An offline electrolytic copper extraction and regeneration system and regeneration process for acidic etching solution

Abstract

The present invention discloses an off-line electrolytic copper extraction and regeneration system and regeneration process for acidic etching solution. By using an acidic etching solution with an iron-based additive formulation, and in combination with the functional settings of the off-line electrolytic copper extraction and regeneration system for acidic etching solution and the process parameter settings of each component, the off-line regeneration and recycling of the etching waste liquid are well achieved. It does not need to be directly connected to the etching production line, effectively inhibits the generation of chlorine gas during the electrolysis process, realizes 100% recycling of the etching solution without increment, and achieves clean production.

Description

Technical Field

[0001] The present invention relates to the technical field of etching, and specifically discloses an off-line acidic etching solution electrolytic copper extraction and regeneration system and a regeneration process. Background Art

[0002] In the manufacturing process of acid etching of circuit boards, a multi-component acid etching sub-solution rich in hydrochloric acid, sodium chloride, sodium chlorate, ammonium chloride, etc. is used to etch the copper foil on the copper clad laminate (oxidation-reduction reaction) to form circuits. At the same time, a copper-containing acidic etching waste liquid with a complex composition rich in copper chloride, hydrochloric acid, sodium chloride, and ammonium chloride is produced. The traditional acid etching process has evolved from the initial process using 31% hydrochloric acid as the sub-solution + air oxidation regeneration process to the process using a single-liquid acid etching sub-solution composed of 15% hydrochloric acid + 100 g / L ammonium chloride + organic additive complexing agent, etc. Due to the high acidity of these two acid etching processes, the difficult treatment of waste liquid ammonia nitrogen, and the high content of monovalent copper that cannot be used for precision circuit etching, etc., these processes have gradually been phased out.

[0003] The copper in the copper-containing acidic etching waste liquid can be removed through chemical or physical reaction methods such as acid neutralization precipitation method, replacement reduction method, distillation, electrolysis, etc. However, the components of the etching solution are damaged, and the tail liquid after copper removal needs further environmental protection physical or chemical treatment and cannot be recycled, resulting in a large environmental protection disposal cost and resource waste.

[0004] Current patents mention obtaining copper plates by electrolytic copper extraction from etching solutions, and the regenerated etching solution after copper extraction is reused. During the entire process of electrolytic copper extraction from acidic etching solutions, copper ions at the cathode become monovalent copper ions and finally become metallic copper and are sucked out. Chloride ions in the anode region become chlorine gas and are precipitated. A large amount of chlorine gas needs to be absorbed by jet absorption, or by reducing substances such as ferrous chloride, or by alkali absorption. Chlorine gas is highly dangerous, and leakage is likely to cause suffocation. At the same time, a large amount of ferric chloride waste liquid is generated after ferrous chloride absorbs chlorine gas, bringing a great load to the subsequent environmental protection water treatment. In addition, the precipitation of chloride ions as chlorine gas makes the production line need to supplement a large amount of hydrochloric acid or sodium chloride to supplement chloride ions, resulting in the expansion of the acidic etching waste liquid after the acidic etching solution is recycled. The recycling rate of the etching solution is only 40 - 60%, and it is impossible to achieve the full recycling of the acidic etching solution.

[0005] An ion membrane copper extraction device and an "online" connection of the etching machine for copper extraction + ORP530 - 550 control method are adopted. Copper plates are extracted at the cathode, and the anode liquid and the acidic etching working liquid of the etching machine are circulated online. The ORP control is consistent with the etching production line at 530 - 550 mV. Monovalent copper is provided by the etching of the circuit board by the etching machine, so that the reaction in the anode region of the copper extraction device changes from chloride ions becoming chlorine gas to monovalent copper becoming divalent copper, avoiding the generation of chlorine gas in the anode region.

[0006] In patents such as Fengshun Jiafeng Electronics Co., Ltd. CN201710258832.7, Guangdong Sancai Environmental Protection Technology Co., Ltd. CN201710213596.7, Jiangsu Jiesian Environmental Protection Technology Co., Ltd. CN201520196918.8, etc., similar methods of copper extraction using membrane electrolysis cathode and on-line circulation of anolyte are mentioned. The above on-line electrolytic copper extraction method can effectively avoid the generation of chlorine gas in the anode area. Since the ORP of the etching solution in the production line is around 530 - 550 mV, it can be seen from Equation 1 that Cu+ - e = Cu2+ φ = 519 mV. When the redox potential is 519 mV, all monovalent copper has been converted into divalent copper. When the ORP is greater than 520 mV, monovalent copper ions cannot be provided for the anode of the electrolytic equipment, and a large amount of chlorine gas will still be generated at the anode of the electrolytic equipment. If a certain amount of monovalent copper ions are to be ensured in the etching solution, the ORP value parameter of the etching production line should be lower than 519 mV. Such parameter settings will affect the etching production speed of the etching production line, and the etching quality accuracy cannot be guaranteed. Therefore, the above method cannot achieve a balance among stable etching speed and quality, complete copper extraction and recycling of acidic etching solution, and avoidance of chlorine gas generation.

[0007] Another example is CN111394726A, which discloses an acidic etching solution recycling and regeneration process. It directly connects the etching solution regeneration equipment to the etching production line to achieve on-line circulation and regeneration. However, in this way, there are 4 disadvantages:

[0008] The equipment installation is restricted by the site. The on-line acidic etching solution recycling and regeneration equipment needs to be directly connected to the etching production line and should be installed as close as possible to the etching production line. If the site is not pre-arranged at the customer's site, the equipment installation will encounter restrictions;

[0009] The temperature of the regenerated solution generated by the etching solution regeneration equipment needs to be matched with the temperature of the etching solution used in the production line. Since the temperature of the regenerated solution just generated by the etching solution regeneration equipment is higher than the temperature of the etching solution used in the etching production line, it needs to be cooled down;

[0010] The fluctuations in the production process of the etching production line will affect the copper extraction process;

[0011] The process of the etching solution regeneration equipment will generate chlorine gas, which poses a safety risk and requires a chlorine gas absorption and treatment device. Summary of the Invention

[0012] To solve the problems existing in the above prior art, the present invention proposes an offline acidic etching solution electrolytic copper extraction and regeneration system and a regeneration process. By using an acidic etching solution with an iron-based additive formulation and in combination with the functional settings of the offline acidic etching solution electrolytic copper extraction and regeneration system and the process parameter settings of each component, the regeneration of the etching waste liquid offline is well achieved, recycled, without direct connection to the etching production line, effectively inhibiting the generation of chlorine gas during electrolysis, realizing 100% recycling of the etching solution, without increment, and achieving clean production.

