An acid etching solution and alkaline etching solution neutralization reaction tank

Abstract

The utility model discloses a kind of acid etching liquid and alkaline etching liquid neutralization reaction tank, including mixing tank and sedimentation tank, the mixing tank and sedimentation tank are sequentially communicated from top to bottom by liquid guide pipe, the outside wall upper portion of the mixing tank is equipped with acidic liquid inlet pipe, alkaline liquid inlet pipe and neutralizing agent inlet pipe in sequence, and all inlet pipes are equipped with metering pump, stirring structure is equipped in the mixing tank, and the inside wall of mixing tank is equipped with ph sensor and temperature sensor, the mixing tank is equipped with cooling jacket outside, the bottom of the mixing tank and sedimentation tank is conical, the bottom of sedimentation tank is connected with sludge discharge pipe, and the sidewall lower portion of sedimentation tank is provided with drain pipe.The utility model is equipped with shunt inlet pipe and equipped with metering pump and flow control valve, realizes the accurate and slow addition of acid etching liquid, alkaline etching liquid and neutralizing agent, fundamentally avoids the violent reaction caused by direct mixing.

Description

Technical Field

[0001] This utility model relates to the field of industrial wastewater treatment technology, and in particular to a neutralization reaction tank for acidic etching solution and alkaline etching solution. Background Technology

[0002] In the PCB manufacturing process, acidic copper chloride etching solution and alkaline ammonia copper etching solution are widely used. These two waste liquids are strongly acidic / alkaline and contain high concentrations of copper ions, which are classified as hazardous waste. If not handled properly, direct discharge will cause serious environmental pollution, and direct mixing will release a large amount of heat and produce highly toxic chlorine gas due to violent reaction, posing a huge safety hazard.

[0003] Currently, traditional treatment methods often involve simple pool-type neutralization or separate treatment followed by mixing. However, direct mixing results in a violent reaction with high risk. The neutralization reaction releases a large amount of heat, causing the reaction system to boil and splash. Furthermore, it fails to separate the reaction and precipitation into one integrated process, making copper sludge recovery inconvenient.

[0004] To address this issue, we propose a neutralization reaction vessel for acidic and alkaline etching solutions. Utility Model Content

[0005] The purpose of this invention is to provide a neutralization reaction vessel for acidic and alkaline etching solutions to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A neutralization reaction vessel for acidic and alkaline etching solutions includes a mixing tank and a settling tank, which are connected sequentially from top to bottom via liquid guide pipes. The upper part of the outer side wall of the mixing tank is provided with an acidic liquid inlet pipe, an alkaline liquid inlet pipe, and a neutralizing agent inlet pipe, and all inlet pipes are equipped with metering pumps. The mixing tank is equipped with a stirring structure, and a pH sensor and a temperature sensor are installed on the inner side wall of the mixing tank. The mixing tank is equipped with a cooling jacket. The bottoms of both the mixing tank and the settling tank are conical. The bottom of the settling tank is connected to a sludge discharge pipe, and a liquid discharge pipe is provided on the lower part of the side wall of the settling tank.

[0008] In a further embodiment, normally closed valves are installed on the liquid guide pipe, sludge discharge pipe, and liquid discharge pipe.

[0009] In a further embodiment, flow control valves are installed on the acidic liquid inlet pipe, the alkaline liquid inlet pipe, and the neutralizing agent inlet pipe.

[0010] In a further embodiment, the stirring structure includes a rotary motor fixed to the top of the mixing tank and a stirring paddle extending into the mixing tank, and the output shaft of the rotary motor is connected to the central rod of the stirring paddle via a coupling.

[0011] In a further embodiment, the top of the mixing tank is also provided with an exhaust pipe, which is connected to an exhaust gas treatment device.

[0012] In a further embodiment, the cooling jacket is fitted onto the lower part of the outer side wall of the mixing tank, and an output pipe and an input pipe are respectively provided on the upper and lower sides of the side wall of the cooling jacket.

[0013] In a further embodiment, the metering pump, flow control valve, stirring structure, pH sensor, and temperature sensor are all electrically connected to a central controller.

[0014] In a further embodiment, the acidic liquid inlet pipe, the alkaline liquid inlet pipe, and the neutralizing agent inlet pipe are provided with an outlet near the inner wall of the mixing tank at one end.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] This invention achieves precise and slow addition of acidic etching solution, alkaline etching solution, and neutralizing agent by setting up branch inlet pipes and equipping them with metering pumps and flow control valves. Combined with pH sensor and central controller, it can monitor and automatically adjust the feed ratio in real time, ensuring that the reaction always takes place within a safe and stable pH range. This fundamentally avoids violent reactions caused by direct mixing and improves operational safety.

