WO2023165021A1

WO2023165021A1 - Method for recycling acidic copper-containing and ammonium-containing waste etching solution

Info

Publication number: WO2023165021A1
Application number: PCT/CN2022/092517
Authority: WO
Inventors: 陈琪
Original assignee: 无锡中天固废处置有限公司
Priority date: 2022-03-03
Filing date: 2022-05-12
Publication date: 2023-09-07
Also published as: CN114561669A; CN114561669B

Abstract

Disclosed is a method for recycling an acidic copper-containing and ammonium-containing waste etching solution, the method comprising the following steps: subjecting an acidic copper-containing and ammonium-containing waste etching solution to be treated to a nanofiltration treatment, and thereby obtaining a permeated liquid and a trapped liquid; mixing the trapped liquid with sulfuric acid, and subjecting same to an evaporation treatment to obtain an evaporated mother liquor; and electrolyzing the evaporated mother liquor to obtain elemental copper. In the method of the present application, valuable components in the waste etching solution are separated and recycled through successive nanofiltration, evaporation and electrolysis operations according to the composition characteristics of the waste etching solution, all the components are thoroughly separated and can be reused, and the obtained copper product has a high purity and a high utilization value; and the method is easy to operate, has a low cost, is suitable for the recovery processing of a waste solution having complex components, and has no secondary pollution.

Description

A method for recycling acidic copper-containing ammonium-containing etching waste liquid

technical field

The embodiment of the present application relates to the technical field of waste liquid recycling, for example, a method for recycling acidic copper-containing ammonium-containing etching waste liquid.

Background technique

Printed circuit board is an important part of electronic products, and its production process has formed a large-scale industry. It is one of the important branches of the electronics industry. According to the raw materials used in the production of printed circuit boards and the production process, a large amount of etching waste liquid will be generated. Due to the It has the characteristics of various types, high toxicity, strong corrosion, etc., and needs to be treated and recycled to avoid environmental pollution and waste of resources.

According to the composition of commonly used etching solutions, it can be divided into acid etching solution and alkaline etching solution. Copper-containing etching solution is the most commonly used type of etching solution at present, with high etching capacity, high etching efficiency, low cost and relatively small environmental pollution. etc., the etching waste liquid it produces is copper-containing etching waste liquid, and according to the type and composition of the etching liquid, the acidic etching waste liquid will exist in the form of ammonium radicals, so the recovery of copper in the etching waste liquid only adopts a single operation Often difficult to achieve.

The recovery methods of copper in etching waste liquid mainly include electrolytic regeneration method, metal replacement method, solvent extraction method, etc.; although electrolytic regeneration method can recover copper in acidic copper chloride etching waste liquid, a large amount of chlorine gas will be produced in the electrolysis process, which has the advantages of Corrosive and toxic, which is harmful to the environment and human body; the amount of metal used in the metal replacement method is large, and another waste liquid will be generated at the same time, and the added value of copper products at this time is low; the use of solvent extraction method has a great impact on the etching waste. The requirement of the liquid is high, it needs to be neutralized first, and the cost of the extractant is high, and the stripping operation is also required. After the stripping, the copper needs to be electrolytically recovered, and the operation is relatively complicated.

CN 106587105A discloses a method for recovering copper chloride acidic etching solution in printed circuit boards. The recovery method comprises: distilling the acidic etching solution after adding sodium chloride solution to obtain hydrochloric acid, diluting the distilled solution, adding hydrogen after filtering Sodium oxide solution to generate copper hydroxide precipitate, separate the precipitated press filtrate for distillation and crystallization to obtain sodium chloride crystals, add a mixed solution of sulfuric acid and copper sulfate after the precipitate is washed, and obtain copper sulfate electrolyte; the acidic acid treated by this method The copper-containing etching solution is a waste solution with a single main component, and it is difficult to effectively treat the waste solution with complex components, or the resulting product has low purity.

