A multi-stage series connection flat plate type electric membrane extraction lithium extraction device

Abstract

The utility model belongs to the technical field of electric membrane extraction, especially relates to a multistage series connection flat plate type electric membrane extraction lithium extraction device. The device includes a feed liquid pool, a stripping pool, a lithium extraction residual liquid pool, a lithium-rich solution pool and a plurality of flat plate membrane extraction assemblies, the flat plate membrane extraction assembly is a multilayer shell structure, including two electrode plates and lithium selective extraction membranes arranged in parallel, the lithium selective extraction membranes divide the flat plate membrane extraction assembly into a feed liquid chamber and a stripping chamber, the feed liquid chambers and the stripping chambers of the plurality of flat plate membrane extraction assemblies are respectively connected in series, the electrode plates on one side of the feed liquid chamber are connected in parallel to form a first circuit, the electrode plates on one side of the stripping chamber are connected in parallel to form a second circuit, and a direct-current stabilized power supply is connected in series between the first circuit and the second circuit. The utility model is controllable in membrane area and series connection number, the flat plate membrane assemblies connected in series and the external direct-current stabilized power supply are used to realize efficient separation and enrichment by relying on the synergistic membrane extraction effect of electric field force and simultaneously completing the extraction and stripping of target lithium ions.

Description

Technical Field

[0001] This utility model belongs to the field of electro-membrane extraction technology, and specifically relates to a multi-stage series flat plate electro-membrane extraction lithium extraction device. Background Technology

[0002] Membrane extraction technology combines the advantages of membrane separation and solvent extraction, enabling simultaneous extraction and back-extraction, simplifying operation, and being environmentally friendly and low-carbon. A utility model patent (CN212998921) discloses a membrane extraction and separation device. However, slow mass transfer rate is a bottleneck in the lithium extraction process. Researchers have addressed this by accelerating ion migration in solution with an electric field and enhancing passive diffusion of target substances within the membrane through potential difference, combining these methods with membrane extraction to improve the transport rate. Electro-membrane extraction, as a cutting-edge technology integrating electric field-driven and membrane separation characteristics, demonstrates great potential in the field of brine separation in salt lakes due to its high selectivity, low energy consumption, and ease of integration.

[0003] Current research on lithium extraction via electroporation mainly focuses on developing high-performance lithium-selective extraction membrane materials to achieve high lithium separation efficiency; however, the devices themselves remain in the laboratory research and development stage. Utility model patent (CN211004705) discloses an electroporation extraction device for separating or enriching metal ions, standardizing the design of traditional electroporation extraction devices. These devices typically consist of two liquid pools and a membrane. While simple in structure and easy to operate, their inherent structural limitations result in bottlenecks such as a small effective mass transfer membrane area, high expansion costs, and weak continuous operation capabilities, leading to low throughput and difficulty in meeting industrial lithium extraction needs. Utility Model Content

[0004] To address the aforementioned problems, the purpose of this invention is to provide a multi-stage series-connected flat-plate electro-membrane extraction lithium extraction device. Through a multi-stage series-connected flat-plate membrane module and an external DC regulated power supply, relying on the synergistic effect of the electric field force and membrane extraction, the extraction and back-extraction processes of target lithium ions are completed simultaneously, achieving efficient separation and enrichment. The flat-plate membrane module occupies a small area, and the membrane area and number of series stages are flexible and variable. By increasing the membrane area and the number of series stages, the processing cycle of the electro-membrane extraction process can be significantly shortened, and the processing capacity of the device can be increased, which is beneficial for ensuring long-term and continuous stable operation.

[0005] The technical solution of this utility model is as follows: a multi-stage series flat-plate electrochemical membrane extraction lithium extraction device, comprising a feed tank, a back-extraction tank, a lithium extraction residue tank, a lithium-rich solution tank, and multiple flat-plate membrane extraction components. Each flat-plate membrane extraction component has a multi-layer shell structure, including two parallel electrode plates. A lithium-selective extraction membrane is disposed in the middle of the two electrode plates. The lithium-selective extraction membrane divides the interior of the flat-plate membrane extraction component into a feed chamber and a back-extraction chamber. The feed chambers of the multiple flat-plate membrane extraction components are connected in series, and the back-extraction chambers of the multiple flat-plate membrane extraction components are also connected in series. The feed chambers are connected in series. One end of the feed chamber is connected to a feed pool via a pipe, and the other end is connected to a lithium extraction residue pool via a pipe. The back-extraction chamber of the flat-panel membrane extraction assembly on one side of the feed pool is connected to a lithium-rich solution pool via a pipe. The back-extraction chamber of the flat-panel membrane extraction assembly on the other side of the lithium extraction residue pool is connected to a back-extraction pool via a pipe. The electrode plates on one side of the feed chambers are connected in parallel to form a first circuit, and the electrode plates on one side of the back-extraction chambers are connected in parallel to form a second circuit. A DC regulated power supply is connected in series between the first circuit and the second circuit.

