Electrochemical reactor and wastewater treatment plant

Abstract

The application provides an electrochemical reactor and wastewater treatment equipment, and belongs to the electrolytic equipment field, wherein the electrochemical reactor comprises a shell with a reaction cavity; and a polar plate assembly which is detachably arranged in the reaction cavity, wherein the polar plate assembly comprises two cation membranes, two cathode plates and two anode plates, the two anode plates are oppositely and spacedly arranged to form a first channel between the two anode plates, and the two cathode plates are respectively arranged on the outer sides of the two anode plates, and a second channel is formed between the cathode plates and the inner wall of the shell. The electrochemical reactor and wastewater treatment equipment provided by the application have the advantages that the anode liquid and the cathode liquid flow paths in the electrochemical reactor are independent of each other, the sealing structure is simple, the cyanide can be effectively inhibited from being oxidized and decomposed at the anode, and the cyanide recovery rate can be improved.

Description

Technical Field

[0001] This application relates to the field of electrolysis equipment technology, specifically to an electrochemical reactor and wastewater treatment equipment. Background Technology

[0002] Currently, cyanide leaching is the most widely used technology in gold mining, and the cyanide tailings treatment equipment is the core facility for realizing tailings recycling and ensuring production safety. The tailings generated from cyanide operations have a complex composition, often containing not only free cyanide but also various metal cyanide complexes such as copper cyanide, zinc cyanide, and iron cyanide. Such cyanide tailings require multi-stage recovery and combined treatment using complete sets of equipment to achieve recycling and meet environmental protection requirements.

[0003] In existing technologies, the treatment of cyanide-containing tailings often employs decentralized, independent single-treatment equipment. Each unit is responsible for only a single treatment stage or the disposal of a single pollutant, lacking systematic coordination. This decentralized treatment model presents several prominent problems in practical industrial applications: independent equipment using acidification recovery processes poses a safety hazard of hydrogen cyanide leakage, making it difficult to guarantee operational safety and stability; independent equipment using adsorption methods requires extremely high raw water purity, and is prone to adsorption saturation and a sharp drop in treatment efficiency when dealing with complex cyanide-containing tailings; independent equipment using direct electrolytic copper extraction is susceptible to interference from zinc-cyanide and iron-cyanide complexes in the tailings, resulting in low copper recovery efficiency and cyanide recovery rates. These existing decentralized, independent single-treatment equipment cannot solve the problem of multiple valuable metals coexisting and mixing in the tailings system, making it difficult to achieve efficient separation and enrichment of valuable metals, leading to low valuable metal recovery efficiency and hindering efficient recovery and reuse of cyanide. Summary of the Invention

[0004] In view of the technical problems existing in the background art, this application provides an electrochemical reactor and wastewater treatment equipment. The anolyte and catholyte flow paths in the electrochemical reactor are independent of each other, and the sealing structure is simple. It can effectively inhibit the anodic oxidation decomposition of cyanide and improve the cyanide recovery rate.

[0005] To achieve the above objectives, in a first aspect, embodiments of this application provide an electrochemical reactor, comprising: The outer shell has a reaction chamber; An electrode assembly is detachably disposed in the reaction chamber. The electrode assembly includes two cation membranes, two cathode plates, and two anode plates. The two anode plates are arranged opposite each other to form a first channel between them. The two cathode plates are respectively disposed on the outside of the two anode plates. A second channel is formed between the cathode plates and the inner wall of the outer shell. Two cation membranes are respectively disposed between the anode plate and the cathode plate to form a third channel with a top opening between the two cation membranes and the corresponding anode plate, and a fourth channel is formed between the two cation membranes and the corresponding cathode plate. The first channel is connected to the third channel, and the second channel is connected to the fourth channel.

[0006] Furthermore, the electrode assembly also includes two frame supports, each of which includes an abutment portion, a pressing portion, and a limiting portion. The abutment portion has a slot, the edge of the anode plate is inserted into the slot, the abutment portion abuts against the pressing portion, and the abutment portion forms an abutment surface. The edge of the cation membrane abuts against the abutment surface. The pressing portion is connected to the abutment portion, and a clamping groove is formed between the pressing portion and the limiting portion. The cathode plate is inserted into the clamping groove.

[0007] Furthermore, the two cation membranes are respectively fixed to the two frame supports, and the bottoms of the two frame supports are closed to form a semi-closed structure of the third channel, and the two cation membranes respectively abut against the corresponding contact surfaces.

[0008] Furthermore, the electrochemical reactor also includes a partition plate disposed within the reaction chamber to divide the reaction chamber into multiple electrolysis sub-chambers. The partition plate has through holes to allow two adjacent electrolysis sub-chambers to communicate with each other, and the electrode plate assembly is correspondingly disposed in each electrolysis sub-chamber.

[0009] Furthermore, the outer casing is provided with a main liquid inlet and a main liquid outlet, the main liquid inlet being connected to the second channel and the main liquid outlet being connected to the fourth channel.

[0010] Furthermore, the electrochemical reactor also includes an aeration section, which is disposed at the bottom of the second channel.

[0011] Furthermore, the outer casing includes an end cap and two conductive components. The end cap covers the reaction chamber, and the two conductive components are disposed in the reaction chamber and electrically connected to the cathode plate and the anode plate, respectively.

[0012] Secondly, embodiments of this application provide a wastewater treatment device, including a physicochemical reactor, a solid-liquid separator, and an electrochemical reactor connected in sequence.

[0013] Furthermore, the physicochemical reactor includes a shell and a stirring system. The shell forms a chamber, and the shell has an outlet and an inlet. The outlet and the inlet are connected to the chamber. The outlet is connected to the solid-liquid separator. The inlet is used to fill wastewater into the chamber. The stirring system is disposed in the chamber.

[0014] Furthermore, the solid-liquid separator includes a pressure shell and a filter element. A cavity is formed inside the pressure shell, and the filter element is disposed in the cavity. The pressure shell has an inlet for the liquid to be filtered and a liquid phase outlet. The inlet for the liquid to be filtered and the liquid phase outlet are connected to the cavity, and the outlet is connected to the inlet for the liquid to be filtered. The filter element is disposed between the inlet for the liquid to be filtered and the liquid phase outlet. The outer shell of the electrochemical reactor is provided with a main liquid inlet, which is connected to the liquid phase outlet.

[0015] The beneficial technical effects of this application are as follows: In the technical solution of this application, two anode plates are arranged at intervals relative to each other, and the space between them constitutes the main flow channel (first channel) of the anolyte. The space between the cation membrane and the anode plate constitutes the side flow channel (third channel) of the anolyte. The two channels are interconnected and together form the anolyte flow channel system. Two cathode plates are respectively arranged on the outside of the two anode plates. The space between the cathode plate and the inner wall of the outer shell (second channel) and the space between the cation membrane and the cathode plate (fourth channel) are interconnected and together form the cathode flow channel system. Two cation exchange membranes are respectively positioned between the anode and cathode plates, physically separating the anolyte and catholyte flow paths. The independent and clearly defined flow paths on both sides reduce the possibility of cross-contamination due to liquid-phase leakage. While enabling ion conduction, the cation exchange membranes prevent communication between the two liquids, thus maintaining the stability of the components of both the anolyte and catholyte. The two cation exchange membranes are independently positioned, requiring no connection or folding, simplifying molding requirements and assembly processes. The simple sealing path reduces weak points in the seal. The entire electrode assembly is detachable within the reaction chamber, with the channel structure naturally formed by the relative positions of the components. Repositioning and channel restoration during disassembly and assembly are relatively simple, reducing maintenance difficulty and readjustment time. The simple sealing structure effectively inhibits cyanide decomposition during anodic oxidation, increasing cyanide recovery to over 82.0%, copper recovery to over 99.0%, and zinc recovery to over 82.0%.

