Waste etching solution recycling treatment system and method

Abstract

The invention relates to the technical field of etching liquid electrolysis, in particular to a system and a method for recycling and treating waste etching liquid generated in an etching process. The treatment system comprises an electrolysis system; an anode chamber and a cathode chamber in the electrolysis system are separated by a polyester fiber anionic membrane with a socket structure, and the anode chamber and the etching production line form a first circulation loop through a driving pump and a pipeline; the cathode chamber and the etching waste liquid tank form a second circulation loop through a driving pump and a pipeline; a liquid level monitoring system and a pH adjusting system are arranged on the second circulation loop; the liquid level monitoring system is connected with a driving pump on the second circulation loop; meanwhile, a PID (Proportion Integration Differentiation) control system is also arranged, and the pH adjusting system and the liquid level monitoring system are both connected with the PID control system; the current intensity is adjusted through a PID control system, and the pH value in the etching waste liquid is controlled in a staged mode. The system is high in treatment capacity and low in treatment energy consumption, material consumption and energy consumption can be reduced, and great economic benefits and social benefits are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of etching liquid electrolysis, and in particular to a recycling and processing system and method for etching waste liquid generated in an etching process. Background Art

[0002] Etching is widely used in various high-tech product fields such as integrated circuit lead frames, surface mount, encoder grating fluorescent display screen display, microelectrode, mask plate, integrated circuit cover plate, cathode ray tube shadow mask, solder paste screen printing board, etc.

[0003] The main components of the etching solution are ferric chloride and hydrochloric acid, which are highly oxidizing and corrosive at a temperature of 50-60°C. During the etching process, metals such as nickel and chromium are oxidized by Fe 3+ Oxidized to Ni 2+ Cr 2+ , Fe 3+ Reduced to Fe 2+ Enter the etching solution. As Fe 3+ The decrease in concentration and Fe 2+ As the concentration increases, the etching efficiency decreases, the product quality does not meet the standard, and the etching liquid must be replaced or regenerated. For this reason, the etching process will produce a large amount of ferric chloride etching waste liquid.

[0004] At present, there are mainly the following treatment methods for ferric chloride etching waste liquid at home and abroad: selective precipitation method, solvent extraction method, crystallization roasting method, direct electrolysis method, and metal reduction method. These treatment methods have problems such as high production cost, immature process, and complex operation, which leads to low value of industrial promotion.

[0005] Regarding the direct electrolysis method, which is one of the above-mentioned treatment methods for etching solution, the ion membrane used in its electrolytic cell has very strict requirements on the composition, temperature, concentration, acidity and electrolysis pressure of the electrolyte due to its selective permeability. Both DuPont of the United States and Asahi Kasei of Japan use tetrafluoro fiber reinforced perfluorosulfonic acid and perfluorocarboxylic acid resin as composite membranes, which have very high requirements on the ion content of the electrolyte and the acidity and alkalinity of the solution, resulting in membrane poisoning or damage, thereby increasing the resistance of the membrane and shortening its service life.

[0006] The inventor's prior Chinese patent with publication number CN113373694A and patent number ZL202110458934.X discloses a preparation method and application of a novel etching liquid electrolytic anion membrane. In this scheme, a polyester fiber anion membrane is used in an electrolytic cell of a direct electrolysis method. Although the electrolytic cell using this membrane can achieve the advantages of strong processing capacity, greatly reduced resistance, voltage, and energy consumption increase, etc., the pressure balance of the cathode and cathode must be maintained during use, and the pressure difference cannot be greater than 100Pa, otherwise the cathode and cathode solutions in the polyester fiber anion membrane will be interchanged. Therefore, it is necessary to overcome the fluctuation of the circulation pump flow caused by current fluctuations and changes in solution concentration, otherwise it will cause the electrolytic cell pressure difference to increase, the cathode and cathode solutions to interlock, and the electrolysis effect to be lost. These factors make the practical operation very difficult.

