Method and device for recycling and regenerating acidic copper chloride etching waste liquid by using composite electrolytic cell

Abstract

The invention discloses a method for recycling and regenerating acidic copper chloride etching waste liquid by using a composite electrolytic bath, which comprises the following steps: (1) the composite electrolytic bath is adopted, the inner part of the composite electrolytic bath is divided into an anode bath area, a middle bath area and a cathode bath area, and the middle bath area is arranged between the anode bath area and the cathode bath area; (2) a middle anode tank area is specially used for oxidizing and regenerating the copper etching agent, and a solution obtained by mixing the waste etching solution (1), the waste etching solution (2) and water and / or other electrolytes, a solution obtained by carrying out electrochemical reaction on the solution (1) and a solution obtained by carrying out electrochemical reaction on the solution (2) are adopted; at least one of the four solutions serves as an electrolyte of the middle tank area, copper ions are supplemented and conveyed to the cathode tank area, and the copper ions are electrically separated into copper; according to the invention, the problem that the electrodeposited copper is back-etched is solved, and the recycling rate of chlorine elements in the etching working solution and / or the waste solution is increased. The invention also discloses a device for recycling and regenerating the acidic copper chloride etching waste liquid by using the composite electrolytic cell.

Description

A method and device for recycling and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell Technical Field

[0001] The invention belongs to the technical field of electrolytic recovery of circuit board etching waste liquid, and particularly relates to a method and device for recovering and regenerating acidic copper chloride etching waste liquid by using a composite electrolytic cell. Background Art

[0002] In the circuit board manufacturing industry, the acid copper chloride etching process is widely used. The main components of the acid copper chloride etching solution are hydrochloric acid and copper chloride, with copper chloride acting as the copper etching agent. Furthermore, ammonium chloride and / or other chloride salt additives are often added to the acid copper chloride etching solution to improve etching performance.

[0003] During the etching process using the acidic copper chloride etching process, the copper etchant copper chloride reacts with metallic copper and is consumed. To maintain the etching solution's copper-etching capacity, hydrochloric acid, an oxidizing agent, and optional additives are added to the etching solution on the etching line as replenishers. Consequently, as etching progresses, the volume of the etching solution on the etching line increases. The industry generally refers to the etching solution on the etching line as the etching working solution, and the replenisher as the etching sub-solution. The solution that overflows from the etching machine due to the increased volume of the etching working solution is called etching waste solution, and the etching replenisher, which is regenerated from the etching waste solution after copper extraction, is called regenerated etching sub-solution.

[0004] The chemical reaction of acidic copper chloride etching copper is as follows: Cu+CuCl2→2CuCl.

[0005] As can be seen from the above formula, the copper etchant, cupric chloride, reacts with metallic copper to form cuprous chloride, converting the copper ion from divalent to monovalent. Cuprous chloride is a slightly soluble copper salt in water. However, because the acidic cupric chloride etching solution contains hydrochloric acid, a small amount of cuprous chloride can remain in the solution as cuprous chloride H₃[CuCl₄]. When the concentration of monovalent copper ions in the etching solution reaches 4g / L, it significantly affects the etching process. Therefore, the concentration of monovalent copper ions in the acidic cupric chloride etching solution is typically controlled to no more than 2g / L. Therefore, the existing etching process requires the addition of an oxidizing agent to regenerate cuprous chloride into the copper etchant. The chemical reaction equation is as follows: 2CuCl + 2HCl + [O] → 2CuCl₂ + H₂O. In addition, the redox potential of the etching solution is typically controlled to be ≥ 510mV.

[0006] The industry generally controls the copper ion concentration of acidic copper chloride etching solutions at 100-180g / L. If copper can be recovered from the etching wastewater and the remaining solution can be prepared as a replenisher for recycling back into the etching process, this would both address environmental concerns and improve efficiency. The replenisher, prepared using the remaining solution after copper recovery from the etching wastewater, is also known as the regeneration solution, or regenerated etching solution. The concentration requirements for the replenishing components required for the etching solution in the regenerated etching solution are the same as for conventional replenishers.

[0007] Currently, there are two common processes in the industry for electrolyzing copper from acidic copper chloride etching wastewater.

[0008] The first method uses a separator to separate the electrolytic cell into two compartments: an anode compartment and a cathode compartment. The separator allows copper ions to pass through while effectively blocking chloride ions. Etching wastewater is directly added to the anode compartment of the electrolytic cell as the anolyte. During the electrolysis process, the copper ions in the anolyte pass through the separator and enter the cathode compartment, where they are electrolytically deposited to form a flat copper plate. The large amount of chlorine gas electrolytically deposited at the anode is then diverted to the reaction tank to oxidize and regenerate the etching solution.

[0009] The second method uses a separator to separate the electrolytic cell into two compartments: an anode compartment and a cathode compartment. The separator allows chloride ions to pass through but effectively blocks copper ions. The etching solution is directly or indirectly directed to the anode compartment of the electrolytic cell for electrolytic oxidation, while the waste etching solution is directed to the cathode compartment of the electrolytic cell to electrolyze copper.

[0010] The electrolytic cell and etching production line of the first process described above operate independently. During the electrolysis process, copper ions in the anode tank area continuously cross the separator and enter the cathode tank area, causing the copper ion concentration of the anolyte to continuously decrease. If the anolyte is directly returned to the etching production line for use, it will affect the stability of the component concentration of the etching working solution. Therefore, the etching waste liquid is put into the anode tank area for whole-tank electrolysis. The copper ions that are electrolyzed as metallic copper in the cathode tank area come from the anode tank area, so the catholyte contains little or no copper etching agent. Therefore, the advantage of this process is that the copper plate electrolyzed on the cathode is flat and dense. Even copper leveling agents (i.e., brighteners) can be added to the catholyte to make the electrolyzed copper more solid. However, because the monovalent copper ions from the etching working solution in the anolyte are quickly and completely oxidized, the lack of monovalent copper ions leads to the electrolysis of a large amount of chlorine gas at the anode. Because the etching solution contains high concentrations of hydrochloric acid and chloride salts but only trace amounts of the reducing agent cuprous chloride, it cannot absorb all of the electrolytically deposited chlorine gas. Therefore, sodium hydroxide or ferrous chloride must be used outside the etching system to absorb the remaining chlorine gas, producing hazardous chemicals such as sodium hypochlorite or ferric chloride that far exceed the company's required usage. Both sodium hypochlorite and ferric chloride are classified as hazardous chemicals under national key monitoring, requiring only chemical companies with hazardous chemical production licenses to produce them. Any excess sodium hypochlorite or ferric chloride beyond the factory's internal usage cannot be sold or transferred outside the factory without authorization; otherwise, it constitutes illegal production. This process fails to recycle the chlorine in the original etching wastewater. Therefore, not only does the etching process require the addition of hydrochloric acid but also an oxidant to assist in oxidation, increasing the amount of etching wastewater and making 100% recycling difficult. Furthermore, if the etching wastewater contains ammonium chloride, there is a risk of the generation and accumulation of explosive nitrogen trichloride in the anolyte.

[0011] The second process uses a combined servo system for copper dissolution and electrolytic copper extraction. The etching solution enters the anode tank area to undergo an oxidation reaction of cuprous chloride. During the electrolysis process, the redox potential of the etching solution controls the operating conditions of the electrolytic cell. Adding an etching solution containing monovalent copper ions to the anode tank area controls the redox potential of the anolyte within a set range, thereby preventing chlorine from escaping and allowing the chlorine element in the original etching waste liquid to be recycled in the etching system. However, its disadvantage is that the etching waste liquid is directly or indirectly fed to the cathode tank area of ​​the electrolytic cell, thereby introducing a copper etchant into the catholyte. This results in the electrolyzed copper blocks being loose and easily broken due to the etching waste liquid, making them difficult to collect. Furthermore, the catholyte after copper electrolysis needs to be reused in etching production. Adding a copper leveler to the catholyte can affect the etching rate and etching quality during reuse.

[0012] In summary, the existing electrolysis process for acid copper chloride etching waste liquid is difficult to simultaneously achieve the recycling of chlorine and prevent the electrolytic copper from being corroded. In order to solve the multiple process problems existing in the existing electrolysis of copper from acid copper chloride etching waste liquid, circuit board manufacturers are looking forward to the launch of a new electrolytic copper regeneration process and equipment that can not only recycle the chlorine in the etching waste liquid in the etching system, but also electrolyze and produce copper plates with smooth and clean surfaces.

[0013] Summary of the Invention

[0014] A first object of the present invention is to provide a method for recovering and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell. The method addresses the problems existing in the prior art when electrolyzing copper from acidic copper chloride etching waste liquid. The anode tank area in the electrolytic cell is dedicated to oxidizing and regenerating the copper etching agent, and auxiliary facilities are added to supplement and transport copper ions to the cathode tank area, thereby solving the problem of electrolytic copper being etched back, improving the recycling rate of chlorine elements in the etching working solution and / or waste liquid, and achieving the purpose of reducing pollution and improving economic benefits.

[0015] The second object of the present invention is to provide a device for the above-mentioned method of recycling and regenerating acidic etching waste liquid in a composite electrolytic cell to solve the problem of electrolytic copper being corroded back, while at the same time improving the recycling rate of chlorine element substances in the etching working solution and / or waste liquid.

[0016] The first object of the present invention is achieved through the following technical solutions:

[0017] A method for recovering and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell comprises the following steps:

[0018] (1) A composite electrolytic cell is used, wherein the interior of the composite electrolytic cell is divided into an anode cell area, an intermediate cell area, and a cathode cell area, wherein the intermediate cell area is located between the anode cell area and the cathode cell area; an electrolytic cell separator A is used to separate the anode cell area and the intermediate cell area, and an electrolytic cell separator B is used to separate the intermediate cell area and the cathode cell area; an electrolytic anode is placed in the anode cell area and connected to the positive electrode of the electrolytic power supply, and an electrolytic cathode is placed in the cathode cell area and connected to the negative electrode of the electrolytic power supply;

[0019] (2) During the etching operation, the electrolytic power supply is turned on according to the process control, the anode tank area and the etching production line form a circulating liquid flow, the etching working liquid is used as the anolyte to be oxidized in the circulating flow to regenerate the copper etching agent, and the electrolyte solution containing copper ions is used as the cathode electrolyte;

[0020] Use: ① Etching waste liquid,

[0021] ② The solution obtained by mixing etching waste liquid with water and / or other electrolytes,

[0022] ③The solution obtained after the electrochemical reaction of the solution ① above,

[0023] ④The solution obtained after the electrochemical reaction of the above solution ②,

[0024] At least one of the four solutions is used as the electrolyte in the middle tank area, so that the copper ions in the electrolyte in the middle tank area pass through the electrolytic cell separator B into the cathode tank area under the action of the electric field force and are electrolyzed into metallic copper on the electrolytic cathode.

[0025] In step (1), the electrolytic cell separator A is a separator material that can effectively prevent copper ions and hydrogen ions in the anode cell region from entering the intermediate cell region, and is preferably at least one of an anion exchange membrane, a bipolar membrane, and a reverse osmosis membrane. The electrolytic cell separator B is a separator material that allows copper ions to pass through during the electrolysis process, and is preferably at least one of a cation exchange membrane, a filter cloth, a filter membrane, and a reverse osmosis membrane, so as to facilitate the copper ions in the intermediate cell region to enter the cathode cell region. The filter membrane includes a nanofiltration membrane and an ultrafiltration membrane.

[0026] In step (2), an electrolyte solution containing copper ions or not containing copper ions is used as the initial cathode electrolyte. When an electrolyte solution not containing copper ions is used as the initial cathode electrolyte, copper ions continuously migrate from the intermediate tank area to the cathode tank area as the electrolysis process proceeds and a certain amount of copper ion accumulation is generated. Preferably, an acidic copper-containing solution is used as the initial cathode electrolyte. When the cathode electrolyte contains etching waste liquid, the electrolyzed cathode electrolyte can be used as the intermediate tank area electrolyte. In addition, the etching working liquid that is no longer returned to the etching system is the etching waste liquid, so the electrolyzed anolyte can also be used as the intermediate tank area electrolyte. Similarly, when the cathode electrolyte and / or the intermediate tank area electrolyte contain etching working liquid, the etching working liquid contained therein is equivalent to the etching waste liquid.

[0027] The method of the present invention utilizes an electrolytic anode to directly electrolytically oxidize and regenerate monovalent copper ions in an etching solution into a copper etchant, replenishing the copper etchant for the etching solution. The intermediate tank region provides copper ions for the cathode tank region. During the electrolysis process, copper ions in the electrolyte migrate through separator B under the action of the electric field into the cathode electrolyte, replenishing the copper ion concentration. This solves the production problem of electrolytic copper powder being corroded back and damaging the electrolytic cell due to the continuously decreasing copper ion concentration in the cathode electrolyte during the electrolysis process. During the electrolysis process, at least a portion of the copper ions required for copper electrolysis in the cathode tank region originate from the intermediate tank region, avoiding the second prior art process in which a large amount of etching waste liquid containing a high concentration of copper etchant is directly added to the cathode tank region for copper electrolysis, resulting in severe corrosion of the electrolytic copper. After the present invention improves the process and electrolytic cell, the cathode electrolyte is replenished with copper ions, and a flat metallic copper block can be electrolytically deposited on the cathode. In the method of the present invention, the copper ion concentration of the electrolyte in the middle tank area is required to be 8-185 g / L, and the copper ion concentration of the cathode electrolyte is required to fall within the range of 5-185 g / L. When the copper ion concentration of the cathode electrolyte is not less than 5 g / L, hydrogen electrolysis can be avoided.

