A recovery device and recovery system for silver etching solution

Abstract

The utility model provides a kind of recovery device and recovery system of silver etching liquid, including the tank, pretreatment unit and membrane capacitance deionization unit connected in sequence, the inlet of the tank is used to access silver etching liquid;The membrane capacitance deionization unit includes chamber, anode plate and cathode plate are oppositely arranged in the chamber, the surface of the anode plate is provided with anion exchange membrane, the surface of the cathode plate is provided with silver ion selective adsorption membrane, and the anode plate and the cathode plate are connected with power supply outside.The utility model is through the structural design of recovery device, can be used for recycling strong acid etching liquid, selectively adsorbs silver using membrane capacitance deionization technology, simple and efficient, under the action of electric field force, silver ion can be adsorbed to electrode surface, realize etching liquid recovery cycle, solve the problem of high cost, complex process, low recycling rate in prior art.

Description

Technical Field

[0001] This utility model belongs to the field of silver etching solution recycling technology, and relates to a silver etching solution recycling device and recycling system. Background Technology

[0002] In the display panel industry, acid silver etching solution is a high-concentration acid etching solution containing phosphoric acid, nitric acid, and acetic acid. It is used to etch silver in the ITO process. During the recycling of the etching solution, the silver ion content increases continuously, and some silver will precipitate, affecting the product yield. It is necessary to remove the silver particles and recycle the etching solution, which can save resources, reduce processing costs and pollution emissions.

[0003] Regarding the current state of etching solution recycling, existing technology CN120205052A discloses a production process for recovering electronic-grade phosphoric acid from waste etching solution. The apparatus includes a raw material storage tank, a multi-stage filtration system, a phosphoric acid evaporation kettle, a purification system, a mixed acid storage tank, and a neutralization reaction and crystallization system. The waste etching solution undergoes a multi-stage filtration system to remove large particulate impurities and then enters the evaporation kettle. Utilizing the difference in boiling points of the mixed acids, phosphoric acid is separated from volatile nitric acid and acetic acid. After purification, electronic-grade phosphoric acid is obtained. The recycling process requires evaporation and purification separation of three mixed acid solutions, making the process complex and energy-intensive.

[0004] Therefore, there is an urgent need to design a silver etching solution recovery device to overcome the shortcomings of existing technologies and meet the needs of practical applications. Utility Model Content

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a silver etching solution recovery device and system. In this invention, through structural design, the recovery device can be used to reuse strong acid etching solutions. It utilizes membrane capacitor deionization technology to selectively adsorb silver, which is simple and efficient. Under the action of an electric field, silver ions can be adsorbed onto the electrode surface, achieving etching solution recycling and solving the problems of high cost, complex processes, and low reuse rates in existing technologies.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, this utility model provides a silver etching solution recovery device, the recovery device comprising a storage tank, a pretreatment unit and a membrane capacitor deionization unit connected in sequence, the inlet of the storage tank being used to receive the silver etching solution; the membrane capacitor deionization unit comprising a chamber, an anode plate and a cathode plate being disposed opposite to each other in the chamber, an anion exchange membrane being disposed on the surface of the anode plate, a silver ion selective adsorption membrane being disposed on the surface of the cathode plate, and a power source being externally connected to the anode plate and the cathode plate.

[0008] In this invention, through the structural design of the recycling device, it can be used to reuse strong acid etching solution. It selectively adsorbs silver using membrane capacitor deionization technology, which is simple and efficient. Under the action of electric field force, silver ions can be adsorbed onto the electrode surface to realize the recycling of etching solution, thus solving the problems of high cost, complex process and low recycling rate in the prior art.

[0009] Preferably, an intermediate tank is provided between the pretreatment unit and the membrane capacitor deionization unit.

[0010] Preferably, the outlet pipe of the pretreatment unit is connected to the inlet of the intermediate tank, and the outlet pipe of the intermediate tank is connected to the inlet of the chamber.

[0011] Preferably, a pump is installed on the pipeline between the intermediate tank and the chamber, the pump being used to pump the liquid from the intermediate tank into the chamber.

[0012] Preferably, the inflow rate of the chamber is 10 mL / min to 15 mL / min, for example, it can be 10 mL / min, 11 mL / min, 12 mL / min, 13 mL / min, 14 mL / min, 15 mL / min, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0013] Preferably, the anode plate and the cathode plate are arranged in parallel.