[0007] Not only is the treatment of ferric chloride etching waste difficult, but also it contains about 3-5% Ni 2+ , 3-8% Fe 2+ If the ferric chloride etching waste liquid with ions is discharged in the form of waste liquid and is discharged as hazardous waste without treatment, it will not only cause environmental pollution but also cause a huge waste of resources.

[0008] Therefore, in view of the current status quo, corresponding improvements need to be made to the above-mentioned problems involved in the current etching process. Summary of the invention

[0009] The purpose of the present invention is to solve the problem that the ferric chloride etching waste liquid generated by the etching process in the background technology is not only difficult to treat, but also arbitrarily discharged to pollute the environment and cause a large amount of waste. A recycling and treatment system for etching waste liquid is provided. This treatment system can meet the requirements of anode and cathode pressure balance when the polyester fiber anion membrane is used, and achieve the advantages of a new electrolytic cell with strong treatment capacity, low resistance, voltage and energy consumption.

[0010] It can not only meet the pressure balance requirements of the cathode and anode when the polyester fiber anion membrane is used, but also achieve the advantages of strong processing capacity, low resistance, voltage and energy consumption of the new electrolytic cell. Oxidation reaction occurs at the anode: oxidize the divalent iron ions into trivalent iron ions, which are connected to the etching production line to recycle the etching solution; reduction reaction occurs at the cathode, and the pH value of the etching waste liquid is controlled in stages by controlling the electrolysis current and the electrolyte temperature. When the pH value reaches 3.5, 0.6%-1% citric acid-sodium citrate-sodium dihydrogen phosphate buffer is added in time to maintain the pH between 2.0 and 3.5, ensuring that the nickel alloy in the etching waste liquid is precipitated from the cathode plate, and the content can reach between 60% and 80%, generating considerable economic value and social efficiency; through a special socket-type electrolysis device, the nickel alloy can be recovered and the ion membrane can be replaced without removing the circulation pipeline and the tank body;.

[0011] Specifically, the present invention adopts the following technical solutions: A recycling and treatment system for etching waste liquid, the treatment system comprising an electrolysis system; the electrolysis system comprising an electrolytic cell provided with a plurality of electrolytic units, the electrolytic cell adopting a spigot-type structure, a polyester fiber anion membrane is provided between the anode chamber and the cathode chamber in the electrolytic unit to separate them, the polyester fiber anion membrane being a spigot-type structure; The anode chamber of the electrolysis system forms a first circulation loop with the etching production line through a driving pump and a pipeline; The cathode chamber of the electrolysis system forms a second circulation loop with the etching waste liquid tank through a driving pump and a pipeline; A liquid level monitoring system for monitoring the liquid level in the cathode chamber and a pH regulating system for regulating the pH in the cathode chamber are provided on the second circulation loop; the liquid level monitoring system is connected to the driving pump on the second circulation loop; The treatment system also includes a PID control system, and the pH adjustment system and the liquid level monitoring system are both linked to the PID control system.

[0012] Further preferably, the electrolysis system adopts a spigot-type electrolytic cell, which comprises a cell body, in which a plurality of electrolytic units are arranged, each electrolytic unit being divided into a cathode chamber and an anode chamber by an ion membrane separator of a spigot-type structure; the ion membrane separator is inserted into the cell body in an inserting manner; The cathode chamber is provided with a cathode feed port and a cathode discharge port, the cathode feed port is located at the lower part, and the cathode discharge port is located at the upper part, and the different cathode feed ports are connected to the etching waste liquid tank through a cathode distribution pipe through a pipeline; The anode chamber is provided with an anode feed port and an anode discharge port, wherein the anode feed port is located at the lower part, and the anode discharge port is located at the lower part. Different anode feed ports are connected through anode distribution pipes and then connected to the etching production line through pipelines.

[0013] Further preferably, a cathode discharge trough is provided at the cathode discharge port, and an anode discharge trough is provided at the anode discharge port, the cathode discharge trough is connected to the etching waste liquid tank through a pipeline, and the anode discharge trough is connected to the etching production line through a pipeline.

