A method for automatically controlling pH in a reaction process for recycling etching waste liquid

Abstract

The application discloses a kind of etching waste liquid recycling reaction process pH automatic control method including preparation reaction buffer and preparation two steps of basic copper chloride, wherein in preparation basic copper chloride step, the pH value of reaction system can be read in real time by pH sensor and feedback to controller, and by controller, the addition volume of acidic etching waste liquid and alkaline etching waste liquid is adjusted in real time according to system pH value, to prepare granular basic copper chloride, can realize strict control the pH value of entire process, ensure the quality of basic copper chloride, without relying on manual detection pH, production efficiency is high, and realizes accurate control feeding amount, avoid excessive addition material to cause cost increase, in addition, response speed is also improved, once reaction system pH value abnormally fluctuates, system can quickly make adjustment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of etching waste liquid recycling and regeneration, in particular to a method for automatically controlling pH in the reaction process of etching waste liquid recycling and regeneration. BACKGROUND

[0002] In the etching process, a circuit board factory often produces a large amount of acidic etching wastewater and alkaline etching wastewater, which contains a large amount of metal ions (such as copper, nickel, lead), among which the concentration of copper ions is relatively large. In order to recover copper, the acid and alkaline etching waste liquid is usually made into basic copper chloride for subsequent processing. Basic copper chloride is sensitive to reaction conditions. Under different reaction temperatures, pH values and other conditions, the color and granularity of basic copper chloride generated will have a large difference. Generally, the granular basic copper chloride is superior to the slurry-like basic copper chloride in terms of external sales or subsequent processing. In order to ensure the quality of the granular basic copper chloride, the pH value of the entire process needs to be strictly controlled. However, the production of granular basic copper chloride currently mainly relies on manual detection of pH. In order to ensure safety, the production line needs to be suspended during detection, resulting in a decrease in production efficiency. In addition, manual detection is easily affected by subjective factors and has operation errors, resulting in inaccurate detection results. SUMMARY

[0003] In order to solve the above problems, the present application provides a method for automatically controlling pH in the reaction process of etching waste liquid recycling and regeneration, comprising the following steps:

[0004] Preparation of reaction buffer: according to the solid-liquid ratio of 1g:(7.5-20)ml, add ammonium chloride and water into a container, heat to 55-65℃ and stir at 350-400r / min to obtain a reaction buffer;

[0005] Preparation of basic copper chloride:

[0006] The container temperature is continuously maintained at 55-65℃ and the stirring is continuously maintained at 350-400 r / min, while the acidic etching waste liquid and the alkaline etching waste liquid are added to the reaction buffer through the peristaltic pump, the pH value of the reaction system is read in real time through the pH sensor and is fed back to the controller, and the addition volume of the acidic etching waste liquid and the alkaline etching waste liquid is adjusted by the peristaltic pump according to the pH value of the system in real time, the pH sensor, the controller and the peristaltic pump are electrically connected, and the pH sensor is detachably connected in the container; in addition, one end of the first hose is inserted into the pump head inlet of the first peristaltic pump, and the other end is inserted into the acidic etching waste liquid, one end of the second hose is pulled out through the pump head outlet of the first peristaltic pump, and the other end is placed in the container; one end of the third hose is inserted into the pump head inlet of the second peristaltic pump, and the other end is inserted into the alkaline etching waste liquid, one end of the fourth hose is pulled out through the pump head outlet of the first peristaltic pump, and the other end is placed in the container, and the first hose, the second hose, the third hose and the fourth hose are made of polytetrafluoroethylene; the preparation of the basic copper chloride is divided into three stages, including the early stage, the middle stage and the late stage;