[0016] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0018] Figure 1 This is a schematic cross-sectional view of an electrochemical reactor provided in an embodiment of this application; Figure 2 This is a top view of an electrochemical reactor provided in an embodiment of this application; Figure 3 This is a top view schematic diagram of an electrode assembly in an electrochemical reactor provided in an embodiment of this application; Figure 4 This is a front view schematic diagram of an electrode assembly in an electrochemical reactor provided in an embodiment of this application; Figure 5 This is a side view of an electrode assembly in an electrochemical reactor provided in an embodiment of this application; Figure 6 A schematic diagram of a wastewater treatment equipment assembly is provided for another embodiment of this application.

[0019] Explanation of reference numerals in the attached figures: 100. Electrochemical reactor; 1. Outer shell; 11. Reaction chamber; 12. Main liquid inlet; 13. Main liquid outlet; 14. End cap; 15. Conductive component; 2. Electrode assembly; 21. Cation membrane; 22. Cathode plate; 23. Anode plate; 24. First channel; 25. Second channel; 26. Third channel; 27. Fourth channel; 28. Frame support; 281. Abutment part; 282. Pressing part; 283. Limiting part; 3. Baffle; 4. Aeration section; 5. Physicochemical reactor; 51. Shell; 511. Inlet; 512. Outlet; 513. Chamber; 52. Stirring system; 6. Solid-liquid separator; 61. Pressure shell; 611. Cavity; 612. Inlet of liquid to be filtered; 613. Liquid phase outlet; 62. Filter element. Detailed Implementation

[0020] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0022] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0023] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0024] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0025] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0026] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0027] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0028] Resource recovery of cyanide-containing wastewater is a crucial issue for industries such as gold smelting and electroplating. Electrochemical methods for recovering valuable metals and cyanides from this wastewater are currently a key research direction. Existing electrochemical reactors typically employ diaphragms to separate the cathode and anode regions to prevent cyanide oxidation and decomposition at the anode.

[0029] However, in such existing devices, the ion exchange membrane is mostly designed as a separate unit, which results in the anolyte and catholyte flow paths being mixed and intertwined. Cyanide-containing electrolyte can easily enter the anode area, leading to the oxidative decomposition of cyanide.

[0030] To resolve the above technical issues, please refer to Figure 1 , Figure 2 as well as Figure 3 To achieve the above objectives, this application provides an electrochemical reactor 100, including a shell 1, a reaction chamber 11, and an electrode assembly 2 detachably disposed in the reaction chamber 11. The electrode assembly 2 includes two cation membranes 21, two cathode plates 22, and two anode plates 23. The two anode plates 23 are arranged at intervals to form a first channel 24 between them. The two cathode plates 22 are respectively disposed on the outside of the two anode plates 23. A second channel 25 is formed between the cathode plates 22 and the inner wall of the shell 1. Two cation membranes 21 are respectively disposed between the anode plate 23 and the cathode plate 22, so as to form a third channel 26 with a top opening between the two cation membranes 21 and the corresponding anode plate 23, and a fourth channel 27 is formed between the two cation membranes 21 and the corresponding cathode plate 22. The first channel 24 is connected to the third channel 26, and the second channel 25 is connected to the fourth channel 27.

[0031] In the technical solution of this application, the anode plate 23 is arranged at intervals to form a first channel 24, and the cation membrane 21 and the anode plate 23 form a third channel 26, which are connected to form an anolyte flow channel system; the cathode plate 22 and the inner wall of the outer shell 1 form a second channel 25, and the cation membrane 21 and the cathode plate 22 form a fourth channel 27, which are connected to form a cathode liquid flow channel system. The two cation membranes 21 are respectively arranged between the anode plate 23 and the cathode plate 22, which physically separates the anolyte flow channel system and the cathode liquid flow channel system. The flow paths on both sides are independent and clearly defined, which helps to reduce the possibility of cross-contamination caused by mutual leakage of liquid phases. The cation membrane 21 enables ion conduction while preventing the liquids on both sides from communicating with each other, which helps maintain the stability of the components of the anolyte and catholyte. The two cation membranes 21 are set independently and positioned separately, without the need for connection or folding, which simplifies the molding requirements and assembly process. The sealing path is simple, which helps reduce weak points in the seal. The electrode assembly 2 is detachably set in the reaction chamber 11. The channel structure is naturally formed by the relative positions of the components, making it relatively easy to position and restore the channel during disassembly and assembly. This helps reduce the difficulty of maintenance and operation and the time for readjustment. The sealing structure is simple, which can effectively inhibit the decomposition of cyanide in the anodic oxidation and improve the cyanide recovery rate.

[0032] Furthermore, it is worth mentioning that when the electrochemical reactor 100 of this embodiment is applied to the treatment of alkaline cyanide-containing wastewater, the cyanide-containing electrolyte can flow as the anolyte in the flow channel system composed of the first channel 24 and the third channel 26, and the catholyte flows in the flow channel system composed of the second channel 25 and the fourth channel 27. The two are kept isolated by the cation membrane 21. In this application scenario, the problem of cyanide oxidation and decomposition caused by the cyanide-containing electrolyte entering the anode area due to poor sealing can be improved. Through the physical isolation formed between the two flow channel systems by the cation membrane 21, the direct contact between the cyanide-containing electrolyte and the anode area is suppressed, thereby helping to reduce the loss of cyanide by oxidation and decomposition at the anode and improving the cyanide recovery efficiency. The anode plate 23 adopts an alkali-resistant titanium-based coated electrode to ensure structural stability under alkaline system. The cathode plate 22 adopts a high specific surface area porous material, such as carbon felt, nickel foam, copper foam, or zinc foam, to improve the deposition efficiency and recovery quality of zinc, and ultimately achieve efficient recovery and closed-loop recycling of valuable metals and cyanides in cyanide tailings.

[0033] It can be explained that the first channel 24 in this application refers to the space region formed between two anode plates 23 which are arranged relatively apart. This space region is used to contain the anolyte and provide a path for the anolyte to flow between the anode plates 23.

[0034] It can be explained that the second channel 25 in this application refers to the space region formed between the cathode plate 22 and the inner wall of the outer casing 1. This space region is used to contain the cathode liquid and provide a path for the cathode liquid to flow between the cathode plate 22 and the inner wall of the outer casing 1.

[0035] It can be explained that the third channel 26 in this application refers to the space region with an opening at the top formed between the cation membrane 21 and the anode plate 23, and the opening at the top is used to allow the anolyte to enter the third channel 26.

[0036] It can be noted that the fourth channel 27 in this application refers to the spatial region formed between the cation membrane 21 and the cathode plate 22.

[0037] It can be explained that the cation membrane 21 in this application refers to a selectively permeable membrane that allows cations to pass through while blocking anions and liquid molecules. In the electrochemical reactor 100, it is used to isolate the anolyte flow channel system and the catholyte flow channel system, so that cations in the anolyte can migrate to the catholyte side under the action of the electric field, while the liquid phases on both sides do not directly mix.

[0038] It should be noted that the detachable configuration in this application refers to the non-permanent fixing method used to assemble the electrode assembly 2 and the reaction chamber 11, so that the electrode assembly 2 can be removed and reinstalled without damaging the overall structure of the electrochemical reactor 100. For example, the electrode assembly 2 can be installed in the reaction chamber 11 by means of snap-fit, plug-in, bolt connection or sliding groove fit, etc. This application does not make specific limitations on this, as long as the detachable assembly of the electrode assembly 2 can be achieved.

[0039] It is understood that in the electrochemical reactor 100 of this application, the first channel 24 and the third channel 26 are connected to form an anolyte flow channel system, and the second channel 25 and the fourth channel 27 are connected to form a catholyte flow channel system. Since the cation membrane 21 is disposed between the anode plate 23 and the cathode plate 22, and the cation membrane 21 itself has selective permeation function, the ion conduction between the anolyte flow channel system and the catholyte flow channel system is only carried out through the cation membrane 21, and the anolyte and the catholyte do not directly mix in the liquid phase. Therefore, when the electrochemical reactor 100 is used for the electrolytic treatment of cyanide-containing wastewater, the cyanide-containing electrolyte (as anolyte or catholyte) is confined within the corresponding flow channel system and is not prone to mutual leakage with the electrolyte on the other side, thereby helping to reduce the unintended oxidative decomposition of cyanide on the electrode surface.