[0014] Further preferably, the electrolysis system includes an adjustable power supply, and the adjustable power supply is connected to the PID control system.

[0015] Further preferably, the ion membrane separator comprises a polyester fiber anion membrane separator, and the periphery of the polyester fiber anion membrane separator is clamped by an ion membrane clamp to form a clamp-shaped ion membrane separator.

[0016] Further preferably, the cell body is divided into a plurality of chambers by ion membrane separation, and vertical plates are arranged on the sides of the chambers, and the cathode feed port, cathode discharge port, anode feed port and anode discharge port are all arranged on the vertical plates.

[0017] Further preferably, the ion membrane clamping plate on the peripheral side of the polyester fiber anion membrane is fixed by bolts.

[0018] A processing method based on the above system, the method specifically comprises: Start the power supply and start the driving pump on the first circulation loop; circulate the etching liquid on the etching production line between the etching production line and the electrolysis system; The electrolysis system is started, and the etching solution is electrolyzed in the electrolysis system to generate an oxidation reaction, and the divalent iron ions in the etching solution are oxidized into trivalent iron ions, and the etching solution is then returned to the etching production line; The driving pump on the second circulation pump is started, and the etching waste liquid enters the electrolysis system from the etching waste liquid tank through the second circulation loop. In the electrolysis system, a reduction reaction occurs, and the trivalent iron ions in the cathode part are converted into divalent iron ions, and the nickel ions are converted into metallic nickel for recovery; The liquid level in the cathode chamber is monitored by a liquid level monitoring system, and the driving pump on the second circulation loop is controlled by a PID control system to keep the liquid level in the cathode chamber at a reasonable level; The real-time pH of the etching waste liquid is monitored by the pH adjustment system, and the current intensity is adjusted by the PID control system to control the pH value of the solution in the etching waste liquid in stages to maintain the pH between 2.0 and 3.5; When the pH reaches 3.5, a citric acid-sodium citrate-sodium dihydrogen phosphate buffer with a content of 0.6-1wt% of the etching waste liquid is added in time.

[0019] Further preferably, the molar ratio of each component in the citric acid-sodium citrate-sodium dihydrogen phosphate buffer is 16-20:1-2:1-2.

[0020] The beneficial effects of the present invention are: The treatment system uses an electrolytic cell with polyester fiber anion membrane, which has strong treatment capacity for ferric chloride etching waste liquid, low treatment energy consumption and long service life; The treatment system can convert the ferric iron ions in the cathode part into divalent iron ions and nickel ions into metallic nickel for recycling, and convert the divalent iron ions in the anode into ferric iron ions for recycling as regenerated etching liquid, thus realizing the recycling of waste and reducing production costs. The treatment system ensures the balance of anode and cathode pressure through automatic control, greatly improving the service life of polyester fiber anion membrane; The treatment system adopts a socket-type electrolysis device through improved design, so that the nickel alloy can be recovered and the ion membrane can be replaced without removing the circulation pipeline and the tank body, which greatly reduces the labor intensity and improves the utilization efficiency of the equipment; The treatment system produces no new wastewater or waste gas during the entire process of recycling the etching waste liquid, thereby achieving a truly green and environmentally friendly etching process, reducing the material and energy consumption of the equipment, and having significant economic benefits and social efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the processing system of the present invention.

[0022] Figure 2 It is an algorithm execution flow chart of the PID control system of the present invention.

[0023] Figure 3 It is a control principle block diagram of the PID control system of the present invention.

[0024] Figure 4 It is an overall schematic diagram of the socket-type electrolytic cell adopted in the present invention.

[0025] Figure 5 It is a cross-sectional schematic diagram of the socket-type electrolytic cell adopted in the present invention.

[0026] Figure 6 It is a top view schematic diagram of the socket-type electrolytic cell adopted in the present invention.

[0027] Figure 7 The figure is a schematic diagram of the ion membrane clamping plate of the socket-type electrolyzer adopted in the present invention.