CN 111925026A discloses a treatment process for acidic copper-containing etching waste liquid, the treatment process includes a neutralization process, a copper extraction process and a deployment process; the copper extraction process includes placing the pH-adjusted solution in an electrolytic cell, and Conduct primary electrolysis at a density of 200-300A/m ² and a temperature of 50-60°C, and perform secondary electrolysis when the concentration of copper ions is less than 10g/L. At this time, the current density is 100-200A/m ² and the electrolysis temperature is When the solubility of copper ions is less than 2g/L, the electrolysis process ends and the electrolyzed elemental copper and clear liquid are recovered; hydrochloric acid, ammonium chloride and copper ions are added to the clear liquid to obtain etching sub-liquid and use. The main operation in this process is two electrolysis, but the anions in the etching waste liquid are not specified. If it is a common chloride ion, the electrolysis product includes chlorine gas, which is highly corrosive and toxic, and it is also not suitable for complex component etching waste. Liquid handling.

In summary, for the treatment of acidic copper-containing ammonium-containing etching waste liquid, it is also necessary to select a suitable combination process for treatment according to the composition of the waste liquid, so that it can realize the recycling of the etching waste liquid, and the purity and The use value is higher.

Contents of the invention

The following is an overview of the topics described in detail in this article. This summary is not intended to limit the scope of the claims.

An embodiment of the present application provides a method for recycling acidic copper-containing ammonium-containing etching waste liquid. According to the composition characteristics of the etching waste liquid, the method sequentially adopts nanofiltration, evaporation and electrolysis to remove valuable The components are separated and recovered, and each component is completely separated and can be reused. The resulting product has high purity and can be applied to fields with higher requirements and has high utilization value.

An embodiment of the present application provides a method for recycling acidic copper-containing ammonium-containing etching waste liquid, the method comprising the following steps:

(1) Carrying out nanofiltration treatment to the acidic copper-containing ammonium-containing etching waste liquid to be treated to obtain permeate and retentate;

(2) carry out evaporation treatment after the retentate obtained in step (1) is mixed with sulfuric acid, obtain evaporation mother liquor;

(3) Electrolyzing the evaporated mother liquor obtained in step (2) to obtain simple copper.

In this application, for the treatment of etching waste liquid, suitable unit operations are usually taken according to the composition of the waste liquid, but the degree of separation is often insufficient, and for waste liquid of complex components, it is difficult to obtain valuable recovery products; in this application, According to the composition of the acidic copper-containing ammonium-containing etching waste liquid, according to the difficulty of separation of each component, the nanofiltration operation is first used to separate copper ions, ammonium ions and other ions with different valence states, so that the two can be recovered separately, and then The hydrogen chloride in the intercepted liquid is evaporated through evaporation treatment, and hydrochloric acid is obtained after absorption, so as to avoid corrosion and pollution caused by the generation of chlorine gas in the subsequent recovery of copper, and the remaining evaporated mother liquor is obtained through electrolysis to obtain high-purity copper, which can be applied to high-purity requirements. Fine industry: the method is simple to operate and low in cost, and can be applied to the recovery and treatment of complex component waste liquid, and the recovered products have high utilization value.

The following are preferred technical solutions of the present application, but not as limitations of the technical solutions provided in the present application. Through the following technical solutions, the technical objectives and beneficial effects of the present application can be better achieved and realized.

As a preferred technical solution of the present application, the sources of the acidic copper-containing ammonium-containing etching waste liquid in step (1) include circuit board etching industry and/or copper-containing alloy surface processing industry.

Preferably, the composition of the acidic copper-containing ammonium-containing etching waste solution in step (1) includes copper chloride, ammonium chloride and hydrogen chloride.

In this application, according to the needs of the etching process, a small amount of etching aids and surfactants will also be added to the etching solution, which will also exist in the resulting etching waste solution. Pass through the nanofiltration membrane without affecting the subsequent treatment of the retentate.

Preferably, the concentration of copper in the acidic copper-containing ammonium-containing etching waste solution in step (1) is 1-8wt%, such as 1wt%, 3wt%, 5wt%, 6wt% or 8wt%, but not limited to the listed The numerical value of , other unlisted numerical values in this numerical range are also applicable.

Preferably, the pH value of the acidic copper-containing ammonium-containing etching waste solution in step (1) is 1 to 6, such as 1, 2, 3, 4, 5 or 6, etc., but not limited to the listed values. Other unrecited values within the range also apply.

