water leakage, eliminating the rubber gaskets and sealing strips set in the relevant technology for sealing and preventing water leakage, effectively simplifying the structure and reducing the production and installation costs.

[0067] The frame 51 is provided with a second cathode side water inlet hole 45, a second anode side water inlet hole 46, a second cathode side water outlet hole 47, and a second anode side water outlet hole 48; the frame 51 of the first partition 11 and the second partition 13 located on both sides of the cathode plate 12 is also provided with a cathode side water inlet channel 53 and a cathode side water outlet channel 54; the frame 51 of the third partition 15 and the fourth partition 17 located on both sides of the anode plate 16 is also provided with an anode side water inlet channel 55 and an anode side water outlet channel 56.

[0068] In this way, the brine to be treated can flow into the cathode chamber through the cathode side water inlet pipe 32, the first cathode side water inlet hole 42, the second cathode side water inlet hole 45 and the cathode side water inlet channel 53 in sequence, and the conductive liquid can flow into the anode chamber through the anode side water inlet pipe 31, the first anode side water inlet hole 41, the second anode side water inlet hole 46 and the anode side water inlet channel 55 in sequence.

[0069] At the same time, the brine to be treated in the cathode chamber can be discharged through the cathode side outlet flow channel 54, the second cathode side outlet hole 47, the first cathode side outlet hole 44 and the cathode side outlet pipe 34 in sequence and enter the cathode chamber of the next membrane stack unit 10, and the conductive liquid in the anode chamber can be discharged through the anode side outlet flow channel 56, the second anode side outlet hole 48, the first anode side outlet hole 43 and the anode side outlet pipe 33 in sequence and enter the anode chamber of the next membrane stack unit 10. Furthermore, the cathode chamber of the next membrane stack unit 10 can further adsorb lithium in the brine to be treated, and the anode chamber of the next membrane stack unit 10 can further desorb lithium.

[0070] For reference, the number of the second cathode side water inlet hole 45, the second anode side water inlet hole 46, the second cathode side water outlet hole 47, and the second anode side water outlet hole 48 provided on the first partition 11, the second partition 13, the third partition 15, and the fourth partition 17 can be multiple.

[0071] In some embodiments, taking the first separator 11 and the second separator 13 on both sides of the cathode plate 12 as an example, the second cathode-side water inlet hole 45 and the second anode-side water inlet hole 46 can be arranged at the lower part of the first separator 11 and the second separator 13, and the second cathode-side water outlet hole 47 and the second anode-side water outlet hole 48 can be arranged at the upper part of the first separator 11 and the second separator 13. A plurality of second cathode-side water inlet holes 45 and a plurality of second anode-side water inlet holes 46 are arranged alternately at intervals at the lower part of the first separator 11 and the second separator 13, and a plurality of second cathode-side water outlet holes 47 and a plurality of second anode-side water outlet holes 48 are arranged alternately at the upper part of the first separator 11 and the second separator 13. The cathode-side water inlet channel 53 is arranged at the lower part of the first separator 11 and the second separator 13, and all the second cathode-side water inlet holes 45 are respectively connected to a corresponding cathode-side water inlet channel 53. The cathode side water outlet channel 54 is disposed on the upper portion of the first separator 11 and the second separator 13 , and all the second cathode side water outlet holes 47 are respectively connected to a corresponding cathode side water outlet channel 54 .

[0072] In other embodiments, the second cathode-side water inlet hole 45 and the second anode-side water inlet hole 46 may be arranged at the upper part of the first partition 11 and the second partition 13, and the second cathode-side water outlet hole 47 and the second anode-side water outlet hole 48 may be arranged at the lower part of the first partition 11 and the second partition 13. A plurality of second cathode-side water inlet holes 45 and a plurality of second anode-side water inlet holes 46 are arranged alternately at intervals at the upper part of the first partition 11 and the second partition 13, and a plurality of second cathode-side water outlet holes 47 and a plurality of second anode-side water outlet holes 48 are arranged alternately at the lower part of the first partition 11 and the second partition 13. A cathode-side water inlet channel 53 is arranged at the upper part of the first partition 11 and the second partition 13, and all the second cathode-side water inlet holes 45 are respectively connected to a corresponding cathode-side water inlet channel 53. A cathode-side water outlet channel 54 is arranged at the lower part of the first partition 11 and the second partition 13, and all the second cathode-side water outlet holes 47 are respectively connected to a corresponding cathode-side water outlet channel 54.

