Device for synchronous extraction of lithium and uranium from seawater by pulse electrochemical method

Abstract

The application discloses a device for synchronously extracting lithium and uranium from seawater by using a pulse electrochemical method, which integrates the technologies of lithium extraction and uranium extraction by using a power supply and a valve control, and simultaneously extracts and recovers lithium ions and uranium ions. The device is divided into five parts, i.e. a seawater inlet, a seawater extraction device, a recovery liquid tank and a precipitation fixing tank. The pulse power is used in the seawater extraction device to improve the selectivity of lithium ions and uranium ions, and an anion exchange membrane is added in the middle. Positive electricity is added on the lithium side, and negative electricity is added on the uranium side, so that lithium recovery and uranium extraction are simultaneously performed. Negative electricity is added on the lithium side, and positive electricity is added on the uranium side, so that uranium recovery and lithium extraction are simultaneously performed. The cycle is repeated for multiple times. Finally, lithium and uranium are fixed in the lithium and uranium recovery liquid, so that the resources in seawater are maximally utilized.

Description

Technical Field

[0001] This invention relates to the fields of electrochemical technology, seawater resource utilization, and lithium and uranium resource recovery technology, and particularly to a device for simultaneous extraction of lithium and uranium from seawater using a pulsed electrochemical method. Background Technology

[0002] Currently, in seawater lithium extraction, a single working electrode is typically used for lithium extraction and recovery. However, this method does not fully utilize the lithium extraction electrode, resulting in low extraction efficiency. The rocking chair battery is currently a hot topic. Its working principle involves a lithium-depleted working electrode responsible for lithium ion extraction and insertion, while a lithium-rich working electrode is responsible for lithium ion recovery and extraction. After extraction and recovery, the lithium-depleted electrode becomes a lithium-rich electrode, and vice versa. By switching the two electrodes, lithium ion extraction continues from the lithium-depleted electrode, and lithium ion recovery from the lithium-rich electrode. This device technology offers advantages such as low energy consumption, low cost, low pollution, high selectivity, and high separation efficiency.

[0003] In recent years, numerous methods for uranium extraction from seawater have been explored to achieve efficient uranium extraction, including membrane separation, chemical deposition, solvent extraction, ion exchange, bioadsorption, reduction, and adsorption. Among these, some researchers have utilized pulsed extraction devices to enhance uranium recovery performance. Others have employed organic solvents for uranium extraction and recovery, enabling uranium extraction from seawater to not only focus on extraction but also recover uranium into the solution.

[0004] However, extracting lithium and uranium separately can only extract a single ion at a time. Since there are many metal ions in seawater, directly discharging the recovered seawater does not maximize the utilization of the metal ions in the seawater. Summary of the Invention

[0005] The purpose of this invention is to provide a device for simultaneous extraction of lithium and uranium from seawater using a pulsed electrochemical method. This is achieved by creating a rocking chair battery that can simultaneously extract lithium and uranium ions and recover them at the same time, thereby maximizing the utilization of ion resources in seawater.

[0006] To achieve the above objectives, the present invention provides an apparatus for simultaneous extraction of lithium and uranium from seawater using a pulsed electrochemical method, the technical solution of which is as follows:

[0007] An apparatus for simultaneous extraction of lithium and uranium from seawater using a pulsed electrochemical method includes a seawater collection tank, an ion recovery tank, a lithium ion precipitation and fixation tank, a uranium ion separation and fixation tank, a lithium recovery liquid tank, and a uranium recovery liquid tank.

[0008] An anion exchange membrane is provided in the ion recovery tank, and the anion exchange membrane divides the ion recovery tank into a first tank and a second tank. A lithium extraction working electrode is provided in the first tank, and a uranium extraction working electrode is provided in the second tank. The lithium extraction working electrode and the uranium extraction working electrode are electrically connected to a power source.

[0009] The first tank and the second tank are respectively connected to a first discharge pipeline and a second discharge pipeline, and a first discharge valve and a second discharge valve are respectively installed on the first discharge pipeline and the second discharge pipeline.