[0028] In an acidic solution, the standard electrode potential of divalent copper ions converted to metallic copper is 0.337V, the standard electrode potential of ferric ions converted to divalent iron ions is 0.771V, and the standard electrode potential of chlorine gas converted to chloride ions is 1.358V. This shows that the priority order of the three oxidized substances, copper ions, chloride ions, and possible iron ions in the etching working solution, is: monovalent copper ions > divalent iron ions > chloride ions. Therefore, when monovalent copper ions are present in the anolyte of the present invention, the electrochemical reaction of converting monovalent copper ions into divalent copper ions is preferentially carried out on the electrolytic anode, and the electrochemical reaction of oxidizing divalent iron ions into trivalent iron ions or oxidizing chloride ions into chlorine gas does not occur until most of the monovalent copper ions in the anolyte are oxidized to generate divalent copper ions. Therefore, the method of the present invention is to form a circulating liquid flow with the anode tank area and the etching production line, so that the anolyte can control the generation of chlorine by controlling the redox potential value (ORP value) of the anolyte under the premise of reaching the regeneration speed of the copper etching agent in the etching working solution, thereby avoiding the escape of a large amount of chlorine. In this case, a small amount of chlorine that is surplus can be dissolved in the anolyte and used as an oxidant, and during the process, it will react with the cuprous chloride in the etching working solution to regenerate more cupric chloride copper etching agent. Because the oxidation reaction of the anolyte is controlled so that chloride ions are difficult to be oxidized to chlorine, compared with the scheme of first electrolyzing a large amount of chlorine and then draining the chlorine to the reaction tank elsewhere to oxidize the monovalent copper ions in the etching working solution in the prior art, the method of directly electrochemically oxidizing the monovalent copper ions of the etching working solution of the present invention is more energy-saving and safer in production. The redox potential control value of the anolyte is set according to the etching process requirements. Preferably, the redox potential value of the anolyte is ≤1000mV.

[0029] When the present invention is applied to regenerate the acidic copper chloride etching solution, the electrochemical redox reaction occurring in the electrolytic cell is as follows.

[0030] Electrolysis anode:

[0031] Cu + -e - →Cu 2+ (priority response);

[0032] 2Cl - -2e - →Cl2.

[0033] The redox reaction of chlorine and cuprous chloride: 2CuCl+Cl2→2CuCl2.

[0034] Electrolytic cathode: Cu 2+ +e - →Cu + ; Cu + +e- →Cu.

[0035] The present invention limits the copper ions and hydrogen ions in the anode tank area from entering the intermediate tank area through the electrolytic tank separator A, so that the etching working solution can flow between the etching production line and the anode tank area without affecting the copper ion concentration and acidity of the etching working solution. Therefore, the monovalent copper ions from the etching working solution are continuously oxidized on the electrolytic anode, and the electrolyzed chlorine and the generated nitrogen trichloride can react with the monovalent copper ions in the anode tank area and be consumed and utilized in time. The present invention adopts a linkage control method of etching copper dissolution and electrolytic copper extraction to oxidize and regenerate the copper etching agent and solve the production safety problem of nitrogen trichloride accumulation. The above process measures of the present invention can also help to realize the recycling of chlorine element substances in the etching waste liquid, reduce or even eliminate the need to add an oxidant on the etching production line, thereby not causing the etching waste liquid volume to expand and increase the processing cost of the discharged waste liquid.

[0036] Furthermore, in the prior art, when the copper ion concentration of the cathode electrolyte is low, the deposited metallic copper is relatively loose. However, the present invention uses an electrolytic cell separator B between the intermediate cell zone and the cathode cell zone. Since the cathode electrolyte is supplemented with copper ions from the intermediate cell zone electrolyte, this creates conditions for depositing relatively flat copper plates even at a lower copper ion concentration in the cathode electrolyte. Adding a brightener to the cathode electrolyte further enhances the ability to deposit a flatter, denser copper plate on the cathode.

[0037] When the electrolytic cell separator A is a bipolar membrane, hydroxide is generated on the side of the bipolar membrane located in the anode tank area to cause the anode electrolyte to undergo an oxidation reaction, while hydrogen ions are generated on the side located in the middle tank area to gradually increase the acidity of the electrolyte in the middle tank area.

[0038] When separator A of the composite electrolytic cell is a reverse osmosis membrane, the anode in the composite electrolytic cell primarily undergoes water electrolysis, as the membrane's pores are small but allow water molecules, hydrogen ions, and hydroxide ions to pass through. This provides similar results to when separator A is a bipolar membrane. Despite the small pore size of the reverse osmosis membrane, a small amount of chloride ions and copper ions still pass through the membrane under the action of the electric field, generating electrochemical reactions at the electrodes.

[0039] When the composite electrolytic cell separator A is an anion exchange membrane, chloride ions in the electrolyte in the intermediate tank area migrate through the separator A under the influence of the electric field to the anode tank area and participate in the regeneration reaction of the copper etching agent. When this solution is adopted, the acidity of the anolyte is more stable, which is more conducive to etching production. Therefore, the electrolytic cell separator A of the present invention is preferably an anion exchange membrane.

[0040] The inventors discovered that, under the same electric field force, using filter cloth and nanofiltration membrane as electrolytic cell separator B will cause water in the middle tank area to seep into the cathode tank area, diluting the copper ion concentration of the cathode electrolyte. During installation, it is preferred to use multiple layers of filter cloth or a method of mixing filter cloth and filter membrane to solve this problem. Filter cloth is cheap, costing only a few tens of times the price of various types of diaphragms, making it a good choice considering the overall cost. When using a cation exchange membrane as the electrolytic cell separator B, the copper ions in the solution in the middle tank area can smoothly pass into the cathode tank area, while reducing water penetration, preventing the copper ion concentration of the cathode electrolyte from being diluted and affecting the flatness of the electrolytic copper plate. Therefore, the electrolytic cell separator B preferably uses a cation exchange membrane or filter cloth.

[0041] In order to extend the service life of the electrolytic cell separator, preferably, the electrolytic cell separator A and / or the electrolytic cell separator B are additionally overlapped with a filter cloth for use.

[0042] The electrolysis anode is made of an insoluble anode. The electrolysis cathode is made of at least one of copper, titanium, and an electrode material coated with metallic copper.

[0043] Preferably, the copper ion concentration of the cathode electrolyte is controlled during the electrolysis process. When the copper ion concentration of the cathode electrolyte is lower than the set value, at least one of the etching waste liquid, the electrolyzed intermediate tank electrolyte, and the electrolyzed cathode electrolyte of the front-stage electrolytic cell is added to the cathode tank area. This can not only electrolyze flat copper plates but also avoid the electrolysis of hydrogen during the electrolysis operation. Since copper ions continuously enter the cathode tank area from the intermediate tank area during the electrolysis process, the amount of copper ions that need to be directly added to the cathode tank area is relatively small. Therefore, only a small amount of etching waste liquid is added during the electrolysis process, or no etching waste liquid is added to the cathode tank area. This avoids directly adding a large amount of etching waste liquid containing a high concentration of copper etching agent to the cathode tank area for electrolytic copper treatment, which may cause the electrolytic copper to be severely etched back. The front-stage electrolytic cell may be a composite electrolytic cell or an ordinary electrolytic cell having only an anode tank area and a cathode tank area.

[0044] The present invention can be improved as follows: referring to the method described in the international application PCT / CN2023 / 093720 proposed by the present applicant, that is, at least two or more independent electrolytic cells are combined in series, wherein at least one electrolytic cell is the composite electrolytic cell, and the other electrolytic cells other than the composite electrolytic cell are electrolytic cells having only an anode cell area and a cathode cell area. The electrolyte overflowing from the cathode cell area and / or the intermediate cell area of ​​the front-stage electrolytic cell is used as the electrolyte of the cathode cell area and / or the intermediate cell area of ​​the rear-stage electrolytic cell, and the electrochemical reduction reaction of the front-stage electrolytic cell is used to eliminate the copper corrosive agent and other oxidizing substances that may be present in the solution that can corrode metallic copper, and the rear-stage electrolytic copper is used for electrolysis to reduce the back corrosion of the electrolytic copper by the copper corrosive agent.

[0045] The above improvements are particularly applicable to acidic copper chloride etching solutions containing iron ions. When the iron ion concentration in the etching solution is high, the electrolyte in the intermediate tank contains a large amount of trivalent iron ions, which can penetrate the electrolytic cell separator B and enter the cathode tank, increasing the etching of the electrolytic copper metal on the electrolytic cathode. The present invention effectively solves this problem by combining two or more electrolytic cells in series.

[0046] As a preferred embodiment of the present invention: the composite electrolytic cell is composed of an anode cell area, an intermediate cell area, and a cathode cell area to form a basic assembly unit, and the intermediate cell area is located between the anode cell area and the cathode cell area; when more than one basic assembly unit is used, the cell areas of the same type in two connected basic assembly units can be combined and shared. Preferably, the composite electrolytic cell can adopt one or more of the following three structures, and composite electrolytic cells with different structures can be used in any combination:

[0047] ① The three-partition structure shown in Figure 1, i.e., the electrolytic cell has a set of electrolytic cell separators A and B inside, and can be set up as an anode cell area, an intermediate cell area, and a cathode cell area in sequence or in reverse order according to the connection method with the electrolysis power supply;

[0048] ② A symmetrical five-partition structure as shown in FIG2 , i.e., there are two sets of electrolytic cell partitions A and B inside the electrolytic cell, and they are sequentially arranged as cathode cell area, middle cell area, anode cell area, middle cell area, and cathode cell area according to the connection method of the electrolysis power supply;

[0049] ③ As shown in Figure 3, there are two sets of electrolytic cell separators A and electrolytic cell separators B inside the electrolytic cell, and they are arranged in sequence as anode cell area, middle cell area, cathode cell area, middle cell area, and anode cell area according to the connection method of the electrolytic power supply.

[0050] The composite electrolytic cell of the second structure is characterized by increasing the effective electrolysis area of ​​the electrolytic cathode, improving the utilization rate of the electrolytic anode, and reducing the average electrolytic current density per unit area of ​​the electrolytic cathode while keeping the electrolytic current density of the electrolytic anode constant, thereby depositing a smoother and denser copper layer. The composite electrolytic cell of the third structure is characterized by increasing the effective electrolysis area of ​​the electrolytic anode, thereby increasing the contact opportunities between the anolyte and the electrolytic anode. Under the working conditions of the same electrolytic current density, it can accelerate the regeneration reaction of the copper etching agent and reduce chlorine gas precipitation. At the same time, it can ensure that the generated chlorine gas can be absorbed in a timely manner, further reducing chlorine gas leakage.

[0051] As another preferred embodiment of the present invention, during the electrolysis process, new intermediate tank electrolyte is added to the intermediate tank, i.e., at least one of the following is added: ① etching waste liquid, ② a solution obtained by mixing etching waste liquid with water and / or other electrolytes, ③ a solution obtained by electrochemically reacting the aforementioned solution ①, or ④ a solution obtained by electrochemically reacting the aforementioned solution ②. When adding or replenishing two or more of the aforementioned intermediate tank electrolytes, they are added individually and / or mixed into a mixed solution.

[0052] Preferably, the copper ion concentration of the electrolyte in the middle tank area is monitored, and the amount of external copper-containing solution added is controlled according to the copper ion concentration of the electrolyte in the middle tank area, so that a certain number of copper ions in the electrolyte in the middle tank area pass through the electrolytic separator B to increase the copper ion concentration of the cathode electrolyte, thereby stabilizing the normal operation of the entire electrolysis system and replenishing the copper ions in the cathode electrolyte to electrolyze flat copper plates.

[0053] The present invention can be improved by adding at least one oxidant spray pipe to at least one of the locations near the electrolytic cell separator B in the cathode cell zone, near the electrolytic cell separator A in the intermediate cell zone, and near the electrolytic cell separator B in the intermediate cell zone. Furthermore, an oxidizing solution is added to locations near the electrolytic cell separators in the cathode cell zone and / or the intermediate cell zone. This is because the electrolyte in the intermediate cell zone contains cuprous chloride, and cuprous chloride is also generated during the electrochemical reduction reaction in the catholyte. This cuprous chloride easily adheres to the electrolytic cell separator, affecting ion throughput. Furthermore, fine metallic copper particles precipitated from the electrolytic cathode can also adhere to the electrolytic cell separator, forming a secondary electrode and directly damaging the electrolytic cell separator. In this case, spraying the oxidizing solution near the electrolytic cell separator where solid cuprous chloride and / or metallic copper powder adheres can effectively eliminate the solid cuprous chloride copper salt and metallic copper powder on the electrolytic cell separator, thereby maintaining unobstructed ion channels in the electrolytic cell separator and extending the service life of the electrolytic cell separator. The oxidizing solution is specifically an oxidant and / or an electrolyzed anolyte, wherein the anolyte contains chlorine and is oxidizing, and the oxidant is hydrogen peroxide and / or sodium chlorate solution.