As a preferred technical solution of the present application, the pressure of the nanofiltration treatment in step (1) is 0.5-2.5MPa, such as 0.5MPa, 1.0MPa, 1.5MPa, 2.0MPa or 2.5MPa, etc., but not limited to the listed values , other unlisted values within this value range are also applicable.

Preferably, the pore size of the nanofiltration membrane used in the nanofiltration treatment in step (1) is 1 to 3 nm, such as 1 nm, 1.5 nm, 2 nm, 2.5 nm or 3 nm, etc., but is not limited to the listed values. Other values not listed also apply.

In the present application, through the nanofiltration treatment and the selection of relevant parameters of the nanofiltration membrane, the monovalent ions and divalent ions in the etching waste liquid are fully separated, which facilitates the separation and recycling of the two.

As a preferred technical solution of the present application, after the nanofiltration treatment in step (1), the copper ions in the etching waste liquid are intercepted.

Preferably, the main composition of the retentate in step (1) includes copper chloride, and the main composition of the permeate includes ammonium chloride.

As a preferred technical solution of the present application, the volume ratio of the retentate to sulfuric acid in step (2) is 0.1 to 1, such as 0.1, 0.3, 0.5, 0.6, 0.8 or 1, but not limited to the listed values, the Other unrecited values within the range of values also apply.

Preferably, the concentration of sulfuric acid in step (2) is 5-20wt%, such as 5wt%, 8wt%, 10wt%, 12wt%, 15wt%, 18wt% or 20wt%, but not limited to the listed values, Other unrecited values within this value range are also applicable.

In this application, the function of adding sulfuric acid is to make chlorine ions and hydrogen ions volatilize in the form of hydrogen chloride during evaporation through the addition of hydrogen ions, so as to avoid the generation of chlorine gas during the subsequent recovery of copper.

As a preferred technical solution of the present application, the temperature of the evaporation treatment in step (2) is 95 to 120°C, such as 95°C, 100°C, 105°C, 110°C, 115°C or 120°C, etc., but not limited to the listed The numerical value of , other unlisted numerical values in this numerical range are also applicable.

Preferably, the end point of the evaporation treatment in step (2) is: the volume of the evaporated mother liquor is 10 to 30% of the volume of the mixed solution of the retentate and sulfuric acid, such as 10%, 15%, 20%, 25% or 30%, etc., However, it is not limited to the listed values, and other unlisted values within the range of values are also applicable.

Preferably, the evaporation treatment in step (2) evaporates the hydrogen chloride in the mixed liquid, and absorbs it with water to obtain hydrochloric acid.

Preferably, the composition of the evaporation mother liquor in step (2) includes copper sulfate.

As a preferred technical solution of the present application, the permeate obtained in step (1) is mixed with the hydrochloric acid obtained in step (2) to prepare the etching solution.

As a preferred technical solution of the present application, the current density of electrolysis in step (3) is 200-1000A/dm ² , such as 200A/dm ² , 300A/dm ² , 400A/dm ² , 500A/dm ² , 600A/dm 2 ² , 800A/dm ² or 1000A/dm ² , etc., but not limited to the listed values, other unlisted values within this range are also applicable.

Preferably, the electrolysis temperature in step (3) is 20-50°C, such as 20°C, 25°C, 30°C, 35°C, 40°C, 45°C or 50°C, etc., but not limited to the listed values, Other unrecited values within this value range are also applicable.

Preferably, simple copper is deposited on the cathode after the electrolysis in step (3).

Preferably, sulfuric acid is obtained by electrolysis in step (3), and the sulfuric acid is returned to step (2) to be mixed with the retentate.

As a preferred technical solution of the present application, the copper element described in step (3) is used as an anode for electrolysis again, and sulfuric acid is used as an electrolyte to obtain a copper sulfate electroplating solution.

Preferably, the sulfuric acid is electronic-grade sulfuric acid, and the purity of the electronic-grade sulfuric acid can reach more than 99%, so that the obtained copper sulfate can reach the purity of electronic grade.