[0013] The present invention can be realized by the following technical solutions:

[0014] An offline acidic etching solution electrolytic copper extraction and regeneration system of the present invention uses the offline acidic etching solution electrolytic copper extraction and regeneration system to treat the acidic etching waste liquid with an iron-based additive formulation. The offline acidic etching solution electrolytic copper extraction and regeneration system includes an electrolytic cell, a circulation tank, a waste liquid bucket, a cathode liquid bucket, a regenerated liquid bucket, an acid gas absorption tower, a rectifier, and a cooling tower; an anode area and a cathode area are provided in the electrolytic cell, and a U-shaped diversion structure anode membrane frame is adopted in the anode area. An anode area and a cathode area are provided in the circulation tank. The anode area of the electrolytic cell is connected to the anode area of the circulation tank, and the cathode area of the electrolytic cell is connected to the cathode area of the circulation tank. The anode area of the circulation tank is connected to the waste liquid bucket, the cathode liquid bucket, and the regenerated liquid bucket, and the cathode area of the circulation tank is connected to the waste liquid bucket and the cathode liquid bucket. The anode areas of the electrolytic cell and the circulation tank are connected to the acid gas absorption tower, the etching production line is connected to the waste liquid bucket and the regenerated liquid bucket, the rectifier is connected to the cathode copper bar and the anode copper bar of the electrolytic cell, and the cooling tower is connected to the cooling coil in the circulation tank.

[0015] The system is offline, not directly connected to the etching production line, and the two do not need to run synchronously. It is only connected to the waste liquid bucket, the cathode liquid bucket, and the regenerated liquid bucket.

[0016] Among them, the acidic etching solution with an iron-based additive formulation specifically consists of divalent copper ions, trivalent iron ions, chloride ions, sodium ions, allylthiourea, hydrochloric acid, and water. Among them, the trivalent iron ions are 1 - 50 g / L, the divalent copper is 100 - 160 g / L, the H+ concentration is 1.0 - 5.0 mol / L, the chloride ions are 200 - 400 g / L, the allylthiourea is 1 - 10 g / L, and the rest is water.

[0017] Among them, the electrolytic cell mainly consists of a cell body, a glass cover, an anode membrane frame, an anode plate, a cathode plate, an anode copper bar, a cathode copper bar, and a conductive copper bar; a cathode area liquid inlet interface is provided at the bottom of the electrolytic cell, which can be used as both the inlet and outlet of the cathode liquid. When the equipment needs to be maintained and the cathode liquid inside is drained, a water pump is used to extract the cathode liquid through the cathode area liquid inlet interface; the waste gas in the electrolytic cell passes through the waste gas connection hole, then through the anode overflow tank, and is drawn away from the waste gas discharge port. The waste gas and the anode liquid share one anode overflow tank without affecting each other; the anode membrane frame adopts a U-shaped flow guiding structure. The inside of the anode membrane frame is divided into two chambers by a partition board. The partition board does not reach the bottom and leaves a connection port, enabling the two chambers to communicate. After the anode liquid enters, it first enters the first chamber, and then enters the second chamber through the bottom connection port. As the liquid level rises, the anode liquid rises from the second chamber to the overflow port and flows out, forming a U-shaped flow of the liquid; the newly flowing-in anode liquid has a lower ORP, and the old anode liquid has a higher ORP. The newly flowing-in anode liquid continuously drives away the old anode liquid, stably controlling the ORP of the anode liquid and inhibiting the generation of chlorine; there are 4 cavities inside the electrolytic cell body, all of which are cathode areas, and the cavity inside the anode membrane frame is the anode area. 12 anode membrane frames are installed in the electrolytic cell; the anode membrane frame consists of a frame, an ion exchange membrane, a filter cloth, a clamping plate, a reinforcing bar, bolts, and nuts; the ion exchange membrane is a heterogeneous cation exchange membrane. The clamping plate is made of epoxy resin and is acid and alkali resistant, with a lattice shape; the reinforcing bar is made of titanium and is acid and alkali resistant. When the inside of the anode membrane frame is filled with liquid, the liquid will cause the ion exchange membrane, the filter cloth, and the clamping plate to bulge outwards, and the reinforcing bar is used to reduce the degree of bulging. The filter cloth plays a role in protecting the ion exchange membrane, preventing the ion exchange membrane from being scratched by the cathode plate when the cathode plate is lifted, and also preventing impurities in the cathode liquid from damaging the ion exchange membrane; the inner cavity of the anode membrane frame has good sealing performance, and the anode liquid inside will not leak into the cathode area. The anode area and the cathode area are completely separated; the splash-proof and height-increased part of the anode membrane frame frame is used to prevent the incoming liquid from splashing outside. There is a semi-circular notch on one of the graphite plates in the anode plate, which can reduce the impact force of the incoming liquid; anode membrane frame installation holes and anode membrane frame limiting structures are provided on the inner wall of the electrolytic cell for installing the anode membrane frame; after the anode membrane frame is installed in place, a liquid inlet pipe made of tetrafluoro material is installed on the anode membrane frame liquid inlet joint, and then fastened with a hose clamp. One end of the tetrafluoro pipe is inserted into the liquid inlet hole of the anode membrane frame, so that the anode liquid can be introduced into the anode membrane frame; the anode plate is installed inside the anode membrane frame, and the cathode plate is installed outside the anode membrane frame. The anode liquid in the electrolytic cell is circulated with the anode liquid in the circulation tank through the anode overflow tank interface. The cathode liquid in the electrolytic cell is circulated with the cathode liquid in the circulation tank through the cathode overflow tank interface. Waste gas connection holes are provided on the inner wall of the electrolytic cell, and the waste gas in the tank passes through the waste gas connection holes and is drawn to the acid gas absorption tower from the waste gas discharge port on the outer wall of the electrolytic cell. Limiters are provided at the bottom of the electrolytic cell to limit the anode membrane frame and the cathode plate to ensure the perpendicularity of these two parts.The circulation tank is an important component in the off-line acid etching solution electrolytic copper extraction and regeneration system. It plays a role in connecting various components and circulating liquids among them. The structure of the circulation tank of the present invention is simple and has a high degree of automation. It can automatically add or discharge various liquids according to the set control strategy in cooperation with real-time sampling data.

