Resource recycling method of rare earth ammonium sulfate leaching wastewater

Abstract

The invention relates to a resource recovery method of rare earth ammonium sulfate leaching wastewater, and a selective electrodialysis device comprises an anode chamber, at least one group of repeating unit chamber consisting of a desalination chamber and a concentration chamber, and a cathode chamber which are arranged in sequence; each repeating unit chamber is formed by separating a membrane unit consisting of an anion exchange membrane, a monovalent / multivalent cation selective separation membrane and an anion exchange membrane; the rare earth ammonium sulfate leaching wastewater comprises a mixed solution of rare earth sulfate and ammonium sulfate; rare earth ammonium sulfate leaching wastewater is introduced into a desalination chamber, rare earth ions are intercepted in the desalination chamber by a monovalent / multivalent cation selective separation membrane and an anion exchange membrane, and NH4 < + > and SO4 < 2-> enter a concentration chamber through the monovalent / multivalent cation selective separation membrane and the anion exchange membrane respectively. Rare earth ions and NH4 < + > are separated by virtue of the Donnan effect and size screening of a monovalent / multivalent cation selective separation membrane in the selective electrodialysis device, so that the resource recovery of the rare earth ammonium sulfate leaching wastewater is realized.

Description

Technical Field

[0001] This invention belongs to the field of solution separation and purification technology, and relates to the separation and purification of rare earth ammonium sulfate leaching wastewater, and particularly to a resource recovery method for rare earth ammonium sulfate leaching wastewater. Background Technology

[0002] Rare earth elements are a collective term for seventeen metallic elements, including the lanthanides and scandium / yttrium in the periodic table. They are valuable strategic resources. The mining process typically involves injecting excess leaching agent (mostly ammonium salts) into the ore body to desorb rare earth elements, followed by collecting the leachate for further rare earth extraction and purification. However, rare earth elements lost or migrated during mining, along with ammonium sulfate wastewater after mining, are directly discharged into surrounding natural water bodies. This causes eutrophication, reduces water transparency and dissolved oxygen levels, and releases toxic substances into the water, affecting water quality and ultimately leading to environmental pollution and ecological imbalance. Therefore, it is essential to treat rare earth ammonium sulfate leaching wastewater to prevent the loss and waste of rare earth elements and ammonium sulfate, and to avoid environmental pollution and ecological imbalance.

[0003] Currently, methods for recovering rare earth elements from rare earth ammonium sulfate leachate wastewater mainly include precipitation, extraction, ion exchange adsorption, and clay adsorption. Methods for recovering ammonia from ammonia nitrogen wastewater mainly include physicochemical methods, biological methods, and combined physicochemical-biological methods. All of these wastewater treatment methods require multi-stage treatment to separate rare earth elements from ammonium ions, making one-step, efficient separation impossible.

[0004] Membrane separation technology is a highly efficient and environmentally friendly separation method. Currently, membrane processes capable of ion separation mainly include pressure-driven nanofiltration, electrodialysis, and electro-driven nanofiltration. CN114735835A discloses a membrane-based treatment system and method for recovering ammonium sulfate from rare earth wastewater. This system includes a filtration device, a nanofiltration membrane separation device, and a reverse osmosis membrane separation device. The method for recovering ammonium sulfate from rare earth wastewater involves first filtering the wastewater to remove rare earth elements, then sequentially performing nanofiltration and reverse osmosis to separate and concentrate the ammonium sulfate solution, ultimately recovering 80%–95% of the ammonium sulfate from the wastewater. However, the ammonium sulfate recovery rate fluctuates significantly, and the recovery of rare earth elements is not considered, leading to the loss and waste of rare earth elements. Furthermore, the process operation remains relatively complex. CN104291483A discloses a membrane separation technology treatment method and device for ion-type rare earth mine wastewater. This method utilizes membrane separation technology to treat rare earth mine wastewater, removing suspended solids through a ceramic membrane and removing rare earth ions (REs) through a nanofiltration membrane. 3+The process of removing ammonia nitrogen through reverse osmosis not only ensures that the treated effluent meets environmental protection requirements but also improves the recovery rate of rare earth elements and the recycling value of ammonium sulfate. However, the separation is primarily pressure-driven, and the separation effect and recovery rate of rare earth elements and ammonium sulfate are easily affected by feed concentration and pH, making it difficult to significantly adjust the treatment effect through operating parameters. Furthermore, the treatment process is relatively complex.

[0005] Therefore, how to develop a new electro-driven membrane separation technology for the resource recovery of rare earth ammonium sulfate leaching wastewater, and achieve efficient separation and recovery of rare earth ions, ammonium ions and sulfate ions, is an urgent problem to be solved. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a method for the resource recovery of rare earth ammonium sulfate leaching wastewater. The resource recovery method provided by this invention utilizes the Donnan effect of the mono / polyvalent cation selective separation membrane and the synergistic effect of size sieving in a selective electrodialysis device to recover rare earth ions and NH4+ from rare earth ammonium sulfate leaching wastewater. + The efficient separation process yields purified ammonium sulfate and rare earth sulfate salts in the concentration and desalination chambers, respectively, enabling the resource recovery of rare earth ammonium sulfate leaching wastewater.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] This invention provides a method for the resource recovery of rare earth ammonium sulfate leaching wastewater, the resource recovery method comprising:

[0009] A selective electrodialysis apparatus is provided: the selective electrodialysis apparatus includes an anode chamber, at least one set of repeating unit chambers consisting of a desalination chamber and a concentration chamber, and a cathode chamber arranged in sequence; the repeating unit chamber is divided by membrane units consisting of anion exchange membranes, monovalent / polyvalent cation selective separation membranes, and anion exchange membranes.

[0010] Resource recovery of rare earth ammonium sulfate leaching wastewater: The rare earth ammonium sulfate leaching wastewater includes a mixed solution of rare earth sulfate and ammonium sulfate; the rare earth ammonium sulfate leaching wastewater is passed into the desalination chamber, where rare earth ions are retained by the mono / polyvalent cation selective separation membrane and the anion exchange membrane, and NH4+ is... + and SO4 2- The ions pass through the mono / polyvalent cation selective separation membrane and the anion exchange membrane, respectively, and enter the concentration chamber.