[0054] Preferably, the oxidizing solution is an anolyte.

[0055] The present invention can also be improved by adding a mixing exchange tank between the etching production line and the anode tank area, where the etching working solution and the anolyte solution converge and flow. Due to the low solubility of chlorine in the anolyte and etching working solution, when the copper etchant concentration in the etching working solution drops rapidly during the etching process, it is difficult to instantly restore the copper etchant concentration to the set level by relying solely on the chlorine dissolved in the solution. The concentration of the copper etchant in the solution can be reflected by its redox potential; the higher the copper etchant concentration in the solution, the higher the redox potential value of the solution. Therefore, when the redox potential value of the solution in the mixing exchange tank is set higher than the redox potential value of the etching working solution, a large mixing exchange tank can be used to store a large amount of solution with a high copper etchant concentration. During the etching process, the large mixing exchange tank can be used to quickly replenish the copper etchant to the etching working solution, maintaining the stability of the etching working solution's various components and concentrations. At the same time, the chlorine in the anolyte can also quickly react with the monovalent copper ions in the mixing exchange tank, further reducing the amount of chlorine escape and enabling the recycling of chlorine in the etching waste liquid within the etching system.

[0056] The present invention can also be improved as follows: a dispersion tube is installed in the mixing exchange tank so that the anolyte can be quickly and evenly dispersed in the mixing exchange tank after entering the dispersion tube. The small amount of excess chlorine dissolved in the anolyte reacts evenly with the monovalent copper ions in the solution in the mixing exchange tank and is quickly consumed, further reducing chlorine escape.

[0057] The present invention can also be improved as follows: because some oxygen is introduced during the etching process, some of the monovalent copper ions in the etching solution are oxidized, reducing the demand for regenerating the copper etchant using the electro-oxidation etching solution. This results in the electrochemical oxidation capacity synchronized with the electrolytic copper extraction exceeding the reaction capacity of the electrochemically regenerated copper etchant required to etch an equal amount of copper. In other words, the demand for electrolytic copper extraction exceeds the demand for electrochemical oxidation. Therefore, if the copper in the etching waste liquid is completely electrolyzed, excess chlorine will be produced. A small amount of chlorine in the anodic electrolysis chlorine cannot be recycled, and this small amount of chlorine needs to be drawn out of the etching system for absorption treatment. To solve the problem of balancing electrochemical oxidation and electrolytic copper extraction, the redox potential value of the solution in the mixed exchange tank is adjusted to a control value of >900mV under safety monitoring to allow chlorine to precipitate in the system. After the etching production line regenerates the copper etchant, the excess small amount of chlorine is drained out of the system for treatment or used to treat wastewater produced by other production activities within the enterprise, so that the etching electrochemical oxidation reaction and the electrolytic copper extraction reaction reach a balance. After treating a small amount of excess chlorine, the redox potential of the solution in the mixed exchange tank is adjusted back to the control set value for normal production according to process requirements, so that the electrolytic power supply of the composite electrolytic cell can be normally controlled to adjust the current or shut down, so that the etching reaction and electrolytic oxidation can return to a normal dynamic balance. When the excess small amount of chlorine is drained out of the system and absorbed by sodium hydroxide or ferrous chloride, the amount of sodium hypochlorite or ferric chloride solution produced is very small and can be easily used for waste liquid treatment in the enterprise. In addition, selling part of the etching waste liquid or neutralizing it can also achieve a balance between electrochemical oxidation and electrolytic copper extraction.

[0058] Preferably, during normal production, the redox potential value of the solution in the mixed exchange tank is controlled at ≤800m to avoid a large amount of chlorine gas escaping.

[0059] The following improvement can also be made: the electrolyte in the middle tank area and / or cathode tank area after electrolysis is prepared into a regenerated etching sub-liquid.

[0060] The second object of the present invention is achieved through the following technical solutions.

[0061] A device for recycling and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell, comprising an electrolytic cell and an etching production line, characterized in that:

[0062] The electrolytic cell is a composite electrolytic cell, specifically an electrolytic device that integrates a cell body and an electrolytic power supply. The cell body is divided into an anode cell area, an intermediate cell area, and a cathode cell area, wherein the intermediate cell area is located between the anode cell area and the cathode cell area. An electrolytic anode and an electrolytic cathode are respectively placed in the anode cell area and the cathode cell area, and the electrolytic anode and the electrolytic cathode are respectively connected to the positive electrode and the negative electrode of the electrolytic power supply. An electrolytic cell separator A is used to separate the anode cell area and the intermediate cell area, and an electrolytic cell separator B is used to separate the intermediate cell area and the cathode cell area.

[0063] The etching production line is connected to the anode tank area of ​​the composite electrolytic cell through a pipeline to form a liquid circulation loop;

[0064] It also includes a copper etching agent regeneration reaction monitor, which is used to control the oxidation regeneration reaction of the copper etching agent in at least one of the anode tank area, the etching production line, the container connected to the anode tank area and / or the etching production line, and the container provided on the connecting pipeline between the etching production line and the anode tank area.

[0065] The copper etching agent regeneration reaction monitoring meter is specifically a redox potentiometer or a combined sensor of a redox potentiometer and a hydrometer.

[0066] Preferably, the composite electrolytic cell adopts one or more of the following three structures:

[0067] ① The three-partition structure shown in Figure 1, i.e., the electrolytic cell has a set of electrolytic cell separators A and B inside, and can be set up as an anode cell area, an intermediate cell area, and a cathode cell area in sequence or in reverse order according to the connection method with the electrolysis power supply;

[0068] ② A symmetrical five-partition structure as shown in FIG2 , i.e., there are two sets of electrolytic cell partitions A and B inside the electrolytic cell, and they are sequentially arranged as cathode cell area, middle cell area, anode cell area, middle cell area, and cathode cell area according to the connection method of the electrolysis power supply;

[0069] ③ As shown in Figure 3, there are two sets of electrolytic cell separators A and electrolytic cell separators B inside the electrolytic cell, and they are arranged into anode cell area, middle cell area, cathode cell area, middle cell area, and anode cell area in sequence according to the connection method of the electrolytic power supply.

[0070] When the present invention uses more than one composite electrolytic cell, any combination of the three composite electrolytic cells can be used.

[0071] Among them, the purpose of the present invention can be achieved by adopting the common circuit board etching production line in the prior art.

[0072] The electrolytic cell separator A is at least one of an anion exchange membrane, a bipolar membrane, and a reverse osmosis membrane. The electrolytic cell separator B is at least one of a cation exchange membrane, a reverse osmosis membrane, a filter cloth, and a filter membrane.

[0073] Preferably, the electrolytic cell separator A is an anion exchange membrane, and the electrolytic cell separator B is a cation exchange membrane and / or at least one layer of filter cloth.

[0074] The electrolytic anode is made of an insoluble anode, preferably at least one of an electrode coated with gold and / or platinum and / or their alloys, graphite, and a titanium-based coating anode. The electrolytic cathode is preferably made of at least one of copper, titanium, and an electrode material coated with metallic copper.

[0075] Preferably, the electrolytic power supply in the electrolytic cell is an electrolytic power supply with a working current control function.

[0076] The present invention may be improved as follows: at least one oxidant spray pipe is provided at at least one of the positions near the electrolytic cell separator B in the cathode cell area, near the electrolytic cell separator A in the intermediate cell area, and near the electrolytic cell separator B in the intermediate cell area, so that an oxidizing solution is added to the cathode cell area and / or the intermediate cell area to dissolve the cuprous chloride solid and metallic copper powder adhering to the electrolytic cell separator.

[0077] The present invention can also be improved as follows: a mixing exchange tank is added as a solution exchange center on the pipeline connecting the etching production line and the anode tank area; the mixing exchange tank is connected to the etching production line and the anode tank area through pipelines for circulating pipeline liquid flow, and the two are connected through the mixing exchange tank to exchange solutions, so that the etching working solution can be better mixed and reacted with the anode electrolyte, thereby reducing chlorine gas escape.

[0078] The present invention can also be improved by adding a dispersion pipe to the mixing and exchange tank, so that the solution from the anode tank area is added to the dispersion pipe in the mixing and exchange tank. The dispersion pipe is provided with one or more liquid outlets below the liquid surface to accelerate solution mixing and further reduce chlorine gas leakage. Preferably, the dispersion pipe is a coil with multiple liquid outlets.

[0079] The present invention can also be improved as follows: an overflow gas-liquid separator is added to each tank area of ​​the composite electrolytic cell, and the overflow gas-liquid separator can connect the gas pressure in each tank area of ​​the electrolytic cell with the atmospheric pressure, thereby reducing the damage to the electrolytic cell partitions caused by the pressure difference.

[0080] The present invention can also be improved as follows: additional sensors are provided, wherein the sensors include at least one of a thermometer, a liquid level meter, a pH meter, a hydrometer, an oxidation-reduction potentiometer (ORP meter), a photoelectric colorimeter, and a chlorine gas detector.

[0081] Preferably, a sensor is added to monitor the copper ion concentration in the electrolyte of the intermediate tank zone, maintaining the copper ion concentration in the electrolyte of the intermediate tank zone to ensure the normal operation of the electrolytic cell. The monitoring sensor is at least one of a hydrometer, a redox potentiometer, and a photoelectric colorimeter, with a hydrometer being preferred. More preferably, a circulating flow tank for the electrolyte in the intermediate tank zone is also provided. The circulating flow tank is connected to the intermediate tank zone via a pipeline to form a liquid circulation system, and the sensor for monitoring the copper ion concentration in the electrolyte of the intermediate tank zone is located in the circulating flow tank. In this preferred embodiment, replenishment of the electrolyte in the intermediate tank zone can be carried out in the circulating flow tank.

[0082] Preferably, a sensor monitoring the copper ion concentration in the cathode tank electrolyte is added. By maintaining the copper ion concentration in the cathode tank electrolyte, a bright, smooth copper plate is deposited at the electrolytic cathode. The monitoring sensor is at least one of a hydrometer and a photoelectric colorimeter. More preferably, a cathode tank electrolyte circulation flow tank is also provided. The cathode tank electrolyte circulation flow tank is connected to the cathode tank via a pipeline to form a liquid circulation system, and the sensor monitoring the copper ion concentration in the cathode tank electrolyte is located in the cathode tank electrolyte circulation flow tank. In this preferred embodiment, supplemental feeding to the cathode tank can be performed in the cathode tank electrolyte circulation flow tank.

[0083] The present invention can also be further improved as follows: an automatic detection and feeding controller is added at the same time, the sensor signal input end of the automatic detection and feeding controller is connected to the sensor signal output end of the sensor, and the control signal output end of the automatic detection and feeding controller is connected to the electrolysis power supply, valve, and pump control signal input end in the device, so that the device can perform automated safe production and safety interlock monitoring according to the process flow.

[0084] The present invention can also be improved as follows: electrolytic cell sealing covers are added to each cell area of ​​the electrolytic cell to collect and process the gas escaping from the electrolyte.

[0085] The present invention can also be improved as follows: a hot and cold temperature exchanger is added to make the temperature of each reaction liquid meet the process requirements, and the exchanger can be installed in the electrolytic cell and / or etching production line and / or mixed exchange tank.

[0086] The present invention can also be improved as follows: an exhaust gas processor is added to treat the exhaust gas generated in the device to reduce the pollution of harmful gases to the environment.

[0087] The present invention can also be improved as follows: a temporary storage tank is added, connected to the electrolytic cell and / or etching production line and / or mixed exchange tank, for temporarily storing materials and used as a normal pressure chemical reaction tank.

[0088] The present invention can also be improved by adding a gas-liquid mixer to the mixing and exchange tank and / or the temporary storage tank. The gas-liquid mixer's suction pipe is connected to at least one container within the device to drain the gas and perform a gas-liquid mixing reaction. The gas-liquid mixer is preferably a vacuum ejector and / or spray tower structure.

[0089] The present invention can also be improved as follows: a stirring device is added to make the concentration and temperature of the reaction liquid uniform. The stirring device is an impeller stirrer or a liquid flow stirrer.

[0090] The present invention can also be improved as follows: an overflow buffer tank is added to the electrolytic tank and / or etching production line and / or mixed exchange tank in the device to solve the problem of solution flow between the containers in the device.

[0091] The present invention can also be improved as follows: a solid-liquid separator is added to separate the solution into solid and liquid to remove solid impurities.

[0092] The present invention can also be improved as follows: a water-oil separator is added to separate the water and oil in the solution to remove some organic impurities.