[0006] The flat membrane extraction assembly has a multi-layer shell structure, which is symmetrically arranged along both sides of the lithium selective extraction membrane and includes, in sequence, a side sealing plate, a gasket, an electrode plate, a channel, and a support mesh.

[0007] A gasket is also provided between the support mesh and the lithium selective extraction membrane.

[0008] The side sealing plate, gasket, electrode plate, channel, support mesh, and lithium selective extraction membrane are fastened together by bolts.

[0009] The flat sheet membrane extraction assembly has water inlets on both sides at the bottom and water outlets on both sides at the top. The water inlets and water outlets are sealed with straight connectors.

[0010] The peristaltic pumps are respectively installed on the connecting pipes on one side of the feed tank and the back-extraction tank.

[0011] Pressure gauges are installed on the connecting pipes on one side of the feed tank, the back-extraction tank, the lithium extraction residue tank, and the lithium-rich solution tank.

[0012] Electric mixers are installed in the feed tank, back-extraction tank, lithium extraction residue tank, and lithium-rich solution tank, respectively.

[0013] The side sealing plate can be made of polymethyl methacrylate, polyetheretherketone, or polycarbonate. The gasket can be made of silicone, nitrile rubber, or fluororubber. The electrode plate can be made of titanium, graphite, ruthenium-iridium titanium, iridium-tantalum titanium, or platinum titanium. The channel and support mesh can be made of polypropylene, polytetrafluoroethylene, or polyvinylidene fluoride.

[0014] The volume of the feed chambers connected in series is 10-50 times the volume of the back-extraction tanks connected in series.

[0015] The technical advantages of this utility model are as follows: 1. This utility model uses a multi-stage series flat sheet membrane module and an external DC regulated power supply to simultaneously complete the extraction and back-extraction process of target lithium ions by relying on the electric field force to coordinate the membrane extraction effect, thereby achieving efficient separation and enrichment. It has green and sustainable technology and process characteristics. 2. This utility model monitors the pressure change in the pipeline through a pressure gauge and achieves precise control of the liquid flow rate in the device through a peristaltic pump. Based on the reaction kinetics characteristics of the membrane material and the target lithium ions, the peristaltic pump is controlled to adjust the residence time of the fluid in the chamber to match the mass transfer requirements. 3. The flat sheet membrane extraction assembly of this utility model has a compact structure and a small footprint. The processing capacity of the flat sheet membrane extraction assembly can be flexibly adjusted by the membrane area, which facilitates multi-stage series connection and production scale expansion, and can effectively realize industrial production.

[0016] The following will provide further explanation in conjunction with the accompanying drawings. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a multi-stage series flat plate electro-membrane extraction lithium extraction device according to this utility model.

[0018] Figure 2 This is a schematic diagram of the structure of the flat sheet membrane extraction component of this utility model.

[0019] Reference numerals: 1-Side sealing plate; 2-Gasket; 3-Electrode plate; 4-Channel; 5-Support mesh; 6-Lithium selective extraction membrane; 7-Inlet; 8-Outlet; 9-Straight connector; 10-Flat sheet membrane extraction assembly; 11-Peristaltic pump; 12-Pressure gauge; 13-Feed tank; 14-Back-extraction tank; 15-DC regulated power supply; 16-Electric stirrer; 17-Lithium extraction residue tank; 18-Lithium-rich solution tank. Detailed Implementation Example 1