[0011] The resource recovery method provided by this invention utilizes a selective electrodialysis device. A repetitive unit chamber, consisting of a desalination chamber and a concentration chamber, is formed by separating membrane units composed of anion exchange membranes, monovalent / polyvalent cation selective separation membranes, and anion exchange membranes. When rare earth ammonium sulfate leaching wastewater is introduced into the desalination chamber, the Donnan effect of the monovalent / polyvalent cation selective separation membrane, the synergistic effect of size sieving, and the electric field force cause NH4+ to... + After passing through the concentration chamber, rare earth ions are retained in the desalination chamber, which promotes the reaction of rare earth ions and NH4+ in the rare earth ammonium sulfate leaching wastewater. + Highly efficient separation; at the same time, SO4 2- Under the influence of an electric field, it will pass through the anion exchange membrane into the concentration chamber, thereby obtaining purified ammonium sulfate and rare earth sulfate salts in the concentration chamber and desalination chamber respectively, thus realizing the resource recovery of rare earth ammonium sulfate leaching wastewater.

[0012] Preferably, in the mixed solution of rare earth sulfate and ammonium sulfate, the rare earth sulfate includes lanthanum sulfate, samarium sulfate, and ytterbium sulfate.

[0013] Preferably, in the mixed solution of rare earth sulfate and ammonium sulfate, the total concentration of rare earth sulfate is 0.015 mol / L to 0.03 mol / L, for example, it can be 0.015 mol / L, 0.018 mol / L, 0.021 mol / L, 0.024 mol / L, 0.027 mol / L or 0.03 mol / L, etc.

[0014] Preferably, in the mixed solution of rare earth sulfate and ammonium sulfate, the concentrations of lanthanum sulfate, samarium sulfate and ytterbium sulfate are each independently 0.005 mol / L to 0.01 mol / L, for example, 0.005 mol / L, 0.006 mol / L, 0.007 mol / L, 0.008 mol / L, 0.009 mol / L or 0.01 mol / L, etc.

[0015] Preferably, in the mixed solution of rare earth sulfate and ammonium sulfate, the concentration of ammonium sulfate is 0.01 mol / L to 0.12 mol / L, for example, it can be 0.01 mol / L, 0.02 mol / L, 0.05 mol / L, 0.08 mol / L, 0.1 mol / L or 0.12 mol / L, etc.

[0016] Preferably, the selective electrodialysis device includes 1 to 100 sets of repeating unit chambers consisting of a desalination chamber and a concentration chamber, for example, it can be 1 set, 5 sets, 10 sets, 15 sets, 20 sets, 30 sets, 50 sets, 60 sets, 80 sets or 100 sets, etc.

[0017] Preferably, the end-capping diaphragm of the selective electrodialysis device is an anion exchange membrane.

[0018] Preferably, the end-capping membrane near the anode chamber is a first anion exchange membrane.

[0019] Preferably, the end-capping membrane near the cathode chamber is a second anion exchange membrane.

[0020] Preferably, the anode chamber is a compartment formed by the anode plate and the first anion exchange membrane.

[0021] Preferably, the cathode chamber is a compartment formed by the cathode plate and the second anion exchange membrane.

[0022] Preferably, a sealing gasket is included between the anode plate and the first anion exchange membrane, and a sealing gasket is included between the cathode plate and the second anion exchange membrane.

[0023] Preferably, a strong electrolyte solution is introduced into the anode chamber and the cathode chamber, and the strong electrolyte solution circulates between the anode chamber and the cathode chamber.

[0024] Preferably, the SO4 2- The method of allowing SO4 to pass through the anion exchange membrane into the concentration chamber includes: 2- Directly enters the concentration chamber and / or SO4 through the anion exchange membrane. 2- After passing through the first anion exchange membrane into the anode chamber, it passes through the cathode chamber and through the second anion exchange membrane into the concentration chamber.

[0025] Preferably, the strong electrolyte solution includes any one or a combination of at least two of ammonium sulfate solution, sodium sulfate solution, or potassium sulfate solution. Typical but non-limiting combinations include combinations of ammonium sulfate solution and sodium sulfate solution, combinations of sodium sulfate solution and potassium sulfate solution, combinations of ammonium sulfate solution and potassium sulfate solution, and combinations of ammonium sulfate solution, sodium sulfate solution, and potassium sulfate solution.

[0026] Preferably, the concentration of the strong electrolyte solution is 0.3 mol / L to 0.5 mol / L, for example, it can be 0.3 mol / L, 0.35 mol / L, 0.4 mol / L, 0.45 mol / L or 0.5 mol / L, etc.

[0027] Preferably, the auxiliary electrolyte solution is introduced into the concentration chamber.

[0028] Preferably, the auxiliary electrolyte solution comprises an ammonium sulfate solution.

[0029] Preferably, the concentration of the auxiliary electrolyte solution is 0.001 mol / L to 0.01 mol / L, for example, it can be 0.001 mol / L, 0.002 mol / L, 0.003 mol / L, 0.004 mol / L, 0.005 mol / L, 0.006 mol / L, 0.007 mol / L, 0.008 mol / L, 0.009 mol / L, or 0.01 mol / L, etc.

[0030] Preferably, the selective electrodialysis device further includes a solution-assisted circulation system and a current power supply system.

[0031] Preferably, the solution-assisted circulation system includes a mechanical pump, a storage tank, and pump tubing.

[0032] Preferably, the mechanical pump includes any one or a combination of at least two of the following: diaphragm pump, peristaltic pump, centrifugal pump, submersible pump, or piston pump. Typical but non-limiting combinations include combinations of diaphragm pump and peristaltic pump, centrifugal pump and submersible pump, submersible pump and piston pump, diaphragm pump, peristaltic pump and centrifugal pump, centrifugal pump, submersible pump and piston pump, diaphragm pump, peristaltic pump, centrifugal pump and submersible pump, and diaphragm pump, peristaltic pump, centrifugal pump and submersible pump.

[0033] Preferably, the pump pipe connects the selective electrodialysis device, the mechanical pump, and the storage tank.

[0034] Preferably, the cathode chamber is connected to the cathode liquid storage tank, the anode chamber is connected to the anode liquid storage tank, the desalination chamber is connected to the feed liquid storage tank, and the concentration chamber is connected to the concentrate storage tank.

[0035] Preferably, the current power supply system includes a DC power supply.

[0036] Preferably, the DC power supply includes a current-regulating power supply and / or a voltage-regulating power supply.

[0037] Preferably, the anode plate and the cathode plate are connected to the positive and negative terminals of the DC power supply, respectively.

[0038] Preferably, the outlets of the desalination chamber and the concentration chamber are each independently equipped with a conductivity sensor and a pH sensor, respectively. The conductivity sensor is connected to a conductivity meter, and the pH sensor is connected to a pH meter.

[0039] Preferably, when the conductivity of the desalination chamber drops to 4 mS / cm~8 mS / cm or the pH of the desalination chamber rises to 5~7, the DC power supply is removed, and the resource recovery of rare earth ammonium sulfate leaching wastewater is terminated.