[0093] The present invention can also be improved as follows: at least two or more independent electrolytic cells are combined, specifically a composite electrolytic cell or a composite electrolytic cell combined with an electrolytic cell having only an anode cell area and a cathode cell area. The combined structure is to connect the electrolytic cells with cathode cell areas and / or intermediate cell areas in series, so that the cathode electrolyte and / or intermediate cell electrolyte of the previous electrolytic cell flow to the cathode cell area and / or intermediate cell area of ​​the next electrolytic cell. This is used as an electrolytic copper treatment method to solve the problem of electrolytic copper being corroded in the second and subsequent stages. Preferably, at least one stage before the composite electrolytic cell uses an electrolytic cell having only an anode cell area and a cathode cell area, and the separator of the electrolytic cell having only an anode cell area and a cathode cell area is an anion exchange membrane. A dedicated ORP meter is installed in the cathode cell area to detect the cathode electrolyte to control and reduce the concentration of the copper corroding agent. The ORP meter also has an auxiliary switch function to control its electrolytic power supply.

[0094] Compared with the prior art, the present invention has the following beneficial effects:

[0095] 1. The present invention improves the recycling rate of chlorine in the etching waste liquid in the etching system. The recycling rate of chlorine in the etching waste liquid in the etching system can reach up to 100%, while the recycling rate of chlorine in the etching system in the first process of the prior art is generally about 30%.

[0096] 2. The present invention adds an electrolyte in the middle tank area to supplement copper ions to the cathode electrolyte, so that the electrolytic cathode deposits a flat cathode copper block, solving the production process problem of electrolytic copper plate corrosion.

[0097] 3. The present invention uses the anode tank area specifically for the oxidation and regeneration of the etching working solution to react with the copper etching agent, thereby reducing or eliminating the need to add additional oxidants to the etching machine to participate in the oxidation and regeneration reaction during the etching process, and preventing the volume of the etching waste liquid from increasing.

[0098] 4. The device of the present invention has a simple structure, safe operation and low operation and maintenance costs.

[0099] 5. The present invention can not only solve environmental pollution, but also recycle materials, with high economic benefits.

[0100] 6. The present invention adopts a linkage process of etching copper and electrolytic copper extraction, which solves the production safety problem of nitrogen trichloride accumulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0101] FIG1 is a schematic diagram of a three-partition structure of a composite electrolytic cell of the present invention;

[0102] FIG2 is a schematic diagram of a five-partition structure of a composite electrolytic cell according to the present invention;

[0103] FIG3 is a second schematic diagram of the five-partition structure of the composite electrolytic cell of the present invention;

[0104] FIG4 is a device for recovering and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell according to Example 1 of the present invention;

[0105] FIG5 is a device for recovering and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell according to Example 2 of the present invention;

[0106] FIG6 is a device for recovering and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell according to Example 3 of the present invention;

[0107] Figure 6-1 is part A in Figure 6;

[0108] Figure 6-2 is part B in Figure 6;

[0109] FIG7 is a device for recovering and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell according to Example 4 of the present invention;

[0110] Figure 7-1 is part A in Figure 6;

[0111] Figure 7-2 is part B in Figure 6.

[0112] Figure numerals: 1-etching production line, 2-electrolytic cell body, 3-electrolytic anode, 4-electrolytic cathode, 5-electrolytic cell separator A, 6-electrolytic cell separator B, 7-electrolytic power supply, 8-copper etching agent regeneration reaction monitor, 9-cold and hot temperature exchanger, 10-electrolytic cell sealing tank cover, 11-overflow gas-liquid separator, 12-water-oil separator, 13-solid-liquid separator, 14-mixing exchange tank, 15-temporary storage tank, 16-overflow buffer tank, 17-tail gas treatment tank, 18-vacuum ejector, 19-spray tower, 20-impeller agitator, 21-liquid flow agitator, 22-sensor, 23-automatic detection and feeding controller, 24- Hydrochloric acid, 25-etching sub-liquid, 26-etching regeneration sub-liquid, 27-etching working solution, 28-etching waste liquid, 29-intermediate tank area electrolysis overflow liquid (electrolyzed intermediate tank area electrolyte), 30-electrolytic metal copper, 31-sodium hydroxide solution, 32-pump, 33-valve, 34-hydrogen peroxide, 35-copper sulfate solution, 36-electroplating brightener, 37-clean water, 38-cathode electrolyte, 39-dispersion pipe, 40-cathode electrolyte overflow liquid (electrolyzed catholyte), 41-oxidant spray pipe, 42-ordinary electrolytic cell with anode tank area and cathode tank area, 43-anolyte, 44-etching processing circuit board. DETAILED DESCRIPTION

[0113] The present invention is further described below with reference to specific examples.

[0114] In the following embodiments, the electrolytic cell and its cathode and anode electrodes, mixed exchange tank, temporary storage tank, liquid flow buffer tank, water-oil separator, overflow gas-liquid separator, impeller agitator, liquid flow agitator, ejector, and spray tower used are all products of Foshan Yegao Environmental Protection Equipment Manufacturing Co., Ltd. in Guangdong Province. The solid-liquid separator, sensor, automatic detection and feeding controller, electrolysis power supply, hot and cold temperature exchanger, etching production line, valve, pump, chemical raw materials, and circuit board are all commercially available products. In addition to the above-mentioned products, those skilled in the art can also select other products with similar performance to the above-mentioned products according to routine selection, and all of them can achieve the purpose of the present invention.

[0115] Example 1

[0116] As shown in FIG4 , the apparatus for recovering and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell according to Example 1 includes an etching production line 1, an electrolytic cell body 2, an electrolytic anode 3, an electrolytic cathode 4, an electrolytic cell separator A 5, an electrolytic cell separator B 6, an electrolytic power supply 7, a copper etching agent regeneration reaction monitor 8, a hot and cold temperature exchanger 9, an electrolytic cell sealing tank cover 10, a temporary storage tank 15, an overflow buffer tank 16, five sensors 22, an etching processing circuit board 44, and multiple pumps and valves.

[0117] The etching tank of the etching production line 1 has a solution storage capacity of 2 cubic meters.

[0118] The electrolytic cell body 2 is divided into an anode cell area, an intermediate cell area and a cathode cell area in sequence by the electrolytic cell separator A 5 and the electrolytic cell separator B 6. An electrolytic cell sealing cell cover 10 is provided above each of the three cell areas.

[0119] The electrolytic cell separator A 5 is a bipolar membrane, and the electrolytic cell separator B 6 is a reverse osmosis membrane.

[0120] The electrolytic anode 3 is a conductive graphite electrode placed in the anode tank and connected to the positive electrode of the electrolytic power supply 7. The electrolytic cathode 4 is a titanium plate placed in the cathode tank and connected to the negative electrode of the electrolytic power supply 7. The above combination forms the three-partition structure composite electrolytic cell. The separator B 6 is a reverse osmosis membrane. Although it has low copper ion transmission efficiency, it can effectively prevent the brightener from penetrating into the etching solution.

[0121] The etching production line 1 is connected to the anode tank area and the middle tank area through pipelines to form two groups of liquid circulation loops; and is connected to the cathode tank area in one direction through a pipeline.

[0122] The copper etching agent regeneration reaction monitoring meter 8 is an ORP meter, which is set in the etching production line and is used to control the working current size or start and stop of the electrolytic power supply.

[0123] Sensors 22-1, 22-2, and 22-3 are provided in the etching production 1, and sensors 22-4 and 22-5 are provided in the cathode tank area.

[0124] Sensor 22-1 is a pH meter used to detect hydrochloric acid concentration. Sensor 22-2 is a hydrometer used to detect copper ion concentration. Sensor 22-3 is a thermometer used to control the temperature of the etching solution. Sensor 22-4 is a level gauge used to control the on / off of pump 32-1. Sensor 22-5 is a hydrometer that sets a lower limit for the copper ion concentration in the catholyte. When the lower limit is reached, the process is shut down and the catholyte is replaced.

[0125] The etching waste liquid 28 that needs to be electrolytically recovered and regenerated is an acidic pure copper chloride solution, which contains 1.4 mol / L of hydrochloric acid and a copper ion concentration of 185 g / L. Its main components are a mixture of hydrochloric acid and copper chloride.

[0126] The cathode electrolyte 38 of the electrolytic cell is a mixture of the etching waste liquid 28 and the electroplating brightener 36.

[0127] The pump 32-2 is a variable frequency pump, and its speed is controlled by the hydrometer 22-2.

[0128] The pump 32 - 5 is a variable frequency pump, and its rotation speed is also controlled by the copper etching agent regeneration reaction monitoring meter 8 .

[0129] The steps of recycling and regenerating the acidic copper chloride etching waste liquid using a composite electrolytic cell in this embodiment are as follows:

[0130] 1. Inject etching working solution 27 into the anode tank area and the middle tank area of ​​the etching production line and the composite electrolytic cell, and fill the cathode tank area with a mixture of etching waste liquid 28 and electroplating brightener 36, so that the electrolytic anode and electrolytic cathode are immersed in their respective electrolytes while connected to the positive and negative electrodes of the electrolytic power supply.

[0131] 2. After opening all valves, start all pumps to circulate the liquid, with pump 32-1 controlled by sensor 22-4. Turn on the hot and cold temperature exchanger 9 located in the etching production line according to the process requirements and control it to adjust the etching working solution 27 to 50°C based on the data from sensor 22-3. Use a pH meter to control the acidity of the etching working solution 27 to 1.4 mol / L. Use a hydrometer to control the specific gravity of the cathode electrolyte to 1.29 g / ml.

[0132] 3. Manually place the etched circuit board 44 into the etching line 1 for etching. If all parameters in step 2 meet the process requirements, turn on the electrolysis power supply 7 to perform the electrolysis operation. The electrolyte in the middle tank area will be electrolyzed to produce newly generated hydrogen ions, a small portion of which will combine with chloride ions to form hydrochloric acid, and the remaining portion will migrate to the cathode tank area together with copper ions under the action of the electric field force. An electrochemical reaction will occur at the cathode to deposit metallic copper. The electrolyte in the anode tank area will produce oxygen due to water electrolysis, so that the cuprous chloride in the anode electrolyte will be oxidized to cupric chloride under acidic conditions.

[0133] 4. As electrolysis and etching proceed, the output current of the electrolysis power supply is manually adjusted based on the feedback from the copper etching agent regeneration reaction monitor 8 ORP meter to stabilize the ORP value of the etching solution on the etching production line at 510mV. In addition, the switches of pumps 32-2 and 32-5 are controlled to maintain the specific gravity of the etching solution at 1.29g / L to ensure etching quality.

[0134] The copper ion concentration of the electrolyte in the middle tank region is 185 g / L, and etching waste liquid is added to the middle tank region based on the measured copper ion concentration of the electrolyte in the middle tank region. The lower limit of the copper ion concentration of the cathode electrolyte is set to 50 g / L, and the upper limit is set to 185 g / L, and etching waste liquid is added to the cathode tank region based on the measured copper ion concentration of the cathode electrolyte. Since copper ions continuously enter the cathode tank region from the middle tank region during the electrolysis process, the amount of etching waste liquid added to the cathode tank region is very small, only about 20% of the amount of etching waste liquid added to the cathode tank region in the second process of the above-mentioned prior art.

[0135] 5. When the etched circuit board is taken out from the etching line, the etching production line and the electrolytic cell are shut down, and the electrolytic copper block is taken out from the cathode cell area for reuse.

[0136] By using the device shown in FIG4 and following the above operating steps, it is possible to achieve the process effect of no chlorine gas precipitation during copper electrolysis and recycling of etching waste liquid. The copper block obtained in the cathode tank area is flat and dense, and the copper block obtained by electrolysis does not obviously break or fall during the process of removing the electrolytic cathode.

[0137] Example 2

[0138] As shown in FIG5 , the apparatus for recycling and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell in Example 2 includes an etching production line 1, an electrolytic cell body 2, an electrolytic anode 3, an electrolytic cathode 4, an electrolytic cell separator A 5, an electrolytic cell separator B 6, an electrolytic power supply 7, a copper etching agent regeneration reaction monitor 8, two hot and cold temperature exchangers 9, an electrolytic cell sealing tank cover 10, an overflow gas-liquid separator 11, five overflow buffer tanks 16, two tail gas treatment tanks 17, a liquid flow agitator 21, nine sensors 22, an automatic detection and feeding controller 23, and multiple pumps and valves.

[0139] The copper etching agent regeneration reaction monitoring meter 8 is a sensor combining an ORP meter and a hydrometer, and is arranged in the mixing exchange tank 14.

[0140] The etching tank of the etching production line 1 has a solution storage capacity of 2 cubic meters.

[0141] The electrolytic cell used in this embodiment is a three-partition composite electrolytic cell. The electrolytic cell body 2 is divided into an anode cell area, an intermediate cell area, and a cathode cell area by the electrolytic cell separator A 5 and the electrolytic cell separator B 6. The electrolytic cell sealing cover 10 is respectively provided above the three cell areas.

[0142] The electrolytic cell separator A 5 is a reverse osmosis membrane, and the electrolytic cell separator B 6 is a cation exchange membrane.

[0143] The material of the electrolytic cell anode 3 is a platinum metal electrode and is connected to the positive electrode of the electrolysis power supply 7. The material of the cathode material 4 is a copper metal electrode and is connected to the negative electrode of the electrolysis power supply 7.