[0020] like Figure 1 , Figure 2As shown, a multi-stage series flat-plate electrochemical membrane extraction lithium extraction device includes a feed tank 13, a back-extraction tank 14, a lithium extraction residue tank 17, a lithium-rich solution tank 18, and multiple flat-plate membrane extraction components 10. Each flat-plate membrane extraction component 10 has a multi-layer shell structure, including two parallel electrode plates 3. A lithium selective extraction membrane 6 is disposed in the middle of the two electrode plates 3. The lithium selective extraction membrane 6 divides the interior of the flat-plate membrane extraction component 10 into a feed chamber and a back-extraction chamber. The feed chambers of the multiple flat-plate membrane extraction components 10 are connected in series, and the back-extraction chambers of the multiple flat-plate membrane extraction components 10 are also connected in series. One end of the series-connected liquid chamber is connected to the liquid tank 13 via a pipe, and the other end is connected to the lithium extraction residue tank 17 via a pipe. The back-extraction chamber of the flat-panel membrane extraction assembly 10 on one side of the liquid tank 13 is connected to the lithium-rich solution tank 18 via a pipe. The back-extraction chamber of the flat-panel membrane extraction assembly 10 on one side of the lithium extraction residue tank 17 is connected to the back-extraction tank 14 via a pipe. The electrode plates 3 on one side of the series-connected liquid chambers are connected in parallel to form a first circuit, and the electrode plates 3 on one side of the series-connected back-extraction chambers are connected in parallel to form a second circuit. A DC regulated power supply 15 is connected in series between the first circuit and the second circuit.

[0021] In use, a brine solution from a salt lake is placed in the feed tank 13. A back-extraction solution matching the lithium selective extraction membrane is placed in the back-extraction tank 14. Simultaneously, a positive terminal of a power supply is connected to the electrode plate 13 on one side of the feed tank 13, and a negative terminal of a power supply is connected to the electrode plate 13 on the other side of the back-extraction tank 14. The feed chamber and the back-extraction chamber are filled with solution and the flow is stable. The DC regulated power supply 15 is turned on, the current mode is set to constant current, and the current density is adjusted. Through the lithium selective extraction membrane 6 of the multi-stage series-connected flat sheet membrane assembly 10 and the external DC regulated power supply 15, the extraction and back-extraction of target lithium ions are completed simultaneously by relying on the electric field force to coordinate the membrane extraction effect, thereby achieving efficient separation and enrichment. Example 2

[0022] Based on Example 1, in this embodiment, preferably, the flat membrane extraction assembly 10 is a multi-layer shell structure, which is symmetrically arranged on both sides of the lithium selective extraction membrane 6, and includes a side sealing plate 1, a gasket 2, an electrode plate 3, a channel 4 and a support mesh 5 in sequence.

[0023] The flat membrane extraction assembly 10 of this invention has a multi-layer shell structure. The multi-layer shell structure is symmetrically arranged on both sides of the lithium selective extraction membrane 6. It has a compact structure, occupies a small area, and the processing capacity of the membrane assembly can be flexibly adjusted by adjusting the effective area of ​​the membrane. Example 3

[0024] Based on Example 1 or Example 2, in this embodiment, preferably, a gasket is also provided between the support mesh 5 and the lithium selective extraction membrane 6.

[0025] A gasket is also provided between the support mesh 5 and the lithium selective extraction membrane 6 of this utility model. The gasket is 0.5mm thick and can be made of silicone, nitrile rubber, or fluororubber. This ensures that the lithium selective extraction membrane 6 completely separates the two-phase solution in the feed chamber and the back-extraction chamber, and has good adhesion to the support mesh 5 to prevent leakage. Example 4

[0026] Based on Example 1 or Example 3, in this embodiment, preferably, the side sealing plate 1, gasket 2, electrode plate 3, channel 4, support mesh 5 and lithium selective extraction membrane 6 are fastened together by bolts.

[0027] The side sealing plate 1, gasket 2, electrode plate 3, channel 4, support mesh 5, and lithium selective extraction membrane 6 of this utility model are fastened together by bolts. This utility model uses bolts and nuts as core connecting parts, and is equipped with washers. By “bolts passing through the pre-drilled holes of the parts → nuts tightening and locking”, the components of the flat sheet membrane extraction assembly 10 can be detachably fixed and assembled, and finally form a stable and reliable flat sheet membrane assembly as a whole. Example 5

[0028] Based on Embodiment 1 or Embodiment 4, in this embodiment, preferably, the bottom of both sides of the flat sheet membrane extraction component 10 is provided with water inlets 7, the top of both sides of the flat sheet membrane extraction component 10 is provided with water outlets 8, and the water inlets 7 and water outlets 8 are sealed and connected with straight connectors 9.