[0040] For example, when the conductivity of the desalination chamber drops to 4 mS / cm, 5 mS / cm, 6 mS / cm, 7 mS / cm or 8 mS / cm, the DC power supply is removed, and the resource recovery of rare earth ammonium sulfate leaching wastewater is terminated.

[0041] For example, when the pH of the desalination chamber rises to 5, 5.5, 6, 6.5 or 7, the DC power supply is removed, and the resource recovery of rare earth ammonium sulfate leaching wastewater is terminated.

[0042] Preferably, the operating temperature of the resource recycling method is 20℃~25℃, for example, it can be 20℃, 21℃, 22℃, 23℃, 24℃ or 25℃.

[0043] Preferably, the current of the DC power supply is 0.1A to 0.3A, for example, it can be 0.1A, 0.15A, 0.2A, 0.25A or 0.3A.

[0044] Preferably, the voltage of the DC power supply is 3V~6V, for example, it can be 3V, 3.5V, 4V, 4.5V, 5V, 5.5V or 6V, and preferably 3V~4V.

[0045] It should be noted that, in the process of resource recovery of rare earth ammonium sulfate leaching wastewater, the present invention also monitors the voltage and current changes at both ends of the anode and cathode chambers in real time.

[0046] Preferably, the rare earth ammonium sulfate leaching wastewater in the desalination chamber, the auxiliary electrolyte solution in the concentration chamber, and the strong electrolyte solution in the anode and cathode chambers are each in an independent circulating state.

[0047] Preferably, the flow rates of the rare earth ammonium sulfate leaching wastewater in the desalination chamber, the auxiliary electrolyte solution in the concentration chamber, and the strong electrolyte solution in the anode and cathode chambers are the same.

[0048] Preferably, the flow rate is 15L / h to 25L / h, for example, it can be 15L / h, 17L / h, 19L / h, 20L / h, 21L / h, 23L / h or 25L / h.

[0049] Preferably, the rare earth ammonium sulfate leaching wastewater is pretreated before being introduced into the desalination chamber.

[0050] Preferably, the pretreatment includes any one or a combination of at least two of nanofiltration, reverse osmosis, or chemical precipitation. Typical but non-limiting combinations include a combination of nanofiltration and reverse osmosis, a combination of reverse osmosis and chemical precipitation, a combination of nanofiltration and chemical precipitation, and a combination of nanofiltration, reverse osmosis, and chemical precipitation.

[0051] Preferably, the resource recycling method includes:

[0052] A selective electrodialysis apparatus is provided, comprising an anode chamber, at least one set of repeating unit chambers consisting of a desalination chamber and a concentration chamber, and a cathode chamber arranged sequentially; the repeating unit chamber is separated by membrane units consisting of anion exchange membranes, monovalent / polyvalent cation selective separation membranes, and anion exchange membranes; the end-capping membrane of the selective electrodialysis apparatus is anion exchange membrane; the end-capping membrane near the anode chamber is a first anion exchange membrane, and the end-capping membrane near the cathode chamber is a second anion exchange membrane; the anode chamber is a compartment formed by an anode plate and the first anion exchange membrane, and the cathode chamber is a compartment formed by a cathode plate and the second anion exchange membrane. The selective electrodialysis device includes a membrane-forming compartment; it further includes a solution-assisted circulation system and a current-powered system; the solution-assisted circulation system includes a mechanical pump, a storage tank, and a pump pipe, the pump pipe connecting the selective electrodialysis device, the mechanical pump, and the storage tank; the current-powered system includes a DC power supply, which includes a constant current power supply and / or a constant voltage power supply; the anode plate and the cathode plate are respectively connected to the positive and negative terminals of the DC power supply; the outlets of the desalination chamber and the concentration chamber are each independently equipped with a conductivity sensor and a pH sensor, the conductivity sensor being connected to a conductivity meter, and the pH sensor being connected to a pH meter.

[0053] Resource recovery of rare earth ammonium sulfate leaching wastewater: The rare earth ammonium sulfate leaching wastewater includes a mixed solution of rare earth sulfate and ammonium sulfate; the rare earth ammonium sulfate leaching wastewater is introduced into the desalination chamber, an auxiliary electrolyte solution is introduced into the concentration chamber, and a strong electrolyte solution is introduced into the anode chamber and the cathode chamber, the strong electrolyte solution circulating between the anode chamber and the cathode chamber; rare earth ions in the rare earth ammonium sulfate leaching wastewater are retained in the desalination chamber by the monovalent / polyvalent cation selective separation membrane and the anion exchange membrane, NH4+. + and SO4 2- The wastewater enters the concentration chamber through the monovalent / polyvalent cation selective separation membrane and the anion exchange membrane, respectively. When the conductivity of the desalination chamber drops to 4 mS / cm~8 mS / cm or the pH of the desalination chamber rises to 5~7, the DC power supply is removed, and the resource recovery of rare earth ammonium sulfate leaching wastewater is terminated.

[0054] In the mixed solution of rare earth sulfate and ammonium sulfate, the rare earth sulfate includes lanthanum sulfate, samarium sulfate and ytterbium sulfate, the total concentration of the rare earth sulfate is 0.015 mol / L to 0.03 mol / L, the concentration of each of the lanthanum sulfate, samarium sulfate and ytterbium sulfate is 0.005 mol / L to 0.01 mol / L, and the concentration of the ammonium sulfate is 0.01 mol / L to 0.12 mol / L.

[0055] The strong electrolyte solution includes ammonium sulfate solution and / or sodium sulfate solution, and the concentration of the strong electrolyte solution is 0.3 mol / L to 0.5 mol / L.

[0056] The auxiliary electrolyte solution includes an ammonium sulfate solution, and the concentration of the auxiliary electrolyte solution is 0.001 mol / L to 0.01 mol / L.

[0057] The operating temperature of the resource recycling method is 20℃~25℃, the current of the DC power supply is 0.1A~0.3A, and the voltage of the DC power supply is 3V~6V.

[0058] The rare earth ammonium sulfate leaching wastewater in the desalination chamber, the auxiliary electrolyte solution in the concentration chamber, and the strong electrolyte solution in the anode and cathode chambers are each in an independent circulating state with the same flow rate of 15 L / h to 25 L / h.

[0059] Before being introduced into the desalination chamber, the rare earth ammonium sulfate leaching wastewater undergoes pretreatment, which includes any one or a combination of at least two of nanofiltration, reverse osmosis, or chemical precipitation.

