Etching waste liquid cyclic regeneration system

Abstract

The utility model relates to an etching waste liquid cyclic regeneration system which comprises a reaction kettle, the reaction kettle is provided with an on-line pH detector, the reaction kettle is respectively connected with an acid etching waste liquid feeding device and an alkaline etching waste liquid feeding device, and the reaction kettle is further sequentially connected with a filter, a drying machine, a filter, an ion exchange resin tank and an evaporator through pipelines in sequence. The evaporator is connected with the re-etching liquid preparation chamber; and the on-line pH detector, the acidic etching waste liquid feeding device and the alkaline etching waste liquid feeding device are all connected with the PLC system. According to the waste etching liquid cyclic regeneration system, resource utilization of effective components of waste etching liquid is guaranteed, the waste liquid utilization rate is high, secondary pollution is avoided, and the automation degree is high.

Description

Technical Field

[0001] This utility model belongs to the field of electroplating wastewater treatment technology, specifically relating to an etching waste liquid recycling system. Background Technology

[0002] In recent years, my country's electronics industry has developed rapidly. Printed circuit boards (PCBs) are an important electronic component, typically used as a support and carrier for electronic components. The manufacturing process of PCBs generally includes steps such as chemical cleaning, photoresist coating, exposure and development, etching, and film removal. During the etching process of PCBs, the etching solution generates a large amount of etching wastewater after multiple cycles of recycling. This wastewater is usually divided into acidic and alkaline types. The main component of alkaline etching wastewater is copper-ammonia complex, while the main component of acidic etching wastewater is copper chloride. The copper content in copper-containing etching solutions can be as high as 70-120 g / L. Since copper is a heavy metal, it is toxic. Directly discharging acidic and alkaline wastewater will pollute the environment, affect the survival of microorganisms in water, damage soil aggregate structure, and waste resources.

[0003] Currently, there are various methods for recovering copper from etching wastewater, such as: chemical methods, which involve adding sodium hydroxide to the wastewater to combine with copper ions to form copper hydroxide precipitate, which is then used to produce copper oxide or copper sulfate; direct electrolysis; and extraction followed by electrolysis of copper. However, these methods are energy-intensive and produce difficult-to-treat wastewater with excessive copper ion concentrations. Therefore, to reduce energy consumption, conserve resources, and lower the copper ion concentration in the wastewater, patents have been developed for devices that neutralize acidic and alkaline etching wastewater to recover copper.

[0004] Chinese patent CN 203128222U discloses an alkaline copper chloride synthesis device for circuit board etching wastewater, including an acidic etching wastewater storage device and an acidic etching wastewater purification and removal tank. The acidic etching wastewater storage device and the acidic etching wastewater purification and removal tank are connected in series, and the alkaline etching wastewater storage device and the alkaline etching wastewater purification and removal tank are connected in series. The acidic etching wastewater purification and removal tank and the alkaline etching wastewater purification and removal tank are respectively connected to a neutralization synthesis tank. The neutralization synthesis tank, a filtration tank, a centrifuge, and an airflow dryer are connected in series. This patent utilizes the acid-base properties of the etching wastewater itself to... Neutralization synthesis effectively reduces the cost of copper ion recovery from wastewater. However, the ammonium chloride produced during neutralization synthesis is not recycled, which not only increases the workload of subsequent wastewater treatment but also wastes resources, failing to achieve the resource utilization of the effective components of the etching wastewater. At the same time, unreacted copper metal still exists in the wastewater after neutralization synthesis to obtain basic copper chloride, which is still far from the goal of harmlessness. In addition, the amount of acidic and alkaline etching wastewater added is not controlled, which can easily lead to excessive amounts of acidic or alkaline etching wastewater, increasing the workload of subsequent processes. Summary of the Invention

[0005] The purpose of this invention is to provide an etching waste liquid recycling system that ensures the resource utilization of effective components in the etching waste liquid, has a high waste liquid utilization rate, avoids resource waste, and does not cause secondary pollution. It realizes the resource utilization and harmlessness of etching waste liquid disposal, and has a high degree of automation.

[0006] The technical solution adopted by this utility model to solve the above problems is as follows: an etching waste liquid recycling system, the system including a reaction vessel, the reaction vessel being equipped with an online pH meter, the reaction vessel being connected to an acidic etching waste liquid feeding device and an alkaline etching waste liquid feeding device respectively, the reaction vessel also being connected in sequence to a filter and a dryer via pipelines, the filter, ion exchange resin tank, and evaporator being connected in sequence via pipelines, the evaporator being connected to a re-etching solution preparation chamber; the online pH meter, the acidic etching waste liquid feeding device, and the alkaline etching waste liquid feeding device are all connected to a PLC system.