[0018] Among them, the circulation tank mainly consists of a tank body, a glass lid, a cooling coil, an ORP detection box, a thermometer, a specific gravity sampling box, a specific gravity controller, a chemical addition box, and a liquid level sensor. There are an anode area overflow interface and a cathode area overflow interface outside the tank body, which are used to connect with the electrolytic cell for liquid circulation. Each of the anode area and the cathode area has a glass lid for convenient observation of the internal situation. In order to make the anode liquid and the cathode liquid reach a certain ratio and to increase the strength of the tank body, the inside of the tank body is divided into 1 anode area, 3 cathode areas, and 1 cathode overflow area by a partition. There are flow-through holes at the bottom of the partition between the 3 cathode areas, and the height of the flow-through holes is 300 mm, so that these 3 areas are connected. There is a certain space left at the top of the partition. When the liquid level rises, the liquid in these 3 cathode areas will overflow into the cathode overflow area. When waste liquid is added to the cathode area, the cathode liquid with a low copper ion specific gravity will be driven to the cathode overflow area. After the high liquid level sensor in the cathode overflow area is triggered, the cathode liquid in the cathode overflow area will be discharged into the anode area of the electrolytic cell or the cathode liquid bucket. The anode area has a corresponding exhaust gas port on the outer wall of the circulation tank, which is connected to the acid gas absorption tower for discharging exhaust gas. The anode area has corresponding waste liquid addition interfaces, cathode liquid addition interfaces, anode liquid circulation pump pressure relief interfaces, anode liquid circulation pump interfaces, and anode drain pump interfaces on the outer wall of the circulation tank. The liquid level sensor in the anode area cooperates with the real-time detection of the ORP detection box to control the addition of liquid from the waste liquid bucket to the anode area of the circulation tank and also to control the drainage of the circulation tank to the regeneration liquid bucket. The thermometer is used to detect the anode liquid passing through the ORP detection box. If the temperature is greater than the set value, the cooling tower will be started to circulate cold water in the cooling coil to reduce the temperatures of the electrolytic cell and the tank body of the circulation tank, thereby protecting the tank body from deformation due to excessive temperature. The cathode area controls the addition of waste liquid from the waste liquid bucket to the cathode area of the circulation tank through the real-time detection of the specific gravity sampling box and the control of the specific gravity controller.

[0019] A liquid level sensor is provided in the cathode overflow area to control the discharge of the cathode liquid from the circulation tank to the anode area of the circulation tank or the cathode liquid bucket. The chemical addition box is used to add copper extraction stabilizer to the cathode liquid to improve the adhesion of copper on the cathode plate and the density of copper. The cathode area has corresponding waste liquid addition interfaces, cathode liquid addition interfaces, cathode liquid circulation pump pressure relief interfaces, cathode liquid circulation pump interfaces, and cathode drain pump interfaces on the outer wall of the circulation tank.

[0020] The present invention also proposes a regeneration process implemented according to the above-mentioned off-line acid etching solution electrolytic copper extraction and regeneration system, including the following steps:

[0021] Step 1: The waste liquid barrel transports the acidic etching waste liquid to the circulation tank;

[0022] Step 2: Liquid circulation is carried out between the anodic area of the circulation tank and the anodic area of the electrolytic cell, and liquid circulation is carried out between the cathodic area of the circulation tank and the cathodic area of the electrolytic cell;

[0023] Step 3: Turn on the rectifier to electrolyze the liquid in the electrolytic cell. In the anodic area of the circulation tank, automatic addition of waste liquid is achieved according to the ORP detection value, and automatic discharge is carried out according to the detected liquid level. In the cathodic area of the circulation tank, automatic addition of waste liquid is achieved according to the detected copper ion specific gravity value, and catholyte is automatically discharged according to the detected liquid level;

[0024] Step 4: The regenerated liquid generated in the anodic area of the circulation tank is stored in the regenerated liquid barrel, and copper is produced in the cathodic area of the electrolytic cell.

[0025] Beneficial effects

[0026] The equipment installation is not restricted by the site and does not need to be installed near the etching production line. The equipment layout can be adjusted according to the actual situation of the customer's site;

[0027] The acidic etching solution electrolytic copper extraction and regeneration system is an off-line type and is not directly connected to the etching production line. The two do not need to operate synchronously. It is only connected to the waste liquid barrel, the catholyte barrel, and the regenerated liquid barrel;

[0028] By adding an acidic etching solution with an iron-based additive formula, controlling the ORP value of the anolyte < 750, and a specially designed U-shaped anode membrane frame diversion structure, the generation of chlorine gas during the electrolysis process is effectively inhibited, and there is no need for a chlorine gas absorption device to generate chlorine gas absorption wastewater;

[0029] High degree of automation and simple system operation. Description of the drawings

[0030] Figure 1 Architecture diagram of the off-line type acidic etching solution electrolytic copper extraction and regeneration system of the present invention;

[0031] Figure 2 Appearance structure of the electrolytic cell of the present invention, angle 1;