[0060] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0061] Compared with the prior art, the present invention has the following beneficial effects:

[0062] (1) The resource recovery method provided by the present invention utilizes a selective electrodialysis device, which separates a desalination chamber and a concentration chamber into repeating unit chambers by membrane units composed of anion exchange membranes, monovalent / polyvalent cation selective separation membranes, and anion exchange membranes; when rare earth ammonium sulfate leaching wastewater is introduced into the desalination chamber, the Donnan effect of the monovalent / polyvalent cation selective separation membrane, the synergistic effect of size sieving, and the effect of electric field force will cause NH4 to... + After passing through the concentration chamber, rare earth ions are retained in the desalination chamber, which promotes the reaction of rare earth ions and NH4+ in the rare earth ammonium sulfate leaching wastewater. + Highly efficient separation; at the same time, SO4 2- Under the influence of an electric field, it will pass through the anion exchange membrane into the concentration chamber, thereby obtaining purified ammonium sulfate and rare earth sulfate salts in the concentration chamber and desalination chamber respectively, thus realizing the resource recovery of rare earth ammonium sulfate leaching wastewater.

[0063] (2) The resource recovery method provided by the present invention can realize the recovery of rare earth ions and NH4. + One-step efficient separation, NH4 + For RE 3+The selective separation coefficient is greater than 100, and more than 90% of ammonium sulfate and more than 98% of rare earth elements are recovered from rare earth ammonium sulfate leaching wastewater, with low energy consumption. Attached Figure Description

[0064] Figure 1 This is a schematic diagram of the selective electrodialysis device used in this invention;

[0065] Figure 2 This is a schematic diagram illustrating the principle of the present invention: using a selective electrodialysis device to recover rare earth sulfates and ammonium sulfate. Detailed Implementation

[0066] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0067] The "range" disclosed in this invention can be defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of the specific range. This type of range definition can include or exclude endpoints; any endpoint can be independently included or excluded, and they can be arbitrarily combined, meaning any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60~120 and 80~110 are listed for specific parameters, it is understood that ranges of 60~110 and 80~120 are also expected. Furthermore, if minimum range values ​​1 and 2 are listed, and maximum range values ​​3, 4, and 5 are also listed, then the following ranges are all expected: 1~3, 1~4, 1~5, 2~3, 2~4, and 2~5. In this invention, unless otherwise stated, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0" and "5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is described as an integer ≥2, it is equivalent to listing integers such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For instance, when a parameter is described as an integer selected from "2~10", it is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0068] In this invention, "a combination of at least two" refers to a quantity greater than or equal to two, unless otherwise specified. For example, "any combination of one or at least two" means one or more or more items. It can be understood that when referring to "a combination of at least two," it refers to any suitable combination of multiple items, that is, a combination of "at least two" items carried out in a manner that does not conflict with and enables the implementation of this invention.

[0069] Unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form new technical solutions.

[0070] The term "embodiment" as used in this invention means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment or implementation of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this invention can be combined with other embodiments.

[0071] Those skilled in the art will understand that the order in which the steps are written in the methods of the various embodiments does not imply a strict execution order. The detailed execution order of each step should be determined by its function and possible internal logic. Unless otherwise specified, all steps of the present invention may be performed sequentially or randomly, but are preferably performed sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the method may also include step (c), meaning that step (c) can be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0072] In this invention, open-ended technical features or solutions described using terms such as "comprising" do not exclude additional members beyond those listed unless otherwise specified. They can be considered as providing both closed-ended features or solutions comprised of the listed members and open-ended features or solutions that include additional members beyond the listed members. For example, A includes a1, a2, and a3. Unless otherwise specified, it may also include other members or exclude additional members. This can be considered as providing both technical features or solutions where "A is composed of a1, a2, and a3" or "A is selected from a1, a2, and a3," and technical features or solutions where "A includes not only a1, a2, and a3, but also other members."

[0073] In this invention, unless otherwise specified, the features or solutions corresponding to "and / or" include any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. For example, "A and / or B" represents a group consisting of A, B, and "a combination of A and B". "Containing A and / or B" can mean "containing A, containing B, and containing A and B", or "containing A, containing B, or containing A and B", and can be appropriately understood according to the context.

[0074] Figure 1 This is a schematic diagram of the selective electrodialysis device used in this invention, which includes a DC power supply, a selective electrodialysis assembly, a mechanical pump, pump tubing, and a storage tank. The selective electrodialysis assembly consists of an anode plate, at least one set of membrane units composed of anion exchange membranes, monovalent / polyvalent cation selective separation membranes, and anion exchange membranes, and a cathode plate. The anode / cathode chamber is a compartment formed by the anode / cathode plate and the anion exchange membrane. The repeating unit chamber, consisting of a desalination chamber and a concentration chamber, is separated by membrane units composed of anion exchange membranes, monovalent / polyvalent cation selective separation membranes, and anion exchange membranes. The anode plate and cathode plate are connected to the positive and negative terminals of the DC power supply, respectively. Each chamber and storage tank in the selective electrodialysis assembly is connected to and circulated with its respective solution via the mechanical pump and pump tubing. The desalination chamber is circulated with rare earth ammonium sulfate leaching wastewater, the concentration chamber with an auxiliary electrolyte solution, and the anode and cathode chambers with a strong electrolyte solution.

[0075] Figure 2 This is a schematic diagram illustrating the principle of the selective electrodialysis device used in this invention to recover rare earth sulfates and ammonium sulfate. + indicates the anode, and - indicates the cathode. Under the action of an electric field, SO42-... 2- It can pass through the anion exchange membrane directly into the concentration chamber and / or pass through the anion exchange membrane into the anode chamber, and then through the cathode chamber into the concentration chamber; under the combined effect of the electric field force and the Donnan effect and size sieving of the mono / polyvalent cation selective separation membrane, NH4 + It will pass directly into the concentration chamber through the monovalent / polyvalent cation selective separation membrane, while rare earth ions are retained in the desalination chamber; thus, purified ammonium sulfate and rare earth sulfate salts are obtained in the concentration chamber and desalination chamber respectively, thereby realizing the resource recovery of rare earth ammonium sulfate leaching wastewater.

[0076] Example 1

[0077] This embodiment provides a method for the resource recovery of rare earth ammonium sulfate leaching wastewater, the resource recovery method comprising:

[0078] A selective electrodialysis (SED) apparatus is provided. The SED apparatus comprises an anode chamber, a repeating unit chamber consisting of a desalination chamber and a concentration chamber, and a cathode chamber arranged sequentially. The repeating unit chamber is divided by membrane units composed of anion exchange membranes, monovalent / polyvalent cation selective separation membranes, and anion exchange membranes. The anode chamber and cathode chamber are compartments formed by an anode plate / cathode plate and anion exchange membrane, respectively. The monovalent / polyvalent cation selective separation membrane is a CIMS manufactured by ASTOM Corporation of Japan, and the anion exchange membrane is an AEM series ion exchange membrane manufactured by Shandong Tianwei Technology Co., Ltd. of China. The anode and cathode plates are iridium-tantalum-titanium electrode plates. The SED apparatus also includes a solution-assisted circulation system and a current-powered system. The solution-assisted circulation system includes a mechanical pump, a storage tank, and pump tubing. The pump tubing connects the SED apparatus, the mechanical pump, and the storage tank. The current-powered system uses a regulated power supply, with the anode and cathode plates connected to the positive and negative terminals of the regulated power supply, respectively. The effective area of ​​the anode plate, cathode plate, and individual membranes is 19.96 cm². 2 .