[0028] Wherein: 1 electrolysis system, 101 electrolytic cell, 102 cell body, 103 anode chamber, 104 cathode chamber, 105 ion membrane separation, 106 anode panel, 107 cathode panel, 108 anode feed port, 109 cathode feed port, 110 anode discharge port, 111 cathode discharge port, 112 anode distribution pipe, 113 cathode distribution pipe, 114 vertical plate, 115 anode discharge trough, 116 cathode discharge trough, 117 adjustable power supply, 118 polyester fiber anion membrane, 119 ion membrane clamping plate, 120 bolts, 2 driving pump, 3 etching waste liquid tank, 4 liquid level monitoring system, 5 pH adjustment system, 6 etching production line, 7 PID control system. DETAILED DESCRIPTION

[0029] The representative embodiments shown in the accompanying drawings will now be further refined. It should be understood that the following description is not intended to limit the embodiments to a preferred embodiment. On the contrary, it is intended to cover alternatives, modifications and equivalents that may be included in the essence and scope of the embodiments defined by the appended claims.

[0030] The present invention first provides a system for recycling and treating etching waste liquid, and also provides a method for recycling and treating etching waste liquid using the system. Figure 1 -Attached Figure 7 .

[0031] First, the etching waste liquid recycling and treatment system is specifically: The invention comprises an electrolysis system 1; the electrolysis system 1 comprises an electrolytic cell 101 provided with a plurality of electrolysis units, and the electrolytic cell 101 adopts a spigot-and-socket structure. A polyester fiber anion membrane 118 is provided between the anode chamber 103 and the cathode chamber 104 in the electrolysis unit to separate them, and the polyester fiber anion membrane 118 is of a spigot-and-socket structure; specifically, the electrolysis system 1 adopts a spigot-and-socket electrolytic cell 101, and the spigot-and-socket electrolytic cell 101 comprises a cell body 102, and a plurality of groups of electrolysis units are provided in the cell body 102, and each group of electrolysis units is separated into a cathode chamber 104 and an anode chamber 103 by an ion membrane separator 105 of a spigot-and-socket structure; the ion membrane separator 105 is inserted into the cell body 102; The cathode chamber 104 is provided with a cathode feed port 109 and a cathode discharge port 111, the cathode feed port 109 is located at the lower part, the cathode discharge port 111 is located at the upper part, and different cathode feed ports 109 are connected to the etching waste liquid tank 3 through a cathode distribution pipe 113 through a pipeline; the anode chamber 103 is provided with an anode feed port 108 and an anode discharge port 110, the anode feed port 108 is located at the lower part, the anode discharge port 110 is located at the lower part, and different anode feed ports are connected through an anode distribution pipe 112 and then connected to the etching production line 6 through a pipeline.

[0032] The specific structure is: a cathode discharge trough 116 is provided at the cathode discharge port 111, and an anode discharge trough 115 is provided at the anode discharge port 110. The cathode discharge trough 116 is connected to the etching waste liquid tank 3 through a pipeline, and the anode discharge trough 115 is connected to the etching production line 6 through a pipeline.

[0033] The anode chamber 103 of the electrolysis system 1 forms a first circulation loop with the etching production line 6 through the driving pump 2 and the pipeline; The cathode chamber 104 of the electrolysis system 1 forms a second circulation loop with the etching waste liquid tank 3 through the driving pump 2 and the pipeline; The second circulation loop is provided with a liquid level monitoring system 4 for monitoring the liquid level of the cathode chamber 104 and a pH regulating system 5 for regulating the pH in the cathode chamber 104; the liquid level monitoring system 4 is connected to the driving pump 2 on the second circulation loop; At the same time, the processing system also includes an adjustable power supply 117 and a PID control system 7. The adjustable power supply 117, the pH adjustment system 5, the liquid level monitoring system 4, and the PID control system 7 are all linked. The algorithm execution flow chart of the control system is shown in FIG. Figure 2 As shown, the control principle is as follows Figure 3 shown.