[0144] The mixing exchange tank 14 in this embodiment is used to mix the etching solution with the anolyte containing a small amount of excess chlorine and the overflow from the electrolysis in the intermediate tank area. The etching production line 1 and the anode tank area are connected to the mixing exchange tank via corresponding overflow buffer tanks for circulating liquid flow. A copper etchant regeneration reaction monitor 8 is installed in the mixing exchange tank. The detected value is fed into the automatic detection and feeding controller 23 to regulate the operating current of the electrolysis power supply 7. During the electrolysis process, when chlorine needs to be electrolyzed and excess chlorine needs to be removed for balanced electrolysis and copper extraction, the controller 23 shuts down pump 32-15 and opens pump 32-16 to pump the overflow from the intermediate tank area to tank 15-3 for temporary storage. After the chlorine electrolysis and copper extraction process is completed, pump 32-16 is shut down and pump 32-15 is opened for reset. The controller 23 automatically resets the ORP meter setting of the copper etchant regeneration reaction monitor 8 to the normal production value of 580mV, restoring the dynamic equilibrium between the etching chemical reaction and the electrolytic oxidation reaction.

[0145] The intermediate tank area is connected to the mixing exchange tank 14 via an overflow buffer tank 16-4 via a circulating pipeline. The intermediate tank area is also connected to the temporary storage tank 15-3 via the overflow buffer tank 16-4, and then connected to the etching production line 1. The cathode tank area is connected to the anode tank area via the overflow buffer tank 16-3 to receive the overflow of the anode electrolysis liquid; the cathode tank area is connected to the temporary storage tank 15-2 via the overflow buffer tank 16-3.

[0146] In this embodiment, tail gas treatment tank 17-1 is specifically designed to absorb and treat chlorine gas precipitated from the anolyte overflow gas-liquid separator 11 and chlorine gas escaping from the various tanks. Tail gas treatment tank 17-1 receives solution from the mixing exchange tank 14 to absorb chlorine gas. The tail gas from tail gas treatment tank 17-1 is then directed to tail gas treatment tank 17-2 for environmentally friendly treatment. Tail gas treatment tank 17-2 is loaded with sodium hydroxide solution 31 and is specifically designed to absorb and neutralize the acidic tail gas escaping from the various tanks for environmentally friendly treatment.

[0147] Sensors 22-1, 22-2, 22-3, and 22-4 are installed in etching production line 1. Sensor 22-1 is a pH meter, sensor 22-2 is a hydrometer, sensor 22-3 is an ORP meter, and sensor 22-4 is a thermometer. Sensors 22-5 and 22-6 are also installed in mixing exchange tank 14. Sensor 22-5 is a liquid level gauge, and sensor 22-6 is a thermometer. Sensor 22-7 is installed in tail gas treatment tank 17-1. Sensor 22-7 is an ORP meter. Sensors 22-8 and 22-9 are installed in the intermediate tank area and cathode tank area, respectively. Sensor 22-8 is a hydrometer, and sensor 22-9 is a photoelectric colorimeter. During operation, each sensor feeds on-site detection data to the automatic detection and feeding controller 23 for processing and control, allowing the entire device to operate safely and automatically according to the pre-programmed process flow. Sensor 22-1 controls pump 32-1 to add etching solution stored in temporary storage tank 15-1 to the etching production line. Sensor 22-2 controls pump 32-12 to add etching regeneration solution 26 to temporary storage tank 15-3 of the etching production line. Sensors 22-4 and 22-6 control the opening and closing of hot and cold temperature exchangers 9-1 and 9-2, respectively. Sensor 22-8 detects the copper ion concentration of the solution in the intermediate tank to control the addition of solution by pump 32-7. Sensor 22-9 detects the copper ion concentration of the cathode electrolyte and controls the addition of solution by pump 32-9.

[0148] Pump 32-4, located in the pipeline leading from mixing exchange tank 14 to etching production line 1, is a variable frequency pump. Normally, the ORP value of the solution in mixing exchange tank 14 is set higher than the ORP value of the etching solution in the etching production line. When the etching solution's ORP value decreases during the copper etching reaction, pump 32-4 adjusts its speed and flow rate based on data from sensor 22-3 via automatic detection and dosing controller 23 to stabilize the etching solution's ORP value within the process settings. Furthermore, the specific gravity of the etching solution is set equal to the set value of the hydrometer in copper etching agent regeneration reaction monitor 8. When the hydrometer's value exceeds the set value, automatic detection and dosing controller 23 adjusts the program to increase the operating current of the electrolytic power supply, accelerating copper electrolysis. Excess chlorine gas generated by the increased current is then directed through tail gas treatment tank 17-1 and then to tail gas treatment tank 17-2 for environmental treatment.

[0149] Sensor 22-5 assists in controlling the on / off of pump 32-15 in the pipeline from the intermediate tank area to the temporary storage tank 15-3. When the liquid level gauge in the mixing and exchange tank reaches the high set point, pump 32-15 is turned on and pump 32-14 is turned off, pumping excess solution to the temporary storage tank 15-3 for temporary storage. Upon completion, the system is reset.

[0150] Pump 32-9 on the pipeline from the anode cell area to the cathode cell area is a time-controlled intermittent feeding pump. Its flow rate can be set according to on-site process conditions. Its function is to spray the anolyte containing a small amount of excess chlorine through the nozzle 41 into the cathode cell area and close to the separator B to oxidize and dissolve the cuprous chloride or sponge copper powder adhering to the separator membrane 6, thereby making the separator B of the electrolytic cell more unobstructed and improving the electrolysis efficiency.

[0151] The etching waste liquid 28 that needs to be electrolytically recovered and regenerated is an acidic copper chloride solution containing ammonium chloride, with an acidity of 1.8 mol / L, an ammonia ion concentration of 1 g / L, and a copper ion concentration of 140 g / L.

[0152] The cathode electrolyte 38 of the electrolytic cell is the overflow liquid of the anode electrolysis, and the copper ion concentration of the electrolyte is controlled to be 60g / L.

[0153] The copper ion concentration of the electrolyte in the middle tank area is controlled at 100g / L.

[0154] The main component of the etching sub-liquid 25 is a mixture of hydrochloric acid and ammonium chloride.

[0155] The ORP value of the etching working solution is set to 510mv in the process. The ORP value in the copper etching agent regeneration reaction monitor 8 is 580mv when the solution in the mixed exchange tank is normally produced. The ORP value in the copper etching agent regeneration reaction monitor 8 is set to 950mv when electrolytic copper is used to remove excess small amounts of chlorine oxidant.

[0156] The steps of recycling and regenerating the acidic copper chloride etching waste liquid using the working solution / composite electrolytic cell in this embodiment are as follows:

[0157] 1. Turn on the power supply of the device, and enable the automatic detection and feeding controller 23 to perform automatic detection. Etching solution 27 is injected into the etching production line, the anode and intermediate tanks of the composite electrolytic cell, the mixing exchange tank, the tail gas treatment tank 17-1, and the cathode tank. Brightener 36 is injected into the cathode tank of the electrolytic cell, so that the electrolytic anode and cathode are immersed in their respective electrolytes. The etching solution injected into the intermediate and cathode tanks cannot be immediately returned to the etching production line to participate in etching, and therefore is equivalent to etching waste liquid.

[0158] 2. Open all valves and start pumps 32-2, 32-3, 32-4, 32-5, 32-6, 32-7, 32-10 and 32-13 to circulate the solutions in the etching production line, electrolytic cell, mixed exchange cell and tail gas treatment cells 17-1 and 17-2. Pump 32-9 is shut down after the cathode cell area is full of liquid, and the liquid flow agitator 21 in the cathode cell area is started. During the operation, the overflow liquid of the anode electrolysis is controlled by sensor 22-9 to be added to the cathode cell area; the overflow liquid of the anode electrolysis is controlled by sensor 22-8 to be added to the cathode cell area. The mixed solution of the etching working solution and the overflowed anodic electrolysis solution in the mixed exchange tank area is added to the intermediate tank area; according to the process set temperature values ​​of sensors 22-4 and 22-6, the hot and cold temperature exchangers 9-1 and 9-2 in the etching production line and the mixed exchange tank are controlled to heat the etching working solution to 50°C. Sensor 22-1 controls pump 32-1 to add etching sub-liquid to control the etching working solution at 1.8 mol / L. Sensor 22-2 controls the addition of etching regeneration sub-liquid 26 in the temporary storage tank 15-2 to the etching production line.

[0159] 3. Turn on the electrolysis power supply 7 to start the electrolysis operation. The anolyte is pumped back to the mixing exchange tank by pump 32-10 to pump the anolyte and the overflow from the middle tank by pump 32-14. Since the electrolysis separator A5 uses a reverse osmosis membrane, the chemical reaction of water electrolysis occurs mainly. Secondly, a small amount of chloride ions in the middle tank migrate through the electrolytic cell separator A5 under the action of the electric field to the anode tank area and react with the [OH] - Together, oxygen and chlorine are electrolytically deposited at the electrolytic anode, and the oxygen and chlorine react with the cuprous salt in the anode electrolyte to oxidize it. In addition, part of the copper ions and hydrogen ions in the electrolyte in the middle tank area pass through the electrolytic cell separator B6 under the action of the electric field force and migrate to the cathode tank area, causing metallic copper to be electrolytically deposited on the electrolytic cathode.

[0160] 4. As electrolysis proceeds, tail gas processor 17-1 absorbs chlorine gas emitted from each tank. The hydrometer in the copper-etching agent regeneration reaction monitor 8 of the mixed exchange tank feeds on-site detection parameters to the automatic detection and feeding controller 23 for processing. The program adjusts the operating current output of the electrolytic power supply 7 according to the specific gravity count value to balance the electrolytic copper extraction.

[0161] 5. The detection value of the sensor 22-3 of the etching production line is sent to the automatic detection and feeding controller 23 for processing and controlling the rotation speed of the pump 32-4, so that the ORP value of the etching working solution reaches the process requirement of 510mv to maintain the etching production. The regeneration speed of the copper etching agent in the etching working solution is controlled by the electrolytic cell through the linkage of the sensor 22-3 and the copper etching agent regeneration reaction monitor 8, so that the etching copper dissolving chemical reaction and the electrolytic oxidation copper extraction reaction reach a dynamic balance.

[0162] 6. During the continuous etching process, the automatic detection and feeding controller 23 will control the pump 32-9 according to the program timing to spray the anode electrolysis overflow liquid containing excess chlorine onto the separator B6 in the cathode tank area, so as to make the electrolysis separator B6 unobstructed and improve the electrolysis efficiency.

[0163] 7. The overflowed liquid from cathode electrolysis is drained into temporary storage tank 15-2 for subsequent treatment to become etching regeneration sub-liquid. The acid waste gas A escaping from each tank is drained into tail gas treatment tank 17-2 for environmental protection treatment.

[0164] 8. After etching, the circuit board 44 is removed from the etching production line, the etching production line, the electrolytic cell and other operating equipment are shut down, and the electrolytic copper blocks are collected from the cathode tank area of ​​the electrolytic cell.

[0165] Using the device of this embodiment and operating according to the above steps, during the process, the etching working liquid circulates into the mixing exchange tank and reacts with the electrolyte rich in chlorine overflowed from the anode tank area. The ORP meter of the etching production line 1 and the ORP meter and hydrometer combination sensor of the copper etching agent regeneration reaction monitor 8 on the mixing exchange tank are combined to control the etching reaction and electrolytic balance copper extraction process, so that the waste liquid can be recycled. During the electrolysis process, chlorine is temporarily electrolyzed to balance the electrolysis and extract copper. The amount of chlorine electrolyzed is small, and the sodium hypochlorite or ferric chloride solution produced by absorbing the chlorine can be fully used and consumed in the waste liquid treatment section of the enterprise. Moreover, the copper block obtained in the cathode tank area is flat and dense, and the copper block obtained by electrolysis does not obviously break or fall during the process of removing the electrolytic cathode.

[0166] Example 3

[0167] As shown in Figure 6, the device for recovering and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell in Example 3 includes an etching production line 1, an electrolytic cell body 2, an electrolytic anode 3, an electrolytic cathode 4, electrolytic cell separators A 5-1 and 5-2 and separators B 6-1 and 6-2, an electrolytic power supply 7, a copper etching agent regeneration reaction monitor 8, hot and cold temperature exchangers 9-1 and 9-2, five electrolytic cell sealing tank covers 10, an overflow gas-liquid separator 11, a water-oil separator 12, a solid-liquid separator 13, seven temporary storage tanks 15, four overflow buffer tanks 16, an exhaust gas treatment tank 17, a vacuum ejector 18, a liquid flow agitator 21, thirteen sensors 22, an automatic detection and feeding controller 23, six liquid spray pipes 41, an etching processing circuit board 44, and multiple pumps and valves.

[0168] The etching tank of the etching production line 1 has a solution storage capacity of 2 cubic meters.

[0169] The electrolytic cell of this embodiment is a composite electrolytic cell with a five-partition structure. Its cell body 2 is sequentially divided into a cathode cell zone, an intermediate cell zone, an anode cell zone, an intermediate cell zone, and a cathode cell zone by cell dividers A 5-1 and 5-2 and cell dividers B 6-1 and 6-2. Each of the five cell zones is provided with a cell sealing cover 10. Cell dividers A 5-1 and 5-2 are both anion exchange membranes, while cell dividers B 6-1 and 6-2 are both cation exchange membranes.