[0014] Preferably, the maximum linear distance between the anode plate and the cathode plate is 1.5mm to 2mm, for example, it can be 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0015] Preferably, the silver ion selective adsorption membrane is a perfluorosulfonic acid membrane or a polybenzimidazole membrane.

[0016] Preferably, the anion exchange membrane is a perfluorosulfonic acid membrane or a polybenzimidazole membrane.

[0017] Preferably, the pretreatment unit is a ceramic membrane filter.

[0018] Secondly, this utility model provides a silver etching solution recovery system, the recovery system including the silver etching solution recovery device described in the first aspect.

[0019] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description.

[0020] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0021] In this invention, through the structural design of the recycling device, it can be used to reuse strong acid etching solution. It selectively adsorbs silver using membrane capacitor deionization technology, which is simple and efficient. Under the action of electric field force, silver ions can be adsorbed onto the electrode surface to realize the recycling of etching solution, thus solving the problems of high cost, complex process and low recycling rate in the prior art. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A schematic diagram of the structure of a silver etching solution recovery device provided in a specific embodiment of this utility model;

[0024] Figure 2 A schematic diagram of the structure of the membrane capacitor deionization unit in the silver etching solution recovery device provided in a specific embodiment of this utility model;

[0025] Among them, 1-storage tank; 2-pretreatment unit; 3-membrane capacitor deionization unit. Detailed Implementation

[0026] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0027] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0028] It should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0029] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0030] As described in the background section, current etching solution recovery processes are complex, energy-intensive, and not suitable for long-term processing on production lines. This application creatively proposes the use of membrane capacitor deionization technology, which combines capacitor deionization with membrane technology. A selective ion-exchange membrane is placed on the electrode, which can prevent the adsorption of ions with the same charge, improving charging efficiency. With its advantages of simplicity, environmental friendliness, high removal efficiency, and low energy consumption, it has attracted widespread attention for the selective separation and recovery of various ions.

[0031] This invention provides a device for recovering silver etching solution, such as... Figure 1 As shown, the recycling device includes a storage tank 1, a pretreatment unit 2, and a membrane capacitor deionization unit 3 connected in sequence. The inlet of the storage tank 1 is used to connect to the silver etching solution; as shown... Figure 2 As shown, the membrane capacitor deionization unit 3 includes a chamber, in which an anode plate and a cathode plate are arranged opposite to each other. An anion exchange membrane is disposed on the surface of the anode plate, and a silver ion selective adsorption membrane is disposed on the surface of the cathode plate. The anode plate and the cathode plate are connected to a power source.

[0032] It should be noted that this invention employs membrane capacitor deionization technology. Polymer membranes are added to the surfaces of the anode and cathode plates as selective ion adsorbents. The anode plate uses an ion membrane that can adsorb silver complex negative ions and prevent acid radical ions. A silver ion selective adsorption membrane is added to the surface of the cathode plate. When a low voltage is applied to the electrode surface, wastewater flows through the channel. The adsorption groups on the surface can specifically adsorb silver ions. The outflowing product can be directly recycled back to the production line. The adsorbed silver ions are temporarily stored in the micropores of the electrode during the charging phase. When the power is disconnected or a reverse voltage is applied, the double-layer structure is destroyed, and the adsorbed ions are desorbed from the electrode surface and return to the solution, thus achieving electrode regeneration.

[0033] Specifically, the recycling device in this invention adds a silver ion selective adsorption membrane to the electrode surface for adsorption. The silver ion selective adsorption membrane blocks the passage of other ions, removing silver from the etching solution and allowing the solution to be recycled. The electrode, once saturated with adsorption, is desorbed by applying a reverse voltage, thus regenerating the electrode. The process is simple, has a high recovery rate, reduces energy consumption, and achieves green and environmentally friendly circular production. No chemical waste or harmful substances are generated during operation, making it an environmentally friendly water treatment technology. The electrode includes an ion-selective functional membrane and a capacitive electrode, which can withstand nitric acid solution. The capacitive electrode can be made of activated carbon or graphite, and the selective functional membrane can also be an electrode modified with ion-selective groups, capable of specifically adsorbing silver ions.

