A device for secondary recovery and treatment of metallic copper from electrolytic copper foil wastewater

Abstract

This invention discloses a secondary copper recovery treatment device for electrolytic copper foil wastewater, belonging to the field of multi-stage wastewater treatment and resource recovery. It includes a recovery treatment unit and a pretreatment unit. The recovery treatment unit comprises a shell with an internal cavity, a detachable cover plate mounted on the upper end of the shell, an insulating shaft rotatably connected to the center of the cavity, a hollow cavity inside the insulating shaft, and a liquid outlet connected to the hollow cavity. The pretreatment unit employs a dual chemical and physical synergy, weakening the solvation cage effect of hydrated ions under the assistance of a pulsed magnetic field, thus increasing the collision probability between the complexing agent and the complexed copper ions. Combined with a bidirectional flow distribution design, the hollow cavity directly replenishes high-concentration wastewater in situ to the upper and middle regions. This design effectively counteracts the concentration polarization in the upper and middle regions, thereby suppressing the "thick at the bottom, thin at the top" morphological deterioration caused by the ion concentration gradient.

Description

Technical Field

[0001] This invention relates to the field of multi-stage wastewater treatment and resource recovery, and more specifically, to a device for secondary recovery of metallic copper from electrolytic copper foil wastewater. Background Technology

[0002] The production process of electrolytic copper foil generates process wastewater containing a certain concentration of copper ions. To reduce production costs and meet environmental protection requirements, swirl electrowinning technology is typically used to recover the metallic copper from the wastewater.

[0003] However, existing cyclone electrowinning recovery devices suffer from the following problems in practical applications: During the cyclone electrowinning recovery of metallic copper, the copper ion concentration reaches its peak when wastewater enters the electrode gap from the bottom, resulting in the strongest electrochemical reaction kinetics. As the liquid flows upward, copper ions are continuously reduced to metallic copper and deposited on the cathode, leading to a significant decrease in the ion concentration of the upper liquid. This directly causes a difference in reaction rates between the bottom and top, ultimately resulting in a cathode deposition layer that is thicker at the bottom and thinner at the top. This uneven deposition not only leads to a decrease in the quality of recovered metallic copper (loose upper deposition layer with poor binding force), but also easily causes nodulation or short circuit risks at the bottom due to excessive deposition, severely limiting the continuous operation capability and recovery depth of the equipment. Summary of the Invention

[0004] In view of the problems existing in the prior art, the purpose of this invention is to provide a device for secondary recovery and treatment of metallic copper from electrolytic copper foil wastewater.

[0005] To solve the above problems, the present invention adopts the following technical solution.

[0006] A device for secondary recovery and treatment of metallic copper from electrolytic copper foil wastewater includes a recovery and treatment section and a pretreatment section; The recycling and processing unit includes a shell with an internal cavity, a cover plate detachably mounted on the upper end of the shell, an insulating shaft rotatably connected to the center of the cavity, a hollow cavity opened inside the insulating shaft and a liquid outlet connected to the hollow cavity, a rotary joint fixed to the upper end of the cover plate with an inner tube passing through the cover plate and fixedly inserted into the hollow cavity, multiple first anodes fixed outside the insulating shaft, a cathode inserted into the inner wall of the cavity, a discharge port opened outside the shell and connected to the cavity, and a feed port tangentially opened outside the shell and connected to the cavity. The pretreatment section is provided in two sets, which are respectively connected to the feed inlet and the rotary joint. The pretreatment section includes a mixing pipe with one end fixed to the feed inlet, a sensor fixed on the inner wall of the mixing pipe, a mixing throat opened inside the mixing pipe, an injection port opened on the mixing pipe and connected to the mixing throat, and an electromagnetic coil fixed outside the mixing pipe.

[0007] Furthermore, a hollow ring is fixed to the bottom of the cavity. The hollow ring is located below the cathode. A tangential opening communicating with the feed inlet is opened inside the hollow ring. Multiple flow guide flanges are integrally formed on the inner wall of the hollow ring.