[0032] Figure 3 Appearance structure of the electrolytic cell of the present invention, angle 2;

[0033] Figure 4 Main body structure of the electrolytic cell of the present invention, angle 1;

[0034] Figure 5 Main body structure of the electrolytic cell of the present invention, angle 2;

[0035] Figure 6 Top view of the main body structure of the electrolytic cell of the present invention;

[0036] Figure 7 Bottom structure of the main body of the electrolytic cell of the present invention;

[0037] Figure 8 Internal structure of the electrolytic cell of the present invention;

[0038] Figure 9 Exploded view of the anode membrane frame of the present invention;

[0039] Figure 10 Disassembly diagram of the frame of the anode membrane frame of the present invention;

[0040] Figure 11 Appearance of the finished product of the anode membrane frame of the present invention;

[0041] Figure 12 Installation of the anode membrane frame of the present invention onto the electrolytic cell;

[0042] Figure 13 Installation of the liquid inlet pipe of the anode membrane frame of the present invention;

[0043] Figure 14 Cross-sectional view of the electrolytic cell of the present invention;

[0044] Figure 15 State of the electrolytic cell of the present invention with the anode plate and cathode plate placed;

[0045] Figure 16 Top view of the electrolytic cell of the present invention;

[0046] Figure 17 Perspective view of the circulation tank of the present invention - Angle 1;

[0047] Figure 18 Perspective view of the circulation tank of the present invention - Angle 2;

[0048] Figure 19 Top cross-sectional view of the circulation tank of the present invention;

[0049] Figure 20 Internal structure of the circulation tank of the present invention;

[0050] Figure 21 Offline acidic etching solution electrolytic copper extraction and regeneration process flow;

[0051] In the figure: electrolytic cell 1, circulation tank 2, waste liquid barrel 3, cathode liquid barrel 4, regenerated liquid barrel 5, acid gas absorption tower 6, cooling tower 7, rectifier 8, etching production line 9, offline acidic etching solution electrolytic copper extraction and regeneration system 10.

[0052] Electrolyzer 1 part: Glass cover 101, Conductive copper busbar 102, Valve 103, Electrolyzer cell body 104, Adjustable feet 105, Anode area inlet main pipe 106, Cathode overflow tank interface 107, Anode overflow tank interface 108, Cathode copper busbar 109, Exhaust gas discharge port 110, Anode copper busbar 111, Cathode area inlet interface 112, Anode membrane frame limit structure 113, Inlet joint 114, Cathode area overflow port 115, Mounting hole 116, Exhaust gas connection hole 117, Cathode area inlet hole 118, Cathode area 119, Cathode area inlet common channel 120, Anode overflow tank 121, Cathode overflow tank 122, Anode membrane frame 123, Anode area 124, Frame 125, Ion exchange membrane 126, Filter cloth 127, Clamping plate 128, Nut 129, Reinforcing strip 130, Bolt 131, Hose clamp 132, Inlet pipe 133, Anode plate 134, Cathode plate 135, Anode inlet branch pipe 136, Partition board 137, Limiting part 138, Bolt 139, Anode area inlet interface 140.

[0053] Anode membrane frame 123 part: Overflow port 125-1, Partition board 125-2, Splash-proof raised part 125-3, Inlet hole 125-4, Inlet side mounting part 125-5, Flow port 125-6, Outlet part mounting bayonet 125-7, First chamber 125-8, Second chamber 125-9.

[0054] Circulation tank 2 part: Exhaust gas port 201, ORP detection box 202, Thermometer 203, Specific gravity sampling box 204, Chemical dosing box 205, Specific gravity controller 206, Ultra-low liquid level sensor 207, Low liquid level sensor 208, High liquid level sensor 209, Ultra-high liquid level sensor 210, Cathode area cover 211, Tank body 212, Anode area cover 213, Anode area overflow interface 214, Cathode area overflow interface 215, Cathode drain pump interface 216, Cathode area waste liquid addition interface 217, Cathode liquid circulation pump interface 218, Cathode area cathode liquid addition interface 219, Anode liquid circulation pressure relief interface 220, Anode area waste liquid addition interface 221, Anode area cathode liquid addition interface 222, Cathode liquid circulation pressure relief interface 223, Cooling coil inlet 224, Cooling pipe inlet 225, Anode drain pump interface 226, Anode liquid circulation pump interface 227, Cathode drain pipe 228, Cathode drain pipe 229, Anode drain pipe 230, Cathode drain pipe 231, Anode area 232, Cathode area 233, Cathode overflow area 234, Cooling coil 235, Cathode area bottom flow port 236, Cathode area overflow part 237, Adjustable feet 238. Specific embodiments

[0055] The following specific embodiments illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0056] As Figure 1 , the offline acidic etching solution electrolytic copper extraction and regeneration system 10 includes an electrolytic cell 1, a circulation tank 2, a waste liquid barrel 3, a cathode liquid barrel 4, a regeneration liquid barrel 5, an acid gas absorption tower 6, a cooling tower 7, and a rectifier 8.

[0057] An anode area 124 and a cathode area 119 are provided inside the electrolytic cell 1.

[0058] An anode area 232 and a cathode area 233 are provided inside the circulation tank 2.

[0059] The anode area 124 of the electrolytic cell 1 is communicated with the anode area 232 of the circulation tank 2, and the cathode area 119 of the electrolytic cell 1 is communicated with the cathode area 233 of the circulation tank 2.

[0060] The anode area 232 of the circulation tank 2 is communicated with the waste liquid barrel 3, the cathode liquid barrel 4, and the regeneration liquid barrel 5.

[0061] The cathode area 233 of the circulation tank 2 is communicated with the waste liquid barrel 3 and the cathode liquid barrel 4.

[0062] The electrolytic cell 1 is communicated with the acid gas absorption tower 6, and the anode area 232 of the circulation tank 2 is communicated with the acid gas absorption tower 6.