[0040] Please see Figure 1 and Figure 3In some embodiments, the electrode assembly 2 further includes two frame supports 28, each frame support 28 including an abutment portion 281, a pressing portion 282 and a limiting portion 283. The abutment portion 281 is formed with a groove, the edge of the anode plate 23 is inserted into the groove, the abutment portion 281 abuts against the pressing portion 282, and the abutment portion forms an abutment surface, the edge of the cation membrane 21 abuts against the abutment surface, the pressing portion 282 is connected to the abutment portion 281, and a clamping groove is formed between the pressing portion 282 and the limiting portion 283, and the cathode plate 22 is inserted into the clamping groove.

[0041] Through the structural arrangement of the frame support 28, the anode plate 23, cation membrane 21, and cathode plate 22 are all assembled and positioned by insertion and abutment. The relative positional relationship between the three is defined by the abutment part 281, pressing part 282, and limiting part 283 of the frame support 28, which helps to simplify the assembly process of the electrode assembly 2. At the same time, since the anode plate 23, cation membrane 21, and cathode plate 22 are positioned by the slot, abutment surface, and clamping groove respectively, the disassembly and assembly of each component can be carried out independently. When a component needs to be replaced, it is not necessary to disassemble the entire electrode assembly 2 for replacement, which helps to reduce the complexity of maintenance operations.

[0042] Under the above structure, the flow paths of the anolyte flow channel system and the catholyte flow channel system are independent and clearly defined, which helps to reduce the possibility of mutual leakage between the anolyte and the catholyte.

[0043] In the above embodiment, the abutting portion 281 and the pressing portion 282 of the frame support 28 form an abutting surface by abutting cooperation to fix the cation membrane 21.

[0044] It is understandable that the specific structural form of the frame support 28 is not limited to this.

[0045] For example, a sealing gasket or elastic strip can be provided between the abutment portion 281 and the pressing portion 282 to enhance the pressing effect and sealing performance on the edge of the cation membrane 21. Alternatively, the shape of the slot and clamping groove can be adapted to the thickness and material of the anode plate 23 and the cathode plate 22, for example, using dovetail grooves, T-grooves, or stepped grooves to provide more reliable insertion positioning. Furthermore, the limiting portion 283 and the pressing portion 282 can be an integrally formed structure or a separate connection structure, which can be selected by those skilled in the art according to the actual manufacturing process and assembly requirements.

[0046] In this embodiment, the frame support 28 is used for the recovery of valuable metals and cyanides from cyanide-containing tailings under alkaline conditions. The frame support 28 is disposed in the module assembly, which is detachably installed in the flow electrolysis compartment of the reaction chamber 11. Each module assembly corresponds to one flow electrolysis compartment, and the compartments are separated by partitions 3 and connected sequentially by through holes on the partitions 3.

[0047] In this embodiment, the frame support 28, besides fixing the anode plate 23, cation exchange membrane 21, and cathode plate 22, has a closed bottom. The closed bottom portions of the two frame supports 28, together with the two cation exchange membranes 21, form a semi-closed third channel 26. This third channel 26 is only open at the top, forming an opening for the anolyte to flow in. During operation, the cyanide-containing tail liquid, after physicochemical reaction and solid-liquid separation treatment, enters the electrochemical reactor 100 and flows as the cathode liquid in the flow channel system connected by the second channel 25 and the fourth channel 27, while the anolyte flows in the flow channel system connected by the first channel 24 and the third channel 26. Under the action of the electric field, the zinc cyanide complex ions in the cathode liquid are reduced and deposited as metallic zinc on the surface of the cathode plate 22. At the same time, the released cyanide ions are enriched in the cathode liquid and discharged through the main outlet 13, and can be returned to the physicochemical reactor 5 for recycling. During this process, since the anolyte flow channel system and the catholyte flow channel system are separated by the cation membrane 21, cyanide in the catholyte is not easily allowed to enter the anode area for oxidative decomposition, which helps to maintain the cyanide recovery efficiency.

[0048] In terms of assembly, the anode plate 23 is positioned by inserting into the slot of the abutment part 281, the edge of the cation membrane 21 is clamped and positioned by the abutment surface between the abutment part 281 and the pressing part 282, and the cathode plate 22 is positioned by inserting into the clamping groove between the pressing part 282 and the limiting part 283. Each is assembled by an independent positioning structure, and the fixation between them does not depend on the same set of fasteners. This structural setting helps to simplify the assembly process of the electrode assembly 2. When assembling or disassembling a certain component, the impact on other components is small, and the assembly independence between each component is strong.

[0049] In terms of maintenance, since the anode plate 23, cation membrane 21, and cathode plate 22 are detachably positioned via slots, contact surfaces, and clamping grooves, when a component needs to be replaced or cleaned due to long-term use, that component can be removed individually from its corresponding positioning structure without completely disassembling the entire electrode assembly 2. For example, when the metal layer deposited on the surface of the cathode plate 22 needs to be stripped and recycled, only the cathode plate 22 can be pulled out of the clamping groove for offline processing, while the anode plate 23 and cation membrane 21 remain in place. This independent disassembly and assembly structure helps reduce the time cost and complexity of maintenance operations, and also helps reduce the accumulation of assembly errors caused by frequent disassembly and assembly.

[0050] Regarding sealing reliability, the edge of the cation exchange membrane 21 is clamped by surface contact between the abutment surface of the contact part 281 and the pressing part 282. Compared to point-tightening methods such as bolts, surface contact clamping helps to form a more uniform force distribution at the edge of the cation exchange membrane 21, reducing the possibility of membrane damage due to excessive local pressure or liquid leakage due to insufficient local pressure. At the same time, since the fixing of the cation exchange membrane 21 is independent of the fixing of the anode plate 23 and the cathode plate 22, the disassembly and assembly of the anode plate 23 and the cathode plate 22 will not directly affect the already established seal between the cation exchange membrane 21 and the contact surface, which is beneficial to maintaining the isolation reliability of the flow channels on both sides of the cation exchange membrane 21 during long-term operation.

[0051] The contact part 281, the pressing part 282, and the limiting part 283 cooperate with each other to form a complete frame support 28. The relative positions of the anode plate 23, the cation membrane 21, and the cathode plate 22 are all defined by the same frame support 28. This integrated positioning structure helps to ensure the assembly accuracy between the three components and reduces the positional deviation that may occur due to the independent installation of each component. This helps to maintain the consistency of the size and shape of the first channel 24, the third channel 26, and the fourth channel 27 during operation, which in turn is conducive to the stable progress of the electrolysis reaction.

[0052] It can be explained that the abutting part 281 in this application refers to the abutting part 281 in the frame support member 28 that is formed to cooperate with the edge of the anode plate 23. The slot opened on the abutting part 281 is used to accommodate the edge of the anode plate 23 and provide insertion positioning for the anode plate 23. At the same time, one side surface of the abutting part 281 contacts the pressing part 282 to form an abutting surface that clamps the edge of the cation membrane 21. The pressing part 282 refers to the component of the frame support 28 disposed between the abutting part 281 and the limiting part 283. One side surface of the pressing part 282 abuts against the corresponding surface of the abutting part 281, forming an abutting surface between the two. The edge of the cation membrane 21 is clamped between the abutting surfaces. A gap is left between the other side surface of the clamping part 282 and the limiting part 283, which forms a clamping groove for accommodating the edge of the cathode plate 22. The limiting part 283 refers to the part of the frame support 28 that cooperates with the clamping part 282 to form a clamping groove. A gap is formed between the limiting part 283 and the clamping part 282. This gap is used to accommodate the edge of the cathode plate 22. The limiting part 283 plays a limiting role on the side of the cathode plate 22 that is away from the clamping part 282, preventing the cathode plate 22 from falling out of the clamping groove. It should be noted that the term "insertion" in this application refers to an assembly method in which the edge of a component is inserted into a corresponding slot to achieve positioning and fixation. For example, the edge of the anode plate 23 is inserted into a slot, and the edge of the cathode plate 22 is inserted into a clamping slot. The insertion fit can be a clearance fit, a transition fit, or an interference fit, and the specific choice can be made based on factors such as the material and thickness of the anode plate 23 and the cathode plate 22, as well as thermal expansion during actual use. This application does not impose specific limitations on this, as long as the component can be positioned on the frame support 28 through insertion.