[0008] Furthermore, the insulating shaft includes a middle column, an upper column and a lower column respectively fixed to the upper and lower ends of the middle column, a flange integrally formed at the lower end of the lower column and extending outward through the housing, and a dynamic seal disposed inside the housing and connected to the outer wall of the flange; the flange is rotatably connected inside the housing, the upper end of the upper column is rotatably connected to the lower end of the cover plate, and the lower end of the lower column is rotatably connected to the bottom wall of the cavity; the hollow cavity is opened inside the upper column and the middle column, the liquid outlet is opened on the outer surface of the middle column, and multiple first anodes are fixed to the outside of the middle column.

[0009] Furthermore, a conductive slip ring is provided at the upper end of the housing. The stator end of the conductive slip ring is fixed to the upper end of the housing, and the mover end of the conductive slip ring is fixed to the outside of the inner tube of the rotary joint.

[0010] Furthermore, it also includes a pitch adjustment unit, which includes multiple guide rods fixed to the lower end of the cover plate, a base plate fixed to the lower end of the multiple guide rods, a lead screw with both ends rotatably connected to the base plate and the cover plate respectively, a second anode movably sleeved outside the multiple guide rods and screwed outside the lead screw, and a first motor fixed to the upper end of the cover plate. The second anode is movably sleeved outside the insulating shaft, and the output shaft of the first motor passes through the cover plate and is connected to one end of the lead screw.

[0011] Furthermore, it also includes a mass transfer enhancement component, which includes a bracket fixed to the upper end of the cover plate, a first gear rotatably connected to the upper end of the cover plate and a second gear meshing with the first gear, a second motor fixed to the upper end of the bracket, and multiple blades fixed to the outside of the insulating shaft. The output shaft of the second motor passes through the bracket and is connected to the first gear. The second gear is fixedly sleeved on the outside of the inner tube of the rotary joint. The multiple blades are equidistantly arranged outside the insulating shaft and located above the first anode.

[0012] Furthermore, it also includes a circumferential homogenization component, which includes a movable groove inside the lower column, a slide block slidably connected in the movable groove, an inclined surface on one side of the slide block, a telescopic part movably disposed inside the lower column and extending outward through the lower column at one end, a support plate disposed outside the insulating shaft and capable of telescopic movement on the insulating shaft, a scraper fixed to the support plate facing the cathode side, and an electric actuator fixed to the lower end of the flange, wherein the telescopic end of the electric actuator passes through the flange into the movable groove and is connected to the slide block.

[0013] Furthermore, the telescopic part includes a slider that is movably inserted into the lower column, a roller that is rotatably connected to one end of the slider and in contact with the inclined surface, and a spring disposed inside the lower column. The two ends of the spring are respectively connected to the inner wall of the lower column and one side of the slider, and the other end of the slider is fixedly connected to the other side of the support plate.

[0014] Furthermore, a piston ring is fixed to the outside of the telescopic end of the electric actuator, and the piston ring is located inside the flange to achieve a dynamic seal between the telescopic end and the flange; multiple guide posts are fixed to the other side of the support plate, and multiple guide grooves are opened on the outer surface of the middle column to accommodate multiple guide posts respectively.

[0015] Furthermore, a heat insulation section is provided between the outside of the mixing pipe and the electromagnetic coil.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) This scheme adopts a dual chemical and physical synergy in the pretreatment section. Under the assistance of a pulsed magnetic field, the solvation cage effect of hydrated ions is weakened, and the collision probability between the complexing agent and the complexed copper ions is increased. Combined with the bidirectional flow distribution design, the hollow cavity directly replenishes the high-concentration waste liquid in situ to the middle and upper part. This design can effectively counteract the concentration polarization in the middle and upper region, thereby suppressing the "thick at the bottom and thin at the top" morphological deterioration caused by the ion concentration gradient.

[0017] (2) This scheme drives the second anode to move up and down through the electrode spacing adjustment section, which can adjust the anode-cathode gap according to the real-time working conditions. When the conductivity in the upper part of the cavity decreases due to the decrease in concentration, the current density in the upper region can be maintained without significantly increasing the voltage by reducing the electrode spacing, thus offsetting the negative effect of the increase in resistivity and avoiding the hydrogen evolution side reaction caused by excessive voltage.

[0018] (3) This scheme uses a mass transfer enhancement component to drive the rotation of the insulating shaft and the agitation of the blades to re-inject mechanical energy into the top region where the fluid kinetic energy is weak. The high shear turbulence generated by the rotating blades in the top material-poor region strips and thins the diffusion layer boundary on the cathode surface. This enables the system to overcome the high activation overpotential and maintain a high limiting deposition current even under extremely low copper ion concentration (poor solution) conditions at the tail end, thus widening the depth copper removal boundary of the device.