[0170] The electrolytic cell anode 3 is made of an insoluble titanium-based coating and is connected to the positive electrode of the electrolytic power supply 7. The two cathode materials 4-1 and 4-2 are both made of titanium plate electrodes and are connected to the negative electrode of the electrolytic power supply 7 respectively.

[0171] Etching line 1 is connected to mixing exchange tank 14 via a circulation pipeline through a water-oil separator 12, an overflow buffer tank 16-1, and a solid-liquid separator 13. Mixing exchange tank 14 is connected to the anode tank area via a circulation pipeline. Mixing exchange tank 14 is also connected to temporary storage tank 15-4 via temporary storage tank 15-2. Solid-liquid separator 13 filters the etching fluid, while water-oil separator 12 separates the organic oil layer from the etching fluid to prevent contaminants from damaging the electrolytic cell.

[0172] The copper etching agent regeneration reaction monitoring meter 8 is an ORP meter, which is arranged in the mixing exchange tank 14 and is used to control the electrolysis power supply 7.

[0173] Sensors 22-1, 22-2, 22-3, and 22-4 are installed within etching production line 1. Sensors 22-5 and 22-6 are installed within mixing exchange tank 14. Sensors 22-8 and 22-9 are installed in the two cathode tank areas. Sensor 22-1 is a pH meter used to control pump 32-1 to add etching solution to the etching production line. Sensor 22-2 is a hydrometer used to control pump 32-18 to add etching regeneration solution 26. Sensor 22-3 is an ORP meter used to control the speed of variable frequency pump 32-4 to adjust the flow rate. Sensor 22-4 is a thermometer used to control the hot and cold temperature exchanger 9-1 to adjust the temperature of the etching solution. Sensors 22-1, 22-2, 22-3, and 22-4 are all located within etching production line 1. The ORP meter of copper etching agent regeneration reaction monitor 8 is used to control the operating current of electrolytic power supply 7 or to turn it on and off. Sensor 22-6 is an ORP meter used for safety monitoring of chlorine gas leakage. Sensor 22-7 is a thermometer used to control and regulate the temperature of the solution in the mixing exchange tank. Sensor 22-5 is a liquid level gauge used to maintain the working liquid level in the mixing exchange tank and control pump 32-6 to pump excess solution in tank 14 to temporary storage tank 15-2 to prevent overflow in the mixing exchange tank. Sensors 22-8 and 22-9 are hydrometers that control pumps 32-13 and 32-12, respectively, to add overflow solution 29 from the intermediate tank to control the copper ion concentration of the cathode electrolyte. Data from these sensors is fed into controller 23 for processing.

[0174] The temporary storage tank 15 - 1 is used to store the etching sub-liquid and is connected to the etching production line 1 so as to add the etching sub-liquid thereto.

[0175] The temporary storage tank 15-4 receives the overflow liquid from the middle tank area and the etching waste liquid 28 of the temporary storage tank 15-2, and adds solution to the middle tank area. A sensor 22-10 and an ORP meter 22-11 are installed in the tank, wherein the sensor 22-10 is a liquid level meter and 22-11 is a hydrometer. The pump 32-7 is controlled according to the detection data to add the etching waste liquid 28 in the temporary storage tank 15-2 to the temporary storage tank 15-4 to adjust the copper ion concentration of the circulating electrolyte in the middle tank area.

[0176] The temporary storage tank 15-5 receives the electrolytic overflow liquid in the middle tank area and the cathode electrolytic overflow liquid of the temporary storage tank 15-4, and is used to oxidize the electrolytic overflow liquid in the middle tank area of ​​the electrolytic tank and the cathode electrolytic overflow liquid. A liquid level meter 22-12 and an ORP meter 22-13 are installed in the tank. During the process, the vacuum ejector 18 absorbs the chlorine gas escaping from other tanks to oxidize the electrolytic overflow liquid in the middle tank area of ​​the electrolytic tank and the cathode electrolytic overflow liquid to prepare an etching regeneration sub-liquid.

[0177] The temporary storage tank 15-3 is filled with hydrogen peroxide and is connected to oxidant spray pipes located in the cathode cell area and the intermediate cell area near the electrolytic cell separator B, as well as an oxidant spray pipe located in the intermediate cell area near the electrolytic cell separator A. The device of this embodiment sprays hydrogen peroxide through the oxidant spray pipes to clean and remove insoluble copper salts and sponge metal copper powder adhered to the electrolytic cell separators A and B, thereby keeping the electrolytic cell separators A and B unobstructed and improving the electrolysis efficiency.

[0178] The tail gas treatment tank 17 is loaded with sodium hydroxide solution 31 and is specifically used to absorb the acid gas escaping from each tank for environmental protection treatment.

[0179] The process sets the ORP value of the solution in the mixing exchange tank 14 to 670mv, which is higher than the ORP value of the etching working fluid in the etching production line, which is 550mv. When the ORP value of the etching working fluid in the etching production line decreases due to the copper corrosion reaction, the automatic detection and feeding controller 23 will adjust the flow rate by controlling the speed of the pump 32-4 on the pipeline from the mixing exchange tank 14 to the etching production line based on the detection data of the sensor 22-3 of the etching production line, so that the ORP value of the etching working fluid is stabilized during the etching process.

[0180] The pump 32-11 connected to the temporary storage tank 15-3 on each oxidant spray pipe is a time-programmed intermittent feed pump, whose flow rate can be set according to the on-site process. Hydrogen peroxide is sprayed through multiple oxidant spray pipes toward the two intermediate tank areas and the two cathode tank areas, near the electrolytic cell dividers A and B, oxidizing and dissolving the cuprous chloride and sponge copper powder adhering to the dividers. This allows for smoother flow between the electrolytic cell dividers A and B, thereby improving electrolysis efficiency.

[0181] The etching waste liquid 28 that needs to be electrolytically recovered and regenerated is an acidic copper chloride etching waste liquid containing ammonium chloride and sodium chloride, with an acidity of 2.5 mol / L, an ammonia ion concentration of 1 g / L, a Na ion concentration of 1 g / L, and a copper ion concentration of 120 g / L.

[0182] The cathode electrolyte 38 of the electrolytic cell is the etching waste liquid 28, and the cathode electrolyte is monitored by sensors 22-8 and 22-9 in the cathode cell area to maintain the copper ion concentration at 5g / L.

[0183] The copper ion concentration of the electrolyte in the middle tank area is controlled at 45g / L.

[0184] The main component of the etching sub-liquid 25 is a mixture of hydrochloric acid, ammonium chloride and sodium chloride.

[0185] The steps of recycling and regenerating the acidic copper chloride etching waste liquid using a composite electrolytic cell in this embodiment are as follows:

[0186] 1. Turn on the power of the device, automatically detect the feeding controller 23 for detection operation, and inject the etching working solution 27 as the starting electrolyte into the anode tank area, cathode tank area, intermediate tank area, mixed exchange tank and temporary storage tank 15-4 in the etching production line and the composite electrolytic cell, so that the electrolytic anode and the two electrolytic cathodes are immersed in their respective electrolytes.

[0187] 2. Open all valves, start pumps 32-3, 32-4, 32-5, 32-9, 32-10, 32-14 and two liquid flow agitators 12-1 and 12-2, so that the etching production line, electrolytic cell, and mixed exchange tank circulate, and heat the etching working solution in the etching production line and mixed exchange tank to 50°C.

[0188] 3. Turn on electrolysis power supply 7 to begin electrolysis. The anolyte is pumped to the mixing exchange tank via pump 32-9. Chloride ions in the intermediate tank electrolyte migrate to the anode tank under the influence of the electric field, causing an oxidation reaction in the anolyte. Copper and hydrogen ions in the intermediate tank electrolyte then migrate through electrolytic cell separators B 6-1 and 6-2 to the two cathode tanks, causing copper to be deposited at both cathodes. Automatic detection and feeding controller 23 controls pump 32-7 based on the value of sensor 22-11 to add etching waste liquid from temporary storage tank 15-2 to temporary storage tank 15-4, which is then transported to the intermediate tank to replenish the copper ion concentration in the circulating electrolyte in the intermediate tank.

[0189] 4. As the electrolysis proceeds, the chlorine gas escaping from multiple tanks is absorbed and processed by the vacuum ejector 18 installed in the temporary storage tank 15-5. The ORP meter in the copper etching agent regeneration reaction monitor 8 of the mixing exchange tank feeds the on-site detection value to the automatic detection and feeding controller 23 for processing, so as to control the working current output size or start and shut down of the electrolysis power supply 7, so that the ORP value of the solution in the mixing exchange tank reaches and stabilizes at 670mv; the etching chemical reaction and the electrolytic oxidation reaction are interlocked through the linkage control of the ORP meter of the copper etching agent regeneration reaction monitor 8 and the sensor 22-3.

[0190] 5. During the production process, the automatic detection and feeding controller 23 will regularly control the pump 32-11 to spray hydrogen peroxide onto both sides of the electrolytic cell separators B 6-1 and 6-2 in the cathode tank area and onto the electrolytic cell separators A 5-1 and 5-2 in the middle tank area, so that the electrolytic cell separators A and B are more unobstructed and the electrolysis efficiency is improved.

[0191] 6. The sensor 22-10 in the temporary storage tank 15-4 controls the pump 32-15 to pump the solution into the temporary storage tank 15-5 for oxidation treatment, and after being mixed, it becomes the etching regeneration sub-liquid and is reused in the etching production line.

[0192] 7. After etching, the circuit board 44 is removed from the etching line. After the etching work is completed, the etching production line, electrolytic cell and other operating devices are shut down and the cathode electrolytic copper block is collected.

[0193] The apparatus of this embodiment, through the copper etching agent regeneration reaction monitoring meter 8, enables the etching production line and the electrolytic cell to work in a linked manner, achieving the process effect of electrolyzing copper from acidic etching waste liquid without chlorine gas leakage and 100% recycling of the waste liquid. Moreover, the copper blocks obtained in the cathode tank area are flat and dense, and the copper blocks obtained by electrolysis do not significantly break or fall during the removal of the electrolytic cathode.

[0194] Example 4

[0195] As shown in FIG7 , the apparatus for recovering and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell in Example 4 includes an etching production line 1, electrolytic cell bodies 2-1 and 2-2, electrolytic anodes 3-1 and 3-2, electrolytic cathodes 4-1 and 4-2, electrolytic cell separators A 5-1 and 5-2, and electrolytic cell separators B. 6-1 and 6-2, electrolytic power supplies 7-2 and 7-3, copper etching agent regeneration reaction monitor 8, two hot and cold temperature exchangers 9, six electrolytic cell sealing tank covers 10, water-oil separator 12, solid-liquid separator 13, nine temporary storage tanks 15, nine overflow buffer tanks 16, tail gas treatment tank 17, vacuum ejector 18, two spray towers 19, two liquid flow agitators 21, seventeen sensors 22, automatic detection and feeding controller 23, dispersion pipe 39, electrolytic cell 42 with common anode tank area and cathode tank area and electrolytic power supply 7-1, etching processing circuit board 44, multiple pumps and valves.

[0196] The etching tank of the etching production line 1 has a solution storage capacity of 2 cubic meters.

[0197] This embodiment is a device that uses a conventional electrolytic cell and two composite electrolytic cells connected in series. The first stage is a conventional electrolytic cell 42 divided into an anode cell area and a cathode cell area. The second and third stages are composite electrolytic cells with a three-partition structure. The electrolytic cell body is divided into an anode cell area, an intermediate cell area and a cathode cell area by electrolytic cell separators A and B, and an electrolytic cell sealing cover is provided above each cell area.

[0198] The three independent electrolytic cells are connected in series via a series of pipelines: the cathode electrolyte of the first-stage electrolytic cell flows through overflow buffer tank 16-3 and temporary storage tank 15-4 to the cathode and intermediate sections of the second-stage electrolytic cell. The cathode electrolyte and electrolyte in the intermediate section of the second-stage electrolytic cell flow through their respective overflow buffer tanks to temporary storage tank 15-5, and then to the cathode section of the tertiary electrolytic cell. Furthermore, the cathode electrolyte overflowing from the third-stage electrolytic cell flows to temporary storage tank 15-6, where it is oxidized by chlorine and then flows to temporary storage tank 15-7. It then merges with the electrolyte overflow from the intermediate section of the third electrolytic cell and flows back to the intermediate section of the third electrolytic cell. The solution in temporary storage tank 15-7 enters temporary storage tank 15-8, where it further absorbs chlorine to become regenerated etching solution, which then flows through temporary storage tank 15-9 to etching production line 1.

[0199] The electrolytic cell 42 of this embodiment is not used for copper electrolysis; it is only used to reduce the concentration of copper etchants in the waste etching solution. The cathode electrolysis overflow from the electrolytic cell 42 is directed to the middle and cathode zones of the electrolytic cell body 2-1 for copper extraction. The combined overflow from the middle and cathode zones of the electrolytic cell body 2-1 is then directed to the cathode and middle zones of the electrolytic cell body 2-2 for further copper electrolysis. Because the cathode electrolysis overflow from the electrolytic cell 42, which is directed to the middle and cathode zones, contains little or no copper etchant, this series-type electrolytic copper extraction process results in a smoother and denser surface for the electrolyzed copper plate.