[0079] Resource recovery of rare earth ammonium sulfate leaching wastewater: 100 mL of pretreated rare earth ammonium sulfate leaching wastewater (ammonium sulfate concentration of 0.1 mol / L, lanthanum sulfate, samarium sulfate, and ytterbium sulfate concentrations of 0.01 mol / L each) is pumped into the desalination chamber from the outlet of the desalination chamber storage tank at a flow rate of 20 L / h using a peristaltic pump, and then circulated back to the desalination chamber storage tank from the outlet of the desalination chamber, maintaining a continuous circulation of the rare earth ammonium sulfate leaching wastewater. Similarly, 100 mL of ammonium sulfate solution (0.01 mol / L) is pumped into the concentration chamber from the outlet of the concentration chamber storage tank at a flow rate of 20 L / h using a peristaltic pump, and then circulated back to the concentration chamber storage tank from the outlet of the concentration chamber, maintaining a continuous circulation of the ammonium sulfate solution. 100 mL of sodium sulfate solution (0.3 mol / L) is introduced into the anode chamber from the outlet of the electrode chamber storage tank using a peristaltic pump at a flow rate of 20 L / h. The solution then flows through the outlet of the anode chamber and the inlet of the cathode chamber into the cathode chamber, and finally circulates back to the electrode chamber storage tank from the outlet of the cathode chamber, maintaining a continuous circulation of the sodium sulfate solution. At 25°C, a constant voltage of 4 V is applied. Rare earth ions are retained in the desalination chamber by the monovalent / polyvalent cation selective separation membrane and the anion exchange membrane. NH4+... + and SO4 2- The wastewater enters the concentration chamber through both monovalent / polyvalent cation selective separation membranes and anion exchange membranes. When the conductivity of the desalination chamber drops to 6 mS / cm, the regulated power supply is removed, ending the resource recovery of rare earth ammonium sulfate leaching wastewater.

[0080] Example 2

[0081] This embodiment provides a method for the resource recovery of rare earth ammonium sulfate leaching wastewater, and the selective electrodialysis device used in the resource recovery method is the same as that in Embodiment 1.

[0082] Resource recovery of rare earth ammonium sulfate leaching wastewater: 100 mL of pretreated rare earth ammonium sulfate leaching wastewater (ammonium sulfate concentration of 0.05 mol / L, and lanthanum sulfate, samarium sulfate, and ytterbium sulfate concentrations of 0.005 mol / L each) is pumped into the desalination chamber from the outlet of the desalination chamber storage tank at a flow rate of 15 L / h using a peristaltic pump, and then circulated back to the desalination chamber storage tank from the outlet of the desalination chamber, maintaining a continuous circulation of the rare earth ammonium sulfate leaching wastewater. Similarly, 100 mL of ammonium sulfate solution (0.001 mol / L) is pumped into the concentration chamber from the outlet of the concentration chamber storage tank at a flow rate of 15 L / h using a peristaltic pump, and then circulated back to the concentration chamber storage tank from the outlet of the concentration chamber, maintaining a continuous circulation of the ammonium sulfate solution. 100 mL of sodium sulfate solution (0.5 mol / L) is introduced into the anode chamber from the outlet of the electrode chamber storage tank using a peristaltic pump at a flow rate of 15 L / h. The solution then flows through the outlet of the anode chamber and the inlet of the cathode chamber into the cathode chamber, and finally circulates back to the electrode chamber storage tank from the outlet of the cathode chamber, maintaining a continuous circulation of the sodium sulfate solution. At 20°C, a constant voltage of 3 V is applied. Rare earth ions are retained in the desalination chamber by the monovalent / polyvalent cation selective separation membrane and the anion exchange membrane. NH4+... + and SO4 2- The wastewater enters the concentration chamber through both monovalent / polyvalent cation selective separation membranes and anion exchange membranes. When the conductivity of the desalination chamber drops to 6 mS / cm, the regulated power supply is removed, ending the resource recovery of rare earth ammonium sulfate leaching wastewater.

[0083] Example 3

[0084] This embodiment provides a method for the resource recovery of rare earth ammonium sulfate leaching wastewater, and the selective electrodialysis device used in the resource recovery method is the same as that in Embodiment 1.

[0085] Resource recovery of rare earth ammonium sulfate leaching wastewater: 100 mL of pretreated rare earth ammonium sulfate leaching wastewater (ammonium sulfate concentration of 0.08 mol / L, and lanthanum sulfate, samarium sulfate, and ytterbium sulfate concentrations of 0.008 mol / L each) is pumped into the desalination chamber from the outlet of the desalination chamber storage tank at a flow rate of 25 L / h using a peristaltic pump, and then circulated back to the desalination chamber storage tank from the outlet of the desalination chamber, maintaining a continuous circulation of the rare earth ammonium sulfate leaching wastewater. Similarly, 100 mL of ammonium sulfate solution (0.005 mol / L) is pumped into the concentration chamber from the outlet of the concentration chamber storage tank at a flow rate of 25 L / h using a peristaltic pump, and then circulated back to the concentration chamber storage tank from the outlet of the concentration chamber, maintaining a continuous circulation of the ammonium sulfate solution. 100 mL of sodium sulfate solution (0.4 mol / L) is introduced into the anode chamber from the outlet of the electrode chamber storage tank using a peristaltic pump at a flow rate of 25 L / h. The solution then flows through the outlet of the anode chamber and the inlet of the cathode chamber into the cathode chamber, and finally circulates back to the electrode chamber storage tank from the outlet of the cathode chamber, maintaining a continuous circulation of the sodium sulfate solution. At 23°C, a constant voltage of 6 V is applied. Rare earth ions are retained in the desalination chamber by the monovalent / polyvalent cation selective separation membrane and the anion exchange membrane. NH4+... + and SO4 2- The wastewater enters the concentration chamber through both monovalent / polyvalent cation selective separation membranes and anion exchange membranes. When the pH in the desalination chamber rises to 6, the regulated power supply is removed, ending the resource recovery of the rare earth ammonium sulfate leaching wastewater.