[0019] (4) In this scheme, the scraper is driven to approach the inner wall of the cathode by the circumferential homogenization component and rotate synchronously with the insulating shaft. The rotating scraper generates mechanical disturbance to the copper layer that grows too fast in a local area, thereby inhibiting dendrite development. At the same time, the local fluid shear force generated by the shrinking gap between the scraper and the copper surface is used to inhibit further deposition in this area, thereby achieving physical self-balance of the deposition layer thickness and ensuring that the product is flat and easy to peel off. Attached Figure Description

[0020] Figure 1This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a cross-sectional view of the preprocessing section of the present invention; Figure 3 This is a schematic diagram of the bottom structure of the housing of the present invention; Figure 4 Cross-sectional view of the present invention Figure 1 ; Figure 5 This is a schematic diagram of the pole pitch adjustment part of the present invention; Figure 6 Cross-sectional view of the present invention Figure 2 ; Figure 7 This is a schematic diagram of the blade structure of the present invention; Figure 8 This is a schematic diagram of the circumferential homogenization component structure of the present invention.

[0021] Explanation of the labels in the diagram: 1. Pretreatment section; 11. Mixing pipe; 12. Sensor; 13. Mixing throat; 14. Inlet; 15. Insulation section; 16. Electromagnetic coil; 2. Recycling section; 21. Housing; 22. Outlet; 23. Inlet; 24. Cover plate; 25. Cathode; 26. Insulating shaft; 261. Middle column; 262. Upper column; 263. Lower column; 264. Dynamic seal; 265. Hollow cavity; 27. First anode; 28. Outlet; 29. ​​Rotary joint; 3. Hollow ring; 31. Guide flange; 32. 1. Tangential opening; 4. Conductive slip ring; 5. Pole adjustment section; 51. Guide rod; 52. Base plate; 53. Lead screw; 54. First motor; 55. Second anode; 6. Mass transfer enhancement component; 61. Support; 62. First gear; 63. Second gear; 64. Second motor; 65. Blade; 7. Circumferential homogenization component; 71. Movable groove; 72. Slide seat; 721. Inclined surface; 73. Telescopic part; 731. Slider; 732. Spring; 733. Roller; 74. Support plate; 75. Scraper; 76. Electric actuator; 77. Guide post. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0023] Please see Figures 1 to 8 A secondary copper recovery and treatment device for electrolytic copper foil wastewater includes a recovery and treatment unit 2 and a pretreatment unit 1. The recycling and processing unit 2 includes a housing 21 with an internal cavity, a cover plate 24 detachably mounted on the upper end of the housing 21, an insulating shaft 26 rotatably connected to the center of the cavity, a hollow cavity 265 opened inside the insulating shaft 26 and a liquid outlet 28 communicating with the hollow cavity 265, a rotary joint 29 fixed to the upper end of the cover plate 24 with an inner tube passing through the cover plate 24 and fixedly inserted into the hollow cavity 265, a plurality of first anodes 27 fixed outside the insulating shaft 26, a cathode 25 inserted into the inner wall of the cavity, a discharge port 22 opened outside the housing 21 and communicating with the cavity, and a feed port 23 tangentially opened outside the housing 21 and communicating with the cavity. The pretreatment section 1 includes a mixing pipe 11 with one end fixed to the feed inlet 23, a sensor 12 fixed on the inner wall of the mixing pipe 11, a mixing throat 13 opened inside the mixing pipe 11, an injection port 14 opened on the mixing pipe 11 and connected to the mixing throat 13, and an electromagnetic coil 16 fixed outside the mixing pipe 11. A heat insulation section 15 is also provided between the outside of the mixing pipe 11 and the electromagnetic coil 16.

[0024] A hollow ring 3 is also fixed to the bottom of the cavity. The hollow ring 3 is located below the cathode 25. A tangential opening 32 communicating with the feed inlet 23 is opened inside the hollow ring 3. A plurality of flow guiding flanges 31 are integrally formed on the inner wall of the hollow ring 3.