[0007] In the early stage, the acidic etching waste liquid and the alkaline etching waste liquid are added to the reaction buffer through the peristaltic pump at a speed a, the total addition volume of the acidic etching waste liquid and the alkaline etching waste liquid accounts for 1 / 40-1 / 20 of the water volume, and the pH value of the reaction system is read through the pH sensor, when the pH value of the reaction system is greater than 4.7, the peristaltic pump is stopped to add the alkaline etching waste liquid under the control of the controller, when the pH value of the reaction system is greater than 4.3, the peristaltic pump is stopped to add the acidic etching waste liquid under the control of the controller, so as to ensure that the pH value of the reaction system is always maintained in the range of 4.3-4.7;

[0008] In the middle stage, the acidic etching waste liquid and the alkaline etching waste liquid are continuously added at a speed b, the total addition volume of the acidic etching waste liquid and the alkaline etching waste liquid is 3.5-5.4 times of the water volume, and the pH value of the reaction system is read through the pH sensor, when the pH value of the reaction system is 4.5-5, the peristaltic pump is controlled by the controller to continuously add the acidic etching waste liquid and the alkaline etching waste liquid at the speed b, when the pH value of the reaction system is less than 4.5, the addition speed of the acidic etching waste liquid is reduced and the alkaline etching waste liquid is continuously added at the speed b, when the pH value of the reaction system is greater than 5, the addition speed of the alkaline etching waste liquid is reduced and the acidic etching waste liquid is continuously added at the speed b;

[0009] In the late stage, the acidic etching waste liquid and the alkaline etching waste liquid are continuously added to the reaction buffer at a speed c according to the pH value of the reaction system, the total addition volume of the acidic etching waste liquid and the alkaline etching waste liquid accounts for 1 / 40-1 / 20 of the water volume, until the pH value is stabilized in the range of 4.3-4.7 and maintained for 15-30 min without change, the peristaltic pump is stopped to work, and the basic copper chloride slurry is obtained, speed a=c≤b.

[0010] Preferably, the heating temperature during preparation of the reaction buffer is 60℃.

[0011] Preferably, the stirring speed during preparation of the reaction buffer is 375 r / min.

[0012] Preferably, the speed a is 1 ml / s.

[0013] Preferably, the speed b is 1-5 ml / s.

[0014] Preferably, the speed c is 1 ml / s.

[0015] Preferably, the speed a is 2 ml / s, the speed b is 4 ml / s, and the speed c is 1 ml / s.

[0016] Preferably, the total volume of the acid etching waste liquid and the alkaline etching waste liquid added in the reaction in the middle stage of the preparation of the basic chlorination process is 4 times the volume of the water.

[0017] Preferably, the total volume of the acid etching waste liquid and the alkaline etching waste liquid added in the reaction in the middle stage of the preparation of the basic chlorination process is 5 times the volume of the water.

[0018] Preferably, in the reaction in the middle stage of the preparation of the basic copper chloride, once the pH value is less than 3.5, the controller immediately controls the peristaltic pump to stop adding the acid etching waste liquid, and once the pH value is greater than 6, the controller immediately controls the peristaltic pump to stop adding the alkaline etching waste liquid.

[0019] The beneficial effect is that the application can read the pH value of the reaction system in real time through the pH sensor and feed back to the controller, and the controller can control the peristaltic pump to adjust the volume of the acid etching waste liquid and the alkaline etching waste liquid according to the pH value of the system in real time to prepare the granular basic copper chloride, which can strictly control the pH value of the whole process to ensure the quality of the basic copper chloride, does not need to rely on manual detection of pH, has high production efficiency, realizes accurate control of the feeding amount, avoids excessive addition of materials to increase the cost, and further improves the response speed. Once the pH value of the reaction system abnormally fluctuates, the system can quickly make adjustments. BRIEF DESCRIPTION OF DRAWINGS

[0020] The drawings described herein are used to provide further understanding of the application, constitute a part of the application, the illustrative embodiments of the application and the description thereof are used to explain the application, and do not constitute an improper limitation on the application. In the drawings:

[0021] Figure 1 The process flow chart of the application. DETAILED DESCRIPTION

[0022] The application will be further described in detail below in combination with specific embodiments, so that those skilled in the art can more clearly understand the application.