[0086] Example 4

[0087] This embodiment provides a resource recovery method for rare earth ammonium sulfate leaching wastewater. In the resource recovery method, except that the flow rates of rare earth ammonium sulfate leaching wastewater, ammonium sulfate solution and sodium sulfate solution are all 10 L / h, everything else is the same as in Embodiment 1.

[0088] Example 5

[0089] This embodiment provides a method for the resource recovery of rare earth ammonium sulfate leaching wastewater. In the resource recovery method, except that the flow rates of rare earth ammonium sulfate leaching wastewater, ammonium sulfate solution and sodium sulfate solution are all 15 L / h, everything else is the same as in Embodiment 1.

[0090] Example 6

[0091] This embodiment provides a resource recovery method for rare earth ammonium sulfate leaching wastewater. In the resource recovery method, except that the flow rates of rare earth ammonium sulfate leaching wastewater, ammonium sulfate solution and sodium sulfate solution are all 25 L / h, everything else is the same as in Embodiment 1.

[0092] Example 7

[0093] This embodiment provides a resource recovery method for rare earth ammonium sulfate leaching wastewater. In the resource recovery method, except that the flow rates of rare earth ammonium sulfate leaching wastewater, ammonium sulfate solution and sodium sulfate solution are all 30 L / h, everything else is the same as in Embodiment 1.

[0094] Example 8

[0095] This embodiment provides a method for the resource recovery of rare earth ammonium sulfate leaching wastewater. Except for applying a constant voltage of 2V, the resource recovery method is the same as that in Embodiment 1.

[0096] Example 9

[0097] This embodiment provides a method for the resource recovery of rare earth ammonium sulfate leaching wastewater. Except for applying a constant voltage of 3V, the resource recovery method is the same as in Embodiment 1.

[0098] Example 10

[0099] This embodiment provides a method for the resource recovery of rare earth ammonium sulfate leaching wastewater. In the resource recovery method, except for applying a constant voltage of 5V and removing the regulated power supply when the pH of the desalination chamber rises to 6 to end the resource recovery of rare earth ammonium sulfate leaching wastewater, everything else is the same as in Embodiment 1.

[0100] Example 11

[0101] This embodiment provides a method for the resource recovery of rare earth ammonium sulfate leaching wastewater. In this resource recovery method, except that a constant voltage of 6V is applied and the regulated power supply is removed when the pH of the desalination chamber rises to 6, thus ending the resource recovery of rare earth ammonium sulfate leaching wastewater, everything else is the same as in Embodiment 1.

[0102] Comparative Example 1

[0103] This comparative example provides a method for the resource recovery of rare earth ammonium sulfate leaching wastewater. In this resource recovery method, except that the mono / polyvalent cation selective separation membrane (CIMS manufactured by ASTOM Corporation of Japan) in the selective electrodialysis device is replaced with a cation exchange membrane (CEM series ion exchange membrane of Shandong Tianwei Technology Co., Ltd. of China) which does not have mono / polyvalent cation selectivity, everything else is the same as in Example 1.

[0104] After the resource recovery of rare earth ammonium sulfate leaching wastewater in Examples 1-11 and Comparative Example 1 was completed, the time taken was recorded. 1 mL of solution was taken from the concentration chamber storage tank, and the La content in the concentration chamber was measured using inductively coupled plasma atomic emission spectrometry. 3+ 、Sm 3+ and Yb 3+ The concentration of NH4 in the concentration chamber was measured using a spectrophotometer. +The concentration.

[0105] Calculate the leakage rate of each rare earth ion and NH4. + Recovery rate, NH4 + For mixed rare earth ions (including La) 3+ 、Sm 3+ Yb 3 + Selective separation coefficient and energy consumption.

[0106] Leakage rates of various rare earth ions and NH4 + The recovery rate is calculated as follows:

[0107] La 3+ Leakage rate = C 11 / C 10 ×100%; Sm 3+ Leakage rate = C 21 / C 20 ×100%; Yb 3+ Leakage rate = C 31 / C 30 ×100%; NH4 + Recovery rate = (C 41 -C 42 ) / C 40 ×100%.

[0108] Among them, C 10 C 20 C 30 and C 40 The values ​​of La in the rare earth ammonium sulfate leaching wastewater before resource recovery are respectively represented. 3+ 、Sm 3+ Yb 3+ and NH4 + Concentration of C; 11 C 21 C 31 and C 41 These represent the La content in the concentration chamber solution after resource recovery. 3+ 、Sm 3 + Yb 3+ and NH4 + Concentration of C; 42 This indicates the NH4 content in the concentration chamber solution before resource recovery. + The concentration.

[0109] NH4 + For mixed rare earth ions (including La) 3+ 、Sm 3+ Yb 3+ Selective separation coefficient () ) used to characterize NH4 + The separation selectivity with mixed rare earth ions is calculated as follows:

[0110]

[0111] in, and They represent NH4 + The flux and the total flux of mixed rare earth ions, C 10 C 20 C 30 and C 40 The values ​​of La in the rare earth ammonium sulfate leaching wastewater before resource recovery are respectively represented. 3+ 、Sm 3+ Yb 3+ and NH4 + The concentration.

[0112] Energy consumption (EC) is used to evaluate the separation of a unit mass of NH4 during selective electrodialysis. + The electrical energy consumed is calculated as follows:

[0113]

[0114] Where E0 represents the applied voltage; E1 represents the voltage across the anode and cathode chambers; I t This represents the current at different times during resource recycling; C 42 This indicates the NH4 content in the concentration chamber solution before resource recovery. + Concentration of C; 41 This indicates the NH4 in the concentration chamber solution after resource recovery is complete. + The concentration of NH4+; V0 represents the solution volume in the concentration chamber before resource recovery, and V1 represents the solution volume in the concentration chamber after resource recovery; M represents NH4+. + The molar mass.

[0115] The results are shown in Table 1.

[0116]

[0117] As can be seen from Table 1, the resource recovery methods for rare earth ammonium sulfate leaching wastewater provided in Examples 1 to 3 can recover rare earth ions and NH4+ from the rare earth ammonium sulfate leaching wastewater. + The efficient separation process yields purified ammonium sulfate and rare earth sulfate salts in the concentration and desalination chambers, respectively, thereby realizing the resource recovery of rare earth ammonium sulfate leaching wastewater.