[0025] The insulating shaft 26 includes a middle column 261, an upper column 262 and a lower column 263 respectively fixed to the upper and lower ends of the middle column 261, a flange integrally formed at the lower end of the lower column 263 and extending outward through the housing 21, and a dynamic sealing element 264 disposed inside the housing 21 and connected to the outer wall of the flange; the flange is rotatably connected inside the housing 21, and an electric slip ring is also provided between the flange and the housing 21, the stator end of the electric slip ring can be fixed on the housing 21, and the rotor end of the electric slip ring is fixed on the flange; the upper end of the upper column 262 is rotatably connected to the lower end of the cover plate 24, and the lower end of the lower column 263 is rotatably connected to the bottom wall of the cavity; the hollow cavity 265 is opened inside the upper column 262 and the middle column 261, the liquid outlet 28 is opened on the outer surface of the middle column 261, and multiple first anodes 27 are fixed to the outside of the middle column 261.

[0026] A conductive slip ring 4 is also provided at the upper end of the housing 21. The stator end of the conductive slip ring 4 is fixed at the upper end of the housing 21, and the mover end of the conductive slip ring 4 is fixed outside the inner tube of the rotary joint 29. The mover end of the conductive slip ring 4 is electrically connected to a plurality of first anodes 27.

[0027] By adopting the above technical solution, the wastewater from electrolytic copper foil production first enters the mixing pipe 11, and the concentration of copper ions in the influent is detected in real time by sensor 12; sensor 12 is an ion-selective electrode; the injection port 14 is connected to an external liquid supply device, which injects a regulator (a complexing agent, such as a 5%-15% DTC heavy metal scavenger or sodium sulfide solution) into the mixing pipe 11 through the injection port 14 at a volume ratio of 1:500 to 1:2000 with the wastewater, and the regulator and wastewater are mixed in the high-flow-rate mixing throat 13 to achieve chemical regulation and treatment of the wastewater; in the production of electrolytic copper foil, the wastewater often contains various complexing agents (such as EDTA, tartrates or certain surfactants), and the charged properties of the complexed copper ions are altered. The ions cannot move towards the cathode 25 under the influence of the electric field, resulting in extremely low electrolysis efficiency. After adjustment by the regulator, copper ions can be uniformly deposited on the cathode 25 in a free state, forming a dense metallic copper plate and improving the recovery purity. The electromagnetic coil 16 can generate a high-frequency pulsed magnetic field, with a frequency selectable from 10kHz to 50kHz and a magnetic field strength selectable from 500Gs to 2000Gs, breaking the solvation cage of ions. Under the action of the magnetic field, the crystal morphology of calcium, magnesium ions or other impurities in the wastewater will change, effectively preventing these impurities from forming hard scale on the cathode 25 in subsequent electrolysis and extending the plate cleaning cycle. At the same time, the magnetic field will change the hydrogen bonding state of water molecules, reduce the solvation layer, and make it easier for copper ions and their complexes to collide with the functional groups of the regulator. Wastewater discharged from the pretreatment unit 1 enters the cavity inside the housing 21 tangentially through the feed inlet 23. This water intake method causes the liquid to swirl within the annular space between the cathode 25 and the first anode 27. The resulting turbulence forces copper ions to be transported to the surface of the cathode 25, allowing the system to maintain high current efficiency even when the copper ion concentration is low. Under the action of the DC power supply, an electric field is formed between the cathode 25 and the first anode 27. The reaction on the cathode 25 is as follows: copper ions in the liquid phase gain electrons on the surface of the cathode 25 and are directly reduced to metallic copper. The reaction on the first anode 27 is usually the electrolysis of water, producing oxygen and hydrogen ions. Copper atoms accumulate layer by layer on the inner wall of the cylindrical cathode 25, eventually forming a dense, high-purity electrolytic copper body. When the copper body reaches a certain thickness, the machine is stopped, the cathode 25 is removed, and the generated copper body is mechanically peeled off to obtain the metallic copper product. Since there are multiple first anodes 27, and they are physically divided into several mutually insulated segments in the vertical direction of the middle column 261, while the insulating shaft 26 is made of insulating material, it can isolate each segment of the first anode 27; each segment of the first anode 27 has an independent current lead connected to the conductive slip ring 4, and the holes of the leads are filled with waterproof sealant to achieve sealing treatment; the voltage / current of the first anode 27 in different segments can be segmentally controlled by a programmable controller. Specifically, the programmable controller has a preset voltage output model that increases in a step-like manner from bottom to top; or, multiple conductivity sensors are arranged axially in the cavity, and the controller receives the sensor signals and performs closed-loop regulation to achieve multiple The electric field strength generated by the first anode 27 in each section is different; the liquid concentration at the bottom of the cavity is high, so a larger current density can be obtained by reducing the output voltage / current of the first anode 27 in the lower section; while the liquid concentration at the top of the cavity is low, so the output voltage / current of the first anode 27 in the upper section is increased to achieve high voltage compensation; by actively differentiating the electric field strength, the decrease in ion concentration is offset, and the difference in deposition rate is smoothed out; the top anode section, due to the higher output voltage, can compensate for the increased ohmic polarization and activation polarization caused by the decrease in ion concentration, improve the reaction rate at the top, and thus correct the phenomenon of thicker at the bottom and thinner at the top; achieving uniform deposition not only facilitates peeling, but also avoids the risk of nodule formation or short circuit caused by excessive deposition at the bottom; There are two pretreatment units 1, one installed at the feed inlet 23 and the other installed at the input end of the rotary joint 29. Part of the wastewater enters the cavity from the bottom of the shell 21, and the other part of the wastewater enters the hollow cavity 265 from the rotary joint 29. Then it is discharged through multiple outlets 28 and directly transported to the middle and upper part of the electrolysis zone. This is equivalent to injecting new reactants in the middle and later stages of the reaction, which directly increases the bulk concentration of the middle and upper reaction zone (which was originally a lean material zone), reduces the thickness of the concentration polarization layer, and makes the concentration distribution in the reaction chamber more linear and consistent. Wastewater that has passed through the electrolysis zone and reached the top of the cavity is discharged from the outlet 22.