[0017] This invention connects the mixing tank and the sedimentation tank via a liquid guide pipe, allowing the reacted mixture to directly enter the sedimentation tank below for settling. This achieves an effective connection between reaction and separation. Furthermore, the conical bottom design and independent sludge and liquid discharge pipes enable the separation and collection of the generated copper hydroxide sludge and supernatant, improving the copper recovery efficiency and purity, simplifying subsequent processing procedures, and reducing secondary handling and disposal costs. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of this utility model;

[0019] Figure 2 This is a schematic diagram of the half-sectional structure of this utility model;

[0020] Figure 3 This is a partial cross-sectional view of the assembly of the neutralizing agent inlet pipe and the mixing tank of this utility model.

[0021] In the diagram: 1. Mixing tank; 2. Sedimentation tank; 3. Liquid guide pipe; 4. Acidic liquid inlet pipe; 5. Alkaline liquid inlet pipe; 6. Neutralizing agent inlet pipe; 7. Metering pump; 8. Flow control valve; 9. Rotary motor; 10. Agitator; 11. Exhaust pipe; 12. pH sensor; 13. Temperature sensor; 14. Cooling jacket; 15. Input pipe; 16. Output pipe; 17. Sludge discharge pipe; 18. Liquid discharge pipe; 19. Liquid outlet. Detailed Implementation

[0022] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0023] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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.

[0024] The technical solutions of the present utility model 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 utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0025] Please see Figure 1-3 A neutralization reaction vessel for acidic and alkaline etching solutions is mainly composed of a mixing tank 1 and a settling tank 2. The mixing tank 1 and the settling tank 2 are connected from top to bottom through a liquid guide pipe 3, and a normally closed solenoid valve is installed on the liquid guide pipe 3.

[0026] Acidic liquid inlet pipe 4, alkaline liquid inlet pipe 5, and neutralizing agent inlet pipe 6 are sequentially welded to the upper circumferential part of the outer side wall of mixing tank 1. Acidic liquid inlet pipe 4 is connected to an acidic etching waste liquid storage tank, alkaline liquid inlet pipe 5 is connected to an alkaline etching waste liquid storage tank, and neutralizing agent inlet pipe 6 is connected to an acid / alkali liquid storage tank. To ensure the accuracy of feeding, a metering pump 7 is sequentially installed on each inlet pipe. To ensure slow and controllable feeding, a flow control valve 8 is also sequentially installed on each inlet pipe. The end of each inlet pipe that extends into mixing tank 1 is located near the inner wall of the tank. The liquid outlet 19 allows the liquid to flow along the tank wall during injection, effectively preventing it from splashing into the tank due to high drop and causing localized violent reactions. A rotary motor 9 is installed on the top flange of the mixing tank 1, and its output shaft extends into the tank through a coupling and is connected to the central rod of the stirring paddle 10 to form a stirring structure, which is used to fully and uniformly mix the reactants. The top of the mixing tank 1 is also equipped with an exhaust pipe 11 to exhaust any trace gases that may be generated during the reaction, and it can be connected to an external waste gas absorption and treatment device, such as an acid / alkali spray tower.

[0027] In order to monitor the reaction status in real time, a pH sensor 12 and a temperature sensor 13 are installed on the inner wall of the mixing tank 1. A cooling jacket 14 is wrapped around the lower part of the outer wall of the mixing tank 1. A cooling medium inlet pipe 15 is provided at the bottom of the cooling jacket 14, and a cooling medium outlet pipe 16 is provided at the top. Cooling water and other media can be introduced for circulating heat exchange to effectively control the reaction temperature.

[0028] Both the mixing tank 1 and the settling tank 2 have conical bottoms to facilitate the settling and aggregation of solid materials. The bottom of the conical bottom of the settling tank 2 is connected to a sludge discharge pipe 17, which is used to discharge copper sludge. A liquid discharge pipe 18 is provided on the lower part of the side wall, which is used to discharge the supernatant of the sediment. Both the sludge discharge pipe 17 and the liquid discharge pipe 18 are equipped with normally closed valves, such as butterfly valves or ball valves.

[0029] In this embodiment, the signal lines of the metering pump 7, flow control valve 8, rotary motor 9, pH sensor 12, and temperature sensor 13 are electrically connected to a central controller (not shown in the diagram), such as a PLC or industrial computer, to form an automatic control system.