[0010] The seawater collection tank is connected to the first tank body and the second tank body through the first pipeline and the second pipeline respectively, and the first pipeline and the second pipeline are respectively equipped with the first valve and the second valve.

[0011] The lithium recovery liquid tank is filled with lithium recovery liquid. The lithium recovery liquid tank is connected to the first tank and the lithium ion precipitation fixing tank through the third pipeline and the fourth pipeline respectively. The third pipeline and the fourth pipeline are respectively equipped with the third valve and the fourth valve. The third pipeline is equipped with the first liquid pump.

[0012] The uranium recovery liquid tank is equipped with uranium recovery liquid. The uranium recovery liquid tank is connected to the second tank and the uranium ion separation and fixing tank through the fifth pipeline and the sixth pipeline, respectively. The fifth pipeline and the sixth pipeline are equipped with the fifth valve and the sixth valve, respectively. The fifth pipeline is equipped with the second liquid pump.

[0013] Furthermore, the seawater collection tank is connected to a water inlet pipe, and a water inlet valve is installed on the water inlet pipe.

[0014] Furthermore, the lithium extraction working electrode is a lithium manganese oxide electrode or a lithium iron phosphate electrode.

[0015] Furthermore, the uranium extraction working electrode is an ortho-substituted isobutylene carborane 1,2-(Ph₂PO)₂-1,2-C₂B 10 H 10 It is made from clustered molecules.

[0016] Furthermore, the lithium recovery solution is a lithium chloride solution.

[0017] Furthermore, the uranium recovery liquid is a mixed solution of 1,2-dichloroethane and heterogeneous carbon additives.

[0018] Furthermore, the power source provides pulsed current to the lithium extraction working electrode and the uranium extraction working electrode.

[0019] Furthermore, the power supply provides pulsed current to the lithium extraction working electrode and the uranium extraction working electrode in a forward-intermittent-forward pulse or forward-intermittent-reverse pulse manner.

[0020] The beneficial effects of this invention are:

[0021] This invention integrates lithium and uranium extraction technologies from seawater using power supply and valve control, simultaneously extracting and recovering lithium and uranium ions. The device consists of five main parts: seawater inlet, seawater extraction unit, recovery liquid tank, and sedimentation tank. The seawater extraction unit uses a pulsed power supply to improve the selectivity of lithium and uranium ions. An anion exchange membrane is added in the middle. Positive charge is applied to the lithium side and negative charge to the uranium side, allowing uranium extraction to occur simultaneously with lithium recovery. This process is repeated multiple times, with negative charge applied to the lithium side and positive charge to the uranium side, allowing lithium extraction to occur simultaneously with uranium recovery. Finally, the recovered lithium and uranium liquid is fixed, maximizing the utilization of resources in seawater. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0023] Figure 1 A structural diagram of an apparatus for simultaneous extraction of lithium and uranium from seawater using a pulsed electrochemical method according to an embodiment of the present invention is shown.

[0024] Figure label:

[0025] 1. Seawater collection tank; 2. Ion recovery tank; 201. First tank body; 202. Second tank body; 3. Lithium ion precipitation and fixation tank; 4. Uranium ion separation and fixation tank; 5. Lithium recovery liquid tank; 6. Uranium recovery liquid tank; 7. Anion exchange membrane; 8. Lithium extraction working electrode; 9. Uranium extraction working electrode; 10. Power supply; 11. First discharge pipeline; 12. Second discharge pipeline; 13. First discharge valve; 14. Second discharge valve; 15. First pipeline; 16. Second pipeline; 17. First valve; 18. Second valve; 19. Third pipeline; 20. Fourth pipeline; 21. Third valve; 22. Fourth valve; 23. First liquid pump; 24. Fifth pipeline; 25. Sixth pipeline; 26. Fifth valve; 27. Sixth valve; 28. Second liquid pump; 29. ​​Inlet pipe; 30. Inlet valve. Detailed Implementation

[0026] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0027] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0028] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0029] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0030] This invention provides an apparatus for simultaneous extraction of lithium and uranium from seawater using a pulsed electrochemical method, such as... Figure 1 As shown, the device for simultaneous lithium and uranium extraction from seawater using a pulsed electrochemical method includes a seawater collection tank 1, an ion recovery tank 2, a lithium ion precipitation and fixation tank 3, a uranium ion separation and fixation tank 4, a lithium recovery liquid tank 5, and a uranium recovery liquid tank 6.

