Cyclic regeneration method for extracting copper from acidic etching solution through ionic membrane electrolysis without generating chlorine

Abstract

The invention relates to a chlorine-free acidic etching liquid ion membrane electrolysis copper extraction cyclic regeneration method, which comprises the following steps: Q1, in the production process of a printed circuit board, obtaining acidic etching waste liquid on a DES line; and Q2, enabling the acidic etching waste liquid on the DES line to flow into an electrolytic anode plate pool for diaphragm electrolysis, electrochemical recycling and Cu < + >-Cu < 2 + >, continuously carrying out reaction, adding oxygen into an anode to convert cl <-> into clO <->, carrying out purification treatment on incompletely converted cl2 through an acid mist absorption system to reach the standard, and keeping the concentration of Cu < + > not lower than 10%. According to the method, cyclic regeneration of the etching liquid is guaranteed, waste liquid discharge and chemical supplement requirements are reduced, the chlorine leakage risk is reduced, and the production safety is improved.

Description

Technical Field

[0001] This invention relates to the field of copper extraction technology using acidic etching solutions, and in particular to a method for the cyclic regeneration of copper extraction using ion-exchange membrane electrolysis of acidic etching solutions that does not generate chlorine gas. Background Technology

[0002] The PCB industry uses copper chloride acidic etching solution. When the copper concentration reaches saturation (120-160 g / L), the waste solution must be discarded. Traditional treatment methods (electrolysis or off-site transportation) pose risks such as chlorine gas escape and reduced activity requiring frequent chemical replenishment. Therefore, how to save energy, ensure no chlorine gas is generated, and guarantee that the recovered acidic etching solution meets etching requirements during the copper extraction and recycling process has become an urgent problem to be solved. Summary of the Invention

[0003] In view of the above problems, the present invention provides a method for recycling and regenerating copper by ion membrane electrolysis of acidic etching solution without generating chlorine gas. This method not only ensures the recycling and regeneration of etching solution, reducing waste liquid discharge and chemical replenishment needs, but also reduces the risk of chlorine gas leakage and improves production safety.

[0004] To achieve the above and other related objectives, the present invention provides the following technical solution: A method for the cyclic regeneration of copper extraction via ion-exchange membrane electrolysis using an acidic etching solution that does not produce chlorine gas, the method comprising: Q1. During the printed circuit board manufacturing process, acidic etching waste liquid is obtained from the DES line; Q2. The acidic etching waste liquid from the DES line is fed into an electrolytic anode plate cell for diaphragm electrolysis and electrochemical regeneration. Cu + →Cu 2+ The reaction continues, and oxygen is added at the anode to make Cl - Converted to ClO - Incompletely converted Cl2 is purified through an acid mist absorption system to meet standards, maintaining Cu + The concentration is not less than 10%; Q3. High Cu content 2+ The acidic etching waste liquid enters the electrolytic cathode plate cell for electrolysis, Cu 2+ At the cathode, it is reduced to Cu, making Cu 2+ The concentration of Cu decreases, and after being adjusted in the anode region, it returns to the etching process, forming a solution circulation loop. 2+ The concentration is less than 5 g / L.

[0005] Furthermore, in step Q2, the chemical reaction formula for membrane electrolysis in the electrolytic anode plate cell is: 2cl - +O2→2clO -, Cu + 2clO - →Cucl2+O2+2e.

[0006] Furthermore, in step Q3, the chemical reaction formula for electrolysis in the electrolytic cathode plate cell is: 2OH - →2H + +O2+2e, Cu 2+ +2e→Cu.

[0007] Furthermore, during the electrolysis of the acidic etching waste liquid on the DES line, as the electrode reaction proceeds, the temperature of the solution increases. Chlorine gas is generated at the cathode of the anion exchange membrane electrolysis, and oxygen gas is generated at the anode of the cation exchange membrane electrolysis. Additionally, some hydrochloric acid mist evaporates and is absorbed into the regeneration solution through a jet.

[0008] To achieve the above and other related objectives, the present invention also provides an acidic etching solution ion membrane electrolytic copper extraction and recycling system that does not generate chlorine gas, comprising an edge computing device, an online total copper detector, an ORP monitor, a pH meter, a thermometer, and a flow meter, wherein the edge computing device is electrically connected to the online total copper detector, the ORP monitor, the pH meter, the thermometer, and the flow meter, respectively.

[0009] Furthermore, the total copper online detector is used to detect Cu in the electrolyte of the electrolytic anode plate cell. + The concentration of Cu in the electrolyte. + The concentration should be maintained at 1.25-1.35 g / L.

[0010] Furthermore, the ORP monitor is used to control the ORP parameter range of the electrolytic anode plate cell to 480-600mV.

[0011] Furthermore, the pH meter is used to control the pH value of the electrolytic anode plate cell within the range of 2.1-2.5.