[0200] Etching line 1 is connected to a mixing exchange tank 14 via a circulation pipeline through a water-oil separator 12, an overflow buffer tank 16-1, and a solid-liquid separator 13. Mixing exchange tank 14 is connected to the anode tanks of three independent electrolytic cells via circulation pipelines. The solid-liquid separator 13 filters the etching fluid, while the water-oil separator 12 separates the organic oil layer from the etching fluid to prevent contaminants from damaging the electrolytic cells.

[0201] In the composite electrolytic cell used in this embodiment, the electrolytic cell separators A 5-1 and 5-2 are anion exchange membranes, the electrolytic cell separator B 6-1 is a filter cloth, and the electrolytic cell separator 6-2 is a nanofiltration membrane. The filter cloth and nanofiltration membrane are preferably products with dense mesh and good water-isolating effect.

[0202] The materials of the composite electrolytic cell anodes 3-1 and 3-2 are both titanium-based coated insoluble anodes and are respectively connected to the positive electrodes of the electrolytic power supplies 7-2 and 7-3. The materials of the cathode materials 4-1 and 4-2 are both titanium metal electrodes and are respectively connected to the negative electrodes of the electrolytic power supplies 7-2 and 7-3.

[0203] The electrolytic cell 42 has a titanium-coated anode, a titanium plate cathode, and an anion exchange membrane separator. The anode is connected to the positive electrode of an electrolytic power supply 7-1, and the cathode is connected to the negative electrode of an electrolytic power supply 7-2. Sensor 22-8, an ORP meter, is installed in the cathode tank area to assist in controlling the on / off of electrolytic power supply 7-1. Specifically, when the liquid level gauge (i.e., sensor 22-17) in temporary storage tank 15-3 reaches its lower limit, the ORP value of the cathode electrolyte decreases as the electrolytic operation progresses, indicating that no copper is deposited on the cathode. The electrolytic power supply 7-1 is then controlled and shut down based on the data from sensor 22-8.

[0204] The copper etching agent regeneration reaction monitoring meter 8 is an ORP meter, which is arranged in the mixing exchange tank 14 and is used to control the working status of the electrolysis power supplies 7-1, 7-2 and 7-3.

[0205] Sensors 22-1, 22-2, 22-3, and 22-4 are installed within etching production line 1. Sensor 22-1 is a pH meter, used to control pump 32-1 to add etching solution 25. Sensor 22-2 is a hydrometer, used to control pump 32-27 to add etching regeneration solution 26. Sensor 22-3 is an ORP meter, used to control the speed of variable frequency pump 32-4 to adjust the flow rate or shut down. Sensor 22-4 is a thermometer, used to adjust the operating temperature of the etching solution via hot and cold temperature exchanger 9-1. Sensors 22-5, 22-6, and 22-7 are installed within mixing exchange tank 14. Sensor 22-5 is an ORP meter, used to safely monitor chlorine gas leakage. Sensor 22-6 is a thermometer, used to control hot and cold temperature exchanger 9-2 to adjust the temperature of the solution in the mixing exchange tank. Sensor 22-7 is a liquid level gauge used to maintain the liquid level in the mixing exchange tank and control pump 32-7 to pump excess solution in the tank to temporary storage tank 15-3 to prevent overflow of the mixing exchange tank. Sensor 22-8 is an ORP meter, located in the cathode tank area of ​​electrolytic cell 42. Its set value is 480mV, which controls pump 32-9 to add etching waste liquid 28. Sensor 22-9 is a hydrometer, located in the middle tank area of ​​electrolytic cell body 2-1. It is used to maintain the copper ion concentration of the electrolyte in the middle tank area at 50g / L and controls pump 32-13 to add solution 40-1 to maintain this concentration. Sensor 22-10 is a hydrometer, located in the cathode tank area of ​​electrolytic cell body 2-1. It monitors and maintains the copper ion concentration of the cathode electrolyte at 50g / L and controls copper ion replenishment. Sensor 22-11 is a hydrometer, located in the cathode tank section of electrolytic cell 2-2, to monitor the copper ion concentration of the cathode electrolyte to maintain it at 30 g / L. Sensors 22-14 and 22-15 are located in temporary storage tank 15-7 and serve as a hydrometer and level gauge, respectively. Specifically, the intermediate tank section of electrolytic cell 2-2 is connected to temporary storage tank 15-7 via a pipeline loop. During operation, sensor 22-14 detects the circulating solution and controls the copper ion concentration at 12 g / L. Pump 32-22 is controlled to add solution to temporary storage tank 15-6 to adjust the copper ion concentration in the intermediate tank section. Sensors 22-12 and 22-13 are located in temporary storage tank 15-6 and serve as an ORP meter and level gauge, respectively. Data from these multiple sensors is fed into the automatic detection and feeding controller 23 for processing, which controls the electrolysis power supply, pumps, and hot and cold temperature exchangers.

[0206] The vacuum ejector 18 is provided in the temporary storage tank 15-6, and is used to absorb the residual chlorine tail gas escaping from part of the tank to oxidize the cathode electrolysis overflow liquid, thereby reducing the concentration of cuprous chloride in the solution in the middle tank area of ​​the electrolytic cell body 2-2.

[0207] The tail gas treatment tank 17 is loaded with sodium hydroxide solution 31, which is specially used to absorb the acidic waste gas escaping from multiple tanks for neutralization and environmental protection treatment.

[0208] Pump 32-4, located in the pipeline from mixing exchange tank 14 to the etching line, is a variable frequency pump. Due to the process setting, the ORP value of the solution in mixing exchange tank 14 is 800 mV, which is higher than the ORP value of the etching process fluid in the etching line by 600 mV. During the etching process, the automatic detection and feeding controller 23 controls the speed of pump 32-4 and adjusts the flow rate based on the data from sensor 22-3 to keep the ORP value of the etching process fluid stable at the set value of 600 mV.

[0209] The mixing exchange tank 14 is provided with a dispersion pipe 39 to reduce the problem of excessively high local chlorine concentration in the solution.

[0210] The etching waste liquid that needs to be electrolytically recovered and regenerated is an acidic copper chloride etching solution containing ferric chloride, with an acidity of 1.8 mol / L, a copper ion concentration of 130 g / L, and an iron ion concentration of 30 g / L.

[0211] The main component of the etching sub-liquid 25 is a mixture of hydrochloric acid and ferric chloride, which is stored in the temporary storage tank 15 - 1 and added to the etching production line 1 .

[0212] The steps of recycling and regenerating the acidic copper chloride etching waste liquid using a composite electrolytic cell in this embodiment are as follows:

[0213] 1. Turn on the power of the device to enable the automatic detection and feeding controller 23 to perform automatic detection operation, and inject the etching working solution 27 as the starting electrolyte into the etching production line, the anode and cathode tank areas of the electrolytic cell 42, the anode tank area, the cathode tank area, the intermediate tank area, the mixed exchange tank, the temporary storage tank 15-6, and the temporary storage tank 15-7, so that each electrolytic anode and each electrolytic cathode of the three electrolytic cells are immersed in their respective electrolytes.

[0214] 2. Open all valves, start pumps 32-2, 32-3, 32-4, 32-5, 32-6, 32-8, 32-9, 32-14, 32-18, 32-19, 32-21, 32-23 and two liquid flow agitators 21-1 and 21-2 to circulate the solutions in the etching production line, three electrolytic cells, mixed exchange cell and other circulation cells, and heat the etching working solution in the etching production line and mixed exchange cell to 50°C.

[0215] 3. Turn on electrolysis power supplies 7-1, 7-2, and 7-3 to conduct electrolysis. The three anode electrolytes containing a small amount of excess chlorine are pumped into a mixing exchange tank. A solution disperser 39 is installed in the mixing exchange tank to accelerate solution mixing. Chloride ions in the electrolytes in the cathode tank area of ​​the electrolytic cell 42 and the intermediate tank area of ​​the composite electrolytic cell migrate to their respective anode tank areas under the action of the electric field force, causing the anode electrolytes to undergo oxidation reactions. Meanwhile, some copper ions and hydrogen ions in the electrolytes in the two intermediate tank areas migrate through the electrolytic cell separators B 6-1 and 6-2, respectively, to the cathode tank areas, where metallic copper is electrolytically deposited on the cathodes.

[0216] 4. As the electrolysis proceeds, a small amount of anode electrolytic chlorine is absorbed by the vacuum ejector 18 as a gas-liquid mixture to oxidize the solution in the temporary storage tank 15-6. The remaining chlorine after the reaction is drained into the temporary storage tank 15-8 for further absorption and oxidation treatment of the etching regeneration sub-liquid.

[0217] 5. The tail gas treatment tank 17 treats the acidic waste gas emitted from some tanks for environmental protection.

[0218] 6. The etched circuit board 44 is removed from the etching production line. After the etching work is completed, the etching production line, electrolytic cell and other operating devices are shut down, and the electrolytic copper blocks are collected from the cathode tank areas of the two composite electrolytic cells.

[0219] The above-described apparatus utilizes three independent electrolytic cells in series to electrolyze and regenerate copper chloride etching wastewater. This achieves the process of electrolyzing copper from acidic etching wastewater without chlorine gas leakage and 100% recycling of the wastewater. Furthermore, the copper blocks obtained in the cathode cell area are smooth and dense, and the copper blocks produced during the removal of the electrolytic cathode exhibit no noticeable breakage or drop.

[0220] Example 5

[0221] The apparatus of Example 1 was used and the method of Example 1 was repeated. The difference between this embodiment and Example 1 lies in that a copper sulfate solution was used as the initial cathode electrolyte, and a mixed solution of etching waste liquid and water in a mass ratio of 1:1 was used as the initial intermediate tank electrolyte. During the electrolysis process, the copper ion concentration of the intermediate tank electrolyte was controlled to be 90 g / L, and etching waste liquid was added to the intermediate tank based on the measured copper ion concentration of the intermediate tank electrolyte. The lower limit of the cathode electrolyte copper ion concentration was set to 20 g / L, and the upper limit was set to 80 g / L. Copper sulfate was added to the cathode tank based on the measured copper ion concentration of the cathode electrolyte. During the electrolysis process, the anolyte was manually tested to monitor the redox potential of the anolyte to be ≤1000 mV.

[0222] After electrolysis, the copper blocks obtained in the cathode tank area are flat and dense. During the process of removing the electrolytic cathode, the copper blocks obtained by electrolysis do not obviously break or fall off. At the same time, the process effect of no chlorine gas precipitation during copper electrolysis and recycling of etching waste liquid is achieved.

[0223] Example 6

[0224] The apparatus of Example 1 was used and the method of Example 1 was repeated. The difference between this embodiment and Example 1 is that a mixed solution of copper sulfate and copper chloride was used as the initial cathode electrolyte, and a mixed solution of etching waste liquid, water, and hydrochloric acid was used as the initial intermediate tank electrolyte. During the electrolysis process, the copper ion concentration of the intermediate tank electrolyte was controlled to be 90 g / L, and based on the measured copper ion concentration of the intermediate tank electrolyte, a solution obtained by electrochemically reducing etching waste liquid and water in a mass ratio of 2:1 was added to the intermediate tank; the copper ion concentration of the cathode electrolyte was 30 g / L, and based on the measured copper ion concentration of the cathode electrolyte, a mixed solution of copper sulfate and copper chloride was added to the cathode tank. During the electrolysis process, the anolyte was manually tested to monitor the redox potential of the anolyte to be ≤1000 mV.

[0225] After electrolysis, the copper blocks obtained in the cathode tank area are flat and dense. During the process of removing the electrolytic cathode, the copper blocks obtained by electrolysis do not obviously break or fall off. At the same time, the process effect of no chlorine gas precipitation during copper electrolysis and recycling of etching waste liquid is achieved.

Claims

1. A method for recycling and regenerating acid copper chloride etching waste liquid using a composite electrolytic cell, characterized in that: The following steps are involved: (1) A composite electrolytic cell is used, wherein the composite electrolytic cell is divided into an anode cell area, an intermediate cell area and a cathode cell area, wherein the intermediate cell area is arranged between the anode cell area and the cathode cell area; an electrolytic cell separator A is used to separate the anode cell area and the intermediate cell area, and an electrolytic cell separator B is used to separate the intermediate cell area and the cathode cell area; an electrolytic anode is placed in the anode cell area and connected to the positive electrode of an electrolytic power source, and an electrolytic cathode is placed in the cathode cell area and connected to the negative electrode of the electrolytic power source; (2) During the etching operation, the electrolytic power supply is turned on according to the process control, the anode tank area and the etching production line form a circulating liquid flow, the etching working liquid is used as the anode electrolyte to be oxidized in the circulating flow to regenerate the copper etching agent, and the electrolyte solution containing copper ions is used as the cathode electrolyte; Use: ① Etching waste liquid, ② The solution obtained by mixing the etching waste liquid with water and / or other electrolytes, ③The solution obtained after the electrochemical reaction of the solution ① above, ④ The solution obtained after the electrochemical reaction of the above solution ②, At least one of the four solutions is used as the electrolyte in the middle tank area, so that the copper ions in the electrolyte in the middle tank area pass through the electrolytic cell separator B into the cathode tank area under the action of the electric field force and are electrolyzed into metallic copper on the electrolytic cathode.