[0053] Please see Figure 3 , Figure 4 as well as Figure 5 In some embodiments, the two cation membranes 21 are respectively fixed to the two frame supports 28, and the bottoms of the two frame supports 28 are closed together to form a semi-closed structure of the third channel 26, and the two cation membranes 21 abut against the corresponding contact surfaces respectively.

[0054] In this embodiment, the electrochemical reactor 100 is used for the recovery and treatment of valuable metals and cyanides in cyanide-containing tail liquid under alkaline conditions. Specifically, the cyanide-containing tail liquid, after physicochemical reaction and solid-liquid separation treatment, enters the electrochemical reactor 100 as catholyte and flows in the catholyte flow channel system formed by the second channel 25 and the fourth channel 27. The anolyte flows in the anolyte flow channel system formed by the first channel 24 and the third channel 26.

[0055] In this embodiment, the third channel 26 is formed by the bottom closure of two cation membranes 21 and two frame supports 28, forming a semi-closed structure with only the top open. The anolyte enters the third channel 26 through the top opening and flows between the first channel 24 and the third channel 26. During electrolysis, zinc cyanide complex ions in the catholy solution migrate to the cathode plate 22 under the action of an electric field, and are reduced and deposited as metallic zinc on the surface of the cathode plate 22. The released cyanide ions are enriched in the catholy solution. Since the anolyte flow channel system and the catholyte flow channel system are physically isolated by the cation membrane 21, the cyanide ions in the catholy solution are not easy to pass through the cation membrane 21 into the anolyte side, which helps to inhibit the oxidative decomposition of cyanide in the anode region.

[0056] In terms of long-term operation, the bottom closure of the frame support 28 provides a stable bottom boundary for the third channel 26. Even if the cation exchange membrane 21 expands or contracts to some extent due to temperature changes or chemical environment during long-term operation, the bottom closure of the third channel 26 is maintained by the mechanical structure of the frame support 28. It is less likely to lose its bottom closure function due to changes in membrane size, thus helping to maintain the integrity of the anolyte flow channel system. Simultaneously, the bottom closure structure of the frame support 28 also facilitates the centralized discharge of residual liquid in the anolyte flow channel system through the top opening during shutdown and drainage, reducing liquid retention at the bottom of the channel and facilitating equipment emptying and maintenance.

[0057] Under the above structural configuration, the third channel 26 is enclosed by the bottom of the frame support 28 and together with the two cation membranes 21 to form a semi-closed structure. Since the bottom enclosure of the third channel 26 is provided by the frame support 28, the cation membrane 21 does not need to be bent, folded or bonded at the bottom. It can be directly installed on the frame support 28 while maintaining a planar shape. This helps to reduce the manufacturing difficulty of the cation membrane 21 and reduce problems such as stress concentration in the membrane or thinning at the bending point that may be caused by bending. At the same time, the planar membrane is less likely to be creased or damaged during storage, transportation and assembly, which helps to ensure the integrity of the cation membrane 21 before use. The bottom closure of the frame support 28 is a rigid mechanical closure. Its sealing effect depends on the structural integrity and dimensional accuracy of the frame support 28 itself. Compared with the method of relying on the bending part of the cation membrane 21 to fit with the frame to form a bottom seal, the mechanical structure closure is less affected by factors such as temperature fluctuations and chemical swelling during long-term operation. The consistency of the bottom closure state is better. In addition, when it is necessary to clean the inside of the third channel 26, the anode plate 23 can be pulled out from the slot to flush the inside of the third channel 26. The flushing liquid can be discharged from the top opening. The bottom closure structure will not be affected by the flushing operation. Because the third channel 26 is open at the top and closed at the bottom, the anolyte can only flow out from the top opening after entering the third channel 26. This creates a relatively clear flow path from top to bottom and then from bottom to top within the third channel 26, which is beneficial for sufficient contact between the anolyte and the surface of the anode plate 23. At the same time, the closed bottom also helps to prevent solid particles or impurities in the anolyte from depositing at the bottom of the third channel 26 under gravity and directly entering other flow areas. Instead, they are confined within the third channel 26, making it easier to clean them through the top opening or to drain them with the anolyte.

[0058] In the above structural configuration, the two cation exchange membranes 21 are respectively fixed to the two frame supports 28. The assembly and positioning process of each cation exchange membrane 21 is independent of the other cation exchange membrane 21, and there is no connection or dependency between them. When one side of the cation exchange membrane 21 needs to be replaced, it can be removed from the corresponding frame support 28 without operating the other side of the cation exchange membrane 21, which helps to reduce the complexity of membrane replacement. The two cation exchange membranes 21 abut against their corresponding contact surfaces, so that each cation exchange membrane 21 independently forms a surface contact clamping seal with the contact surface. The stress state and sealing effect of one side of the cation exchange membrane 21 are not affected by the other side of the cation exchange membrane 21. During long-term operation, even if the sealing performance of one side of the cation exchange membrane 21 deteriorates due to chemical environment or mechanical fatigue, the other side of the cation exchange membrane 21 can still maintain an effective isolation function. The two cation exchange membranes 21 independently cooperate with their corresponding frame supports 28 to jointly form a double isolation barrier between the anolyte flow channel system and the catholyte flow channel system, which helps to improve the reliability of flow channel isolation.

[0059] Please see Figure 1 In some embodiments, the electrochemical reactor 100 further includes a partition 3, which is disposed in the reaction chamber 11 to divide the reaction chamber 11 into multiple electrolysis chambers. The partition 3 has through holes to allow two adjacent electrolysis chambers to communicate with each other. The electrode assembly 2 is disposed in the corresponding electrolysis chamber.

[0060] In this embodiment, the electrochemical reactor 100 further includes a partition 3, which is disposed within the reaction chamber 11. The partition 3 extends along a certain direction of the reaction chamber 11, dividing the internal space of the reaction chamber 11 into multiple electrolysis sub-chambers. Each electrolysis sub-chamber is a relatively independent reaction space, and the multiple electrolysis sub-chambers are arranged sequentially along the length or width direction of the reaction chamber 11. A through-hole is provided on the partition 3, penetrating both sides of the partition 3, allowing adjacent electrolysis sub-chambers to communicate with each other through the through-hole. There can be one or more through-holes, and their shape can be circular, rectangular, or elongated, depending on the liquid flow requirements and processing technology.

[0061] The electrode assembly 2 is disposed within the electrolysis chamber. Specifically, each electrolysis chamber has a corresponding set of electrode assemblies 2, and each set of electrode assemblies 2 is detachably installed in its respective electrolysis chamber. Each set of electrode assemblies 2 forms a first channel 24, a second channel 25, a third channel 26, and a fourth channel 27 within its respective electrolysis chamber, and the flow channels in adjacent electrolysis chambers are interconnected through through holes on the partition plate 3.

[0062] In the above structure, after the reaction chamber 11 is divided into multiple electrolysis chambers by the partition 3, the flow path of the liquid in the reaction chamber 11 is guided by the through holes on the partition 3. The liquid can enter an adjacent electrolysis chamber from one electrolysis chamber through the through holes and flow sequentially along multiple electrolysis chambers to form a relatively orderly flow path. This partitioned flow method is more conducive to the liquid making more sufficient contact with the electrode assembly 2 in each electrolysis chamber compared to the liquid freely diffusing in the entire reaction chamber 11.