[0073] Similarly, the difference between the third partition 15 and the fourth partition 17 on both sides of the anode plate 16 and the first partition 11 and the second partition 13 on both sides of the cathode plate 12 is that the cathode side water inlet channel 53 is correspondingly set as the anode side water inlet channel 55, and the cathode side water outlet channel 54 is correspondingly set as the anode side water outlet channel 56.

[0074] The positions of the water inlet holes of the first partition 11, the second partition 13, the third partition 15, and the fourth partition 17 correspond to the positions of the water inlet holes in the water distribution plate 21 at the water inlet end, and the positions of the water outlet holes of the first partition 11, the second partition 13, the third partition 15, and the fourth partition 17 correspond to the positions of the water outlet holes of the water distribution plate 22 at the water outlet end.

[0075] Please combine again Figure 6 and Figure 7 In this embodiment, the anode plate 16 and the cathode plate 12 both include a metal mesh electrode sheet 61 and a metal outer frame 62 disposed on the periphery of the metal mesh electrode sheet 61. The anode plate 16 and the third separator 15 and the fourth separator 17 disposed on the left and right sides thereof form an anode chamber together, and the cathode plate 12 and the first separator 11 and the second separator 13 disposed on the left and right sides thereof form a cathode chamber together.

[0076] For reference, the metal mesh electrode piece 61 is a mesh metal, which can increase the adhesion of the coating material 63. The metal outer frame 62 can be a metal sheet. The material coated on the metal mesh electrode piece 61 can be, for example but not limitatively, lithium iron phosphate / ferrous phosphate, lithium vanadium phosphate / vanadium phosphate, lithium manganese phosphate / manganese phosphate, lithium nickel phosphate / nickel phosphate, etc. Taking lithium iron phosphate / ferrous phosphate as an example, it can be understood that: in the same sub-membrane unit, the anode plate 16 is coated with lithium iron phosphate, and the cathode plate 12 is coated with ferrous phosphate. The metals used for the above-mentioned metal mesh electrode piece 61 and the metal outer frame 62 can be, for example but not limitatively, titanium, nickel or silver, etc.

[0077] In this embodiment, the metal outer frame 62 is provided with a third anode-side water inlet hole 66 , a third cathode-side water inlet hole 67 , a third anode-side water outlet hole 68 and a third cathode-side water outlet hole 69 .

[0078] In this way, the brine to be treated can flow into the cathode chamber through the cathode side water inlet pipe 32, the first cathode side water inlet hole 42, the second cathode side water inlet hole 45, the third cathode side water inlet hole 67 and the cathode side water inlet channel 53 in sequence, and the conductive liquid can flow into the anode chamber through the anode side water inlet pipe 31, the first anode side water inlet hole 41, the second anode side water inlet hole 46, the third anode side water inlet hole 66 and the anode side water inlet channel 55 in sequence.

[0079] At the same time, the brine to be treated in the cathode chamber can be discharged sequentially through the cathode side outlet flow channel 54, the third cathode side outlet hole 69, the second cathode side outlet hole 47, the first cathode side outlet hole 44 and the cathode side outlet pipe 34 and enter the cathode chamber of the next membrane stack unit 10, and the conductive liquid in the anode chamber can be discharged sequentially through the anode side outlet flow channel 56, the third anode side outlet hole 68, the second anode side outlet hole 48, the first anode side outlet hole 43 and the anode side outlet pipe 33 and enter the anode chamber of the next membrane stack unit 10. Furthermore, the cathode chamber of the next membrane stack unit 10 can further adsorb lithium in the brine to be treated, and the anode chamber of the next membrane stack unit 10 can further desorb lithium.

[0080] In some embodiments, taking the cathode plate 12 as an example, the third cathode-side water inlet hole 67 and the third anode-side water inlet hole 66 may be disposed at the lower portion of the cathode plate 12, and the third cathode-side water outlet hole 69 and the third anode-side water outlet hole 68 may be disposed relatively at the upper portion of the cathode plate 12. A plurality of third cathode-side water inlet holes 67 and a plurality of third anode-side water inlet holes 66 are disposed at staggered intervals at the lower portion of the cathode plate 12, and a plurality of third cathode-side water outlet holes 69 and a plurality of third anode-side water outlet holes 68 are disposed at staggered intervals at the upper portion of the cathode plate 12.