[0063] The etching production line 7 is communicated with the waste liquid barrel 3 and the regeneration liquid barrel 5.

[0064] The positive pole of the rectifier is connected to the anode copper bar 111, and the negative pole of the rectifier is connected to the anode copper bar 109 of the electrolytic cell.

[0065] The inlet and outlet of the cold area tower are connected to the inlet and outlet of the cooling coil 235.

[0066] The detailed description of the electrolytic cell 1 is as follows:

[0067] The electrolytic cell 1 is mainly composed of a cell body 104, a glass cover 101, an anode membrane frame 123, an anode plate 134, a cathode plate 135, an anode copper bar 111, a cathode copper bar 109, and a conductive copper bar 102.

[0068] As Figure 6 , there are 4 cavities inside the cell body 104, all of which are cathode areas 119. As Figure 14 , the cavity inside the anode membrane frame 123 is the anode area 124. As Figure 16 , 12 anode membrane frames 123 are installed inside the electrolytic cell.

[0069] As Figure 2 , Figure 3, the electrolytic cell 1 has a total of 2 anodic overflow tank interfaces 108 and 2 cathodic overflow tank interfaces 107. When there is 1 electrolytic cell 1 in an off-line acidic etching solution electrolytic copper extraction and regeneration system 10, 1 anodic overflow tank interface 108 is connected to the anodic area overflow interface 214 of the circulation tank 2, and the cathodic overflow tank interface 107 on the same side is connected to the cathodic area overflow interface 215 of the circulation tank 2. The anodic overflow tank interface 108 and the cathodic overflow tank interface 107 on the other side of the electrolytic cell 1 are blocked with flange blind plates. When there are multiple electrolytic cells 1 in an off-line acidic etching solution electrolytic copper extraction and regeneration system 10, the multiple electrolytic cells 1 are connected in series, the anodic overflow tank interfaces 108 of different electrolytic cells 1 are connected to each other, and the cathodic overflow tank interfaces 107 are connected to each other. The anodic overflow tank interface 108 and the cathodic overflow tank interface 107 at the end are blocked with flange blind plates.

[0070] As Figure 9 , it is an explosion diagram of the anodic membrane frame 123, which is composed of a frame 125, an ion membrane 126, a filter cloth 127, a clamping plate 128, a nut 129, a reinforcing bar 130, a bolt 131, and a bolt 139. During assembly, first stack the ion membrane 126, the filter cloth 127, and the clamping plate 128 on the frame 125, and fasten them with the bolt 139 and the nut 129. Then clamp the reinforcing bars 130 on both the front and back sides with the nut 129 and the bolt 131 to clamp the frame 125 for locking. The finished product is as Figure 11 .

[0071] As Figure 4 , a limit structure 113 for the anodic membrane frame is provided on the inner wall of the electrolytic cell 1, and the installation part 125-5 on the liquid inlet side of the anodic membrane frame is placed thereon to play a limiting role. As Figure 5 , an installation hole 116 is provided on the inner wall of the electrolytic cell 1, and the installation bayonet 125-7 at the liquid outlet part of the anodic membrane frame is buckled thereon to play a limiting role. As Figure 12 , install the anodic membrane frame 123 into the electrolytic cell 1.

[0072] As Figure 6 、 Figure 8 , the limiting member 138 is used to guide and limit the anodic membrane frame 123 and the cathodic plate 135.

[0073] As Figure 13 , install the anodic area inlet pipe 133 onto the inlet joint 114, tighten the hose clamp 132, and place the other end of the anodic area inlet pipe 133 into the anodic membrane frame inlet hole 125-4. Figure 14 , when the anodic liquid is discharged from the anodic area inlet pipe 133, the anodic liquid impacts the anti-splash notch 134-6, and the anti-splash notch 134-6 alleviates the impact force of the anodic liquid, reducing splashing. The anti-splash raised part 123-3 prevents the liquid from splashing to the outside.

[0074] When the anode membrane frame 123 needs to be removed, first loosen the hose clamp 132, then pull out the anode area inlet pipe 133 from the inlet joint 114, and then take out the anode membrane frame 123.

[0075] The flow process of the anolyte in the electrolytic cell 1 is as Figure 2 , Figure 14 , the anolyte transported from the circulation tank 2 enters the main anolyte inlet pipe 106 through the anolyte inlet interface 140 in the anode area, and then flows through 12 anode inlet branch pipes 136 to the inlet joint 114 and into the anode membrane frame 123. The anolyte first enters the first chamber 125-8, then enters the second chamber 125-9 through the flow port 125-6, then overflows from the overflow port 125-1 to the anode overflow tank 121, and then flows through the anode overflow tank interface 108 to the anode area 232 of the circulation tank 2. Among them, the valve 103 is used to control the flow rate of the anolyte to ensure that the flow rates of the anolytes coming out of the 12 inlet joints 114 are uniform.

[0076] The flow process of the catholyte in the electrolytic cell 1 is as Figure 3 , Figure 14 , after the catholyte comes from the circulation tank 2, it flows into the common catholyte inlet passage 120 through the catholyte inlet interface 112, and then enters the cathode area 119 of the electrolytic cell 1 through the catholyte inlet hole 118. As Figure 8 , after the level of the catholyte rises, it overflows from the cathode area overflow port 115 to the cathode overflow tank 122, and then flows through the cathode overflow tank interface 107 to the cathode area 233 of the circulation tank 2.

[0077] An exhaust gas discharge port 110 is provided on the wall of the electrolytic cell 1, which is connected to the acid gas absorption tower 6. The exhaust gas in the electrolytic cell 1 enters the anode overflow tank 121 through the exhaust gas communication hole 117 and is then sucked away from the exhaust gas discharge port 110.

[0078] Adjustable feet 105 are installed at the bottom of the electrolytic cell 1 to enable the electrolytic cell 1 to adapt to the uneven ground.