[0028] like Figure 4 and Figure 5 As shown, it also includes a pitch adjustment unit 5, which includes a plurality of guide rods 51 fixed to the lower end of the cover plate 24, a base plate 52 fixed to the lower end of the plurality of guide rods 51, a lead screw 53 whose two ends are respectively rotatably connected to the base plate 52 and the cover plate 24, a second anode 55 movably sleeved outside the plurality of guide rods 51 and screwed to the outside of the lead screw 53, and a first motor 54 fixed to the upper end of the cover plate 24. The second anode 55 is movably sleeved outside the insulating shaft 26, and the output shaft of the first motor 54 passes through the cover plate 24 and is connected to one end of the lead screw 53.

[0029] By adopting the above technical solution, the first motor 54 drives the lead screw 53 to rotate, and the rotation of the lead screw 53 drives the second anode 55 to move up and down. When the second anode 55 moves to the outside of the middle column 261, the distance between the second anode 55 and the upper section of the cathode 25 decreases. According to the basic formula of electrochemistry, the ohmic resistance of the electrolytic cell... Interpole spacing Proportional: ;in, The resistivity of the electrolyte. For effective area, The distance between the anode and cathode; In the upper part of the cavity, the decrease in copper ion concentration leads to a decrease in electrolyte conductivity. (Increase), at this time by reducing the interelectrode spacing It can offset the negative effects of increased resistivity and maintain the current density in the upper region by reducing the physical gap without significantly increasing the voltage (thus avoiding hydrogen evolution), effectively solving the problem of "thin upper layer" deposition rate.

[0030] like Figure 6 and Figure 7 As shown, it also includes a mass transfer enhancement component 6, which includes a bracket 61 fixed to the upper end of the cover plate 24, a first gear 62 rotatably connected to the upper end of the cover plate 24 and a second gear 63 meshing with the first gear 62, a second motor 64 fixed to the upper end of the bracket 61, and a plurality of blades 65 fixed to the outside of the insulating shaft 26. The output shaft of the second motor 64 passes through the bracket 61 and is connected to the first gear 62. The second gear 63 is fixedly sleeved on the outside of the inner tube of the rotary joint 29. The plurality of blades 65 are equidistantly arranged on the outside of the insulating shaft 26 and located above the first anode 27.