[0034] Regarding the adopted ion membrane separator 105, its structure includes a polyester fiber anion membrane 118 separator, and the periphery of the polyester fiber anion membrane 118 separator is clamped by an ion membrane clamping plate 119 to form a clamped ion membrane separator 105. The tank body 102 is divided into a plurality of chambers by the ion membrane separator 105, and a vertical plate 114 is arranged on the side of the chamber, and the cathode feed port 109, the cathode discharge port 111, the anode feed port 108 and the anode discharge port 110 are all arranged on the vertical plate 114. The ion membrane clamping plate 119 on the peripheral side of the polyester fiber anion membrane 118 is fixed by bolts 120.

[0035] The above provides a processing system suitable for recycling and treating etching liquid. Based on the processing system, the processing method specifically includes: Start the power supply, start the driving pump 2 on the first circulation loop; circulate the etching liquid on the etching production line 6 between the etching production line 6 and the electrolysis system 1; The electrolysis system 1 is started, and the etching solution is electrolyzed in the electrolysis system 1 to generate an oxidation reaction, and the divalent iron ions in the etching solution are oxidized into trivalent iron ions, and the etching solution is then returned to the etching production line 6; The driving pump 2 on the second circulation pump is started, and the etching waste liquid enters the electrolysis system 1 from the etching waste liquid tank 3 through the second circulation loop. In the electrolysis system 1, a reduction reaction occurs, and the trivalent iron ions in the cathode part are converted into divalent iron ions, and the nickel ions are converted into metallic nickel for recovery; The liquid level in the cathode chamber 104 is monitored by the liquid level monitoring system 4, and the driving pump 2 on the second circulation loop is controlled by the PID control system 7 to keep the liquid level in the cathode chamber 104 at a reasonable level; The real-time pH of the etching waste liquid is monitored by the pH adjustment system 5, and the current intensity is adjusted by the PID control system 7 to control the pH value of the solution in the etching waste liquid in stages to maintain the pH between 2.0 and 3.5; When the pH reaches 3.5, a citric acid-sodium citrate-sodium dihydrogen phosphate buffer with a content of 0.6-1wt% of the etching waste liquid is added in time, and the molar ratio of each component in the citric acid-sodium citrate-sodium dihydrogen phosphate buffer is 16-20:1-2:1-2.

[0036] The following will discuss and analyze specific practical use cases.

[0037] Embodiment 1: Based on the above scheme, a recycling and treatment system for etching waste liquid is designed. Based on this system, the following methods are adopted: First, the power supply is started, and the driving pump 2 on the first circulation loop is started; the result of this is that the etching liquid on the etching production line 6 circulates between the etching production line 6 and the electrolysis system 1; Then, the electrolysis system 1 is started, the etching solution is electrolyzed in the electrolysis system 1 to generate an oxidation reaction, the divalent iron ions in the etching solution are oxidized into trivalent iron ions, and the etching solution is returned to the etching production line 6; The driving pump 2 on the second circulation pump is started, and the etching waste liquid enters the electrolysis system 1 from the etching waste liquid tank 3 through the second circulation loop. In the electrolysis system 1, a reduction reaction occurs, and the trivalent iron ions in the cathode part are converted into divalent iron ions, and the nickel ions are converted into metallic nickel for recovery; The liquid level in the cathode chamber 104 is monitored by the liquid level monitoring system 4, and the driving pump 2 on the second circulation loop is controlled by the PID control system 7 to keep the liquid level in the cathode chamber 104 at a reasonable level; The real-time pH of the etching waste liquid is monitored by the pH adjustment system 5, and the current intensity is adjusted by the PID control system 7 to control the pH value of the solution in the etching waste liquid in stages to maintain the pH between 2.0 and 3.5; When the pH reaches 3.5, a citric acid-sodium citrate-sodium dihydrogen phosphate buffer with a content of 0.6-1wt% of the etching waste liquid is added in time, and the molar ratio of each component in the citric acid-sodium citrate-sodium dihydrogen phosphate buffer is 16:1:1.