[0079] The detailed description of the circulation tank 2 is as follows:

[0080] As Figure 17 , Figure 18 , Figure 19 , the circulation tank 2 mainly consists of a tank body 212, an anode area cover 213, a cathode area cover 211, an ORP detection box 202, a thermometer 203, a specific gravity sampling box 204, a chemical dosing box 205, a specific gravity controller 206, an ultra-low liquid level sensor 207, a low liquid level sensor 208, a high liquid level sensor 209, an ultra-high liquid level sensor 210, and a cooling coil 235.

[0081] As Figure 17 ​, an anode area overflow interface 214 is provided on the groove wall for connecting to the anode overflow tank interface 108 of the electrolytic cell 1. A cathode area overflow interface 215 is provided for connecting to the cathode overflow tank interface 107 of the electrolytic cell 1. The anode area cover 213 is used to observe the situation in the anode area, and the cathode area cover 211 is used to observe the situation in the cathode area. Adjustable feet 238 are installed at the bottom of the circulation tank 2 to enable the circulation tank 2 to adapt to the uneven ground.

[0082] Such as Figure 19 , Figure 20 , the interior of the circulation tank 2 is designed into 5 compartments, 1 anode area 232, 3 cathode areas 233, and 1 cathode overflow area 234. Such as Figure 21 , a bottom flow port 236 is provided below the partition of the cathode area 233 to connect the cathode liquids in the 3 cathode areas 233 into one body. The cathode area overflow part 237 has a certain sinking height. When the liquid level of the cathode liquid in the cathode area 233 rises to the highest point, it will overflow into the cathode overflow area 234.

[0083] Such as Figure 18 , an exhaust gas port 201, which is connected to the acid gas absorption tower 6 for discharging exhaust gas. A cathode liquid addition interface 222 is used to add cathode liquid from the cathode drain pump interface 216 or the cathode liquid bucket 4. A waste liquid addition interface 221 enables the waste liquid bucket 3 to add waste liquid to the anode area of the circulation tank 2. The anode drain pump interface 226 is connected to a magnetic pump, and the outlet of the magnetic pump will be connected to the waste liquid bucket 3 and the regenerated liquid bucket 5 by pipes. The anode liquid circulation pump interface 227 is connected to a magnetic pump, and the outlet of the magnetic pump will be connected to the anode area inlet interface 140 of the electrolytic cell 1 by a pipe, and a branch will be provided on the outlet pipe of the magnetic pump to the anode liquid circulation pump pressure relief interface 220. The ORP detection box 202 is used to detect the ORP value of the anode liquid, and there is a thermometer 203 in it for detecting the temperature of the anode liquid passing through the ORP detection box. When the detected temperature is higher than the set value, the cooling tower 7 will be started to circulate the cooling water in the cooling coil 235. The specific gravity sampling box 204 is used to detect the copper ion specific gravity of the cathode liquid. The dosing box 205 is used to add copper extraction stabilizer to the cathode liquid during the operation of the rectifier. The cathode liquid circulation pump interface 218 is connected to a magnetic pump, and the outlet of the magnetic pump will be connected to the cathode area inlet interface 112 of the electrolytic cell 1 by a pipe, and a branch will be provided on the outlet pipe of the magnetic pump to the cathode liquid circulation pump pressure relief interface 223. The cathode drain pump interface 216 is connected to a magnetic pump, and the outlet of the magnetic pump will be connected to the cathode liquid addition interface 222 or the cathode liquid bucket 4 by a pipe. The cathode area waste liquid addition interface 217 enables the waste liquid bucket 3 to add waste liquid to the cathode area of the circulation tank 2. The cathode liquid addition interface 219 enables the cathode liquid bucket 4 to add cathode liquid to the cathode area of the circulation tank 2. The cooling coil inlet 224 and the cooling pipe inlet 225 are used to connect the inlet and outlet pipelines of the cooling tower.

[0084] Process Flow of Anode Region of Recirculation Tank

[0085] Example 1, as follows Figure 21 , the waste liquid barrel 3 adds waste liquid to the anode region 232 of the recirculation tank 2, and at the same time, the anolyte of the recirculation tank 2 and the anolyte of the electrolytic cell 1 are circulated.

[0086] Case 1, when the high-level sensor 209 of the anode region 232 of the recirculation tank 2 is triggered and the ORP detection box 202 detects that the ORP value of the anolyte > 600 mV, control the waste liquid barrel 3 to stop adding waste liquid.

[0087] Case 2, when the low-level sensor 208 of the anode region 232 of the recirculation tank 2 is triggered and the ORP detection box 202 detects that the ORP value of the anolyte > 600 mV, control the waste liquid barrel 3 to add waste liquid to the anode region 232 of the recirculation tank 2.

[0088] Case 3, when the high-level sensor 209 of the anode region 232 of the recirculation tank 2 is triggered and the ORP detection box 202 detects that the ORP value of the anolyte > 700 mV, control the recirculation tank 2 to discharge the regenerated liquid to the regenerated liquid barrel 5.

[0089] Example 2 has one more catholyte barrel 4 than Example 1. The specific content is as follows.

[0090] as follows Figure 21 , the waste liquid barrel 3 adds waste liquid to the anode region 232 of the recirculation tank 2, and the catholyte barrel 4 adds catholyte to the anode region 232 of the recirculation tank 2. At the same time, the anolyte of the recirculation tank 2 and the anolyte of the electrolytic cell 1 are circulated.

[0091] Case 1, when the high-level sensor 209 of the anode region 232 of the recirculation tank 2 is triggered and the ORP detection box 202 detects that the ORP value of the anolyte > 600 mV, control the waste liquid barrel 3 to stop adding waste liquid and the catholyte barrel 4 to stop adding catholyte.

[0092] Case 2, when the low-level sensor 208 of the anode region 232 of the recirculation tank 2 is triggered and the ORP detection box 202 detects that the ORP value of the anolyte > 600 mV, control the waste liquid barrel 3 to add waste liquid to the anode region 232 of the recirculation tank 2 and the catholyte barrel 4 to add catholyte to the anode region 232 of the recirculation tank 2.