Preferably, the electrolysis current density is 500-800A/dm ² , such as 500A/dm ² , 550A/dm ² , 600A/dm ² , 650A/dm ² , 700A/dm ² , 750A/dm ² or 800A/dm 2 dm ² , etc., but not limited to the listed values, other unlisted values within this range are also applicable.

Preferably, the temperature of the electrolysis is 30-60°C, such as 30°C, 35°C, 40°C, 45°C, 50°C, 55°C or 60°C, etc., but it is not limited to the listed values. Other values not listed also apply.

As the preferred technical solution of the present application, the method includes the following steps:

(1) The acidic copper-containing ammonium-containing etching waste liquid to be treated is subjected to nanofiltration treatment. The source of the acidic copper-containing ammonium-containing etching waste liquid includes the circuit board etching industry and/or the copper-containing alloy surface processing industry, and its composition includes chlorine Copper chloride, ammonium chloride and hydrogen chloride, wherein the concentration of copper is 1-8wt%, the pH value is 1-6, the pressure of the nanofiltration treatment is 0.5-2.5MPa, and the aperture of the nanofiltration membrane used is 1-3nm, Obtain permeate and retentate, the main composition of described retentate comprises cupric chloride, the main composition of described permeate comprises ammonium chloride;

(2) The retentate obtained in step (1) is mixed with sulfuric acid, the volume ratio of the retentate to sulfuric acid is 0.1 to 1, the concentration of the sulfuric acid is 5 to 20 wt%, and then evaporated, the evaporated The temperature of the evaporation treatment is 95-120°C. The hydrogen chloride in the mixed solution is evaporated in the evaporation treatment, and hydrochloric acid is obtained by absorbing it with water. The end point of the evaporation treatment is: the volume of the evaporated mother liquor is 10-30 %, to obtain the evaporated mother liquor, the composition of the evaporated mother liquor includes copper sulfate; the hydrochloric acid and the permeated liquid obtained in step (1) are mixed for preparing the etching solution;

(3) Electrolyzing the evaporated mother liquor obtained in step (2), the current density of the electrolysis is 200-1000A/dm ² , the temperature of the electrolysis is 20-50°C, after the electrolysis, the copper element is precipitated on the cathode, and the solution becomes sulfuric acid , the sulfuric acid returns to step (2) and is mixed with the retained solution; the copper element is used as an anode for electrolysis again, and the electronic grade sulfuric acid is used as an electrolyte to obtain a copper sulfate electroplating solution.

Compared with related technologies, the present application has the following beneficial effects:

(1) According to the composition characteristics of the etching waste liquid, the method described in the embodiment of the present application adopts the operation of nanofiltration, evaporation and electrolysis to separate and recycle the valuable components in the etching waste liquid, and each component is completely separated, and It can be reused, and the obtained copper product has high purity, which can reach more than 99%, and has high utilization value;

(2) The method described in the embodiment of the present application is simple in operation and low in cost, and can be applied to the recovery and treatment of complex component waste liquid without secondary pollution.

Other aspects will be apparent to others upon reading and understanding the drawings and detailed description.

Description of drawings

The accompanying drawings are used to provide a further understanding of the technical solutions herein, and constitute a part of the description, and are used together with the embodiments of the application to explain the technical solutions herein, and do not constitute limitations to the technical solutions herein.

Figure 1 is a process flow diagram of the method for recycling acidic copper-containing ammonium-containing etching waste solution provided in Example 1 of the present application.

Detailed ways

In order to better illustrate the present application and facilitate the understanding of the technical solutions of the present application, the present application is further described in detail below. However, the following embodiments are only simple examples of the present application, and do not represent or limit the protection scope of the present application, and the protection scope of the present application shall be determined by the claims.