[0038] In this embodiment, a polyester fiber anion membrane is used to separate the anode and cathode. Under the conditions of a constant current of 600A / M2, an operating temperature of 50-60°C, balanced anode and cathode pressures, and a circulation flow rate of 5-10L / min, an etching waste liquid containing 30% ferric chloride, 10% ferrous chloride, 10% nickel chloride, and 8% chromium chloride is electrolyzed. The processing capacity is proportional to the total area of ​​the electrode plate of the electrolytic cell 101 and the current intensity, which conforms to the electrochemical principle. The recovery rate of nickel ions reaches 65%.

[0039] Embodiment 2: Based on the above scheme, a recycling and treatment system for etching waste liquid is designed. Based on this system, the following methods are adopted: First, the power supply is started, and the driving pump 2 on the first circulation loop is started; the result of this is that the etching liquid on the etching production line 6 circulates between the etching production line 6 and the electrolysis system 1; Then, the electrolysis system 1 is started, the etching solution is electrolyzed in the electrolysis system 1 to generate an oxidation reaction, the divalent iron ions in the etching solution are oxidized into trivalent iron ions, and the etching solution is returned to the etching production line 6; The driving pump 2 on the second circulation pump is started, and the etching waste liquid enters the electrolysis system 1 from the etching waste liquid tank 3 through the second circulation loop. In the electrolysis system 1, a reduction reaction occurs, and the trivalent iron ions in the cathode part are converted into divalent iron ions, and the nickel ions are converted into metallic nickel for recovery; The liquid level in the cathode chamber 104 is monitored by the liquid level monitoring system 4, and the driving pump 2 on the second circulation loop is controlled by the PID control system 7 to keep the liquid level in the cathode chamber 104 at a reasonable level; The real-time pH of the etching waste liquid is monitored by the pH adjustment system 5, and the current intensity is adjusted by the PID control system 7 to control the pH value of the solution in the etching waste liquid in stages to maintain the pH between 2.0 and 3.5; When the pH reaches 3.5, a citric acid-sodium citrate-sodium dihydrogen phosphate buffer with a content of 0.6-1wt% of the etching waste liquid is added in time, and the molar ratio of each component in the citric acid-sodium citrate-sodium dihydrogen phosphate buffer is 20:2:2.

[0040] In this embodiment, a polyester fiber anion membrane is used to separate the anode and cathode. Under the conditions of a constant current of 600A / M2, an operating temperature of 50-60°C, balanced anode and cathode pressures, and a circulation flow rate of 8L / min, an etching waste liquid containing 30% ferric chloride, 5% ferrous chloride, 8% nickel chloride, and 8% chromium chloride is electrolyzed. The processing capacity is proportional to the total area of ​​the electrode plates of the electrolytic cell 101 and the current intensity, which conforms to the electrochemical principle. The recovery rate of nickel ions reaches 60%.

[0041] Embodiment 3: Based on the above scheme, a recycling and treatment system for etching waste liquid is designed. Based on this system, the following methods are adopted: First, the power supply is started, and the driving pump 2 on the first circulation loop is started; the result of this is that the etching liquid on the etching production line 6 circulates between the etching production line 6 and the electrolysis system 1; Then, the electrolysis system 1 is started, the etching solution is electrolyzed in the electrolysis system 1 to generate an oxidation reaction, the divalent iron ions in the etching solution are oxidized into trivalent iron ions, and the etching solution is returned to the etching production line 6; The driving pump 2 on the second circulation pump is started, and the etching waste liquid enters the electrolysis system 1 from the etching waste liquid tank 3 through the second circulation loop. In the electrolysis system 1, a reduction reaction occurs, and the trivalent iron ions in the cathode part are converted into divalent iron ions, and the nickel ions are converted into metallic nickel for recovery; The liquid level in the cathode chamber 104 is monitored by the liquid level monitoring system 4, and the driving pump 2 on the second circulation loop is controlled by the PID control system 7 to keep the liquid level in the cathode chamber 104 at a reasonable level; The real-time pH of the etching waste liquid is monitored by the pH adjustment system 5, and the current intensity is adjusted by the PID control system 7 to control the pH value of the solution in the etching waste liquid in stages to maintain the pH between 2.0 and 3.5; When the pH reaches 3.5, a citric acid-sodium citrate-sodium dihydrogen phosphate buffer with a content of 0.6-1wt% of the etching waste liquid is added in time, and the molar ratio of each component in the citric acid-sodium citrate-sodium dihydrogen phosphate buffer is 16:2:1.