[0093] Case 3, when the high-level sensor 209 of the anode region 232 of the recirculation tank 2 is triggered and the ORP detection box 202 detects that the ORP value of the anolyte > 700 mV, control the recirculation tank 2 to discharge the regenerated liquid to the regenerated liquid barrel 5.

[0094] Process Flow of Cathode Region of Recirculation Tank

[0095] Example 1, as follows Figure 21, The waste liquid bucket 3 adds waste liquid to the cathode area 233 of the circulation tank 2. At the same time, the cathode liquid of the circulation tank 2 and the cathode liquid of the electrolytic cell 1 are circulated.

[0096] Case 1, when the copper ion specific gravity detected by the specific gravity sampling box 204 < the set value, control the waste liquid bucket 3 to add waste liquid to the cathode area 233 of the circulation tank 2.

[0097] Case 2, when the copper ion specific gravity detected by the specific gravity sampling box 204 > the set value, control the waste liquid bucket 3 to stop adding waste liquid to the cathode area 233 of the circulation tank 2

[0098] Case 3, when the high liquid level sensor 209 in the cathode overflow area 234 is triggered, through valve control, discharge the cathode liquid of the circulation tank 2 to the anode area 232 of the circulation tank 2.

[0099] Case 4, when the low liquid level sensor 208 in the cathode overflow area 234 is triggered, control the circulation tank 2 to stop discharging the cathode liquid.

[0100] After the liquid circulation of the electrolytic cell 1 and the circulation tank 2 is stable, turn on the rectifier for electrolysis. After 40 - 80 hours, turn off the rectifier, and a certain thickness of copper grows on the surface of the titanium plate 135 - 3 of the cathode plate 135.

[0101] Example 2 has one more cathode liquid bucket 4 than Example 1. The specific content is as follows.

[0102] Such as Figure 21 , The waste liquid bucket 3 adds waste liquid to the cathode area 233 of the circulation tank 2. At the same time, the cathode liquid of the circulation tank 2 and the cathode liquid of the electrolytic cell 1 are circulated.

[0103] Case 1, when the copper ion specific gravity detected by the specific gravity sampling box 204 < the set value, control the waste liquid bucket 3 to add waste liquid to the cathode area 233 of the circulation tank 2.

[0104] Case 2, when the copper ion specific gravity detected by the specific gravity sampling box 204 > the set value, control the waste liquid bucket 3 to stop adding waste liquid to the cathode area 233 of the circulation tank 2

[0105] Case 3, when the high liquid level sensor 209 in the cathode overflow area 234 is triggered, through valve control, discharge the cathode liquid of the circulation tank 2 to the cathode liquid bucket 4.

[0106] Case 4, when the low liquid level sensor 208 in the cathode overflow area 234 is triggered, control the circulation tank 2 to stop discharging the cathode liquid.

[0107] After the liquid circulation of the electrolytic cell 1 and the circulation tank 2 is stable, turn on the rectifier for electrolysis. After 40 - 80 hours, turn off the rectifier, and a certain thickness of copper grows on the surface of the titanium plate 135 - 3 of the cathode plate 135.

[0108] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An offline acidic etching solution electrolytic copper extraction and regeneration system, characterized in that, The offline acidic etchant electrolytic copper extraction and regeneration system is used to treat the acidic etchant waste liquid with an iron-based additive formulation. The offline acidic etchant electrolytic copper extraction and regeneration system includes an electrolytic cell (1), a circulation tank (2), a waste liquid barrel (3), a catholyte barrel (4), a regenerated liquid barrel (5), an acid gas absorption tower (6), a rectifier (8), and a cooling tower (7); an anode area and a cathode area are provided in the electrolytic cell (1). The anode area of the electrolytic cell (1) adopts a U-shaped diversion structure anode membrane frame. An anode area and a cathode area are provided in the circulation tank (2). The anode area of the electrolytic cell (1) is communicated with the anode area of the circulation tank (2), and the cathode area of the electrolytic cell (1) is communicated with the cathode area of the circulation tank (2). The anode area of the circulation tank (2) is communicated with the waste liquid barrel (3), the catholyte barrel (4), and the regenerated liquid barrel (5). The cathode area of the circulation tank (2) is communicated with the waste liquid barrel (3) and the catholyte barrel (4). The anode areas of the electrolytic cell (1) and the circulation tank (2) are communicated with the acid gas absorption tower (6). The etching production line (9) is communicated with the waste liquid barrel (3) and the regenerated liquid barrel (5). The rectifier (8) is connected to the cathode copper busbar and the anode copper busbar of the electrolytic cell (1). The cooling tower (7) is connected to the cooling coil in the circulation tank (2); The electrolytic cell includes a cell body, a glass cover, an anode membrane frame, an anode plate, a cathode plate, an anode copper busbar, a cathode copper busbar, and a conductive copper busbar; there are 4 cavities inside the cell body, all of which are cathode areas. The cavity inside the anode membrane frame is the anode area. An anode membrane frame mounting hole and an anode membrane frame limiting structure are provided on the inner wall of the electrolytic cell for installing the anode membrane frame. The anode plate is installed inside the anode membrane frame, and the cathode plate is installed outside the anode membrane frame; 12 anode membrane frames are installed in the electrolytic cell; the inside of the anode membrane frame is separated into 2 chambers by a partition. The partition does not reach the bottom and leaves a communication port so that the 2 chambers can communicate. After the anolyte enters, it first enters the first chamber, and then enters the second chamber from the bottom communication port. As the liquid level rises, the anolyte rises from the second chamber to the overflow port and flows out. The flow of the liquid forms a U shape.

2. The offline acidic etchant electrolytic copper extraction and regeneration system according to claim 1, wherein The acidic etchant with an iron-based additive formulation specifically consists of divalent copper ions, trivalent iron ions, chloride ions, sodium ions, allylthiourea, hydrochloric acid, and water. Among them, the trivalent iron ions are 1 - 50 g / L, the divalent copper is 100 - 160 g / L, the H+ concentration is 1.0 - 5.0 mol / L, the chloride ions are 200 - 400 g / L, the allylthiourea is 1 - 10 g / L, and the rest is water.