[0030] Workflow: According to the preset program, the central controller first starts the rotary motor 9 of mixing tank 1, then controls the metering pump 7 and flow control valve 8 on the acidic liquid inlet pipe 4 / alkaline liquid inlet pipe 5 to pump one of the etching solutions into mixing tank 1 in a certain amount as the base liquid. Then, the other etching solution is slowly pumped into mixing tank 1 in a certain proportion for mixing. The pH sensor 12 monitors the acidity or alkalinity of the liquid in the tank in real time and feeds the signal back to the central controller. The controller dynamically adjusts the feeding rate of the etching solution or starts the neutralizing agent inlet pipe 6 to add a neutralizing agent, such as a small amount of acid or alkali, to stabilize the pH value near the neutral range. At the same time, the temperature sensor 13 monitors the reaction temperature. When the temperature exceeds the set threshold, the controller will activate the cooling system. Cooling water enters the cooling jacket 14 from the input pipe 15 and flows out from the output pipe 16, thereby carrying away the heat of reaction. When the reaction reaches its endpoint, that is, when the pH value is stable and no longer changes, the feeding is stopped. After standing for a while, the valve on the liquid guide pipe 3 is opened to introduce the neutralized mixture into the sedimentation tank 2 below. In the sedimentation tank 2, the generated copper hydroxide sludge slowly settles to the bottom of the cone. After standing for a sufficient time, the supernatant is discharged through the side drain pipe 18, and the thick copper sludge that has settled at the bottom is discharged through the bottom sludge discharge pipe 17. The waste gas that may be generated during the reaction is discharged through the exhaust pipe 11 and sent to the waste gas treatment device for purification before being discharged.

[0031] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0032] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A neutralization reaction vessel for an acidic etching solution and an alkaline etching solution, comprising a mixing vessel (1) and a precipitation vessel (2), characterized in that: The mixing tank (1) and the sedimentation tank (2) are connected from top to bottom through a liquid guide pipe (3). The upper part of the outer side wall of the mixing tank (1) is provided with an acid liquid inlet pipe (4), an alkaline liquid inlet pipe (5) and a neutralizing agent inlet pipe (6). A metering pump (7) is installed on all the inlet pipes. The mixing tank (1) is provided with a stirring structure. A pH sensor (12) and a temperature sensor (13) are installed on the inner side wall of the mixing tank (1). The mixing tank (1) is provided with a cooling jacket (14). The bottom of the mixing tank (1) and the sedimentation tank (2) are both conical. The bottom of the sedimentation tank (2) is connected to a sludge discharge pipe (17). A drain pipe (18) is provided on the lower part of the side wall of the sedimentation tank (2).

2. The neutralization reaction vessel for acidic etching solution and alkaline etching solution according to claim 1, characterized in that: Normally closed valves are installed on the liquid guide pipe (3), sludge discharge pipe (17) and liquid discharge pipe (18).

3. The neutralization reaction vessel for acidic etching solution and alkaline etching solution according to claim 1, characterized in that: Flow control valves (8) are installed on the acidic liquid inlet pipe (4), alkaline liquid inlet pipe (5), and neutralizing agent inlet pipe (6).

4. The neutralization reaction vessel for acidic etching solution and alkaline etching solution according to claim 1, characterized in that: The stirring structure includes a rotary motor (9) fixed to the top of the mixing tank (1) and a stirring paddle (10) extending into the mixing tank (1), and the output shaft of the rotary motor (9) is connected to the center rod of the stirring paddle (10) through a coupling.

5. The neutralization reaction vessel for acidic etching solution and alkaline etching solution according to claim 1, characterized in that: The mixing tank (1) is also provided with an exhaust pipe (11) at the top, and the exhaust pipe (11) is connected to the waste gas treatment device.

6. The neutralization reaction vessel for acidic etching solution and alkaline etching solution according to claim 1, characterized in that: The cooling jacket (14) is fitted on the lower part of the outer side wall of the mixing tank (1), and the upper and lower sides of the side wall of the cooling jacket (14) are respectively provided with an output pipe (16) and an input pipe (15).

7. The neutralization reaction vessel for acidic etching solution and alkaline etching solution according to claim 3, characterized in that: The metering pump (7), flow control valve (8), stirring structure, pH sensor (12), and temperature sensor (13) are all electrically connected to a central controller.

8. The neutralization reaction vessel for acidic etching solution and alkaline etching solution according to claim 1, characterized in that: The acidic liquid inlet pipe (4), alkaline liquid inlet pipe (5), and neutralizing agent inlet pipe (6) are provided with an outlet (19) near the inner wall of the mixing tank (1) at one end.

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