[0042] In this embodiment, a polyester fiber anion membrane is used to separate the anode and cathode. Under the conditions of a constant current of 500A / M2, an operating temperature of 50-60°C, balanced anode and cathode pressures, and a circulation flow rate of 5L / min, an etching waste liquid containing 40% ferric chloride, 5% ferrous chloride, 10% nickel chloride, and 8% chromium chloride is electrolyzed. The processing capacity is proportional to the total area of ​​the electrode plates of the electrolytic cell 101 and the current intensity, which conforms to the electrochemical principle. The recovery rate of nickel ions reaches 70%.

[0043] In the above-mentioned Examples 1, 2 and 3, the environment used is a pilot environment. When this solution is applied to an actual factory, 1000 tons of etching waste liquid can be processed annually, and 30-40 tons of metallic nickel containing about 70% can be extracted, which can save about 2.1-2.8 million yuan in costs.

[0044] In summary, it can be seen that the etching waste liquid recycling treatment system provided by the present invention, by using the electrolytic cell 101 of the polyester fiber anion membrane, has a strong treatment capacity for ferric chloride etching waste liquid, low treatment energy consumption, and a long service life; through the treatment system, the corresponding etching waste liquid is treated, the trivalent iron ions in the cathode part can be effectively converted into divalent iron ions, and the nickel ions can be converted into metallic nickel for recycling, and the divalent iron ions in the anode can be converted into trivalent iron ions for recycling as regenerated etching liquid, thereby realizing the recycling of waste and reducing production costs; at the same time, in the treatment process, no new waste water and waste gas are added, thereby realizing the true green and environmental protection of the etching process section, reducing the material consumption and energy consumption of the device, and having significant economic benefits and social efficiency.

[0045] It is obvious to those skilled in the art that certain modifications, combinations and variations can be made based on the above teachings.

Claims

1. A system for recycling and treating etching waste liquid, characterized in that: The treatment system comprises an electrolysis system (1); the electrolysis system (1) comprises an electrolysis cell (101) provided with a plurality of electrolysis units, the electrolysis cell (101) adopts a spigot-and-socket structure, a polyester fiber anion membrane (118) is provided between the anode chamber (103) and the cathode chamber (104) in the electrolysis unit to separate them, and the polyester fiber anion membrane (118) is a spigot-and-socket structure; The anode chamber (103) of the electrolysis system (1) forms a first circulation loop with the etching production line (6) through a driving pump (2) and a pipeline; The cathode chamber (104) of the electrolysis system (1) forms a second circulation loop with the etching waste liquid tank (3) through a driving pump (2) and a pipeline; A liquid level monitoring system (4) for monitoring the liquid level of the cathode chamber (104) and a pH adjustment system (5) for adjusting the pH in the cathode chamber (104) are provided on the second circulation loop; the liquid level monitoring system (4) is connected to the driving pump (2) on the second circulation loop; The treatment system further comprises a PID control system (7), and the pH adjustment system (5) and the liquid level monitoring system (4) are both linked to the PID control system (7).