[0031] An anion exchange membrane 7 is provided in the ion recovery tank 2, and the anion exchange membrane 7 divides the ion recovery tank 2 into a first tank body 201 and a second tank body 202. A lithium extraction working electrode 8 is provided in the first tank body 201, and a uranium extraction working electrode 9 is provided in the second tank body 202. The lithium extraction working electrode 8 and the uranium extraction working electrode 9 are electrically connected to the power supply 10.

[0032] The first tank 201 and the second tank 202 are respectively connected to a first discharge pipe 11 and a second discharge pipe 12, and a first discharge valve 13 and a second discharge valve 14 are respectively provided on the first discharge pipe 11 and the second discharge pipe 12.

[0033] The seawater collection tank 1 is connected to the first tank body 201 and the second tank body 202 through the first pipe 15 and the second pipe 16 respectively. The first pipe 15 and the second pipe 16 are respectively equipped with a first valve 17 and a second valve 18.

[0034] The lithium recovery liquid tank 5 is provided with lithium recovery liquid. The lithium recovery liquid tank 5 is connected to the first tank 201 and the lithium ion precipitation and fixing tank 3 through the third pipeline 19 and the fourth pipeline 20 respectively. The third pipeline 19 and the fourth pipeline 20 are respectively provided with the third valve 21 and the fourth valve 22. The third pipeline 19 is provided with the first liquid pump 23.

[0035] The uranium recovery liquid tank 6 is provided with uranium recovery liquid. The uranium recovery liquid tank 6 is connected to the second tank body 202 and the uranium ion separation and fixing tank 4 through the fifth pipeline 24 and the sixth pipeline 25 respectively. The fifth pipeline 24 and the sixth pipeline 25 are respectively provided with the fifth valve 26 and the sixth valve 27. The fifth pipeline 24 is provided with the second liquid pump 28.

[0036] In this embodiment, the lithium extraction working electrode 8 is selected as a lithium manganese oxide electrode, and the uranium extraction working electrode 9 is an ortho-substituted isobutylene carborane 1,2-(Ph2PO)2-1,2-C2B 10 H 10 The electrode is made of clustered molecules, the lithium recovery solution is a lithium chloride solution, and the uranium recovery solution is a mixed solution of 1,2-dichloroethane and heterogeneous carbon additives.

[0037] Based on the selection of the electrodes and recovery solution mentioned above, the specific workflow of this device is as follows:

[0038] Step 1: Open the first valve 17 to allow seawater from the seawater collection tank 1 to be transported to the first tank 201 via the first pipeline 15. Open the second liquid pump 28 and the fifth valve 26 to allow the uranium recovery liquid (a mixture of 1,2-dichloroethane and heterogeneous carbon additive) from the uranium recovery liquid tank 6 to be transported to the second tank 202 via the fifth pipeline. After the first tank 201 and the second tank 202 have sufficient solution, close the first valve 17, the second liquid pump 28, and the fifth valve 26. The power supply 10 provides a negative charge to the lithium extraction working electrode 8, which acts as the cathode for lithium extraction, and a positive charge to the uranium extraction working electrode 9, which acts as the anode for uranium recovery until the recovery is complete. After the recovery is complete, the first discharge valve 13 is opened to discharge the lithium-extracted seawater from the first tank 201; the fifth valve 26 is opened to return the uranium recovery liquid (the mixture of 1,2-dichloroethane (DCE) and heterogeneous carbon additive) to the uranium recovery liquid tank 6. After the recovery is completed, the first discharge valve 13 and the fifth valve 26 are closed.