[0118] Examples 4-7 investigated the effect of flow rate on rare earth ammonium sulfate leaching wastewater on rare earth ions and NH4+. +The effects of separation were investigated. Results showed that increasing the flow rate of rare earth ammonium sulfate leaching wastewater reduced the thickness of the fluid boundary layer, decreased the solution resistivity, and resulted in a larger membrane stack current within the same time frame. This also led to better separation of rare earth ions and NH4+. + The separation is more thorough and energy consumption is reduced; however, further increasing the flow rate results in a greater impact force of the solution on the membrane stack, which can damage the membrane and thus affect the separation effect. Furthermore, NH4... + The selective separation coefficient for mixed rare earth ions gradually decreases with increasing flow rate, indicating that a higher flow rate is not always better, and there exists a suitable flow rate range that balances multiple performance indicators. In the system of this invention, 15 L / h to 25 L / h is the optimal flow rate range. Within this range, the advantages of increased flow rate—reduced solution resistance, lower energy consumption, and more thorough separation—can be utilized, while effectively avoiding the decrease in separation selectivity caused by excessive shear force on the membrane surface. This is beneficial for achieving the desired separation of NH4+. + Highly efficient and selective separation from rare earth ions.

[0119] Examples 8-11 investigated the effect of applied voltage on rare earth ions and NH4+. + The effect of separation. Results show that increasing the applied voltage increases the driving force for ion transport and shortens the separation time. NH4 + The recovery rate will increase, but the leakage rate of rare earth ions will also increase; however, excessive voltage (such as 5V and 6V) will cause the pH in the desalination chamber to rise rapidly. To avoid precipitation of rare earth ions, the separation needs to be terminated prematurely, leading to NH4+ leakage. + The recovery rate of NH4 decreased significantly. Meanwhile, NH4... + The selective separation coefficient of mixed rare earth ions increases significantly with increasing applied voltage, indicating that a suitable high voltage is crucial for enhancing the separation of NH4+. + The key to the selective separation of mixed rare earth ions lies in the fact that 3V~4V is the suitable voltage range for improving the selective separation in the system of this invention; however, voltage regulation must take into account both the selective separation and NH4+. + Recovery rate and energy consumption should be optimized to avoid rare earth ion precipitation and NH4+ caused by a sudden increase in pH due to excessively high voltage. + The decline in recovery rate and the surge in energy consumption provide a core basis for optimizing process voltage parameters.

[0120] Compared to Example 1, Comparative Example 1 replaced the mono / polyvalent cation selective separation membrane (CIMS manufactured by ASTOM Corporation, Japan) in the selective electrodialysis device with a cation exchange membrane (CEM series ion exchange membrane from Shandong Tianwei Technology Co., Ltd., China) that lacks mono / polyvalent cation selectivity. This cation exchange membrane was unable to retain rare earth ions, resulting in the separation of rare earth ions and NH4+. + All of them will pass through the cation exchange membrane into the concentration chamber, resulting in extremely poor separation.

[0121] In summary, the resource recovery method provided by this invention utilizes a selective electrodialysis device, which separates a desalination chamber and a concentration chamber into repeating unit chambers using membrane units composed of anion exchange membranes, monovalent / polyvalent cation selective separation membranes, and anion exchange membranes. When rare earth ammonium sulfate leaching wastewater is introduced into the desalination chamber, the Donnan effect of the monovalent / polyvalent cation selective separation membrane, the synergistic effect of size sieving, and the electric field force will cause NH4+ to... + After passing through the concentration chamber, rare earth ions are retained in the desalination chamber, which promotes the reaction of rare earth ions and NH4+ in the rare earth ammonium sulfate leaching wastewater. + Highly efficient separation; at the same time, SO4 2- Under the influence of an electric field, it will pass through the anion exchange membrane into the concentration chamber, thereby obtaining purified ammonium sulfate and rare earth sulfate salts in the concentration chamber and desalination chamber respectively, thus realizing the resource recovery of rare earth ammonium sulfate leaching wastewater.

[0122] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for the resource recovery of rare earth ammonium sulfate leaching wastewater, characterized in that, The resource recycling method includes: A selective electrodialysis apparatus is provided: the selective electrodialysis apparatus includes an anode chamber, at least one set of repeating unit chambers consisting of a desalination chamber and a concentration chamber, and a cathode chamber arranged sequentially; the repeating unit chamber is separated by membrane units consisting of anion exchange membranes, mono / polyvalent cation selective separation membranes, and anion exchange membranes. Resource recovery of rare earth ammonium sulfate leaching wastewater: The rare earth ammonium sulfate leaching wastewater includes a mixed solution of rare earth sulfate and ammonium sulfate; the rare earth ammonium sulfate leaching wastewater is passed into the desalination chamber, where rare earth ions are retained by the mono / polyvalent cation selective separation membrane and the anion exchange membrane, and NH4+ is... + and SO4 2- The ions pass through the mono / polyvalent cation selective separation membrane and the anion exchange membrane, respectively, and enter the concentration chamber.

2. The resource recycling method according to claim 1, characterized in that, In the mixed solution of rare earth sulfate and ammonium sulfate, the rare earth sulfate includes lanthanum sulfate, samarium sulfate and ytterbium sulfate; Preferably, in the mixed solution of rare earth sulfate and ammonium sulfate, the total concentration of the rare earth sulfate is 0.015 mol / L to 0.03 mol / L; Preferably, in the mixed solution of rare earth sulfate and ammonium sulfate, the concentrations of lanthanum sulfate, samarium sulfate and ytterbium sulfate are each independently 0.005 mol / L to 0.01 mol / L; Preferably, in the mixed solution of rare earth sulfate and ammonium sulfate, the concentration of ammonium sulfate is 0.01 mol / L to 0.12 mol / L.

3. The resource recycling method according to claim 1 or 2, characterized in that, The selective electrodialysis device includes 1 to 100 sets of repeating unit chambers consisting of desalination chambers and concentration chambers.

4. The resource recycling method according to any one of claims 1 to 3, characterized in that, The end-capping dialysis membrane of the selective electrodialysis device is an anion exchange membrane; Preferably, the end-capping membrane near the anode chamber is a first anion exchange membrane; Preferably, the sealing membrane near the cathode chamber is a second anion exchange membrane; Preferably, the anode chamber is a compartment formed by the anode plate and the first anion exchange membrane; Preferably, the cathode chamber is a compartment formed by the cathode plate and the second anion exchange membrane.

5. The resource recycling method according to any one of claims 1 to 4, characterized in that, A strong electrolyte solution is introduced into the anode chamber and the cathode chamber, and the strong electrolyte solution circulates between the anode chamber and the cathode chamber; Preferably, the SO4 2- The method of allowing SO4 to pass through the anion exchange membrane into the concentration chamber includes: 2- Directly enters the concentration chamber and / or SO4 through the anion exchange membrane. 2- After passing through the first anion exchange membrane into the anode chamber, it passes through the cathode chamber and through the second anion exchange membrane into the concentration chamber; Preferably, the strong electrolyte solution includes any one or a combination of at least two of ammonium sulfate solution, sodium sulfate solution, or potassium sulfate solution; Preferably, the concentration of the strong electrolyte solution is 0.3 mol / L to 0.5 mol / L; Preferably, the auxiliary electrolyte solution is introduced into the concentration chamber; Preferably, the auxiliary electrolyte solution comprises an ammonium sulfate solution; Preferably, the concentration of the auxiliary electrolyte solution is 0.001 mol / L to 0.01 mol / L.