2. The etching waste liquid recycling treatment system according to claim 1, characterized in that: The electrolysis system (1) adopts a spigot-type electrolytic cell (101), wherein the spigot-type electrolytic cell (101) comprises a cell body (102), wherein a plurality of electrolytic units are arranged in the cell body (102), and each electrolytic unit is divided into a cathode chamber (104) and an anode chamber (103) by an ion membrane separator (105) of a spigot-type structure; the ion membrane separator (105) is inserted into the cell body (102); A cathode feed port (109) and a cathode discharge port (111) are provided on the cathode chamber (104); the cathode feed port (109) is located at the lower part, and the cathode discharge port (111) is located at the upper part; and the different cathode feed ports (109) are connected to the etching waste liquid tank (3) through a cathode distribution pipe (113) via a pipeline; The anode chamber (103) is provided with an anode feed port (108) and an anode discharge port (110), wherein the anode feed port (108) is located at the lower part, and the anode discharge port (110) is located at the lower part. The different anode feed ports are connected through an anode distribution pipe (112) and then connected to the etching production line (6) through a pipeline.

3. The etching waste liquid recycling treatment system according to claim 1, characterized in that: A cathode discharge trough (116) is provided at the cathode discharge port (111), and an anode discharge trough (115) is provided at the anode discharge port (110); the cathode discharge trough (116) is connected to the etching waste liquid tank (3) via a pipeline, and the anode discharge trough (115) is connected to the etching production line (6) via a pipeline.

4. The etching waste liquid recycling treatment system according to claim 1, characterized in that: The electrolysis system (1) further comprises an adjustable power supply (117), and the adjustable power supply (117) is connected to the PID control system (7).

5. The etching waste liquid recycling treatment system according to claim 1, characterized in that: The ion membrane separator (105) comprises a polyester fiber anion membrane (118), and the periphery of the polyester fiber anion membrane (118) is clamped by an ion membrane clamp (119) to form a clamp-shaped ion membrane separator (105).

6. The etching waste liquid recycling treatment system according to claim 2, characterized in that: The tank body (102) is divided into a plurality of chambers by an ion membrane separator (105), and a vertical plate (114) is arranged on the side of the chamber. The cathode feed port (109), the cathode discharge port (111), the anode feed port (108) and the anode discharge port (110) are all arranged on the vertical plate (114).

7. The etching waste liquid recycling treatment system according to claim 1, characterized in that: The ion membrane clamping plate (119) on the circumferential side of the polyester fiber anion membrane (118) is fixed by bolts (120).

8. A processing method based on the system according to any one of the above claims, characterized in that: The method specifically comprises: Starting the power supply and starting the driving pump (2) on the first circulation loop; circulating the etching liquid on the etching production line (6) between the etching production line (6) and the electrolysis system (1); The electrolysis system (1) is started, and the etching solution is electrolyzed in the electrolysis system (1) to generate an oxidation reaction, and the divalent iron ions in the etching solution are oxidized into trivalent iron ions, and the etching solution is then returned to the etching production line (6); The driving pump (2) on the second circulation pump is started, and the etching waste liquid enters the electrolysis system (1) from the etching waste liquid tank (3) through the second circulation loop. In the electrolysis system (1), a reduction reaction occurs, and the trivalent iron ions in the cathode part are converted into divalent iron ions, and the nickel ions are converted into metallic nickel for recovery; The liquid level in the cathode chamber (104) is monitored by a liquid level monitoring system (4), and the driving pump (2) on the second circulation loop is controlled by a PID control system (7) to maintain the liquid level in the cathode chamber (104) at a reasonable level; The real-time pH value of the etching waste liquid is monitored by the pH adjustment system (5), and the current intensity is adjusted by the PID control system (7), so as to control the pH value of the solution in the etching waste liquid in stages and maintain the pH value between 2.0 and 3.5; When the pH reaches 3.5, a citric acid-sodium citrate-sodium dihydrogen phosphate buffer with a content of 0.6-1wt% of the etching waste liquid is added in time.

9. The processing method according to claim 8, characterized in that: The molar ratio of each component in the citric acid-sodium citrate-sodium dihydrogen phosphate buffer is 16-20:1-2:1-2.

Images