[0029] The flat sheet membrane extraction assembly 10 of this invention has water inlets 7 on both sides at the bottom and water outlets 8 on both sides at the top. A straight connector 9 is sealed to the water inlets 7 and water outlets 8. A pipe is connected to the outside of the straight connector 9. The straight connector 9 forms a structured and sealed connection between the feed liquid chamber, the back-extraction chamber, and the pipe. The pipe leads to four pools: feed liquid pool 13, back-extraction pool 14, lithium extraction residue pool 17, and lithium-rich solution pool 18, forming a continuous fluid transmission. Multiple flat sheet membrane extraction assemblies 10 are connected in series through pipes. Example 6

[0030] Based on Example 1 or Example 5, in this embodiment, preferably, a peristaltic pump 11 is provided on the connecting pipe on one side of the feed tank 13 and the back-extraction tank 14.

[0031] The present invention has peristaltic pumps 11 installed on the connecting pipes on one side of the feed tank 13 and the back-extraction tank 14. The peristaltic pumps 11 provide driving force so that the solution flows and is separated in the device. The peristaltic pumps achieve precise control of the liquid flow rate in the device. Example 7

[0032] Based on Example 1 or Example 6, in this embodiment, preferably, pressure gauges 12 are provided on the connecting pipes on one side of the feed tank 13, the back-extraction tank 14, the lithium extraction residue tank 17, and the lithium-rich solution tank 18.

[0033] Pressure gauges 12 are respectively installed on the connecting pipes on one side of the feed tank 13, the back-extraction tank 14, the lithium extraction residue tank 17, and the lithium-rich solution tank 18 of this utility model. These gauges are used to monitor the pressure changes in the pipelines. Based on the reaction kinetics characteristics of the membrane material and the target lithium ions, the peristaltic pump is controlled to adjust the residence time of the fluid in the chamber to match the mass transfer requirements and ensure the stability of the electro-membrane extraction process. Example 8

[0034] Based on Example 1, in this embodiment, preferably, an electric stirrer 16 is provided in the feed tank 13, the back-extraction tank 14, the lithium extraction residue tank 17 and the lithium-rich solution tank 18 respectively.

[0035] The present invention provides electric stirrers 16 in the feed tank 13, back-extraction tank 14, lithium extraction residual liquid tank 17 and lithium-rich solution tank 18, with a rotation speed of 500-1000 rpm. The stirrers mix the solutions in the feed tank 13, back-extraction tank 14, lithium extraction residual liquid tank 17 and lithium-rich solution tank 18 in real time to eliminate concentration differences. Example 9

[0036] Based on Example 1, in this embodiment, preferably, the side sealing plate 1 is made of polymethyl methacrylate, polyetheretherketone, or polycarbonate; the gasket 2 is made of silicone, nitrile rubber, or fluororubber; the electrode plate 3 is made of titanium, graphite, ruthenium-iridium titanium, iridium-tantalum titanium, or platinum titanium; and the channel 4 and support mesh 5 are made of polypropylene, polytetrafluoroethylene, or polyvinylidene fluoride.

[0037] The side sealing plate 1 of this utility model can be made of polymethyl methacrylate, polyetheretherketone, or polycarbonate, selected according to the corrosiveness, transparency requirements, and mechanical load of the process; the gasket 2 can be made of silicone, nitrile rubber, or fluororubber, selected according to the pH value, temperature, polar solvent, and oxidizing properties of the medium; the electrode plate 3 can be made of titanium, graphite, ruthenium-iridium titanium, iridium-tantalum titanium, or platinum titanium, selected according to the two-phase solution conditions and electric field strength of different membrane materials; the channel 4 and the support mesh 5 can be made of polypropylene, polytetrafluoroethylene, or polyvinylidene fluoride, determined comprehensively according to the temperature, pH value, and mechanical strength requirements of the chamber solution. Example 10

[0038] Based on Example 1, in this example, preferably, the volume of the series-connected feed chamber is 10-50 times the volume of the series-connected back-extraction tank.

[0039] Based on the scale of lithium extraction, this invention needs to consider the membrane area, the number of multi-stage series connections, and the lithium extraction mass transfer efficiency of the membrane material. The volume of the series-connected feed chamber is 10-50 times the volume of the series-connected back-extraction tank, which can better achieve the target separation and enrichment effect of lithium ions.