[0034] It should be noted that the electrode material selected in this invention can be activated carbon, mesoporous carbon, carbon nanotubes, or metal-organic framework-derived carbon, etc.

[0035] It should be noted that the specific operating parameters of the membrane capacitor deionization unit 3 in this utility model may include a voltage setting of 0.3~1.2V; an influent flow rate of 5~15L / min; an electro-adsorption time of 60min; and an operating temperature of 25~30℃. Those skilled in the art can make adaptive adjustments to the specific operating scheme according to the actual situation.

[0036] Furthermore, an intermediate tank is provided between the pretreatment unit 2 and the membrane capacitor deionization unit 3.

[0037] It should be noted that the intermediate tank design in this utility model is beneficial to the stability of flow rate and water quality; this utility model does not impose special limitations on the specific structure, material, etc. of the intermediate tank, and those skilled in the art can make adaptive selections according to the actual situation.

[0038] Furthermore, the outlet pipe of the pretreatment unit 2 is connected to the inlet of the intermediate tank, and the outlet pipe of the intermediate tank is connected to the inlet of the chamber.

[0039] Furthermore, a pump is installed on the pipeline between the intermediate tank and the chamber, which is used to pump the liquid from the intermediate tank into the chamber.

[0040] It should be noted that in this invention, the filtrate after treatment by the pretreatment unit 2 and the intermediate tank flows into the fluid channel inside the chamber. Under the action of the electric field, silver ions and silver complexes have a higher electrostatic attraction and specifically bind to the electrode plate and are adsorbed. Acid radical ions are repelled near the anode. The fluid flows through the outlet and reaches adsorption saturation. An acid solution is introduced to apply a reverse voltage, desorb, and recover the silver-containing waste liquid.

[0041] It should be noted that the pump components designed in this utility model are beneficial for circulating flow control. This utility model does not impose special limitations on the specific structure, material, and quantity of the pump components, and those skilled in the art can make adaptive selections according to the actual situation.

[0042] Furthermore, the influent flow rate of the chamber is 10 mL / min to 15 mL / min, for example, it can be 10 mL / min, 11 mL / min, 12 mL / min, 13 mL / min, 14 mL / min, 15 mL / min, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0043] The influent flow rate of the middle chamber in this invention is 10 mL / min to 15 mL / min, because this range is conducive to improving removal efficiency and reducing energy consumption.

[0044] Furthermore, the anode plate and the cathode plate are arranged in parallel.

[0045] Furthermore, the maximum linear distance between the anode plate and the cathode plate is 1.5mm to 2mm, for example, it can be 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0046] In this invention, the maximum linear distance between the anode plate and the cathode plate is 1.5mm to 2mm, because this range helps to reduce resistance and improve operational stability.

[0047] Furthermore, the silver ion selective adsorption membrane is a perfluorosulfonic acid membrane or a polybenzimidazole membrane.

[0048] It should be noted that the functional groups of the silver ion selective adsorption membrane in this invention are sulfonic acid compounds, containing one or more of mercapto, thiourea, and imidazole groups to adsorb silver ions. The material is perfluorosulfonic acid or polybenzimidazole, which can withstand strong acid solutions and can permeate and adsorb silver ions. When a voltage is applied and set to 0.3V, the filtrate flows out through the channel and enters the subsequent product tank through the pipeline, thus achieving the separation of silver and the purpose of purification. The desorption process is that after the electrode surface of the membrane capacitor deionization unit 3 is saturated with adsorption, an acid solution is introduced to apply a reverse voltage to desorb silver ions, thereby regenerating the electrode and recovering the silver-containing waste liquid for further treatment.

[0049] Furthermore, the anion exchange membrane is a perfluorosulfonic acid membrane or a polybenzimidazole membrane.

[0050] It should be noted that the functional groups of the anion exchange membrane in this invention are quaternary ammonium salts, and the material is perfluorosulfonic acid and polybenzimidazole, which can withstand strong acid solutions and can retain anions that diffuse to the surface of the anode plate.

[0051] Furthermore, the pretreatment unit 2 is a ceramic membrane filter.

[0052] It should be noted that the pretreatment unit 2 in this utility model adopts a strong acid-resistant ceramic membrane filter with an operating pressure of 0.3 MPa. The ceramic membrane filter intercepts macromolecules and suspended impurities, and the filtrate permeates through the membrane into the product water pipeline, which is connected to the intermediate tank for collection.