The specific embodiment part of the present application provides a method for recycling acidic copper-containing ammonium-containing etching waste liquid, the method comprising the following steps:

The following are typical but non-limiting examples of the application:

Example 1:

This embodiment provides a method for recycling acidic copper-containing ammonium-containing etching waste liquid. The process flow diagram of the method is shown in Figure 1, including the following steps:

(1) The acidic copper-containing ammonium-containing etching waste liquid to be treated is subjected to nanofiltration treatment, and the source of the acidic copper-containing ammonium-containing etching waste liquid is the circuit board etching industry, and its composition includes copper chloride, ammonium chloride and hydrogen chloride, Wherein the concentration of copper is 5wt%, and the pH value is 3, and the pressure of described nanofiltration treatment is 1.5MPa, and the aperture of nanofiltration membrane used is 2nm, obtains permeate and retentate, and the main composition of described retentate comprises chlorine Copper chloride, the main composition of the permeated liquid includes ammonium chloride;

(2) the retentate obtained in step (1) is mixed with sulfuric acid, the volume ratio of the retentate to sulfuric acid is 0.5:1, the concentration of the sulfuric acid is 10wt%, and then evaporated, the temperature of the evaporated is 100°C, the evaporation treatment evaporates the hydrogen chloride in the mixed solution, absorbs it with water to obtain hydrochloric acid, and the end point of the evaporation treatment is: the volume of the evaporated mother liquor is 20% of the volume of the mixed solution of the retentate and sulfuric acid, and the evaporated mother liquor is obtained. The composition of the evaporated mother liquor includes copper sulfate; the hydrochloric acid is mixed with the permeated liquid obtained in step (1) to prepare the etching solution;

(3) Electrolyze the evaporated mother liquor obtained in step (2), the current density of the electrolysis is 500A/dm ² , the temperature of the electrolysis is 30°C, after the electrolysis, the copper element is precipitated on the cathode, and the solution becomes sulfuric acid, and the sulfuric acid Go back to step (2) and mix with the retained solution; the copper element is used as the anode for electrolysis again, using electronic grade sulfuric acid as the electrolyte, the electrolysis current density is 600A/dm ² , and the temperature is 40°C to obtain a copper sulfate electroplating solution.

In this embodiment, the waste etching liquid is recycled through the above combination process, the components in the waste liquid are completely separated, and the purity of the obtained copper product is high, which can reach 99.5%.

Example 2:

This embodiment provides a method for recycling acidic copper-containing ammonium-containing etching waste liquid, the method comprising the following steps:

(1) The acidic copper-containing ammonium-containing etching waste liquid to be treated is subjected to nanofiltration treatment, and the source of the acidic copper-containing ammonium-containing etching waste liquid is the circuit board etching industry, and its composition includes copper chloride, ammonium chloride and hydrogen chloride, Wherein the concentration of copper is 1wt%, and the pH value is 6, and the pressure of described nanofiltration treatment is 2.5MPa, and the pore diameter of nanofiltration membrane used is 1nm, obtains permeate and retentate, and the main composition of described retentate comprises chlorine Copper chloride, the main composition of the permeated liquid includes ammonium chloride;

(2) the retentate obtained in step (1) is mixed with sulfuric acid, the volume ratio of the retentate to sulfuric acid is 1:1, the concentration of the sulfuric acid is 20wt%, and then evaporated, the temperature of the evaporated It is 110 ℃, and the hydrogen chloride in the mixed solution is evaporated by the evaporation treatment, and absorbed by water to obtain hydrochloric acid. The end point of the evaporation treatment is: the volume of the evaporated mother liquor is 10% of the volume of the mixed solution of the retained liquid and sulfuric acid, and the evaporated mother liquor is obtained. The composition of the evaporated mother liquor includes copper sulfate; the hydrochloric acid is mixed with the permeated liquid obtained in step (1) to prepare the etching solution;

(3) Electrolyze the evaporated mother liquor obtained in step (2), the current density of the electrolysis is 1000A/dm ² , the temperature of the electrolysis is 20°C, after the electrolysis, the copper element is precipitated on the cathode, and the solution becomes sulfuric acid, and the sulfuric acid Return to step (2) and mix with the retentate; the copper element is used as the anode for electrolysis again, using electronic grade sulfuric acid as the electrolyte, the electrolysis current density is 800A/dm ² , and the temperature is 30°C to obtain a copper sulfate electroplating solution.

In this embodiment, the waste etching liquid is recycled through the above combination process, the components in the waste liquid are completely separated, and the purity of the obtained copper product is high, which can reach 99.2%.