[0040] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model should be included within the protection scope of the present utility model.

Claims

1. A multi-stage series flat-plate electroporation lithium extraction device, characterized in that: The system includes a feed tank (13), a back-extraction tank (14), a lithium extraction residue tank (17), a lithium-rich solution tank (18), and multiple flat-plate membrane extraction components (10). Each flat-plate membrane extraction component (10) has a multi-layer shell structure, including two parallel electrode plates (3). A lithium selective extraction membrane (6) is provided in the middle of the two electrode plates (3). The lithium selective extraction membrane (6) divides the interior of the flat-plate membrane extraction component (10) into a feed chamber and a back-extraction chamber. The feed chambers of the multiple flat-plate membrane extraction components (10) are connected in series, and the back-extraction chambers of the multiple flat-plate membrane extraction components (10) are connected in series. One end of the chamber is connected to a feed liquid tank (13) via a pipe, and the other end is connected to a lithium extraction residue tank (17) via a pipe. The back-extraction chamber of the flat sheet membrane extraction assembly (10) on the side of the feed liquid tank (13) is connected to a lithium-rich solution tank (18) via a pipe. The back-extraction chamber of the flat sheet membrane extraction assembly (10) on the side of the lithium extraction residue tank (17) is connected to a back-extraction tank (14) via a pipe. The electrode plates (3) on the side of the feed liquid chamber connected in series are connected in parallel to form a first circuit. The electrode plates (3) on the side of the back-extraction chamber connected in series are connected in parallel to form a second circuit. A DC regulated power supply (15) is connected in series between the first circuit and the second circuit.

2. The multi-stage series flat-plate electroporation lithium extraction device according to claim 1, characterized in that: The multi-layer shell structure of the flat membrane extraction assembly (10) is symmetrically arranged on both sides of the lithium selective extraction membrane (6), and includes a side sealing plate (1), a gasket (2), an electrode plate (3), a channel (4) and a support mesh (5) in sequence.

3. The multi-stage series flat-plate electroporation lithium extraction device according to claim 2, characterized in that: A gasket is also provided between the support mesh (5) and the lithium selective extraction membrane (6).

4. The multi-stage series flat-plate electroporation lithium extraction device according to claim 2, characterized in that: The side sealing plate (1), gasket (2), electrode plate (3), channel (4), support mesh (5) and lithium selective extraction membrane (6) are fastened together by bolts.

5. The multi-stage series flat-plate electroporation lithium extraction device according to claim 1, characterized in that: The flat sheet membrane extraction assembly (10) has water inlets (7) at the bottom of both sides and water outlets (8) at the top of both sides. A straight connector (9) is sealed to the water inlets (7) and water outlets (8).

6. The multi-stage series flat-plate electroporation lithium extraction device according to claim 1, characterized in that: The peristaltic pump (11) is installed on the connecting pipe on one side of the feed tank (13) and the back-extraction tank (14).

7. The multi-stage series flat-plate electroporation lithium extraction device according to claim 1, characterized in that: Pressure gauges (12) are respectively installed on the connecting pipes on one side of the feed tank (13), the back-extraction tank (14), the lithium extraction residue tank (17), and the lithium-rich solution tank (18).

8. The multi-stage series flat-plate electroporation lithium extraction device according to claim 1, characterized in that: Electric mixers (16) are respectively installed in the feed tank (13), the back-extraction tank (14), the lithium extraction residue tank (17), and the lithium-rich solution tank (18).

9. The multi-stage series flat-plate electroporation lithium extraction device according to claim 2, characterized in that: The side sealing plate (1) can be made of polymethyl methacrylate, polyether ether ketone, or polycarbonate. The gasket (2) can be made of silicone, nitrile rubber, or fluororubber. The electrode plate (3) can be made of titanium, graphite, ruthenium-iridium titanium, iridium-tantalum titanium, or platinum titanium. The channel (4) and support mesh (5) can be made of polypropylene, polytetrafluoroethylene, or polyvinylidene fluoride.

10. The multi-stage series flat-plate electroporation lithium extraction device according to claim 1, characterized in that: The volume of the series-connected feed chambers is 10-50 times the volume of the series-connected back-extraction tanks.

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