[0012] Furthermore, the thermometer is used to control the temperature range of the electrolyte in the electrolytic anode plate cell or electrolytic cathode plate cell to be 45-53℃.

[0013] Furthermore, the flow meter is used to acquire real-time data on the flow rate of acidic etching waste liquid flowing into the electrolytic anode plate pool from the DES line.

[0014] The present invention has the following positive effects: This invention involves electrochemically regenerating and reusing the acidic etching waste liquid from the DES line by flowing it into an electrolytic anode plate cell for diaphragm electrolysis, and then combining this with electrolysis in an electrolytic cathode plate cell, using Cu... 2+ At the cathode, it is reduced to Cu, making Cu 2+The concentration of the solution is reduced, and after being mixed in the anode area, it is returned to the etching process to form a solution circulation loop. This not only ensures the recycling of the etching solution and reduces waste liquid discharge and chemical replenishment needs, but also reduces the risk of chlorine leakage and improves production safety. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the process flow of the present invention. Detailed Implementation

[0016] The exemplary embodiments of this disclosure are described below with reference to the accompanying drawings, including various details of the embodiments to aid understanding, and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this disclosure. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0017] Example: Figure 1 As shown, a method for the cyclic regeneration of copper extraction via ion-exchange membrane electrolysis using an acidic etching solution that does not produce chlorine gas includes: Q1. During the printed circuit board manufacturing process, acidic etching waste liquid is obtained from the DES line; Q2. The acidic etching waste liquid from the DES line is fed into an electrolytic anode plate cell for diaphragm electrolysis and electrochemical regeneration. Cu + →Cu 2+ The reaction continues, and oxygen is added at the anode to make Cl - Converted to ClO - Incompletely converted Cl2 is purified through an acid mist absorption system to meet standards, maintaining Cu + The concentration is not less than 10%; Q3. High Cu content 2+ The acidic etching waste liquid enters the electrolytic cathode plate cell for electrolysis, Cu 2+ At the cathode, it is reduced to Cu, making Cu 2+ The concentration of Cu decreases, and after being adjusted in the anode region, it returns to the etching process, forming a solution circulation loop. 2+ The concentration is less than 5 g / L.

[0018] In this embodiment, in step Q2, the chemical reaction formula for membrane electrolysis in the electrolytic anode plate cell is: 2cl - +O2→2clO - , Cu + 2clO - →Cucl2+O2+2e.

[0019] In this embodiment, in step Q3, the chemical reaction formula for the electrolysis of the electrolytic cathode plate cell is: 2OH - →2H + +O2+2e, Cu 2+ +2e→Cu.

[0020] In this embodiment, during the electrolysis of the acidic etching waste liquid on the DES line, as the electrode reaction proceeds, the temperature of the solution increases. Chlorine gas is generated at the cathode of the anion exchange membrane electrolysis, and oxygen gas is generated at the anode of the cation exchange membrane electrolysis. In addition, some hydrochloric acid mist evaporates and is absorbed into the regeneration liquid through a jet.

[0021] In this embodiment, the present invention provides an acidic etching solution ion membrane electrolytic copper extraction and recycling system that does not generate chlorine gas, including an edge computing device, an online total copper detector, an ORP monitor, a pH meter, a thermometer, and a flow meter. The edge computing device is electrically connected to the online total copper detector, the ORP monitor, the pH meter, the thermometer, and the flow meter, respectively.

[0022] In this embodiment, the online total copper analyzer is used to detect Cu in the electrolyte of the electrolytic anode plate cell. + The concentration of Cu in the electrolyte. + The concentration should be maintained at 1.25-1.35 g / L.

[0023] In this embodiment, the ORP monitor is used to control the ORP parameter range of the electrolytic anode plate cell to be 480-600mV.

[0024] In this embodiment, the pH meter is used to control the pH value of the electrolytic anode plate cell to a range of 2.1-2.5.

[0025] In this embodiment, the thermometer is used to control the temperature range of the electrolyte in the electrolytic anode plate cell or electrolytic cathode plate cell to be 45-53℃.

[0026] In this embodiment, the flow meter is used to acquire real-time data on the flow rate of acidic etching waste liquid flowing into the electrolytic anode plate pool from the DES line.

[0027] In this embodiment, the application process of the present invention is described in detail using the actual production of a printed circuit board factory as an example. First, sensors are installed in the acid etching bath to collect real-time data on pH, ORP, and temperature. Then, a decision tree model is constructed using the PythOn programming language, taking the collected data as input and outputting a predicted value for copper ion concentration. Finally, the optimal copper ion concentration is determined. Experimental results show that this method not only effectively suppresses the generation of chlorine gas but also significantly improves the copper recovery rate.

[0028] Comparative Analysis and Application Examples: Through comparative analysis of traditional methods and the method of this invention, it was found that the present invention has significant advantages in several aspects. For example, the copper recovery rate of traditional methods is approximately 85%, while the method of this invention can reach over 95%. Furthermore, the method of this invention produces almost no chlorine gas during the processing, greatly reducing the risk of environmental pollution. Specific comparative data are shown in Table 1 below:

[0029] Table 1 As shown in Table 1, compared with the prior art, this invention has higher environmental protection and economic efficiency, and has good prospects for promotion and application.