Example 3:

(1) The acidic copper-containing ammonium-containing etching waste liquid to be treated is subjected to nanofiltration treatment, and the source of the acidic copper-containing ammonium-containing etching waste liquid is the circuit board etching industry, and its composition includes copper chloride, ammonium chloride and hydrogen chloride, Wherein the concentration of copper is 8wt%, and the pH value is 1, and the pressure of described nanofiltration treatment is 0.5MPa, and the aperture of nanofiltration membrane used is 3nm, obtains permeate and retentate, and the main composition of described retentate comprises chlorine Copper chloride, the main composition of the permeated liquid includes ammonium chloride;

(2) the retentate obtained in step (1) is mixed with sulfuric acid, the volume ratio of the retentate to sulfuric acid is 0.1:1, the concentration of the sulfuric acid is 5wt%, and then evaporated, the temperature of the evaporated is 120°C, the evaporation treatment evaporates the hydrogen chloride in the mixed solution, absorbs it with water to obtain hydrochloric acid, and the end point of the evaporation treatment is: the volume of the evaporated mother liquor is 30% of the volume of the mixed solution of the retentate and sulfuric acid, and the evaporated mother liquor is obtained. The composition of the evaporated mother liquor includes copper sulfate; the hydrochloric acid is mixed with the permeated liquid obtained in step (1) to prepare the etching solution;

(3) The evaporated mother liquor obtained in step (2) is electrolyzed, the current density of the electrolysis is 200A/dm ² , the temperature of the electrolysis is 50°C, copper is precipitated on the cathode after the electrolysis, and the solution becomes sulfuric acid, and the sulfuric acid Go back to step (2) and mix with the retained solution; the copper element is used as the anode for electrolysis again, using electronic grade sulfuric acid as the electrolyte, the electrolysis current density is 500A/dm ² , and the temperature is 60°C to obtain a copper sulfate electroplating solution.

In this embodiment, the waste etching liquid is recycled through the above combination process, the components in the waste liquid are completely separated, and the purity of the obtained copper product is high, which can reach 99.4%.

Example 4:

(1) The acidic copper-containing ammonium-containing etching waste liquid to be treated is subjected to nanofiltration treatment. The source of the acidic copper-containing ammonium-containing etching waste liquid is the copper-containing alloy surface processing industry, and its composition includes copper chloride, ammonium chloride and Hydrogen chloride, wherein the concentration of copper is 3wt%, the pH value is 4, the pressure of the nanofiltration treatment is 2.0MPa, the aperture of the nanofiltration membrane used is 1.5nm, obtains permeate and retentate, the main content of the retentate is The composition includes copper chloride, and the main composition of the permeated liquid includes ammonium chloride;

(2) the retentate obtained in step (1) is mixed with sulfuric acid, the volume ratio of the retentate to sulfuric acid is 0.75:1, the concentration of the sulfuric acid is 15wt%, and then evaporated, the temperature of the evaporated is 95°C, the evaporation treatment evaporates the hydrogen chloride in the mixed solution, and absorbs it with water to obtain hydrochloric acid. The end point of the evaporation treatment is: the volume of the evaporated mother liquor is 25% of the volume of the mixed solution of the retentate and sulfuric acid, and the evaporated mother liquor is obtained. The composition of the evaporated mother liquor includes copper sulfate; the hydrochloric acid is mixed with the permeated liquid obtained in step (1) to prepare the etching solution;

(3) The evaporated mother liquor obtained in step (2) is electrolyzed, the current density of the electrolysis is 750A/dm ² , the temperature of the electrolysis is 35°C, copper is precipitated on the cathode after electrolysis, and the solution becomes sulfuric acid, and the sulfuric acid Go back to step (2) and mix with the retained solution; the copper element is used as the anode for electrolysis again, using electronic grade sulfuric acid as the electrolyte, the electrolysis current density is 550A/dm ² , and the temperature is 45°C to obtain a copper sulfate electroplating solution.

