阅读说明：本技术 一种电解碱性蚀刻液回收铜用的添加剂及使用其制备铜的方法 (Additive for recovering copper from electrolytic alkaline etching solution and method for preparing copper by using additive ) 是由 罗国华 顾晓聪 刘碧华 于 2020-08-03 设计创作，主要内容包括：本发明涉及蚀刻废液回收再利用技术领域,尤其涉及一种电解碱性蚀刻液回收铜用的添加剂及使用其制备铜的方法。本发明的每升添加剂的水溶液中含有如下组分：30-110ppm结晶细化剂、5-50ppm光亮剂、5-30ppm整平剂、5-20ppm表面活性剂。本发明的电解碱性蚀刻液回收铜用的添加剂,通过在碱性蚀刻液中加入包含光亮剂、整平剂和表面活性剂的添加剂,可以提高过电位,增加极化,减慢电极反应速率,最终获得晶粒细小、光亮的铜镀层,从而可以回收得到表面光亮平整,纯度高,结构致密,富有延展性的铜层。(The invention relates to the technical field of etching waste liquid recycling, in particular to an additive for recycling copper from an electrolytic alkaline etching solution and a method for preparing copper by using the additive. The aqueous solution of the additive of the invention contains the following components per liter: 30-110ppm of crystallization refiner, 5-50ppm of brightener, 5-30ppm of leveling agent and 5-20ppm of surfactant. The additive for recovering copper from the electrolytic alkaline etching solution can improve overpotential, increase polarization, slow down electrode reaction rate and finally obtain a copper coating with fine and bright grains by adding the additive containing a brightening agent, a leveling agent and a surfactant into the alkaline etching solution, so that a copper layer with bright and smooth surface, high purity, compact structure and high ductility can be recovered.)

1. An additive for recovering copper from an electrolytic alkaline etching solution is characterized in that: the additive aqueous solution contains the following components per liter:

2. the additive for recovering copper from an electrolytic alkaline etching solution according to claim 1, wherein: the additive aqueous solution contains the following components per liter:

3. the additive for recovering copper from an electrolytic alkaline etching solution according to claim 1, wherein: the crystallization refiner is any one or a mixture of more of formaldehyde, gelatin, polyethylene glycol or benzylated polyethyleneimine.

4. The additive for recovering copper from an electrolytic alkaline etching solution according to claim 1, wherein: the brightening agent is 1, 2-ethylene thiourea; the leveling agent is sodium polydithio-dipropyl sulfonate.

5. The additive for recovering copper from an electrolytic alkaline etching solution according to claim 1, wherein: the surfactant is any one or a mixture of more of hexadecyl betaine, methylene naphthalene disulfonate or hexadecyl trimethyl ammonium chloride.

6. A method for preparing copper by using the additive for recovering copper from an electrolytic alkaline etching solution as claimed in any one of claims 1 to 5, characterized in that: the method comprises the following steps:

1) carrying out micropore precision filtration on the alkaline etching solution waste liquid;

2) diluting the alkaline etching solution waste liquid filtered in the step 1), and adding the additive into the alkaline etching solution waste liquid to prepare electrolyte;

3) pumping the electrolyte into an ion membrane electrolytic cell for direct electrolytic treatment;

4) in the electrolytic process, stripping copper dendrite on the cathode every 12 hours, and scraping the copper dendrite on the surface of the coating to obtain copper;

5) and blending the residual liquid after electrolysis to prepare alkaline etching liquid regeneration liquid, and returning the alkaline etching liquid to the etching production line for utilization.

7. The method for preparing copper by using the additive for recovering copper from the electrolytic alkaline etching solution as claimed in claim 6, wherein: the step 2) is specifically as follows: diluting the alkaline etching solution waste liquid filtered in the step 1) to the concentration of copper ions of 30-50g/L, the concentration of chloride ions of 180-200g/L and the pH value of 8-9, and adding 20-70ml/L of additive into the alkaline etching solution waste liquid to prepare the electrolyte.