[0039] Step 2: Open the second valve 18, allowing seawater to enter the second tank 202 through the second pipe 16. Open the third valve 21 and the first liquid pump 23 to introduce lithium chloride recovery solution into the first tank 201. When water flows to suitable positions on both sides of the ion recovery tank 2, close the second valve 18, the third valve 21, and the first liquid pump 23. Power supply 10 supplies positive electricity to the first tank 201, i.e., the lithium extraction working electrode 8 acts as the anode for uranium recovery; power supply 10 supplies negative electricity to the second tank 202, i.e., the uranium extraction working electrode 9 acts as the cathode for uranium extraction. Both sides are supplied with pulsed current. After recovery, the second discharge valve 14 opens, discharging the uranium-extracted brine from the second tank 202; the third valve 21 opens, allowing the lithium chloride recovery solution to enter the lithium recovery solution tank 5. After recovery, the second discharge valve 14 and the third valve 21 close.

[0040] Step 3: Repeat steps 1 and 2 multiple times until the lithium chloride and uranium recovery solution reach the extraction limit concentration for maximum suitable efficiency of lithium and uranium.

[0041] The specific number of cycles is determined based on the concentrations of lithium and uranium in the seawater, as well as the maximum extractable amounts of lithium and uranium ions from the lithium chloride and uranium recovery solutions. For example, the maximum extractable lithium and uranium ion concentrations in the lithium chloride and uranium recovery solutions are a and b (in mass units, such as μg or mg), respectively, while the concentrations of lithium and uranium in the seawater are c and d (in μg / ml or mg / ml), respectively. Assuming the volume of seawater introduced in steps 1 and 2 is the same, Q (in ml), and the experimentally measured efficiency of lithium and uranium extraction from seawater in a single cycle is m and n (i.e., the amount of lithium and uranium extracted divided by the total amount of lithium and uranium in the seawater), then cycles a / Qcm can reach the lithium extraction limit concentration, and cycles b / Qdn can reach the lithium extraction limit concentration. It is best to round down the number of cycles. For example, if 3.1 cycles are needed to reach the lithium extraction limit concentration, then the number of cycles should be 3.

[0042] Step 4: After the cycle is completed, open the fourth valve 22 to recover the lithium chloride solution to the lithium ion precipitation and fixing tank 3, and open the sixth valve 27 to recover the mixed solution of uranium-containing dichloroethane (DCE) and heterogeneous carbon additive to the uranium ion separation and fixing tank 4.

[0043] It should be noted that the various valves and pump assemblies described in this article can be connected to a controller, which controls the opening and closing of each valve and pump assembly according to the above process, thereby realizing the automated workflow of the device.

[0044] This embodiment achieves the separation of lithium ions and uranium ions in a single device. Exemplarily, potassium carbonate is added to the lithium ion precipitation tank 3, the precipitate in the tank is collected, filtered, and dried to obtain solid lithium carbonate. The uranium-containing solution in the uranium ion separation tank 4 can be extracted by extraction. Extraction utilizes specific compounds or solvents to form complexes with uranium, and then uranium is extracted by separating and recovering these complexes. Commonly used complexes include organic acids, organic ketones, organic keto acids, and organic phosphates. Solvent extraction can also be used, where uranium is transferred from the solution to an organic solvent. The key to solvent extraction is selecting a suitable organic solvent and adjusting the pH of the solution, as well as adding complexing agents to enhance the partition coefficient between uranium and the organic phase. Commonly used organic solvents include large-volume organic phases with thirty carbon atoms and phosphate-based organic solvents.

[0045] It is understood that the core of this invention lies in the simultaneous extraction and separation of lithium ions and uranium ions from seawater. The specific implementation of the precipitation and solidification extraction of lithium ions and uranium ions in solution can be achieved based on existing technologies, including but not limited to the methods exemplified above. Other known methods can also be applied to the extraction of lithium and uranium from lithium ion and uranium ion solutions.

[0046] In some embodiments, such as Figure 1As shown, the seawater collection tank 1 is connected to an inlet pipe 29, and an inlet valve 30 is installed on the inlet pipe 29. The inlet pipe 29 can be connected to a storage device that stores a large amount of seawater. This storage device can be implemented as a pressure vessel. When the inlet valve 30 is opened, the seawater stored in it will enter the seawater collection tank 1.