[0007] Preferably, the reactor is also connected to a steam chamber.

[0008] Preferably, the reaction vessel is equipped with a stirring device.

[0009] Preferably, the acid etching waste liquid feeding device includes an acid etching waste liquid metering tank and an acid etching waste liquid feeding pump, wherein the acid etching waste liquid feeding pump is connected to the PLC system.

[0010] Preferably, the alkaline etching waste liquid feeding device includes an alkaline etching waste liquid metering tank and an alkaline etching waste liquid feeding pump, wherein the alkaline etching waste liquid feeding pump is connected to the PLC system.

[0011] Preferably, the pipe connecting the filter and the ion exchange resin tank is equipped with a flow meter.

[0012] Preferably, the ion exchange resin tank is also connected to an electrolytic cell.

[0013] Preferably, the electrolytic cell includes a cathode chamber and an anode chamber, which are arranged at intervals by a separating membrane.

[0014] Compared with the prior art, the advantages of this utility model are:

[0015] (1) The recycling system of this utility model first neutralizes and recovers basic copper chloride from acidic etching waste liquid and alkaline etching liquid, which effectively reduces the copper content in the etching liquid. Then, the remaining unreacted copper is adsorbed by an ion exchange resin tank to ensure that the copper content in the waste liquid is less than the emission standard, thus reducing pollution. After the waste liquid is adsorbed by the ion exchange resin tank, a portion of the water is evaporated by an evaporator to obtain ammonium chloride solution. The ammonium chloride solution is used as a raw material to prepare regenerated etching liquid, which not only avoids secondary waste liquid pollution generated by the neutralization reaction, but also realizes resource utilization and achieves resource utilization and harmlessness of the etching waste liquid disposal.

[0016] (2) The reactor in the recycling system of this utility model is equipped with an online pH meter. The reactor is also connected to an acid etching waste liquid feeding device and an alkaline etching waste liquid feeding device. The online pH meter, the acid etching waste liquid feeding device, and the alkaline etching waste liquid feeding device are respectively connected to the PLC system. This setting saves manpower, makes operation simple, and increases reaction efficiency. It avoids excessive acid etching waste liquid or alkaline etching waste liquid, which may lead to incomplete reaction. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the etching waste liquid recycling system in an embodiment of this utility model.

[0018] Wherein: 1 is a reaction vessel, 2 is an online pH meter, 3 is an acidic etching waste liquid feeding device, 3-1 is an acidic etching waste liquid metering tank, 3-2 is an acidic etching waste liquid feeding pump, 4 is an alkaline etching waste liquid feeding device, 4-1 is an alkaline etching waste liquid metering tank, 4-2 is an alkaline etching waste liquid feeding pump, 5 is a filter, 6 is a dryer, 7 is an ion exchange resin tank, 8 is an evaporator, 9 is a re-etching solution preparation chamber, 10 is a PLC system, and 11 is an electrolytic cell. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0020] like Figure 1 The diagram shown is a structural schematic of the etching waste liquid recycling system in this embodiment.

[0021] An etching waste liquid recycling system includes a reaction vessel 1 equipped with an online pH meter 2. The reaction vessel 1 is connected to an acidic etching waste liquid feeding device 3 and an alkaline etching waste liquid feeding device 4. The acidic etching waste liquid feeding device 3 includes an acidic etching waste liquid metering tank 3-1 and an acidic etching waste liquid feeding pump 3-2. The alkaline etching waste liquid feeding device 4 includes an alkaline etching waste liquid metering tank 4-1 and an alkaline etching waste liquid feeding pump 4-2. The reaction vessel 1 is also connected to a filter 5 and a dryer 6 via pipelines. The filter 5, an ion exchange resin tank 7, and an evaporator 8 are connected sequentially via pipelines. The evaporator 8 is connected to a re-etching solution preparation chamber 9. The online pH meter 2, the acidic etching waste liquid feeding pump 3-1 of the acidic etching waste liquid feeding device 3, and the alkaline etching waste liquid feeding pump 4-1 of the alkaline etching waste liquid feeding device 4 are all connected to a PLC system 10.

[0022] The reactor 1 is also connected to a steam chamber and is equipped with a stirring device; the filter 5 is connected to the ion exchange resin tank 7 via a pipe equipped with a flow meter; the ion exchange resin tank 7 is also connected to an electrolytic cell 11, which includes a cathode chamber and an anode chamber, and the cathode chamber and the anode chamber are arranged at intervals through a separating membrane.