Example 5:

(1) The acidic copper-containing ammonium-containing etching waste liquid to be treated is subjected to nanofiltration treatment. The source of the acidic copper-containing ammonium-containing etching waste liquid is the copper-containing alloy surface processing industry, and its composition includes copper chloride, ammonium chloride and Hydrogen chloride, wherein the concentration of copper is 6wt%, the pH value is 2, the pressure of the nanofiltration treatment is 1.0MPa, the aperture of the nanofiltration membrane used is 2nm, and the permeate and the retentate are obtained, and the main components of the retentate are Including copper chloride, the main component of the permeated liquid includes ammonium chloride;

(2) the retentate obtained in step (1) is mixed with sulfuric acid, the volume ratio of the retentate to sulfuric acid is 0.3:1, the concentration of the sulfuric acid is 8wt%, and then evaporated, the temperature of the evaporated is 105°C, the evaporation treatment evaporates the hydrogen chloride in the mixed solution, and absorbs it with water to obtain hydrochloric acid. The end point of the evaporation treatment is: the volume of the evaporated mother liquor is 15% of the volume of the mixed solution of the retentate and sulfuric acid, and the evaporated mother liquor is obtained. The composition of the evaporated mother liquor includes copper sulfate; the hydrochloric acid is mixed with the permeated liquid obtained in step (1) to prepare the etching solution;

(3) The evaporated mother liquor obtained in step (2) is electrolyzed, the current density of the electrolysis is 400A/dm ² , the temperature of the electrolysis is 40°C, copper is precipitated on the cathode after electrolysis, and the solution becomes sulfuric acid, and the sulfuric acid Go back to step (2) and mix with the retained solution; the copper element is used as the anode for electrolysis again, using electronic grade sulfuric acid as the electrolyte, the electrolysis current density is 700A/dm ² , and the temperature is 50°C to obtain a copper sulfate electroplating solution.

In this embodiment, the waste etching liquid is recycled through the above combination process, the components in the waste liquid are completely separated, and the purity of the obtained copper product is high, which can reach 99.1%.

Comparative example 1:

This comparative example provides a method for recycling acidic copper-containing ammonium-containing etching waste liquid. The method refers to the method in Example 1, the only difference being that the operation of step (1) is not included.

In this comparative example, since the etching waste liquid was not subjected to nanofiltration treatment, the ammonium ions in it could not be separated in advance. At this time, the acidic waste liquid was directly evaporated, so that the evaporated mother liquid contained a large amount of ammonium sulfate, and the salt concentration was too high to cause Cannot be electrolyzed normally.

Based on the above examples and comparative examples, it can be seen that according to the composition characteristics of the etching waste liquid, the method described in the present application sequentially adopts the operations of nanofiltration, evaporation and electrolysis to separate and recycle the valuable components in the etching waste liquid. The components are completely separated and can be reused. The obtained copper product has high purity, which can reach more than 99%, and has high utilization value. Secondary pollution.

The present application illustrates the detailed method of the present application through the above-mentioned embodiments, but the present application is not limited to the above-mentioned detailed method, that is, it does not mean that the present application must rely on the above-mentioned detailed method to be implemented. Those skilled in the art should understand that any improvement to the present application, equivalent replacement of the method of the present application, addition of auxiliary steps, selection of specific methods, etc., all fall within the scope of protection and disclosure of the present application.

Claims

A method for recycling acidic copper-containing ammonium-containing etching waste liquid, comprising the following steps:

(1) Carrying out nanofiltration treatment to the acidic copper-containing ammonium-containing etching waste liquid to be treated to obtain permeate and retentate;

(2) carry out evaporation treatment after the retentate obtained in step (1) is mixed with sulfuric acid, obtain evaporation mother liquor;

(3) Electrolyzing the evaporated mother liquor obtained in step (2) to obtain simple copper.
The method according to claim 1, wherein the source of the acidic copper-containing ammonium-containing etching waste liquid in step (1) includes circuit board etching industry and/or copper-containing alloy surface processing industry.
The method according to claim 1, wherein the composition of the acidic copper-containing ammonium-containing etching waste solution in step (1) comprises copper chloride, ammonium chloride and hydrogen chloride.
The method according to claim 1, wherein the concentration of copper in the acidic copper-containing ammonium-containing etching waste solution in step (1) is 1-8 wt%.
The method according to claim 1, wherein the pH value of the acid copper-containing ammonium-containing etching waste solution in step (1) is 1-6.
The method according to any one of claims 1-5, wherein the pressure of the nanofiltration treatment in step (1) is 0.5-2.5 MPa;