[0023] The following examples are used to illustrate the present application but not to limit the scope of the present application. Based on the specific examples in the present application, all other examples obtained by those skilled in the art without creative work are within the scope of the present application.

[0024] In the embodiments of the present application, all raw material components are commercially available products well known to those skilled in the art unless otherwise specified; in the embodiments of the present application, the technical means used are conventional means well known to those skilled in the art unless otherwise specified.

[0025] Raw material sources:

[0026] Acid etching waste liquid and alkaline etching waste liquid were purchased from Jiangmen Chongda Circuit Technology Co., Ltd.;

[0027] Equipment sources:

[0028] Peristaltic pump, model Camil KPHM100-HBB10, purchased from Hefei Wuyaxian Technology Co., Ltd.;

[0029] PH sensor, model Ruixin Hengcheng RXHC, purchased from Shenzhen Ruixin Hengcheng Electronics Co., Ltd.;

[0030] The first hose, the second hose, the third hose and the fourth hose were purchased from Shenzhen Nuole Hose Co., Ltd.

[0031] The remaining reagents and equipment are conventional commercially available.

[0032] Example 1

[0033] A kind of etching waste liquid recycling reaction process pH automatic control method, comprising the following steps:

[0034] Preparation of reaction buffer: add 50 g of ammonium chloride and 1000 ml of water to a container, heat to 55℃ and stir at 350 r / min to obtain a reaction buffer;

[0035] Preparation of basic copper chloride:

[0036] Continue to maintain the temperature of the container at 55℃ and continue to stir at 350 r / min, while adding acid etching waste liquid and alkaline etching waste liquid to the reaction buffer through the peristaltic pump, in this process, the pH value of the reaction system is read in real time by the pH sensor and fed back to the controller, and the controller adjusts the volume of acid etching waste liquid and alkaline etching waste liquid according to the pH value of the system in real time, the whole process of preparing basic copper chloride is divided into three stages including early stage, middle stage and late stage;

[0037] The acid etching waste liquid and the alkaline etching waste liquid are added into the reaction buffer solution by the peristaltic pump at a speed a, the total volume of the acid etching waste liquid and the alkaline etching waste liquid is 50-100 ml, and the pH value of the reaction system is read by the pH sensor, when the pH value of the reaction system is greater than 4.7, the controller controls the peristaltic pump to stop adding the alkaline etching waste liquid, and when the pH value of the reaction system is greater than 4.3, the controller controls the peristaltic pump to stop adding the acid etching waste liquid, so as to ensure that the pH value of the reaction system is always maintained in the range of 4.3-4.7;

[0038] The acid etching waste liquid and the alkaline etching waste liquid are continuously added at a speed b in the middle stage, the total volume of the acid etching waste liquid and the alkaline etching waste liquid is 3500-4000 ml, and the pH value of the reaction system is read by the pH sensor, when the pH value of the reaction system is in the range of 4.5-5, the controller controls the peristaltic pump to continuously add the acid etching waste liquid and the alkaline etching waste liquid at the speed b, when the pH value of the reaction system is less than 4.5, the adding speed of the acid etching waste liquid is reduced and the alkaline etching waste liquid is continuously added at the speed b, and when the pH value of the reaction system is greater than 5, the adding speed of the alkaline etching waste liquid is reduced and the acid etching waste liquid is continuously added at the speed b; since the change of the pH value is not completed at the moment of adding, when the pH sensor reads that the pH value of the reaction system is less than 4.5, even if the adding speed of the acid etching waste liquid is reduced and the alkaline etching waste liquid is continuously added at the speed b, the reaction system will still move towards the direction of reducing the pH value, therefore, once the pH value is less than 3.5, the controller needs to immediately control the peristaltic pump to stop adding the acid etching waste liquid, and for the same reason, once the pH value is greater than 6, the controller needs to immediately control the peristaltic pump to stop adding the alkaline etching waste liquid;