[0023] The working process of this embodiment will be described in detail below with reference to the accompanying drawings:

[0024] The acid etching waste liquid metering tank 3-1 of the acid etching waste liquid feeding device 3 contains acid etching waste liquid, and the alkaline etching waste liquid metering tank 4-1 of the alkaline etching waste liquid feeding device 4 contains alkaline etching waste liquid. Simultaneously, the acid etching waste liquid and alkaline etching waste liquid are added to the reaction vessel 1 from the acid etching waste liquid feeding device 3 and the alkaline etching waste liquid feeding device 4, respectively. A stirring device in the reaction vessel 1 ensures uniform mixing of the acid etching waste liquid and alkaline etching waste liquid. The pH in the reaction vessel 1 is monitored in real time by an online pH meter 2. The detection results are transmitted to the PLC system 10. When the pH value in the reactor is lower or higher than the set value (pH is 4.5~5.5), the PLC system 10 controls the shutdown of the acid etching waste liquid feeding pump 3-1 and the alkaline etching waste liquid feeding pump 4-1 to stop adding the corresponding acid etching waste liquid or alkaline etching waste liquid and adjust the pH to the set range. When the pH in the reactor 1 is within the set range, the PLC system 10 simultaneously shuts down the acid etching waste liquid feeding pump 3-1 and the alkaline etching waste liquid feeding pump 4-1, and the automatic feeding device stops.

[0025] The reaction formula for the reaction mixture is:

[0026]

[0027] After the reaction is complete, the reaction mixture is filtered by filter 5 and dried by dryer 6 to obtain basic copper chloride. The filtrate produced after filtration by filter 5 is adsorbed by ion exchange resin tank 7 to remove the remaining unreacted copper ions. The copper-removed waste liquid is evaporated by evaporator 8 for a period of time to obtain ammonium chloride solution. The ammonium chloride solution enters the regeneration etching solution preparation chamber 9 as raw material to prepare regeneration etching solution. The prepared regeneration etching solution is then used for etching. After adsorbing copper ions, ion exchange resin tank 7 can be washed by dilute sulfuric acid to obtain copper-containing acid solution, which is then sent to electrolytic cell 11 for electrolysis.

[0028] In addition to the above embodiments, this utility model also includes other implementation methods. All technical solutions formed by equivalent transformation or equivalent substitution should fall within the protection scope of the claims of this utility model.

Claims

1. An etching waste solution recycling system characterized by: The reaction kettle (1) is provided with an on-line pH detector (2), and is connected with an acidic etching waste liquid feeding device (3), an alkaline etching waste liquid feeding device (4) respectively, and is further connected with a filter (5) and a drying machine (6) in sequence through a pipeline, the filter (5), an ion exchange resin tank (7) and an evaporator (8) are sequentially connected through a pipeline, and the evaporator (8) is connected with a re-etching liquid preparation chamber (9); the on-line pH detector (2), the acidic etching waste liquid feeding device (3) and the alkaline etching waste liquid feeding device (4) are connected with a PLC system (10).

2. The etching waste solution recycling system according to claim 1, characterized in that: The reaction kettle (1) is further connected with a steam chamber.

3. The etch spent liquor recycling system of claim 1, wherein: The reaction kettle (1) is provided with a stirring device.

4. The etch spent liquor recycling system of claim 1, wherein: The acidic etching waste liquid feeding device (3) comprises an acidic etching waste liquid metering tank (3-1) and an acidic etching waste liquid feeding pump (3-2), and the acidic etching waste liquid feeding pump (3-2) is connected with the PLC system (10).

5. The etch spent liquor recycling system of claim 1, wherein: The alkaline etching waste liquid feeding device (4) comprises an alkaline etching waste liquid metering tank (4-1) and an alkaline etching waste liquid feeding pump (4-2), and the alkaline etching waste liquid feeding pump (4-2) is connected with the PLC system (10).

6. The etch spent liquor recycling system of claim 1, wherein: The pipeline, through which the filter (5) communicates with the ion exchange resin tank (7), is provided with a flow meter.

7. The etch spent liquor recycling system of claim 1, wherein: The ion exchange resin tank (7) is further connected with an electrolytic tank (11).

8. The etch spent liquor recycling system of claim 7, wherein: The electrolytic tank (11) comprises a cathode chamber and an anode chamber, and the cathode chamber and the anode chamber are arranged in a spaced manner through a separation film.

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