[0081] In other embodiments, the third cathode-side water inlet hole 67 and the third anode-side water inlet hole 66 may be disposed at the upper portion of the cathode plate 12, and the third cathode-side water outlet hole 69 and the third anode-side water outlet hole 68 may be disposed relatively at the lower portion of the cathode plate 12. A plurality of third cathode-side water inlet holes 67 and a plurality of third anode-side water inlet holes 66 are disposed at staggered intervals at the upper portion of the cathode plate 12, and a plurality of third cathode-side water outlet holes 69 and a plurality of third anode-side water outlet holes 68 are disposed at staggered intervals at the lower portion of the cathode plate 12.

[0082] Similarly, the arrangement manner and position of each water inlet and outlet hole in the anode plate 16 are the same as those of the cathode plate 12 .

[0083] The positions of the water inlet holes of the above-mentioned cathode plate 12 and anode plate 16 correspond to the positions of the water inlet holes in the first partition plate 11, the second partition plate 13, the third partition plate 15, the fourth partition plate 17 and the water distribution plate 21 at the water inlet end, and the positions of the water outlet holes of the cathode plate 12 and the anode plate 16 correspond to the positions of the water outlet holes of the first partition plate 11, the second partition plate 13, the third partition plate 15, the fourth partition plate 17 and the water distribution plate 22 at the water outlet end.

[0084] In some embodiments, the number of water inlets and water outlets of the cathode plate 12, the anode plate 16, the first partition plate 11, the second partition plate 13, the third partition plate 15, the fourth partition plate 17, the water inlet distribution plate 21 and the water outlet distribution plate 22 can be 6-12, such as 6, 7, 8, 9, 10, 11 or 12, etc.

[0085] In addition, the metal outer frames 62 of the cathode plate 12 and the anode plate 16 are also provided with pole ears 64, and the pole ears 64 are provided with a connection port 65 for connecting to a power source, the anode plate 16 is connected to the positive electrode, and the cathode plate 12 is connected to the negative electrode. By connecting the cathode plate 12 and the anode plate 16 to the power source, the electrochemical reaction of the lithium-rich brine and the lithium-poor conductive liquid under conductive conditions can be realized.

[0086] In this embodiment, the anion membrane 14 is specifically an anion selective permeable membrane, which only allows monovalent anions to pass through. For reference, its length and width may be consistent with the electrode plate.

[0087] For reference, the lithium extraction device further includes a crossbeam 95 , which is disposed on the bracket 80 and is used to support the membrane stack unit 10 .

[0088] In some embodiments, two ends of the crossbeam 95 are respectively connected to the left end plate 91 and the right end plate 92, which can be used to support the membrane stack units 10 so that all the membrane stack units 10 are on the same horizontal line.

[0089] In this embodiment, both the water distribution plate 21 at the water inlet end and the water distribution plate 22 at the water outlet end are provided with support ears 71 , and the support ears 71 are connected to the bracket 80 to play a supporting and stabilizing role.

[0090] When the lithium extraction device is working, the brine and conductive liquid to be treated flow in from the water distribution plate 21 at the water inlet end of the previous membrane stack unit 10, and are processed by each sub-membrane unit in turn before flowing out from the water distribution plate 22 at the water outlet end of the previous membrane stack unit 10. Then, they flow in from the water distribution plate 21 at the water inlet end of the next membrane stack unit 10 through the connecting pipe, and are processed by each sub-membrane unit in turn before flowing out from the water distribution plate 22 at the water outlet end of the next membrane stack unit 10. This achieves the purpose of connecting water in series between the membrane stack units 10 to form a large-scale lithium extraction device, which effectively increases the number of electrochemical lithium extractions during one cycle, thereby improving the lithium extraction efficiency. At the same time, by connecting water in series, each sub-membrane unit of the previous membrane stack unit 10 and each sub-membrane unit of the next membrane stack unit 10 are connected in series between any two adjacent membrane stack units, so that the flow rate of any two adjacent membrane stack units 10 is equal, that is, the circulation flow rate of the lithium extraction device will not increase with the increase in the number of membrane stack units 10. Compared with the parallel connection between each sub-membrane unit and each sub-membrane unit in the related art, the series connection can greatly reduce the circulation flow rate of the anode and cathode chamber solutions during the lithium extraction process, save the power consumption of the circulation pump, improve the efficiency of electrochemical lithium extraction, and save energy. In addition, the form of modular membrane stack units 10 is also conducive to overhaul and maintenance, and can save production space to a certain extent and reduce equipment manufacturing costs.