[0039] In the later stage, the acid etching waste liquid and the alkaline etching waste liquid are continuously added into the reaction buffer solution at a speed c according to the pH value of the reaction system, the total volume of the acid etching waste liquid and the alkaline etching waste liquid is 50-100 ml, until the pH value is stabilized in the range of 4.3-4.7 and maintained for 15-30 min without further change, the peristaltic pump is stopped, and the basic copper chloride slurry is obtained, the speed a=c≤b, wherein the speed a is 1 ml / s, the speed b is 1-5 ml / s, and the speed c is 1 ml / s.

[0040] Example 2

[0041] A pH automatic control method for an etching waste liquid recycling reaction process, comprising the following steps:

[0042] Preparation of reaction buffer solution: 100 g of ammonium chloride and 750 ml of water are added into a container, heated to 60℃ and stirred at 375 r / min to obtain a reaction buffer solution;

[0043] Preparation of basic copper chloride:

[0044] Continue to maintain the temperature of the container at 60℃ and continue to stir at 375 r / min, while adding acidic etching waste liquid and basic etching waste liquid to the reaction buffer through the peristaltic pump, in the process, the pH sensor is used to read the pH value of the reaction system in real time and feedback to the controller, and the controller controls the peristaltic pump to adjust the volume of the acidic etching waste liquid and the basic etching waste liquid according to the pH value of the system in real time. The preparation of basic copper chloride is divided into three stages, including early, middle and late stages.

[0045] In the early stage, the acidic etching waste liquid and the basic etching waste liquid are added to the reaction buffer through the peristaltic pump at speed a, the total volume of the acidic etching waste liquid and the basic etching waste liquid is 50-100 ml, and the pH value of the reaction system is read through the pH sensor. When the pH value of the reaction system is greater than 4.7, the controller controls the peristaltic pump to stop adding the basic etching waste liquid. When the pH value of the reaction system is greater than 4.3, the controller controls the peristaltic pump to stop adding the acidic etching waste liquid, so as to ensure that the pH value of the reaction system is always maintained in the interval of 4.3-4.7.

[0046] In the middle stage, the acidic etching waste liquid and the basic etching waste liquid are continuously added at speed b, the total volume of the acidic etching waste liquid and the basic etching waste liquid is 3750-4050 ml, and the pH value of the reaction system is read through the pH sensor. When the pH value of the reaction system is 4.5-5, the controller controls the peristaltic pump to continue to add the acidic etching waste liquid and the basic etching waste liquid at speed b. When the pH value of the reaction system is less than 4.5, the speed of adding the acidic etching waste liquid is reduced and the basic etching waste liquid is continuously added at speed b. When the pH value of the reaction system is greater than 5, the speed of adding the basic etching waste liquid is reduced and the acidic etching waste liquid is continuously added at speed b. Since the change of pH value is not completed at the moment of adding, when the pH sensor reads that the pH value of the reaction system is less than 4.5, even if the speed of adding the acidic etching waste liquid is reduced and the basic etching waste liquid is continuously added at speed b, the reaction system will still move towards the direction of reducing pH value. Therefore, once the pH value is less than 3.5, the controller needs to immediately control the peristaltic pump to stop adding the acidic etching waste liquid. Similarly, once the pH value is greater than 6, the controller needs to immediately control the peristaltic pump to stop adding the basic etching waste liquid.

[0047] In the late stage, the acidic etching waste liquid and the basic etching waste liquid are continuously added to the reaction buffer at speed c according to the pH value of the reaction system, the total volume of the acidic etching waste liquid and the basic etching waste liquid is 50-100 ml, until the pH value is stable in the interval of 4.3-4.7 and maintains for 15-30 min without changing, the peristaltic pump stops working, and the basic copper chloride slurry is obtained. Speed a=c≤b, wherein speed a is 2 ml / s, speed b is 4 ml / s, and speed c is 1 ml / s.