[0063] In terms of structural scalability, the number of electrolysis chambers can be adjusted by increasing or decreasing the number of baffles 3, thereby changing the total processing capacity of the electrochemical reactor 100. When it is necessary to expand the processing scale, baffles 3 can be added in the reaction chamber 11 to form more electrolysis chambers, and corresponding electrode assemblies 2 can be added. When the processing scale is smaller, the number of baffles 3 and electrode assemblies 2 can be reduced. This modular expansion method is conducive to flexibly adjusting the equipment configuration according to the actual working conditions without having to redesign the entire reactor structure.

[0064] Regarding the installation and maintenance of the electrode assembly 2, since each electrode assembly 2 is respectively set in its own electrolysis chamber, when the electrode assembly 2 in a certain electrolysis chamber needs to be replaced or maintained, the electrode assembly 2 in that electrolysis chamber can be operated individually, while the electrode assemblies 2 in other electrolysis chambers can remain stationary, which helps to reduce the impact of maintenance operations on the operation of the entire electrochemical reactor 100.

[0065] In one specific embodiment, the electrochemical reactor 100 is used for the recovery and treatment of valuable metals and cyanides in alkaline cyanide-containing tailings; Specifically, the reaction chamber 11 is a square cavity, and the partitions 3 are spaced apart along the length of the reaction chamber 11, dividing the reaction chamber 11 into multiple flow electrolysis chambers. The through holes on the partitions 3 are opened at or near the bottom of the partitions 3, so that the liquid flows between adjacent electrolysis chambers in a bottom-connected manner, simulating the flow mode of the cathodic liquid flowing sequentially between multiple electrolysis chambers.

[0066] Each electrolysis chamber is equipped with a set of electrode assembly 2, each set of electrode assembly 2 including two cation exchange membranes 21, two cathode plates 22, and two anode plates 23, forming corresponding anolyte flow channel systems and catholyte flow channel systems. After physicochemical reaction and solid-liquid separation treatment, the cyanide-containing tail liquid enters the first electrolysis chamber as catholyte through the main inlet 12 of the electrochemical reactor 100. Within this electrolysis chamber, it flows through the catholyte flow channel system formed by the second channel 25 and the fourth channel 27, where zinc deposition occurs on the surface of the cathode plate 22. Subsequently, the catholyte flows through the through-hole at the bottom of the partition 3 into the next electrolysis chamber, sequentially flowing through each electrolysis chamber, gradually completing zinc recovery and cyanide enrichment. The anolyte flows within the first channel 24 and the third channel 26 of each electrolysis chamber, and ions are conducted with the catholyte through the cation exchange membrane 21.

[0067] Because the reaction chamber 11 is divided into multiple independent but sequentially connected electrolysis chambers by the partition 3, the catholyte undergoes electrolysis reaction in each zone during the flow process. The zinc ion concentration and current density distribution in each zone are relatively uniform. Compared with the method of electrolysis using a single flow channel in the entire reaction chamber 11, the zoned flow is beneficial to extend the contact path length between the catholyte and the electrode assembly 2 and increase the residence time of the catholyte in the reaction chamber 11, thereby helping to improve the zinc deposition efficiency and cyanide recovery effect. At the same time, the electrolysis chambers are physically separated by the partition 3, so the local concentration fluctuations or flow abnormalities that may occur in one zone have a relatively limited impact on other zones, which is conducive to maintaining the stability of the overall electrolysis process.

[0068] Because each electrolysis chamber and its corresponding electrode assembly 2 are modularly configured, the number of electrolysis chambers can be flexibly adjusted according to the actual treatment scale and influent water quality. For example, for high-concentration cyanide-containing tailings, the number of electrolysis chambers and electrode assemblies 2 can be increased to extend the treatment path; for low-concentration cyanide-containing tailings, the number of electrolysis chambers can be reduced accordingly to decrease equipment footprint and operating energy consumption. This scalable structure improves the adaptability of the electrochemical reactor 100 to different operating conditions and provides a structural basis for standardized production and on-site assembly of the equipment.

[0069] In terms of equipment maintenance, when the electrode assembly 2 in a certain electrolysis chamber needs to be repaired or replaced, the liquid inlet of that section can be shut off or the electrode assembly 2 can be removed from the reaction chamber 11, while other electrolysis chambers can continue to operate. This helps to reduce the overall downtime caused by local maintenance and improve the utilization rate of the equipment in continuous production.

[0070] Please see Figure 1 In some embodiments, the outer casing 1 is provided with a main liquid inlet 12 and a main liquid outlet 13. The main liquid inlet 12 is connected to the second channel 25, and the main liquid outlet 13 is connected to the fourth channel 27.

[0071] In this embodiment, the outer shell 1 is provided with a main liquid inlet 12 and a main liquid outlet 13. Both the main liquid inlet 12 and the main liquid outlet 13 are openings formed on the wall of the outer shell 1 to realize the liquid transport between the electrochemical reactor 100 and the external pipeline. The main liquid inlet 12 is used to introduce the liquid to be treated from the outside into the electrochemical reactor 100, and the main liquid outlet 13 is used to discharge the treated liquid from the inside of the electrochemical reactor 100.

[0072] In terms of liquid circuit connectivity, the main inlet 12 is connected to the second channel 25, which is a spatial region formed between the cathode plate 22 and the inner wall of the outer casing 1. The main inlet 12 is directly or through a pipeline connected to this spatial region, allowing the liquid entering from the main inlet 12 to first enter the second channel 25. The main outlet 13 is connected to the fourth channel 27, which is a spatial region formed between the cation exchange membrane 21 and the cathode plate 22. The liquid after electrolysis is discharged from the electrochemical reactor 100 through the main outlet 13 from the fourth channel 27.

[0073] Since the electrochemical reactor 100 is divided into multiple electrolysis chambers by partitions 3, and each electrolysis chamber is equipped with an electrode assembly 2, each electrolysis chamber has a corresponding second channel 25 and a fourth channel 27. The second channels 25 and the fourth channels 27 of adjacent electrolysis chambers are interconnected through the through holes on the partitions 3. Based on the connection between the main inlet 12 and the second channel 25, the liquid entering from the main inlet 12 flows sequentially through the second channels 25 of each electrolysis chamber. Based on the connection between the main outlet 13 and the fourth channel 27, the liquid in the fourth channel 27 of each electrolysis chamber finally collects and is discharged through the main outlet 13.

[0074] Under the above structure, the flow path of the liquid in the electrochemical reactor 100 is as follows: the liquid enters the second channel 25 of the first electrolysis chamber from the main inlet 12 on the outer shell 1, flows along the second channel 25 in this section and exchanges ions with the fourth channel 27 through the cation membrane 21, and then enters the second channel 25 of the next electrolysis chamber through the through hole on the partition 3, flowing through each electrolysis chamber in sequence, and finally being discharged from the main outlet 13 through the fourth channel 27 in the last electrolysis chamber. This helps to form a more orderly flow sequence of the liquid in the electrochemical reactor 100, reducing the disordered diffusion and local short-circuit flow of the liquid in the reaction chamber 11. The main inlet 12 is centrally located in one place on the outer shell 1. After the liquid to be treated enters from the main inlet 12, it is distributed to each electrolysis chamber in sequence through the second channel 25. Compared with the method of opening inlets at multiple locations, single-point liquid inlet is conducive to simplifying the connection of external pipelines and also facilitates centralized control and adjustment of the liquid flow rate.

[0075] Finally, the liquid in the fourth channel 27 of each electrolysis chamber is collected and discharged uniformly at the main outlet 13, which facilitates centralized monitoring and adjustment of the effluent quality and also makes it easier for the effluent to enter the next treatment unit or be recycled.

[0076] In one specific embodiment, the cyanide-containing tail liquid after physicochemical reaction and solid-liquid separation is used as cathodic liquid and enters the electrochemical reactor 100 through the main inlet 12 on the outer shell 1. The main inlet 12 is located at the end of the outer shell 1 near the first electrolysis chamber, and the main outlet 13 is located at the end of the outer shell 1 near the last electrolysis chamber.