[0031] By adopting the above technical solution, the second motor 64 drives the first gear 62 to rotate, the first gear 62 drives the second gear 63 to rotate, the second gear 63 drives the inner tube of the rotary joint 29 to rotate, the inner tube rotates and drives the entire insulating shaft 26 and the first anode 27 to rotate, and at the same time, the blades 65 on the outside of the insulating shaft 26 also rotate; the blades 65 act as a booster, re-injecting mechanical energy into the top region where the fluid rotational kinetic energy is weakest, forcibly maintaining the high-speed swirling state; according to electrochemical kinetics, the limiting current density is inversely proportional to the diffusion layer thickness; the shear force generated by the rotation of the blades 65 can significantly reduce the diffusion layer thickness, and even if the copper ion concentration at the top is low, by minimizing the diffusion layer thickness, a high reaction rate can still be maintained, thereby offsetting the "thinning at the top" trend.

[0032] Meanwhile, in static electrodes, if the top concentration is low, the voltage must be significantly increased to maintain the current; mechanical rotation improves mass transfer efficiency and reduces concentration polarization, while "segmented electrical control" optimizes the driving force; the combination of the two means that the expected deposition rate can be achieved at a lower overpotential; this can broaden the equipment's ability to deeply remove copper from wastewater with extremely low concentrations.

[0033] Furthermore, the fresh wastewater originally discharged from the outlet 28 on the middle column 261 may experience localized uneven mixing during its ascent. At this time, the centrifugal force and radial shear generated by the rotation of the insulating shaft 26 can quickly throw the high-concentration wastewater discharged from the outlet 28 toward the surface of the cathode 25. The mechanical agitation of the blades 65 promotes the mixing of fresh components with lean liquid, making the concentration field near the surface of the cathode 25 more uniform and further optimizing the smoothness of the deposition layer.

[0034] like Figure 6 and Figure 8 As shown, it also includes a circumferential homogenizing component 7, which includes a movable groove 71 opened inside the lower column 263, a slide block 72 slidably connected in the movable groove 71, an inclined surface 721 opened on one side of the slide block 72, a telescopic part 73 movably disposed inside the lower column 263 and extending outward through the lower column 263 at one end, a support plate 74 disposed outside the insulating shaft 26 and capable of telescopic movement on the insulating shaft 26, a scraper 75 fixedly connected to the support plate 74 on the side facing the cathode 25, and an electric push rod 76 fixedly connected to the lower end of the flange. The telescopic end of the electric push rod 76 passes through the flange and enters the movable groove 71 and is connected to the slide block 72. The rotor end of the electric slip ring on the flange is electrically connected to the electric push rod 76 to realize the transmission of electrical energy during rotation.

[0035] The telescopic part 73 includes a slider 731 movably inserted into the lower column 263, a roller 733 rotatably connected to one end of the slider 731 and in contact with the inclined surface 721, and a spring 732 disposed inside the lower column 263. The two ends of the spring 732 are respectively connected to the inner wall of the lower column 263 and one side of the slider 731, and the other end of the slider 731 is fixedly connected to the other side of the support plate 74.

[0036] The telescopic end of the electric actuator 76 is fixed with a piston ring, and the piston ring is located inside the flange to achieve a dynamic seal between the telescopic end and the flange; multiple guide posts 77 are fixed to the other side of the support plate 74, and multiple guide grooves are opened on the outer surface of the middle column 261 to accommodate multiple guide posts 77 respectively; the inner wall of the guide groove and the outer surface of the guide post 77 are coated with polytetrafluoroethylene anti-corrosion and wear-resistant coating, or an anti-corrosion corrugated pipe is sleeved on the outside of the guide post 77 to prevent the electrolyte from crystallizing and causing jamming.