[0048] Example 3

[0049] An automatic pH control method for etching waste liquid recycling reaction process, comprising the following steps:

[0050] Preparation of reaction buffer: 50 g of ammonium chloride and 750 ml of water are added to a container, heated to 65°C and stirred at 400 r / min to obtain a reaction buffer;

[0051] Preparation of basic copper chloride:

[0052] Continue to maintain the temperature of the container at 65°C and continue to stir at 400 r / min, while adding acidic etching waste liquid and basic etching waste liquid to the reaction buffer through a peristaltic pump, during which the pH value of the reaction system is read in real time by a pH sensor and fed back to the controller, and the controller controls the addition volume of the acidic etching waste liquid and the basic etching waste liquid according to the pH value of the system in real time. The whole process of preparing basic copper chloride is divided into three stages, including early, middle and late stages;

[0053] In the early stage, the acidic etching waste liquid and the basic etching waste liquid are added to the reaction buffer through the peristaltic pump at a speed a, the total addition volume of the acidic etching waste liquid and the basic etching waste liquid is 50-100 ml, and the pH value of the reaction system is read by the pH sensor, when the pH value of the reaction system is greater than 4.7, the controller controls the peristaltic pump to stop adding the basic etching waste liquid, when the pH value of the reaction system is greater than 4.3, the controller controls the peristaltic pump to stop adding the acidic etching waste liquid, to ensure that the pH value of the reaction system is always maintained in the interval of 4.3-4.7;

[0054] In the middle stage, the acidic etching waste liquid and the basic etching waste liquid are continuously added at a speed b, the total addition volume of the acidic etching waste liquid and the basic etching waste liquid is 3750-4050 ml, and the pH value of the reaction system is read by the pH sensor, when the pH value of the reaction system is in the range of 4.5-5, the controller controls the peristaltic pump to continue to add the acidic etching waste liquid and the basic etching waste liquid at speed b, when the pH value of the reaction system is less than 4.5, the addition speed of the acidic etching waste liquid is reduced and the basic etching waste liquid is continuously added at speed b, when the pH value of the reaction system is greater than 5, the addition speed of the basic etching waste liquid is reduced and the acidic etching waste liquid is continuously added at speed b; Since the change of pH value is not completed at the moment of feeding, when the pH sensor reads that the pH value of the reaction system is less than 4.5, even if the addition speed of the acidic etching waste liquid is reduced and the basic etching waste liquid is continuously added at speed b, the reaction system will still proceed in the direction of reducing pH, therefore, once the pH value is less than 3.5, the controller needs to immediately control the peristaltic pump to stop adding the acidic etching waste liquid; Similarly, once the pH value is greater than 6, the controller needs to immediately control the peristaltic pump to stop adding the basic etching waste liquid;

[0055] In the later stage, the acidic etching waste liquid and the basic etching waste liquid are continuously added to the reaction buffer at a speed c until the pH value is stabilized in the range of 4.3-4.7 and remains unchanged for 15-30 min, and the peristaltic pump is stopped, to obtain the basic copper chloride slurry, wherein the speed a is 1 ml / s, the speed b is 1 ml / s, and the speed c is 1 ml / s.

[0056] Example 4

[0057] A pH automatic control method for an etching waste liquid recycling reaction process, comprising the following steps:

[0058] Preparation of the reaction buffer: 100 g of ammonium chloride and 1000 ml of water are added to a container, heated to 65°C and stirred at 400 r / min to obtain the reaction buffer;

[0059] Preparation of the basic copper chloride:

[0060] The temperature of the container is continuously maintained at 65°C and the stirring is continuously maintained at 400 r / min, while the acidic etching waste liquid and the basic etching waste liquid are added to the reaction buffer by the peristaltic pump. During this process, the pH value of the reaction system is read in real time by the pH sensor and fed back to the controller, and the controller controls the addition volume of the acidic etching waste liquid and the basic etching waste liquid according to the pH value of the system in real time. The whole process of preparing the basic copper chloride is divided into three stages, including the early stage, the middle stage and the later stage.