6. The resource recycling method according to any one of claims 1 to 5, characterized in that, The selective electrodialysis device also includes a solution-assisted circulation system and a current power supply system; Preferably, the solution-assisted circulation system includes a mechanical pump, a storage tank, and pump tubing; Preferably, the pump pipe connects the selective electrodialysis device, the mechanical pump, and the storage tank; Preferably, the current power supply system includes a DC power supply; Preferably, the DC power supply includes a current-regulating power supply and / or a voltage-regulating power supply; Preferably, the anode plate and the cathode plate are connected to the positive and negative terminals of the DC power supply, respectively.

7. The resource recycling method according to any one of claims 1 to 6, characterized in that, The outlets of the desalination chamber and the concentration chamber are each independently equipped with a conductivity sensor and a pH sensor. The conductivity sensor is connected to a conductivity meter, and the pH sensor is connected to a pH meter. Preferably, when the conductivity of the desalination chamber drops to 4 mS / cm~8 mS / cm or the pH of the desalination chamber rises to 5~7, the DC power supply is removed, and the resource recovery of rare earth ammonium sulfate leaching wastewater is terminated.

8. The resource recycling method according to any one of claims 1 to 7, characterized in that, The operating temperature of the resource recycling method is 20℃~25℃; Preferably, the current of the DC power supply is 0.1A to 0.3A; Preferably, the voltage of the DC power supply is 3V~6V, more preferably 3V~4V; Preferably, the rare earth ammonium sulfate leaching wastewater in the desalination chamber, the auxiliary electrolyte solution in the concentration chamber, and the strong electrolyte solution in the anode and cathode chambers are each in an independent circulating state; Preferably, the flow rates of the rare earth ammonium sulfate leaching wastewater in the desalination chamber, the auxiliary electrolyte solution in the concentration chamber, and the strong electrolyte solution in the anode and cathode chambers are the same; Preferably, the flow rate is 15L / h to 25L / h.

9. The resource recycling method according to any one of claims 1 to 8, characterized in that, The rare earth ammonium sulfate leaching wastewater is pretreated before being introduced into the desalination chamber; Preferably, the pretreatment includes any one or a combination of at least two of nanofiltration, reverse osmosis, or chemical precipitation.

10. The resource recycling method according to claim 1, characterized in that, The resource recycling method includes: A selective electrodialysis apparatus is provided, comprising an anode chamber, at least one set of repeating unit chambers consisting of a desalination chamber and a concentration chamber, and a cathode chamber arranged sequentially; the repeating unit chamber is separated by membrane units consisting of anion exchange membranes, monovalent / polyvalent cation selective separation membranes, and anion exchange membranes; the end-capping membrane of the selective electrodialysis apparatus is anion exchange membrane; the end-capping membrane near the anode chamber is a first anion exchange membrane, and the end-capping membrane near the cathode chamber is a second anion exchange membrane; the anode chamber is a compartment formed by an anode plate and the first anion exchange membrane, and the cathode chamber is a compartment formed by a cathode plate and the second anion exchange membrane. The selective electrodialysis device includes a membrane-forming compartment; it further includes a solution-assisted circulation system and a current-powered system; the solution-assisted circulation system includes a mechanical pump, a storage tank, and a pump pipe, the pump pipe connecting the selective electrodialysis device, the mechanical pump, and the storage tank; the current-powered system includes a DC power supply, which includes a constant current power supply and / or a constant voltage power supply; the anode plate and the cathode plate are respectively connected to the positive and negative terminals of the DC power supply; the outlets of the desalination chamber and the concentration chamber are each independently equipped with a conductivity sensor and a pH sensor, the conductivity sensor being connected to a conductivity meter, and the pH sensor being connected to a pH meter; Resource recovery of rare earth ammonium sulfate leaching wastewater: The rare earth ammonium sulfate leaching wastewater includes a mixed solution of rare earth sulfate and ammonium sulfate; the rare earth ammonium sulfate leaching wastewater is introduced into the desalination chamber, an auxiliary electrolyte solution is introduced into the concentration chamber, and a strong electrolyte solution is introduced into the anode chamber and the cathode chamber, circulating between the anode chamber and the cathode chamber; rare earth ions in the rare earth ammonium sulfate leaching wastewater are retained in the desalination chamber by the monovalent / polyvalent cation selective separation membrane and the anion exchange membrane, NH4+. + and SO4 2- The wastewater enters the concentration chamber through the monovalent / polyvalent cation selective separation membrane and the anion exchange membrane, respectively. When the conductivity of the desalination chamber drops to 4 mS / cm~8 mS / cm or the pH of the desalination chamber rises to 5~7, the DC power supply is removed, and the resource recovery of rare earth ammonium sulfate leaching wastewater is terminated. In the mixed solution of rare earth sulfate and ammonium sulfate, the rare earth sulfate includes lanthanum sulfate, samarium sulfate and ytterbium sulfate, the total concentration of the rare earth sulfate is 0.015 mol / L to 0.03 mol / L, the concentration of each of the lanthanum sulfate, samarium sulfate and ytterbium sulfate is 0.005 mol / L to 0.01 mol / L, and the concentration of the ammonium sulfate is 0.01 mol / L to 0.12 mol / L. The strong electrolyte solution includes ammonium sulfate solution and / or sodium sulfate solution, and the concentration of the strong electrolyte solution is 0.3 mol / L to 0.5 mol / L; The auxiliary electrolyte solution includes an ammonium sulfate solution, and the concentration of the auxiliary electrolyte solution is 0.001 mol / L to 0.01 mol / L; The operating temperature of the resource recycling method is 20℃~25℃, the current of the DC power supply is 0.1A~0.3A, and the voltage of the DC power supply is 3V~6V. The rare earth ammonium sulfate leaching wastewater in the desalination chamber, the auxiliary electrolyte solution in the concentration chamber, and the strong electrolyte solution in the anode and cathode chambers are each in an independent circulating state with the same flow rate of 15L / h to 25L / h. Before being introduced into the desalination chamber, the rare earth ammonium sulfate leaching wastewater undergoes pretreatment, which includes any one or a combination of at least two of nanofiltration, reverse osmosis, or chemical precipitation.

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