[0030] In this embodiment, the preset threshold is 50 g / L. If the concentration of copper ions is less than 50 g / L, the copper ion concentration meets the requirement and electrolysis is stopped. If the concentration of copper ions is greater than 50 g / L, the copper ion concentration does not meet the requirement and electrolysis continues.

[0031] In summary, this invention not only ensures the recycling and regeneration of etching solution, reducing waste liquid discharge and the need for chemical replenishment, but also reduces the risk of chlorine leakage and improves production safety.

[0032] The specific embodiments described above do not constitute a limitation on the scope of protection of this disclosure. 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 disclosure should be included within the scope of protection of this disclosure.

Claims

1. A method for the cyclic regeneration of copper extraction via ion-exchange membrane electrolysis using an acidic etching solution that does not produce chlorine gas, characterized in that... The method includes: Q1. During the printed circuit board manufacturing process, acidic etching waste liquid is obtained from the DES line; Q2. The acidic etching waste liquid from the DES line is fed into an electrolytic anode plate cell for diaphragm electrolysis and electrochemical regeneration. Cu + →Cu 2+ The reaction continues, and oxygen is added at the anode to make Cl - Converted to ClO - Incompletely converted Cl2 is purified through an acid mist absorption system to meet standards, maintaining Cu + The concentration is not less than 10%; Q3. High Cu content 2+ The acidic etching waste liquid enters the electrolytic cathode plate cell for electrolysis, Cu 2+ At the cathode, it is reduced to Cu, making Cu 2+ The concentration of Cu decreases, and after being adjusted in the anode region, it returns to the etching process, forming a solution circulation loop. 2+ The concentration is less than 5 g / L.

2. The method for recycling and regenerating copper extraction via ion-exchange membrane electrolysis using an acidic etching solution that does not generate chlorine gas, as described in claim 1, is characterized in that... In step Q2, the chemical reaction formula for membrane electrolysis in the electrolytic anode plate cell is: 2cl - +O2→2clO - , Cu+2clO - →Cucl2+O2+2e。 3. The method for recycling and regenerating copper extraction via ion-exchange membrane electrolysis using an acidic etching solution that does not generate chlorine gas, as described in claim 1, is characterized in that... In step Q3, the chemical reaction formula for electrolysis in the electrolytic cathode cell is: 2OH - →2H + +O2+2e, With 2+ +2e→Cu.

4. The method for recycling and regenerating copper extraction via ion-exchange membrane electrolysis using an acidic etching solution that does not generate chlorine gas, as described in claim 1, is characterized in that: During the electrolysis of the acidic etching waste liquid on the DES line, as the electrode reaction proceeds, the temperature of the solution increases. Chlorine gas is generated at the cathode of the anion exchange membrane electrolysis, and oxygen gas is generated at the anode of the cation exchange membrane electrolysis. In addition, some hydrochloric acid mist evaporates and is absorbed into the regeneration solution through the jet.

5. A circulating regeneration system for ion-exchange membrane electrolytic copper extraction using an acidic etching solution that does not produce chlorine gas, characterized in that: It includes an edge computing device, an online total copper detector, an ORP monitor, a pH meter, a thermometer, and a flow meter, wherein the edge computing device is electrically connected to the online total copper detector, the ORP monitor, the pH meter, the thermometer, and the flow meter, respectively.

6. The acidic etching solution ion-exchange membrane electrolytic copper extraction recycling system according to claim 5, characterized in that: The online total copper detector is used to detect Cu in the electrolyte of the electrolytic anode plate cell. + The concentration of Cu in the electrolyte. + The concentration should be maintained between 1.25% and 1.3%. 5g / L.

7. The acidic etching solution ion-exchange membrane electrolytic copper extraction recycling system according to claim 5, characterized in that: The ORP monitor is used to control the ORP parameters of the electrolytic anode plate cell within the range of 480-600mV.

8. The acidic etching solution ion-exchange membrane electrolytic copper extraction recycling system that does not generate chlorine gas according to claim 5, characterized in that: The pH meter is used to control the pH value of the electrolytic anode plate cell within the range of 2.1-2.

5.

9. The acidic etching solution ion-exchange membrane electrolytic copper extraction recycling system that does not generate chlorine gas according to claim 5, characterized in that: The thermometer is used to control the temperature range of the electrolyte in the electrolytic anode plate cell or electrolytic cathode plate cell to 45-53℃.

10. The acidic etching solution ion-exchange membrane electrolytic copper extraction recycling system according to claim 5, characterized in that: The flow meter is used to acquire real-time data on the flow rate of acidic etching waste liquid flowing into the electrolytic anode plate pool from the DES line.

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