Preferably, the pore size of the nanofiltration membrane used in the nanofiltration treatment in step (1) is 1-3 nm.
The method according to any one of claims 1-6, wherein, after the nanofiltration treatment in step (1), the copper ions in the etching waste liquid are intercepted;

Preferably, the main composition of the retentate in step (1) includes copper chloride, and the main composition of the permeate includes ammonium chloride.
The method according to any one of claims 1-7, wherein the volume ratio of the retentate in step (2) to sulfuric acid is 0.1 to 1;

Preferably, the concentration of sulfuric acid in step (2) is 5-20wt%.
The method according to any one of claims 1-8, wherein the temperature of the evaporation treatment in step (2) is 95-120°C;

Preferably, the end point of the evaporation treatment in step (2) is: the volume of the evaporated mother liquor is 10% to 30% of the volume of the mixed liquid of the retained liquid and sulfuric acid;

Preferably, the evaporation treatment in step (2) evaporates the hydrogen chloride in the mixed solution, and absorbs it with water to obtain hydrochloric acid;

Preferably, the composition of the evaporation mother liquor in step (2) includes copper sulfate.
The method according to any one of claims 1-9, wherein the permeate obtained in step (1) is mixed with the hydrochloric acid obtained in step (2) to prepare an etching solution.
The method according to any one of claims 1-10, wherein the current density of the electrolysis in step (3) is 200 to 1000A/dm 2 ;

Preferably, the electrolysis temperature in step (3) is 20-50°C;

Preferably, copper elemental substance is precipitated on the cathode after the electrolysis in step (3);

Preferably, sulfuric acid is obtained by electrolysis in step (3), and the sulfuric acid is returned to step (2) to be mixed with the retentate.
The method according to any one of claims 1-11, wherein, the copper element described in step (3) is electrolyzed again as an anode, and sulfuric acid is used as an electrolyte to obtain a copper sulfate electroplating solution;

Preferably, the sulfuric acid is electronic grade sulfuric acid;

Preferably, the current density of the electrolysis is 500-800A/dm 2 ;

Preferably, the temperature of the electrolysis is 30-60°C.
The method according to any one of claims 1-12, comprising the steps of:

(1) The acidic copper-containing ammonium-containing etching waste liquid to be treated is subjected to nanofiltration treatment. The source of the acidic copper-containing ammonium-containing etching waste liquid includes the circuit board etching industry and/or the copper-containing alloy surface processing industry, and its composition includes chlorine Copper chloride, ammonium chloride and hydrogen chloride, wherein the concentration of copper is 1-8wt%, the pH value is 1-6, the pressure of the nanofiltration treatment is 0.5-2.5MPa, and the aperture of the nanofiltration membrane used is 1-3nm, Obtain permeate and retentate, the main composition of described retentate comprises cupric chloride, the main composition of described permeate comprises ammonium chloride;

(2) The retentate obtained in step (1) is mixed with sulfuric acid, the volume ratio of the retentate to sulfuric acid is 0.1 to 1, the concentration of the sulfuric acid is 5 to 20 wt%, and then evaporated, the evaporated The temperature of the evaporation treatment is 95-120°C. The hydrogen chloride in the mixed solution is evaporated in the evaporation treatment, and hydrochloric acid is obtained by absorbing it with water. The end point of the evaporation treatment is: the volume of the evaporated mother liquor is 10-30 %, to obtain the evaporated mother liquor, the composition of the evaporated mother liquor includes copper sulfate; the hydrochloric acid and the permeated liquid obtained in step (1) are mixed for preparing the etching solution;

(3) Electrolyzing the evaporated mother liquor obtained in step (2), the current density of the electrolysis is 200-1000A/dm 2 , the temperature of the electrolysis is 20-50°C, after the electrolysis, the copper element is precipitated on the cathode, and the solution becomes sulfuric acid , the sulfuric acid returns to step (2) and is mixed with the retained solution; the copper element is used as an anode for electrolysis again, and the electronic grade sulfuric acid is used as an electrolyte to obtain a copper sulfate electroplating solution.