[0053] In one specific embodiment, the present invention provides a silver etching solution recovery system, the recovery system including the silver etching solution recovery device described above.

[0054] It should be noted that the specific structure of the silver etching solution recovery system in this utility model is not specifically limited. It may include a post-processing unit set after the recovery device to further recover the liquid. Those skilled in the art can make adaptive selections according to the actual situation.

[0055] Example 1

[0056] This embodiment provides a device for recovering silver etching solution, wherein:

[0057] The recovery device includes a storage tank 1, a pretreatment unit 2, and a membrane capacitor deionization unit 3 connected in sequence. The inlet of the storage tank 1 is used to receive the silver etching solution. The membrane capacitor deionization unit 3 includes a chamber in which an anode plate and a cathode plate are arranged opposite each other. An anion exchange membrane is provided on the surface of the anode plate, and a silver ion selective adsorption membrane is provided on the surface of the cathode plate. The anode plate and the cathode plate are connected to a power source.

[0058] An intermediate tank is provided between the pretreatment unit 2 and the membrane capacitor deionization unit 3. The outlet pipe of the pretreatment unit 2 is connected to the inlet of the intermediate tank, and the outlet pipe of the intermediate tank is connected to the inlet of the chamber. A pump is provided on the pipe between the intermediate tank and the chamber, and the pump is used to pump the liquid from the intermediate tank into the chamber.

[0059] The influent flow rate to the chamber is 12 mL / min.

[0060] The anode plate and cathode plate are arranged in parallel, and the maximum linear distance between the anode plate and cathode plate is 1.7 mm.

[0061] The silver ion selective adsorption membrane is a perfluorosulfonic acid membrane, and the anion exchange membrane is a polybenzimidazole membrane.

[0062] Pretreatment unit 2 is a ceramic membrane filter.

[0063] In summary, this invention, through its structural design of the recycling device, can be used to reuse strong acid etching solution. It utilizes membrane capacitor deionization technology to selectively adsorb silver, which is simple and efficient. Under the action of electric field force, silver ions can be adsorbed onto the electrode surface, realizing the recycling of etching solution and solving the problems of high cost, complex process, and low recycling rate in the existing technology.

[0064] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A device for recovering silver etching solution, characterized in that, The recycling device includes a storage tank, a pretreatment unit, and a membrane capacitor deionization unit connected in sequence. The inlet of the storage tank is used to connect to the silver etching solution. The membrane capacitor deionization unit includes a chamber, in which an anode plate and a cathode plate are arranged opposite to each other. An anion exchange membrane is disposed on the surface of the anode plate, and a silver ion selective adsorption membrane is disposed on the surface of the cathode plate. The anode plate and the cathode plate are connected to an external power source.

2. The silver etching solution recovery device according to claim 1, characterized in that, An intermediate tank is provided between the pretreatment unit and the membrane capacitor deionization unit.

3. The silver etching solution recovery device according to claim 2, characterized in that, The outlet pipe of the pretreatment unit is connected to the inlet of the intermediate tank, and the outlet pipe of the intermediate tank is connected to the inlet of the chamber.

4. The silver etching solution recovery device according to claim 3, characterized in that, A pump is installed on the pipeline between the intermediate tank and the chamber, and the pump is used to pump the liquid from the intermediate tank into the chamber.

5. The silver etching solution recovery device according to claim 1, characterized in that, The water inflow rate to the chamber is 10 mL / min to 15 mL / min.

6. The silver etching solution recovery device according to claim 1, characterized in that, The anode plate and the cathode plate are arranged in parallel.

7. The silver etching solution recovery device according to claim 6, characterized in that, The maximum linear distance between the anode plate and the cathode plate is 1.5 mm to 2 mm.

8. The silver etching solution recovery device according to claim 1, characterized in that, The silver ion selective adsorption membrane is a perfluorosulfonic acid membrane or a polybenzimidazole membrane; The anion exchange membrane is a perfluorosulfonic acid membrane or a polybenzimidazole membrane.

9. The silver etching solution recovery device according to claim 1, characterized in that, The pretreatment unit is a ceramic membrane filter.

10. A silver etching solution recovery system, characterized in that, The recycling system includes the silver etching solution recycling device according to any one of claims 1-9.

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