3. The offline acidic etchant electrolytic copper extraction and regeneration system according to claim 1, characterized in that, The system is of the offline type and is not directly connected to the etching production line and has no relationship with it. The two do not need to operate synchronously. It only has a connection relationship with the waste liquid barrel, the catholyte barrel, and the regenerated liquid barrel.

4. The offline acidic etching solution electrolytic copper extraction and regeneration system according to claim 1, wherein The waste gas in the electrolytic cell passes through the waste gas communication hole, passes through the anode overflow tank, and is then drawn to the acid gas absorption tower from the waste gas discharge port. The waste gas and the anolyte share an anode overflow tank and do not affect each other.

5. The offline acidic etchant electrolytic copper extraction and regeneration system according to claim 1, wherein A cathode area liquid inlet interface is provided at the bottom of the electrolytic cell, serving as the inlet and outlet of the catholyte.

6. The offline acidic etching solution electrolytic copper extraction and regeneration system according to claim 1, wherein The anode membrane frame is composed of a frame, an ion membrane, filter cloth, a clamping plate, a reinforcing bar, bolts, and nuts. The ion membrane is a heterogeneous cation exchange membrane. The clamping plate is made of epoxy resin and is acid and alkali resistant, with a lattice shape. The reinforcing bar is made of titanium and is acid and alkali resistant. When the inside of the anode membrane frame is filled with liquid, the liquid will cause the ion membrane, filter cloth, and clamping plate to bulge outwards, and the reinforcing bar is used to reduce the degree of bulging.

7. The offline acidic etching solution electrolytic copper extraction and regeneration system according to claim 1, characterized in that, The anolyte in the electrolytic cell is circulated with the anolyte in the circulation tank through the anolyte overflow tank interface, and the catholyte in the electrolytic cell is circulated with the catholyte in the circulation tank through the catholyte overflow tank interface.

8. The offline acidic etching solution electrolytic copper extraction and regeneration system according to claim 1, wherein The circulation tank includes a tank body, a glass cover, a cooling coil, an ORP detection box, a thermometer, a specific gravity sampling box, a specific gravity controller, a chemical addition box, and a liquid level sensor. There are an anode area overflow interface and a cathode area overflow interface outside the tank body for connecting with the electrolytic cell to conduct liquid circulation.

9. The offline acidic etchant electrolytic copper extraction and regeneration system according to claim 8, wherein, The inside of the tank body of the circulation tank is divided into 1 anode area, 3 cathode areas, and 1 cathode overflow area by partitions. There are flow holes at the bottom of the partitions between the 3 cathode areas, and the height of the flow holes is 300 mm to connect these 3 areas. There is a certain space left at the top of the partitions. When the liquid level rises, the liquid in these 3 cathode areas will overflow into the cathode overflow area. When waste liquid is added to the cathode area, the catholyte with a low copper ion specific gravity will be driven to the cathode overflow area. After the high liquid level sensor in the cathode overflow area is triggered, the catholyte in the cathode overflow area will be discharged into the anode area of the electrolytic cell or the catholyte bucket. The anode area has a corresponding exhaust gas port on the outer wall of the circulation tank, which is connected to an acid gas absorption tower for discharging exhaust gas. The anode area has corresponding waste liquid addition interfaces, catholyte addition interfaces, anolyte circulation pump pressure relief interfaces, anolyte circulation pump interfaces, and anolyte drainage pump interfaces on the outer wall of the circulation tank. The cathode area has corresponding waste liquid addition interfaces, catholyte addition interfaces, catholyte circulation pump pressure relief interfaces, catholyte circulation pump interfaces, and catholyte drainage pump interfaces on the outer wall of the circulation tank.

10. The offline acidic etching solution electrolytic copper extraction and regeneration system according to claim 9, characterized in that, The liquid level sensor in the anode area cooperates with the real-time detection of the ORP detection box to control the addition of liquid from the waste liquid bucket to the anode area of the circulation tank and also control the drainage of the circulation tank to the regeneration liquid bucket. The thermometer is used to detect the anolyte passing through the ORP detection box. If the temperature is greater than the set value, the cooling tower will be started to circulate cold water in the cooling coil to reduce the temperatures of the electrolytic cell and the tank body of the circulation tank, thereby protecting the tank body from deformation due to excessive temperature. The cathode area controls the addition of waste liquid from the waste liquid bucket to the cathode area of the circulation tank through the real-time detection of the specific gravity sampling box and the control of the specific gravity controller. There is a liquid level sensor in the cathode overflow area to control the discharge of the catholyte from the circulation tank to the anode area of the circulation tank or the catholyte bucket. The chemical addition box is used to add copper extraction stabilizer to the catholyte to improve the adhesion of copper on the cathode plate and the density of copper.

11. The regeneration process implemented by the offline acidic etching solution electrolytic copper extraction and regeneration system according to any one of claims 1-10, characterized in that, It includes the following steps: Step 1: The waste liquid bucket transports the acidic etching waste liquid containing an iron-based additive formula to the circulation tank. Step 2: Liquid circulation is carried out between the anode area of the circulation tank and the anode area of the electrolytic cell, and liquid circulation is carried out between the cathode area of the circulation tank and the cathode area of the electrolytic cell. Step 3: Turn on the rectifier to electrolyze the liquid in the electrolytic cell. In the anodic area of the circulation tank, waste liquid is automatically added according to the ORP detection value and automatically discharged according to the detected liquid level. In the cathodic area of the circulation tank, waste liquid is automatically added according to the detected copper ion specific gravity value, and the catholyte is automatically discharged according to the detected liquid level. Step 4: The regenerated liquid generated in the anodic area of the circulation tank is stored in the regenerated liquid barrel, and copper is produced in the cathodic area of the electrolytic cell.

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