[0037] By adopting the above technical solution, the retraction of the electric push rod 76 can drive the slide 72 to slide downward in the movable groove 71. When the slide 72 slides downward, it pushes the roller 733 and the slider 731 towards the support plate 74 through the inclined surface 721. The spring 732 is compressed and stores energy. The movement of the slider 731 drives the support plate 74 to move. The support plate 74 and the scraper 75 on one side of the support plate 74 move towards the inner wall of the cathode 25, so that the scraper 75 is close to the cathode 25 and maintains a certain gap. The electric push rod 76 is connected to an external controller, which is used to communicate with the voltage monitoring module of the electrolysis power supply. In the constant current electrolysis mode, when the copper deposition layer on the inner wall of the cathode continues to thicken, causing the electrode spacing to become smaller, and the system detects an abnormal downward trend in the cell voltage of the electrolysis cell (for example, the voltage drop exceeds the preset safety threshold of 5%), the controller immediately issues a command to control the cylinder 76 to retract in microsteps, so that the scraper 75 retreats with a certain safety margin (such as 0.5mm-1mm). Through this closed-loop control, the radial extension and retraction displacement of the scraper 75 is dynamically adjusted in real time, which not only maintains a constant fluid shear force but also completely avoids the risk of short circuit and explosion caused by local dendrites piercing the electrode spacing. In conjunction with the rotation of the insulating shaft 26 in the above scheme, the scraper 75 also rotates synchronously with the insulating shaft 26. When copper ions accumulate layer by layer on the cathode 25, the rotating scraper 75 will mechanically disturb or restrict the locally growing copper layer, preventing excessive dendrite development. At the same time, as the thickness of the copper body on the inner wall of the cathode 25 increases, the gap between the scraper 75 and the copper surface decreases, which will locally increase the fluid shear force at that point, inhibiting further deposition in that area, thereby achieving thickness self-balancing.

[0038] Usage: The wastewater from electrolytic copper foil first passes through the pretreatment section 1, where chemical complex breaking and electromagnetic pulse magnetization are combined in the mixing throat 13 to prevent scale formation. The treated wastewater is divided into two streams: one stream enters tangentially from the bottom of the shell 21 to form a vortex, and the other stream is directly transported from inside the insulating shaft 26 to the upper middle material-poor zone for concentration compensation. Under the segmented control of the electric field and the dynamic adjustment of the electrode spacing, copper ions are reduced and deposited on the inner wall of the cathode 25. At the same time, the insulating shaft 26 drives the blades 65 to rotate to enhance mass transfer, thin the diffusion layer, and cooperate with the scraper 75 to physically disturb and intervene in the morphology of the deposited layer in real time, ultimately achieving uniform and dense deposition and efficient recovery of high-purity metallic copper.

[0039] The above description is merely a preferred embodiment of the present invention; however, the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and its improved concepts, should be covered within the scope of protection of the present invention.

Claims

1. A device for secondary recovery and treatment of metallic copper from electrolytic copper foil wastewater, comprising a recovery and treatment unit (2) and a pretreatment unit (1), characterized in that: The recycling unit (2) includes a housing (21) with an inner cavity, a cover plate (24) detachably mounted on the upper end of the housing (21), an insulating shaft (26) rotatably connected to the center of the cavity, a hollow cavity (265) opened inside the insulating shaft (26) and a liquid outlet (28) connected to the hollow cavity (265), a rotary joint (29) fixed to the upper end of the cover plate (24) with an inner tube passing through the cover plate (24) and fixedly inserted into the hollow cavity (265), a plurality of first anodes (27) fixed outside the insulating shaft (26), a cathode (25) inserted into the inner wall of the cavity, a discharge port (22) opened outside the housing (21) and connected to the cavity, and a feed port (23) tangentially opened outside the housing (21) and connected to the cavity. The pretreatment section (1) is provided with two sets, which are respectively connected to the feed inlet (23) and the rotary joint (29). The pretreatment section (1) includes a mixing pipe (11) with one end fixed to the feed inlet (23), a sensor (12) fixed on the inner wall of the mixing pipe (11), a mixing throat (13) opened inside the mixing pipe (11), an injection port (14) opened on the mixing pipe (11) and connected to the mixing throat (13), and an electromagnetic coil (16) fixed outside the mixing pipe (11).

2. The device for secondary recovery and treatment of metallic copper from electrolytic copper foil wastewater according to claim 1, characterized in that: A hollow ring (3) is also fixed to the bottom of the cavity. The hollow ring (3) is located below the cathode (25). A tangential opening (32) communicating with the feed inlet (23) is opened inside the hollow ring (3). A plurality of flow guiding flanges (31) are integrally formed on the inner wall of the hollow ring (3).