[0077] During the electrolysis process, after the catholyte enters through the main inlet 12, it first enters the second channel 25 of the first electrolysis chamber. In this section, it undergoes ion conduction with the anolyte through the cation exchange membrane 21. The zinc-cyanide complex ions in the catholyte are reduced and deposited on the surface of the cathode plate 22 to form metallic zinc. The released cyanide ions are enriched in the catholyte. Subsequently, the catholyte flows into each subsequent electrolysis chamber through the through-hole at the bottom of the partition 3, and the above-mentioned electrodeposition reaction takes place in each section. The catholyte after being processed in the last electrolysis chamber enters the fourth channel 27 of that section and is discharged through the main outlet 13.

[0078] Cyanide is enriched in the discharged catholyte and can be returned to the physicochemical reactor 5 as a source of cyanide for recycling, realizing a closed-loop cyanide cycle. The anolyte flows in a flow channel system connected by the first channel 24 and the third channel 26, and conducts ion transfer with the catholyte through the cation membrane 21. During the reaction, the anolyte does not directly contact the cyanide-containing catholyte, which helps to suppress the oxidative decomposition of cyanide in the anode region.

[0079] In terms of continuous operation, the catholyte enters from the main inlet 12, flows sequentially through each electrolysis chamber, and exits from the main outlet 13, forming a continuous flow system. During operation, the inlet flow rate and current parameters can be adjusted according to the influent flow rate and water quality to control the residence time and reaction degree of the catholyte in each electrolysis chamber. The electrolysis chambers are sequentially connected by through holes at the bottom of the partition 3, which helps maintain the consistency of liquid level and reduces flow obstruction caused by excessive liquid level differences between zones. At the same time, the main inlet 12 and the main outlet 13 are centrally located, facilitating connection with the pipelines of the upstream physicochemical reactor 5 and the solid-liquid separator 6, simplifying the pipeline layout of the entire wastewater treatment equipment, and reducing the risk of leakage at pipeline connections.

[0080] Please see Figure 1 and Figure 3 In some embodiments, the electrochemical reactor 100 further includes an aeration section 4 disposed at the bottom of the second channel 25.

[0081] In this embodiment, the electrochemical reactor 100 further includes an aeration section 4, which is a component for introducing gas into the liquid. It is disposed at the bottom of the second channel 25, which is a spatial region formed between the cathode plate 22 and the inner wall of the outer shell 1. The aeration section 4 is located at the bottom of this spatial region, that is, near the bottom surface of the inner wall of the outer shell 1.

[0082] During operation, the aeration unit 4 is connected to an external air source, and gas enters the catholyte in the second channel 25 through the aeration unit 4, forming bubbles in the catholyte. Under the action of buoyancy, the bubbles move upward from the bottom of the second channel 25, passing through the catholyte in the second channel 25 and causing flow disturbance in the catholyte. This liquid disturbance caused by the rising bubbles helps to promote mixing of the catholyte in the second channel 25, making the ion concentration distribution in the catholyte more uniform and reducing the possibility that the electrochemical reaction rate will be affected by the local decrease in ion concentration near the surface of the cathode plate 22.

[0083] Since the aeration section 4 is located at the bottom of the second channel 25, the bubbles move upwards across the surface area of ​​the cathode plate 22, which helps to reduce the thickness of the diffusion layer near the surface of the cathode plate 22 and promotes the migration of ions in the solution to the surface of the cathode plate 22, thereby improving the ion mass transfer efficiency. At the same time, the bubbles also have a certain lifting effect on the catholyte during their ascent, which helps to promote the circulation of the catholyte between the second channel 25 and the fourth channel 27 and enhances the renewal rate of the catholyte on both sides of the cathode plate 22.

[0084] Furthermore, a certain distance is maintained between the aeration section 4 and the cathode plate 22, so that the bubbles can come into full contact with the catholy liquid during the rising process, without directly impacting the surface of the cathode plate 22 and causing interference with the deposition layer on the surface of the cathode plate 22. At the same time, the aeration section 4 is located near the bottom of the inner wall of the outer shell 1, which facilitates connection to the external air source pipeline through the interface on the outer shell 1, and also facilitates the maintenance or replacement of the aeration section 4 during maintenance.

[0085] It is worth mentioning that in the electrolytic treatment of cyanide-containing wastewater, the gas introduced into the catholyte by the aeration section 4 can be a gas that does not adversely react with cyanide, such as nitrogen or an inert gas. The disturbance effect generated by aeration promotes the migration of zinc-cyanide complex ions in the catholyte to the surface of the cathode plate 22, thereby helping to improve the zinc deposition efficiency. At the same time, the disturbance of the liquid also helps to make the concentration of cyanide ions in the catholyte tend to be uniform between the second channel 25 and the fourth channel 27, which facilitates the enrichment of cyanide in the catholyte and subsequent recovery and utilization.

[0086] In one specific embodiment, the aeration section 4 is a microporous aerator, which is disposed at the bottom of the second channel 25 corresponding to each electrolysis chamber.

[0087] During the electrolysis process, the cyanide-containing tail liquid, after undergoing physicochemical reactions and solid-liquid separation, enters the second channel 25 of the electrochemical reactor 100 as the cathode liquid. A microporous aerator introduces gas into the cathode liquid, generating a large number of tiny bubbles. These bubbles rise from the bottom of the second channel 25, forming a gas-liquid two-phase flow in the cathode liquid, causing disturbance and mixing. Since the zinc-cyanide complex ions in the cathode liquid need to migrate to the surface of the cathode plate 22 under the influence of an electric field to undergo reduction deposition, the concentration of zinc-cyanide complex ions near the surface of the cathode plate 22 gradually decreases as the deposition reaction proceeds. The bubble disturbance generated by microporous aeration helps accelerate the replenishment of zinc-cyanide complex ions from the bulk solution to the area near the surface of the cathode plate 22, thereby helping to maintain a relatively stable ion concentration near the surface of the cathode plate 22 and improving the zinc deposition efficiency and the quality of the deposited layer.

[0088] At this time, the cyanide ions released after the zinc cyanide complex ions are reduced on the surface of the cathode plate 22 are enriched in the catholy liquid. The liquid disturbance generated by aeration helps the released cyanide ions to diffuse more quickly into the entire catholy liquid flow channel system, avoiding the concentration polarization phenomenon that may be caused by the local enrichment of cyanide ions near the surface of the cathode plate 22. It also facilitates the recycling of cyanide after it is discharged through the total outlet 13 with the catholy liquid flow.

[0089] The microporous aerator is located at the bottom of the second channel 25. The generated microbubbles are evenly distributed in the catholyte during their ascent. Compared with large bubbles, microbubbles have a larger specific surface area, resulting in more thorough contact with the catholyte and a more uniform disturbance effect on the liquid. This is beneficial for forming a more consistent liquid mixing effect in each electrolysis chamber. At the same time, the aeration intensity can be controlled by adjusting the gas source pressure and gas volume to adapt to the needs of different treatment scales and water quality conditions, which helps to improve the adaptability of the electrochemical reactor 100 to different operating conditions.

[0090] Please see Figure 1 and Figure 2 In some embodiments, the outer casing 1 further includes an end cap 14 and two conductive elements 15. The end cap 14 covers the reaction chamber 11, and the two conductive elements 15 are disposed in the reaction chamber 11 and electrically connected to the cathode plate 22 and the anode plate 23, respectively.

[0091] In this embodiment, the outer casing 1 includes an end cap 14 and two conductive elements 15. Its internal space constitutes the main body of the reaction chamber 11. The end cap 14 is placed over the reaction chamber 11, and the end cap 14 and the reaction chamber 11 can be detachably connected, for example, by means of bolts, buckles or hinges, so that the end cap 14 can be opened to operate inside the reaction chamber 11 when needed.