[0061] In the early stage, the acidic etching waste liquid and the basic etching waste liquid are added to the reaction buffer by the peristaltic pump at a speed a, and the total addition volume of the acidic etching waste liquid and the basic etching waste liquid is 50-100 ml. The pH value of the reaction system is read by the pH sensor. When the pH value of the reaction system is greater than 4.7, the controller controls the peristaltic pump to stop adding the basic etching waste liquid. When the pH value of the reaction system is greater than 4.3, the controller controls the peristaltic pump to stop adding the acidic etching waste liquid, so as to ensure that the pH value of the reaction system is always maintained in the range of 4.3-4.7.

[0062] The acidic etching waste liquid and the alkaline etching waste liquid are continuously added at the speed b in the middle stage, the total adding volume of the acidic etching waste liquid and the alkaline etching waste liquid is 3500-4000 ml, and the pH value of the reaction system is read by the pH sensor, when the pH value of the reaction system is 4.5-5, the controller controls the peristaltic pump to continuously add the acidic etching waste liquid and the alkaline etching waste liquid at the speed b, when the pH value of the reaction system is less than 4.5, the adding speed of the acidic etching waste liquid is reduced and the alkaline etching waste liquid is continuously added at the speed b, when the pH value of the reaction system is greater than 5, the adding speed of the alkaline etching waste liquid is reduced and the acidic etching waste liquid is continuously added at the speed b; since the change of the pH value is not completed at the instant of adding, when the pH sensor reads that the pH value of the reaction system is less than 4.5, even if the adding speed of the acidic etching waste liquid is reduced and the alkaline etching waste liquid is continuously added at the speed b, the reaction system will still proceed in the direction of reducing the pH value, therefore, once the pH value is less than 3.5, the controller needs to immediately control the peristaltic pump to stop adding the acidic etching waste liquid; similarly, once the pH value is greater than 6, the controller needs to immediately control the peristaltic pump to stop adding the alkaline etching waste liquid;

[0063] The acidic etching waste liquid and the alkaline etching waste liquid are continuously added to the reaction buffer at the speed c according to the pH value of the reaction system in the later stage, the total adding volume of the acidic etching waste liquid and the alkaline etching waste liquid is 50-100 ml, until the pH value is stably in the interval of 4.3-4.7 and does not change any more for 15-30 min, the peristaltic pump is stopped to work, and the basic copper chloride slurry is obtained, the speed a=c≤b, wherein the speed a is 1 ml / s, the speed b is 3 ml / s, and the speed c is 2 ml / s.

[0064] The above only describes the embodiments of the present application and is not used to limit the present application. The present application can have various changes and modifications for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the scope of claims of the present application.