3. The device for secondary recovery and treatment of metallic copper from electrolytic copper foil wastewater according to claim 1, characterized in that: The insulating shaft (26) includes a middle column (261), an upper column (262) and a lower column (263) respectively fixed to the upper and lower ends of the middle column (261), a flange integrally formed on the lower end of the lower column (263) and extending outward through the housing (21), and a dynamic sealing element (264) disposed inside the housing (21) and connected to the outer wall of the flange; the flange is rotatably connected inside the housing (21), the upper end of the upper column (262) is rotatably connected to the lower end of the cover plate (24), and the lower end of the lower column (263) is rotatably connected to the bottom wall of the cavity; the hollow cavity (265) is opened inside the upper column (262) and the middle column (261), the liquid outlet (28) is opened on the outer surface of the middle column (261), and multiple first anodes (27) are fixed on the outside of the middle column (261).

4. The device for secondary recovery and treatment of metallic copper from electrolytic copper foil wastewater according to claim 1, characterized in that: The upper end of the housing (21) is also provided with a conductive slip ring (4). The stator end of the conductive slip ring (4) is fixed to the upper end of the housing (21), and the mover end of the conductive slip ring (4) is fixed to the outside of the inner tube of the rotary joint (29).

5. The device for secondary recovery and treatment of metallic copper from electrolytic copper foil wastewater according to claim 1, characterized in that: It also includes a pitch adjustment unit (5), which includes a plurality of guide rods (51) fixed to the lower end of the cover plate (24), a base plate (52) fixed to the lower end of the plurality of guide rods (51), a lead screw (53) whose two ends are respectively rotatably connected to the base plate (52) and the cover plate (24), a second anode (55) movably sleeved outside the plurality of guide rods (51) and screwed to the outside of the lead screw (53), and a first motor (54) fixed to the upper end of the cover plate (24). The second anode (55) is movably sleeved outside the insulating shaft (26), and the output shaft of the first motor (54) passes through the cover plate (24) and is connected to one end of the lead screw (53).

6. A secondary copper recovery treatment device for electrolytic copper foil wastewater according to claim 1 or 3, characterized in that: It also includes a mass transfer enhancement component (6), which includes a bracket (61) fixed to the upper end of the cover plate (24), a first gear (62) rotatably connected to the upper end of the cover plate (24) and a second gear (63) meshing with the first gear (62), a second motor (64) fixed to the upper end of the bracket (61), and multiple blades (65) fixed to the outside of the insulating shaft (26). The output shaft of the second motor (64) passes through the bracket (61) and is connected to the first gear (62). The second gear (63) is fixedly sleeved on the outside of the inner tube of the rotary joint (29). The multiple blades (65) are equidistantly arranged outside the insulating shaft (26) and located above the first anode (27).

7. The device for secondary recovery and treatment of metallic copper from electrolytic copper foil wastewater according to claim 3, characterized in that: It also includes a circumferential homogenizing component (7), which includes a movable groove (71) opened inside the lower column (263), a slide (72) slidably connected in the movable groove (71), an inclined surface (721) opened on one side of the slide (72), a telescopic part (73) movably set inside the lower column (263) and extending outward through the lower column (263) at one end, a support plate (74) set outside the insulating shaft (26) and capable of telescopic movement on the insulating shaft (26), a scraper (75) fixedly connected to the side of the support plate (74) facing the cathode (25), and an electric push rod (76) fixedly connected to the lower end of the flange. The telescopic end of the electric push rod (76) passes through the flange and enters the movable groove (71) and is connected to the slide (72).

8. The device for secondary recovery and treatment of metallic copper from electrolytic copper foil wastewater according to claim 7, characterized in that: The telescopic part (73) includes a slider (731) movably inserted into the lower column (263), a roller (733) rotatably connected to one end of the slider (731) and in contact with the inclined surface (721), and a spring (732) disposed inside the lower column (263). The two ends of the spring (732) are respectively connected to the inner wall of the lower column (263) and one side of the slider (731), and the other end of the slider (731) is fixedly connected to the other side of the support plate (74).

9. A secondary copper recovery treatment device for electrolytic copper foil wastewater according to claim 7 or 8, characterized in that: The telescopic end of the electric push rod (76) is fixed with a piston ring, and the piston ring is located inside the flange to achieve dynamic sealing between the telescopic end and the flange; multiple guide posts (77) are fixed to the other side of the support plate (74), and multiple guide grooves are opened on the outer surface of the middle column (261) to accommodate multiple guide posts (77).

10. The device for secondary recovery and treatment of metallic copper from electrolytic copper foil wastewater according to claim 1, characterized in that: A heat insulation part (15) is also provided between the outside of the mixing pipe (11) and the electromagnetic coil (16).

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