[0092] Two conductive elements 15 are disposed on the reaction chamber 11. Each conductive element 15 is a conductive component used to conduct electrical energy from an external power source to the electrode assembly 2 inside the reaction chamber 11. The two conductive elements 15 are electrically connected to the cathode plate 22 and the anode plate 23, respectively. Specifically, one conductive element 15 is electrically connected to both cathode plates 22, and the other conductive element 15 is electrically connected to both anode plates 23. A portion of the conductive element 15 is located outside the reaction chamber 11 for connection to a cable from the external power source; another portion of the conductive element 15 extends into the reaction chamber 11 or passes through the wall of the reaction chamber 11 to achieve electrical conductivity with the corresponding electrode plate.

[0093] In the above structure, the reaction chamber 11 and the end cap 14 together constitute the outer shell 1. The two work together to form a closed reaction chamber 11, providing a closed space for the electrode assembly 2 and the electrolyte. Two conductive elements 15 serve as electrical connection interfaces on the outer shell 1, connecting the external power supply to the cathode plate 22 and anode plate 23 inside the reaction chamber 11, so that the current required for electrolysis can be conducted from the external power supply to the electrode surface through the conductive elements 15.

[0094] Since the end cap 14 is placed over the reaction chamber 11, it helps to prevent external impurities from entering the interior of the reaction chamber 11 and also helps to prevent the liquid inside the reaction chamber 11 from overflowing or evaporating during operation. When it is necessary to inspect or replace the electrode assembly 2 inside the reaction chamber 11, the end cap 14 can be removed to expose the reaction chamber 11, and the operator can operate on the components inside the reaction chamber 11. After the operation is completed, the end cap 14 is placed back over the reaction chamber 11.

[0095] Regarding electrical connections, the conductive element 15 is disposed on the reaction chamber 11 as part of the outer casing 1. The position of the conductive element 15 is fixed, and the electrical connection between it and the electrode assembly 2 remains stable after assembly. This helps to reduce the possibility of cable loosening or poor contact caused by the cable directly extending into the reaction chamber 11 to connect to the electrode. At the same time, the cable of the external power supply only needs to be connected to the interface of the conductive element 15 located outside the reaction chamber 11, without having to pass the cable through the wall of the outer casing 1 to enter the interior of the reaction chamber 11, which helps to reduce the sealing difficulty of the outer casing 1.

[0096] In one specific embodiment, the reaction chamber 11 is a square tank made of insulating material to meet the requirements of corrosion resistance and insulation of the outer shell 1 under alkaline system. The reaction chamber 11 is open upward, and the end cap 14 is a cover plate corresponding to the shape of the reaction chamber 11. By covering the reaction chamber 11, a sealing gasket or sealing ring can be provided on the contact surface between the end cap 14 and the reaction chamber 11 to enhance the sealing effect between the two.

[0097] Both conductive elements 15 are made of copper or copper alloy and are respectively disposed at both ends or the same end of the reaction chamber 11. The conductive element 15 electrically connected to the cathode plate 22 passes through the wall of the reaction chamber 11 and is electrically connected to the two cathode plates 22 respectively via flexible connection or welding; the conductive element 15 electrically connected to the anode plate 23 is electrically connected to the two anode plates 23 in a similar manner. The portions of the two conductive elements 15 located outside the reaction chamber 11 are respectively provided with cable terminals for connecting to the positive and negative terminals of an external DC power supply.

[0098] During the electrolysis process, an external DC power supply supplies power to the anode plate 23 and the cathode plate 22 through two conductive components 15, respectively, forming an electric field between the anode plate 23 and the cathode plate 22. Zinc cyanide complex ions in the catholyte migrate towards the cathode plate 22 under the influence of the electric field, and are reduced and deposited on the surface of the cathode plate 22 as metallic zinc; a corresponding oxidation reaction occurs on the surface of the anode plate 23. During the reaction, the reaction chamber 11 is jointly sealed by the reaction chamber 11 and the end cap 14, which helps maintain the stability of the liquid level and the controllability of the gas environment within the reaction chamber 11.

[0099] Since the cyanide-containing tail liquid is treated under alkaline conditions, the reaction chamber 11 is made of insulating material, which helps to reduce electrical safety hazards caused by the conductivity of the outer casing 1. The sealed fit between the end cap 14 and the reaction chamber 11 helps to reduce the disorderly escape of trace amounts of gas that may be generated during the reaction process. The gas can be centrally discharged or collected and treated through a preset exhaust port.

[0100] When it is necessary to replace the electrode assembly 2 or clean the inside of the reaction chamber 11, the connection between the conductive element 15 and the external power supply can be disconnected, the bolts between the end cover 14 and the reaction chamber 11 can be removed, and the end cover 14 can be removed. The internal components can then be accessed through the slot in the reaction chamber 11. The conductive element 15 is fixed to the reaction chamber 11 and is not connected to the end cover 14. Removing the end cover 14 will not affect the existing electrical connection between the conductive element 15 and the electrode, which helps to reduce interference with the electrical connection structure during maintenance. After maintenance, the end cover 14 is replaced and secured, restoring the reaction chamber 11 to its closed state.

[0101] Please see Figure 6 Secondly, embodiments of this application provide a wastewater treatment device, including a physicochemical reactor 5, a solid-liquid separator 6, and an electrochemical reactor 100 connected in sequence.

[0102] In some embodiments, the physicochemical reactor 5 includes a shell 51 and a stirring system 52. The shell 51 forms a chamber 513. The shell 51 has an outlet 512 and an inlet 511, which are connected to the chamber 513. The outlet 512 is connected to the solid-liquid separator 6. The inlet 511 is used to fill wastewater into the chamber 513. The stirring system 52 is disposed in the chamber 513. The shell 51 also has a dosing port, which is connected to the chamber 513.

[0103] In some embodiments, the solid-liquid separator 6 includes a pressure shell 61 and a filter element 62. A cavity 611 is formed inside the pressure shell 61, and the filter element 62 is disposed in the cavity 611. The pressure shell 61 has an inlet 612 for the liquid to be filtered and a liquid phase outlet 613. The inlet 612 and the liquid phase outlet 613 are in communication with the cavity 611, and the outlet 512 is in communication with the inlet 612 for the liquid to be filtered. The filter element 62 is disposed between the inlet 612 for the liquid to be filtered and the liquid phase outlet 613. The outer shell 1 of the electrochemical reactor 100 is provided with a main liquid inlet 12, which is connected to the liquid phase outlet 613.

[0104] In one specific embodiment, the wastewater treatment equipment is used for the recovery and treatment of valuable metals and cyanides in alkaline cyanide-containing tailings. The physicochemical reactor 5 is specifically a conventional stirred reactor, with its shell 51 made of insulating material to meet normal temperature and pressure operating conditions. A dosing port is provided at the top of the shell 51 for adding zinc powder, a physicochemical material, into the chamber 513. After the cyanide-containing tailings enter the chamber 513 through the inlet 511, the stirring system 52 is activated to uniformly mix the cyanide-containing tailings with the zinc powder. Under stirring conditions, the zinc powder undergoes a displacement reaction with the copper-cyanide complex in the cyanide-containing tailings, and copper precipitates out in elemental form. At the same time, the copper-cyanide complex in the filtrate is transformed into a zinc-cyanide complex with a lower stability constant. After the reaction is completed, the solid-liquid mixture is discharged through the outlet 512 and pumped through pipeline to the inlet 612 of the solid-liquid separator 6 for the filtrate.

[0105] The solid-liquid separator 6 is specifically a cartridge filter. The pressure shell 61 is made of stainless steel to meet the corrosion resistance requirements of the alkaline cyanide-containing system. The filtration accuracy and flow rate of the filter element 62 are rationally selected based on the particle size and content of solid particles in the solid-liquid mixture after the displacement reaction. After the solid-liquid mixture enters the cavity 611 of the pressure shell 61 through the inlet 612, the liquid phase passes through the filter element 62 and enters the outlet side under the pressure provided by the pump, while the copper-zinc mixture solid is retained on the inlet side of the filter element 62. The separated filtrate (rich in zinc-cyanide complexes) is discharged through the liquid outlet 613 and transported to the total inlet 12 of the electrochemical reactor 100 through pipeline. The retained copper-zinc mixture can be periodically recovered from the pressure shell 61 to achieve the resource recovery of copper.