Claims

1. A method for automatically controlling pH in a reaction process for recycling etching waste liquid, characterized in that, The method comprises the following steps: Preparation of reaction buffer: add ammonium chloride and water into a container according to the solid-liquid ratio of 1 g:(7.5-20) ml, heat to 55-65 DEG C and stir at 350-400 r / min to obtain a reaction buffer; Preparation of basic copper chloride: Continue to maintain the temperature of the container at 55-65 DEG C and continue to stir at 350-400 r / min, while adding acidic etching waste liquid and alkaline etching waste liquid into the reaction buffer through a peristaltic pump, in this process, the pH value of the reaction system is read in real time by a pH sensor and fed back to a controller, and the controller controls the peristaltic pump to adjust the volume of the acidic etching waste liquid and the alkaline etching waste liquid according to the pH value of the system in real time, the pH sensor, the controller and the peristaltic pump are electrically connected, and the whole process of preparing the basic copper chloride is divided into three stages including early stage, middle stage and late stage; In the early stage, the acidic etching waste liquid and the alkaline etching waste liquid are added into the reaction buffer through the peristaltic pump at a speed a, the total volume of the acidic etching waste liquid and the alkaline etching waste liquid accounts for 1 / 40-1 / 20 of the volume of the water, and the pH value of the reaction system is read by the pH sensor, when the pH value of the reaction system is greater than 4.7, the controller controls the peristaltic pump to stop adding the alkaline etching waste liquid, when the pH value of the reaction system is greater than 4.3, the controller controls the peristaltic pump to stop adding the acidic etching waste liquid, so as to ensure that the pH value of the reaction system is always maintained in the range of 4.3-4.7; In the middle stage, the acidic etching waste liquid and the alkaline etching waste liquid are continuously added at a speed b, the total volume of the acidic etching waste liquid and the alkaline etching waste liquid accounts for 3.5-5.4 times of the volume of the water, and the pH value of the reaction system is read by the pH sensor, when the pH value of the reaction system is in the range of 4.5-5, the controller controls the peristaltic pump to continue to add the acidic etching waste liquid and the alkaline etching waste liquid at the speed b, when the pH value of the reaction system is less than 4.5, the speed of adding the acidic etching waste liquid is reduced and the alkaline etching waste liquid is continuously added at the speed b, when the pH value of the reaction system is greater than 5, the speed of adding the alkaline etching waste liquid is reduced and the acidic etching waste liquid is continuously added at the speed b; In the late stage, the acidic etching waste liquid and the alkaline etching waste liquid are continuously added into the reaction buffer at a speed c according to the pH value of the reaction system, the total volume of the acidic etching waste liquid and the alkaline etching waste liquid accounts for 1 / 40-1 / 20 of the volume of the water, until the pH value is stabilized in the range of 4.3-4.7 and maintained for 15-30 min without change, the peristaltic pump stops working, and a basic copper chloride slurry is obtained, and the speed a=c≤b.

2. The etching waste solution recycling reaction process pH automatic control method according to claim 1, characterized in that, In the process of preparing the reaction buffer, the heating temperature is 60 DEG C.

3. The etching waste solution recycling reaction process pH automatic control method according to claim 1, characterized in that, In the process of preparing the reaction buffer, the stirring speed is 375 r / min.

4. The method for automatically controlling pH in an etching waste solution recycling and regenerating reaction process according to claim 1, characterized in that, The speed a is 1 ml / s.

5. The method for automatically controlling pH in an etching waste solution recycling and regenerating reaction process according to claim 1, characterized in that, The speed b is 1-5 ml / s.

6. The method for automatically controlling pH in an etching waste solution recycling and regenerating reaction process according to claim 1, characterized in that, The speed c is 1 ml / s.

7. The method for automatically controlling pH in an etching waste solution recycling and regenerating reaction process according to claim 1, characterized in that, The speed a is 2 ml / s, the speed b is 4 ml / s, and the speed c is 1 ml / s.

8. The method for automatically controlling pH in an etching waste solution recycling and regenerating reaction process according to claim 1, characterized in that, During the reaction of the preparation of the basic chlorination process, the total volume of the acidic etching waste solution and the basic etching waste solution added is 4 times the volume of the water.

9. The method for automatically controlling pH in an etching waste solution recycling and regenerating reaction process according to claim 1, characterized in that, During the reaction of the preparation of the basic chlorination process, the total volume of the acidic etching waste solution and the basic etching waste solution added is 5 times the volume of the water.

10. The method for automatically controlling pH in an etching waste solution recycling and regenerating reaction process according to claim 1, characterized in that, During the reaction of the preparation of the basic copper chlorination, once the pH value is less than 3.5, the controller immediately controls the peristaltic pump to stop the addition of the acidic etching waste solution, and once the pH value is greater than 6, the controller immediately controls the peristaltic pump to stop the addition of the basic etching waste solution.

Images