2. The method for reclaiming and regenerating acidic cupric chloride etching waste liquid with a composite electrolytic cell according to claim 1, characterized in that: The electrolytic cell separator A is at least one of an anion exchange membrane, a bipolar membrane, and a reverse osmosis membrane; the electrolytic cell separator B is at least one of a cation exchange membrane, a filter cloth, a filter membrane, and a reverse osmosis membrane, so as to facilitate the copper ions in the middle tank area to enter the cathode tank area.

3. The method for reclaiming and regenerating acidic cupric chloride etching waste liquid with a composite electrolytic cell according to claim 2, characterized in that: The copper ion concentration of the electrolyte in the middle tank area is 8 to 185 g / L, and the copper ion concentration of the cathode electrolyte is 5 to 185 g / L.

4. The method for reclaiming and regenerating acidic cupric chloride etching waste liquid with a composite electrolytic cell according to claim 3, characterized in that: The generation of chlorine gas is controlled by controlling the redox potential of the anolyte.

5. The method for reclaiming and regenerating acidic cupric chloride etching waste liquid with a composite electrolytic cell according to claim 4, characterized in that: At least two or more independent electrolytic cells are combined in series, wherein at least one electrolytic cell is the composite electrolytic cell, and the other electrolytic cells except the composite electrolytic cell are electrolytic cells having only an anode cell area and a cathode cell area, and the electrolyte overflowing from the cathode cell area and / or the middle cell area of ​​the preceding electrolytic cell is used as the electrolyte of the cathode cell area and / or the middle cell area of ​​the succeeding electrolytic cell.

6. The method for recycling and regenerating acidic cupric chloride etching waste liquid by using a composite electrolytic cell according to claim 5, characterized in that: During the electrolysis process, the copper ion concentration of the cathode electrolyte is controlled. When the copper ion concentration of the cathode electrolyte is lower than a set value, at least one of the etching waste liquid, the electrolyzed intermediate tank electrolyte, and the electrolyzed cathode electrolyte of the previous electrolytic tank is added to the cathode tank area.

7. The method for reclaiming and regenerating acidic cupric chloride etching waste liquid with a composite electrolytic cell according to claim 6, characterized in that: The composite electrolytic cell adopts one or more of the following three structures: ① Three-partition structure, that is, there is a set of electrolytic cell partitions A and B inside the electrolytic cell, and they are set as anode cell area, middle cell area, cathode cell area in the order or reverse order of connection with the electrolytic power supply; ② Symmetrical five-partition structure, that is, there are two sets of electrolytic cell partitions A and electrolytic cell partitions B inside the electrolytic cell, and they are sequentially arranged as cathode cell area, middle cell area, anode cell area, middle cell area, and cathode cell area according to the connection mode of electrolytic power supply; ③ Symmetrical five-partition structure, that is, there are two sets of electrolytic cell partitions A and electrolytic cell partitions B inside the electrolytic cell, and they are arranged in sequence as anode cell area, middle cell area, cathode cell area, middle cell area, and anode cell area according to the connection method of the electrolytic power supply.

8. The method for recycling and regenerating acidic cupric chloride etching waste liquid by using a composite electrolytic cell according to claim 7, characterized in that: During the electrolysis process, new electrolyte is added to the middle tank area, that is, at least one of the following four solutions is added: ① etching waste liquid, ② a solution obtained by mixing etching waste liquid with water and / or other electrolytes, ③ a solution obtained by electrochemical reaction of the above solution ①, and ④ a solution obtained by electrochemical reaction of the above solution ②.

9. The method for reclaiming and regenerating acidic cupric chloride etching waste liquid with a composite electrolytic cell according to claim 8, wherein At least one oxidant liquid spray pipe is added to at least one of the positions near the electrolytic cell separator B in the cathode cell area, the position near the electrolytic cell separator A in the middle cell area, and the position near the electrolytic cell separator B in the middle cell area, and an oxidizing solution is added to the position near the electrolytic cell separator in the cathode cell area and / or the middle cell area; The oxidizing solution is specifically an oxidizing agent and / or an electrolyzed anolyte.

10. The method for recovering and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell according to claim 9, characterized in that: A mixing exchange tank is added between the etching production line and the anode tank area, where the etching working solution and the anode electrolyte solution meet and flow; When the redox potential of the solution in the mixing exchange tank is set higher than the redox potential of the etching working solution in the process, a large amount of solution with a higher copper etching agent concentration is stored in a mixing exchange tank with a larger volume. During the etching process, the copper etching agent is quickly added to the etching working solution using the large mixing exchange tank to maintain the stability of the components and concentrations of the etching working solution.

11. The method for recycling and regenerating acidic copper chloride etching waste liquid by using a composite electrolytic cell according to claim 10, characterized in that: A dispersion tube is installed in the mixing exchange tank so that the anode electrolyte can be quickly and evenly dispersed in the mixing exchange tank after entering the dispersion tube.

12. The method for recycling and regenerating acidic copper chloride etching waste liquid by using a composite electrolytic cell according to claim 11, characterized in that: When the demand for electrolytic copper extraction is greater than the demand for electrochemical oxidation, the redox potential value of the solution in the mixed exchange tank is controlled to >900mv under safety monitoring to allow chlorine to precipitate from the system. After meeting the needs of the etching production line to regenerate the copper etching agent, the excess small amount of chlorine is drained out of the system for treatment or used for waste liquid treatment within the enterprise.

13. A device for recycling and regenerating acid copper chloride etching waste liquid using a composite electrolytic cell, comprising an electrolytic cell and an etching production line, characterized in that: The electrolytic cell is a composite electrolytic cell, specifically an electrolytic device in which a cell body and an electrolytic power source are integrated. The cell body is divided into an anode cell area, an intermediate cell area and a cathode cell area, wherein the intermediate cell area is arranged between the anode cell area and the cathode cell area; an electrolytic anode and an electrolytic cathode are respectively arranged in the anode cell area and the cathode cell area, wherein the electrolytic anode and the electrolytic cathode are respectively connected to the positive electrode and the negative electrode of the electrolytic power source; an electrolytic cell separator A is used to separate the anode cell area and the intermediate cell area, and an electrolytic cell separator B is used to separate the intermediate cell area and the cathode cell area; The etching production line is connected to the anode tank area of ​​the composite electrolytic cell through a pipeline to form a liquid circulation loop; It also includes a copper etching agent regeneration reaction monitoring meter, which is used to control the oxidation regeneration reaction of the copper etching agent in at least one of the anode tank area, the etching production line, the container connected to the anode tank area and / or the etching production line, and the container arranged on the connecting pipeline between the etching production line and the anode tank area.

14. The device for recovering and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell according to claim 13, characterized in that: The composite electrolytic cell adopts one or more of the following three structures: ① Three-partition structure, that is, there is a set of electrolytic cell partitions A and B inside the electrolytic cell, and they are set as anode cell area, middle cell area, cathode cell area in the order or reverse order of connection with the electrolytic power supply; ② Symmetrical five-partition structure, that is, there are two sets of electrolytic cell partitions A and electrolytic cell partitions B inside the electrolytic cell, and they are sequentially arranged as cathode cell area, middle cell area, anode cell area, middle cell area, and cathode cell area according to the connection mode of electrolytic power supply; ③ Symmetrical five-partition structure, that is, there are two sets of electrolytic cell partitions A and electrolytic cell partitions B inside the electrolytic cell, and they are arranged into anode cell area, middle cell area, cathode cell area, middle cell area, and anode cell area in sequence according to the connection method of the electrolytic power supply.

15. The device for recovering and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell according to claim 14, characterized in that: The electrolytic cell separator A is at least one of an anion exchange membrane, a bipolar membrane, and a reverse osmosis membrane. The electrolytic cell separator B is at least one of a cation exchange membrane, a reverse osmosis membrane, a filter cloth, and a filter membrane; The material of the electrolytic anode is an insoluble anode, and the material of the electrolytic cathode is at least one of copper, titanium, and an electrode material with metal copper coated on the surface.

16. The device for recovering and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell according to claim 15, characterized in that: At least one oxidant liquid spray pipe is added at least one of the positions near the electrolytic cell separator B in the cathode cell area, near the electrolytic cell separator A in the middle cell area, and near the electrolytic cell separator B in the middle cell area, and an oxidizing solution is added to the cathode cell area and / or the middle cell area to dissolve the cuprous chloride solid and metallic copper powder adhering to the electrolytic cell separator.

17. The device for recovering and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell according to claim 16, characterized in that: A mixing exchange tank is added, and the mixing exchange tank is connected to the etching production line and the anode tank area through pipelines for circulating pipeline liquid flow. The two are connected through the mixing exchange tank to exchange solutions.

18. The device for recovering and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell according to claim 17, characterized in that: A dispersion tube is added to the mixing exchange tank so that the solution from the anode tank area is added to the dispersion tube in the mixing exchange tank. The dispersion tube is provided with one or more liquid outlets at a position below the liquid surface.

19. The device for recovering and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell according to claim 18, characterized in that: An overflow gas-liquid separator is additionally provided for each tank area of ​​the electrolytic cell. The overflow gas-liquid separator can connect the gas pressure in each tank area of ​​the electrolytic cell with the atmospheric pressure, thereby reducing the damage to the separator of the electrolytic cell caused by the pressure difference.

20. The device for recovering and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell according to claim 19, characterized in that: A sensor is added, wherein the sensor includes at least one of a thermometer, a liquid level meter, an acidity meter, a hydrometer, a redox potentiometer, a photoelectric colorimeter, and a chlorine gas detector.

21. The device for recovering and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell according to claim 20, characterized in that: A monitoring sensor for the copper ion concentration of the electrolyte in the middle tank area is added to maintain the copper ion concentration of the electrolyte in the middle tank area so that the electrolytic cell can work normally; The monitoring sensor is at least one of a hydrometer, a redox potentiometer, and a photoelectric colorimeter; a circulating flow tank for electrolyte in the middle tank area is provided at the same time, the circulating flow tank for electrolyte in the middle tank area is connected with the middle tank area by a pipeline to form a liquid flow circulation, and a monitoring sensor for the copper ion concentration of electrolyte in the middle tank area is provided in the circulating flow tank for electrolyte in the middle tank area; A monitoring sensor for the copper ion concentration of the electrolyte in the cathode tank area is added to maintain the copper ion concentration of the electrolyte in the cathode tank area so that a bright and smooth copper plate is deposited at the electrolytic cathode; The monitoring sensor is at least one of a hydrometer and a photoelectric colorimeter; a cathode tank area electrolyte circulation flow trough is provided at the same time, and the cathode tank area electrolyte circulation flow trough is connected with the cathode tank area by a pipeline to form a liquid flow circulation, and a monitoring sensor for the copper ion concentration of the cathode tank area electrolyte is provided in the cathode tank area electrolyte circulation flow trough.

22. The device for recovering and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell according to claim 21, characterized in that: An automatic detection and feeding controller is added, and the sensor signal input end of the automatic detection and feeding controller is connected to the sensor signal output end of the sensor, and the control signal output end of the automatic detection and feeding controller is connected to the electrolysis power supply, valve, and pump control signal input end of the device, so that the device can perform automated safe production and safety interlock monitoring according to the process flow.

23. The device for recovering and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell according to claim 22, characterized in that: Adding sealed tank covers to each tank area of ​​the electrolytic tank to collect and process the gas escaping from the electrolyte; Add hot and cold temperature exchangers to ensure that the temperature of the reaction liquid in each tank meets the process requirements; add stirring devices to ensure that the concentration and temperature of the reaction liquid are uniform; Add an exhaust gas processor to treat the exhaust gas generated in the device and reduce the pollution of harmful gases to the environment; A temporary storage tank is added and connected to the electrolytic cell and / or etching production line and / or mixed exchange tank for temporary storage of materials and use as a normal pressure chemical reaction tank.

24. The device for recovering and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell according to claim 23, characterized in that: A gas-liquid mixer is added to the mixing exchange tank and / or the temporary storage tank. The air intake pipe of the gas-liquid mixer is connected to at least one container in the device for draining gas and performing gas-liquid mixing reaction.

25. The device for recovering and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell according to claim 24, characterized in that: Add overflow buffer tanks to the electrolytic cells and / or etching production lines and / or mixed exchange tanks in the device to solve the problem of solution flow between containers in the device 26. The device for recovering and regenerating acidic copper chloride etching waste liquid using a composite electrolytic cell according to claim 25, characterized in that: At least two or more independent electrolytic cells are used in combination, specifically a composite electrolytic cell or a composite electrolytic cell and an electrolytic cell having only an anode cell area and a cathode cell area. The combined structure is that the cathode cell area and / or the intermediate cell area are connected in series with step-by-step pipelines between the electrolytic cells, so that the cathode electrolyte and / or the intermediate cell area electrolyte of the previous electrolytic cell flow to the cathode cell area and / or the intermediate cell area of ​​the next electrolytic cell.

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