[0106] After the filtrate enters the electrochemical reactor 100 through the main inlet 12, it flows sequentially as the catholyte in the second channel 25 and the fourth channel 27 of each electrolysis chamber. Under the action of the electric field, zinc cyanide complex ions in the catholyte are reduced and deposited on the surface of the cathode plate 22 to form metallic zinc, and the released cyanide ions are enriched in the catholyte. After being processed by the last electrolysis chamber, the catholyte is discharged from the main outlet 13. The cyanide in the discharged catholyte is enriched and can be returned to the physicochemical reactor 5 as a source of cyanide for recycling, thereby realizing a closed-loop cyanide cycle. The anolyte circulates independently in the flow channel system connected by the first channel 24 and the third channel 26, and is isolated from the cyanide-containing catholyte by the cation exchange membrane 21 to inhibit the oxidative decomposition of cyanide in the anode region.

[0107] In terms of overall treatment efficiency, this wastewater treatment equipment utilizes a physicochemical reactor 5 to achieve copper displacement precipitation and complex transformation, a solid-liquid separator 6 to achieve efficient separation of copper-zinc mixtures and copper recovery, and an electrochemical reactor 100 to achieve zinc electrolytic deposition and cyanide enrichment and recovery. These three treatment units are connected in series and work collaboratively, operating under alkaline conditions throughout the process, which facilitates the resource recovery and recycling of copper, zinc, and cyanide from cyanide-containing tailings. Regarding equipment composition, the physicochemical reactor 5 and solid-liquid separator 6 employ conventional market equipment, while the electrochemical reactor 100 integrates all three into a complete system via pipelines and pumps. This reduces the overall R&D difficulty and manufacturing cost of the equipment. Furthermore, the stable operation of each conventional component, validated by the market, ensures the overall reliability of the complete system.

[0108] Specific embodiments are listed below. Example 1: The experimental water sample was a complex cyanide-containing tailings solution from the cyanidation treatment of copper-gold ore by a gold enterprise. Its main components are shown in Table 1 below. The units are mg / L.

[0109] Using the complete set of equipment described in this application, zinc powder, a physicochemical material, is added to the physicochemical reactor 5 at the front end. The solid-liquid mixture after the reaction is then pumped into the solid-liquid separator 6. The filtered copper is recovered, while the filtrate enters the electrochemical reactor 100. When the anode plate 23 is a titanium-based iridium-tantalum oxide coated electrode and the cathode plate 22 is a carbon felt, sodium carbonate electrolysis promoter is added. When the electrolysis parameters are set to 350.0A, 6.0V, and the reaction time is 4.0h, the final CNT recovery rate is 82.0%, the copper recovery rate is 99.7%, and the zinc recovery rate is 82.2%.

[0110] For the same batch of water samples, instead of using a complete set of equipment for processing, electrochemical reactor 100 was used for electrolysis. When titanium-based iridium-tantalum oxide coated electrode was selected for anode plate 23 and carbon felt was selected for cathode plate 22, sodium carbonate electrolysis promoter was added. When the electrolysis parameters were set to 350.0 A, 6.0 V and the reaction time was 4.0 h, the CNT recovery rate was 77.6%, the copper recovery rate was 78.0% and the zinc recovery rate was 63.1%.

[0111] The results show that the treatment effect of this complete set of treatment equipment on complex cyanide-containing wastewater is better than that of direct electrolysis of cyanide-containing wastewater. The working process of this application: Step 1: The cyanide-containing waste liquid is pumped into the physicochemical reactor 5, the stirring system 52 of the physicochemical reactor 5 is turned on, and the physicochemical materials are added through the dosing port to carry out the physicochemical reaction. Step 2: The solid-liquid mixture after the reaction in the physicochemical reactor 5 is sent to the solid-liquid separator 6 by a pump. The solid-liquid separator collects the metal obtained after the reaction through the filtration of the filter element 62 and discharges the filtrate. Step 3: Before the filtrate discharged from the filter enters the electrochemical reactor 100, turn on the aeration section 4 of the electrochemical reactor 100. As the filtrate flows out of the outlet of the electrochemical reactor 100, turn on the power supply, connect the power supply to the positive and negative terminals of the electrochemical reactor 100, adjust to the specified current and voltage, and carry out electrolysis. Step 4: Take water samples for testing.

[0112] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. An electrochemical reactor, characterized in that, include: The outer shell has a reaction chamber; An electrode assembly is detachably disposed in the reaction chamber. The electrode assembly includes two cation membranes, two cathode plates, and two anode plates. The two anode plates are arranged opposite each other to form a first channel between them. The two cathode plates are respectively disposed on the outside of the two anode plates. A second channel is formed between the cathode plates and the inner wall of the outer shell. Two cation membranes are respectively disposed between the anode plate and the cathode plate to form a third channel with a top opening between the two cation membranes and the corresponding anode plate, and a fourth channel is formed between the two cation membranes and the corresponding cathode plate. The first channel is connected to the third channel, and the second channel is connected to the fourth channel.

2. The electrochemical reactor according to claim 1, characterized in that, The electrode assembly further includes two frame supports, each of which includes an abutment portion, a pressing portion, and a limiting portion. The abutment portion has a slot, and the edge of the anode plate is inserted into the slot. The abutment portion abuts against the pressing portion, and the abutment surface is formed at the abutment point. The edge of the cation membrane abuts against the abutment surface. The pressing portion is connected to the abutment portion, and a clamping groove is formed between the pressing portion and the limiting portion. The cathode plate is inserted into the clamping groove.

3. The electrochemical reactor according to claim 2, characterized in that, The two cation membranes are respectively fixed to the two frame supports. The bottoms of the two frame supports are closed and together enclose the third channel to form a semi-closed structure. The two cation membranes abut against the corresponding contact surfaces.

4. The electrochemical reactor according to claim 1, characterized in that, The electrochemical reactor further includes a partition plate disposed within the reaction chamber to divide the reaction chamber into multiple electrolysis sub-chambers. The partition plate has through holes to allow two adjacent electrolysis sub-chambers to communicate with each other. The electrode plate assembly is correspondingly disposed in each electrolysis sub-chamber.

5. The electrochemical reactor according to claim 4, characterized in that, The outer casing is provided with a main liquid inlet and a main liquid outlet. The main liquid inlet is connected to the second channel, and the main liquid outlet is connected to the fourth channel.

6. The electrochemical reactor according to claim 1, characterized in that, The electrochemical reactor further includes an aeration section located at the bottom of the second channel.

7. The electrochemical reactor according to claim 1, characterized in that, The outer casing includes an end cap and two conductive components. The end cap covers the reaction chamber, and the two conductive components are disposed in the reaction chamber and electrically connected to the cathode plate and the anode plate, respectively.

8. A wastewater treatment device, characterized in that, It includes a physicochemical reactor, a solid-liquid separator, and an electrochemical reactor as described in any one of claims 1-7, connected in sequence.

9. The wastewater treatment equipment according to claim 8, characterized in that, The physicochemical reactor includes a shell and a stirring system. The shell forms a chamber and has an outlet and an inlet. The outlet and the inlet are connected to the chamber. The outlet is connected to the solid-liquid separator. The inlet is used to fill wastewater into the chamber. The stirring system is located inside the chamber.

10. The wastewater treatment equipment according to claim 9, characterized in that, The solid-liquid separator includes a pressure shell and a filter element. A cavity is formed inside the pressure shell, and the filter element is disposed in the cavity. The pressure shell has an inlet for the liquid to be filtered and a liquid phase outlet. The inlet for the liquid to be filtered and the liquid phase outlet are connected to the cavity, and the outlet is connected to the inlet for the liquid to be filtered. The filter element is disposed between the inlet for the liquid to be filtered and the liquid phase outlet. The outer shell of the electrochemical reactor is provided with a main liquid inlet, which is connected to the liquid phase outlet.

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