[0047] In some embodiments, the power supply 10 provides pulsed current to the lithium extraction working electrode 8 and the uranium extraction working electrode 9.

[0048] Specifically, the power supply 10 provides pulsed current to the lithium extraction working electrode 8 and the uranium extraction working electrode 9 in a forward-intermittent-forward pulse or forward-intermittent-reverse pulse manner. Under the pulsed power supply, the selectivity of lithium ion extraction and uranium ion extraction and recovery can be enhanced.

[0049] In summary, this invention simultaneously extracts lithium and uranium, further utilizing precious metal ions in seawater, improving the efficiency of lithium and uranium ion extraction, and fixing lithium and uranium ions for subsequent use.

[0050] The above embodiments are only used to illustrate the present invention and are not intended to limit the present invention. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also fall within the scope of the present invention, and the patent protection scope of the present invention should be defined by the claims.

Claims

1. A device for simultaneous extraction of lithium and uranium from seawater using a pulsed electrochemical method, characterized in that, This includes seawater collection tanks, ion recovery tanks, lithium ion precipitation and fixation tanks, uranium ion separation and fixation tanks, lithium recovery liquid tanks, and uranium recovery liquid tanks. An anion exchange membrane is provided in the ion recovery tank, and the anion exchange membrane divides the ion recovery tank into a first tank and a second tank. A lithium extraction working electrode is provided in the first tank, and a uranium extraction working electrode is provided in the second tank. The lithium extraction working electrode and the uranium extraction working electrode are electrically connected to a power source. The first tank and the second tank are respectively connected to a first discharge pipeline and a second discharge pipeline, and a first discharge valve and a second discharge valve are respectively installed on the first discharge pipeline and the second discharge pipeline. The seawater collection tank is connected to the first tank body and the second tank body through the first pipeline and the second pipeline respectively, and the first pipeline and the second pipeline are respectively equipped with the first valve and the second valve. The lithium recovery liquid tank is filled with lithium recovery liquid. The lithium recovery liquid tank is connected to the first tank and the lithium ion precipitation fixing tank through the third pipeline and the fourth pipeline respectively. The third pipeline and the fourth pipeline are respectively equipped with the third valve and the fourth valve. The third pipeline is equipped with the first liquid pump. The uranium recovery liquid tank is equipped with uranium recovery liquid. The uranium recovery liquid tank is connected to the second tank and the uranium ion separation and fixing tank through the fifth pipeline and the sixth pipeline respectively. The fifth pipeline and the sixth pipeline are respectively equipped with the fifth valve and the sixth valve. The fifth pipeline is equipped with the second liquid pump. The lithium extraction working electrode is a lithium manganese oxide electrode or a lithium iron phosphate electrode. The uranium extraction working electrode uses o-substituted isobutylene carborane 1,2-(Ph₂PO)₂-1,2-C₂B 10 H 10 It is made from clustered molecules; The power source provides pulsed current to the lithium extraction working electrode and the uranium extraction working electrode.

2. The apparatus for simultaneous lithium and uranium extraction from seawater using a pulsed electrochemical method as described in claim 1, characterized in that, The seawater collection tank is connected to a water inlet pipe, and a water inlet valve is installed on the water inlet pipe.

3. The apparatus for simultaneous lithium and uranium extraction from seawater using a pulsed electrochemical method as described in claim 1, characterized in that, The lithium recovery solution is a lithium chloride solution.

4. The apparatus for simultaneous lithium and uranium extraction from seawater using a pulsed electrochemical method as described in claim 1, characterized in that, The uranium recovery solution is a mixed solution of 1,2-dichloroethane and heterogeneous carbon additives.

5. The apparatus for simultaneous lithium and uranium extraction from seawater using a pulsed electrochemical method as described in claim 1, characterized in that, The power supply provides pulsed current to the lithium extraction working electrode and the uranium extraction working electrode in a forward-intermittent-forward pulse or forward-intermittent-reverse pulse manner.

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