[0091] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A lithium extraction device, characterized in that: include: Bracket (80); A pressing device (90) is arranged on the support (80); A membrane stack unit group, one end of which is connected to the bracket (80) and the other end of which is connected to the pressing device (90); The membrane stack unit group comprises at least two membrane stack units (10), the membrane stack units (10) are connected in sequence, and any two adjacent membrane stack units (10) are connected in series via a connecting pipe.

2. The lithium extraction device according to claim 1, characterized in that: The membrane stack unit (10) comprises a water distribution plate (21) at the water inlet end, at least two sub-membrane units and a water distribution plate (22) at the water outlet end; Each of the sub-membrane units comprises a first separator (11), a cathode plate (12), a second separator (13), an anion membrane (14), a third separator (15), an anode plate (16) and a fourth separator (17) which are arranged in sequence; The sub-membrane units are arranged in sequence in the order that the fourth partition (17) in the previous sub-membrane unit corresponds to the first partition (11) in the next sub-membrane unit; and in two adjacent sub-membrane units, the fourth partition (17) of the previous sub-membrane unit and the first partition (11) in the next sub-membrane unit are separated by a separately arranged anion membrane (14); the water inlet end distribution plate (21) is connected to the outer side of the first partition (11) of the first sub-membrane unit, and the water outlet end distribution plate (22) is connected to the outer side of the fourth partition (17) of the last sub-membrane unit, so that the brine to be treated flows in from the water inlet end distribution plate (21) and flows out from the water outlet end distribution plate (22) after being treated by each sub-membrane unit in sequence.

3. The lithium extraction device according to claim 2, characterized in that: The membrane stack unit (10) further comprises an anode-side water inlet pipe (31) and a cathode-side water inlet pipe (32); The water inlet end water distribution plate (21) is provided with a first anode side water inlet hole (41) and a first cathode side water inlet hole (42); the first anode side water inlet hole (41) is connected to the anode side water inlet pipe (31), and the first cathode side water inlet hole (42) is connected to the cathode side water inlet pipe (32).

4. The lithium extraction device according to claim 3, characterized in that: The membrane stack unit (10) further comprises an anode-side water outlet pipe (33) and a cathode-side water outlet pipe (34); The water outlet distribution plate (22) is provided with a first anode side water outlet hole (43) and a first cathode side water outlet hole (44); the first anode side water outlet hole (43) is connected to the anode side water outlet pipe (33), and the first cathode side water outlet hole (44) is connected to the cathode side water outlet pipe (34).

5. The lithium extraction device according to claim 2, characterized in that: The first partition plate (11), the second partition plate (13), the third partition plate (15), and the fourth partition plate (17) all comprise a frame (51) and a water distribution net (52), wherein the frame (51) is arranged on the outer periphery of the water distribution net (52); The frame (51) is provided with a second cathode side water inlet hole (45), a second anode side water inlet hole (46), a second cathode side water outlet hole (47), and a second anode side water outlet hole (48); the frame (51) of the first partition (11) and the second partition (13) located on both sides of the cathode plate (12) is also provided with a cathode side water inlet flow channel (53) and a cathode side water outlet flow channel (54); the frame (51) of the third partition (15) and the fourth partition (17) located on both sides of the anode plate (16) is also provided with an anode side water inlet flow channel (55) and an anode side water outlet flow channel (56).

6. The lithium extraction device according to claim 5, characterized in that: The frame (51) is made of rubber or silicone.

7. The lithium extraction device according to claim 2, characterized in that: The anode plate (16) and the cathode plate (12) both comprise a metal mesh electrode sheet (61) and a metal outer frame (62) arranged on the outer periphery of the metal mesh electrode sheet (61); The metal outer frame (62) is provided with a third anode-side water inlet hole (66), a third cathode-side water inlet hole (67), a third anode-side water outlet hole (68) and a third cathode-side water outlet hole (69).

8. The lithium extraction device according to claim 7, characterized in that: The metal outer frame (62) is also provided with a pole ear (64), and the pole ear (64) is provided with a wiring port (65) for connecting to a power source.

9. The lithium extraction device according to claim 2, characterized in that: The water inlet end water distribution plate (21) and the water outlet end water distribution plate (22) are both provided with support ears (71), and the support ears (71) are connected to the bracket (80).

10. The lithium extraction device according to any one of claims 1 to 9, characterized in that: The lithium extraction device further comprises a crossbeam (95), wherein the crossbeam (95) is arranged on the support (80) and is used to support the membrane stack unit (10).

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