8. The method for preparing copper using the additive for recovering copper from an electrolytic alkaline etching solution as set forth in claim 6, wherein: the anode in the electrolytic cell in the step 3) is any one of a titanium-based manganese dioxide electrode, a titanium-based iridium tantalum coating electrode and a titanium-based iridium ruthenium coating electrode, and the cathode is a stainless steel electrode or a copper electrode.

9. The method for preparing copper using the additive for recovering copper from an electrolytic alkaline etching solution as set forth in claim 6, wherein: the temperature of the electrolyte in the electrolysis process in the step 3) is controlled to be 25-50 ℃, and the current density is controlled to be 200-400A/m²The electrolysis time is 20-24 h.

10. The method for preparing copper using the additive for recovering copper from an electrolytic alkaline etching solution as set forth in claim 6, wherein: the ionic membrane in the electrolysis process in the step 3) is a cation exchange membrane.

Technical Field

The invention relates to the technical field of etching waste liquid recycling, in particular to an additive for recycling copper from an electrolytic alkaline etching solution and a method for preparing copper by using the additive.

Background

Alkaline etching solutions are a chemical used in large quantities in the production of Printed Circuit Boards (PCBs). An alkaline etching waste solution containing a high concentration of copper can be produced by using the alkaline etching solution. In order to save resources, the copper in the waste liquid is generally subjected to a regeneration cycle treatment.

At present, there are two methods for recycling the alkaline etching solution. One is an extraction method, which utilizes copper ions in an extracting agent andthe distribution ratio of the etching waste liquid is different, copper ions in the etching waste liquid are transferred into the extracting agent by mixing the extracting agent and the etching waste liquid, and the copper ions are back-extracted by using a sulfuric acid solution to obtain a copper sulfate solution for electrolysis, so that the purposes of etching liquid regeneration and copper recovery are achieved; one is electrolytic process, in which the etching solution is oxidized at the anode under the action of direct current to oxidize Cu⁺Oxidation to Cu²⁺The etching solution is returned to the etching step for use, and the cathode is subjected to a reduction reaction to convert Cu into Cu⁺/Cu²⁺Reducing the copper into elemental copper. The electrolysis process is relatively simple, easy to operate, low in operation cost and more suitable for industrial popularization.

However, since the alkaline etching solution contains a large amount of chloride ions, Cu⁺Can generate cuprous chloride precipitate with chloride ions, the cuprous chloride precipitate can be attached to a cathode plate, and then the cuprous chloride precipitate can be complexed with a large amount of free ammonia to form free Cu (NH)₄)⁴⁺Re-dissolved in the etching solution and then reduced into elemental copper, thereby forming a filling effect, enabling the electrolytic copper on the cathode plate to be easily changed into granular or dendritic, and simultaneously enabling the electrolytic copper to carry the etching solution easily, and enabling the product form and quality of the recovered copper to be reduced. For this reason, the above-described problems are urgently needed to be solved.

Disclosure of Invention

The invention aims to provide an additive for recovering copper from an electrolytic alkaline etching solution and a method for preparing copper by using the additive, which can solve the problems of the form and the quality of a copper product recovered by a conventional recovery method.

The invention is realized by the following technical scheme.

An additive for recovering copper from electrolytic alkaline etching solution, wherein the aqueous solution of each liter of the additive contains the following components:

preferably, the additive for recovering copper from the electrolytic alkaline etching solution contains the following components in each liter of aqueous solution of the additive:

the crystallization refiner promotes the crystallization refinement of the electroplated layer; the leveling agent promotes the smoothness of an electroplated layer and reduces dendritic crystals; the surfactant reduces the oxygen evolution overpotential of the solution.

Wherein the crystallization refiner is any one or a mixture of more of formaldehyde, gelatin, polyethylene glycol or benzylated polyethyleneimine.

Wherein the brightener is 1, 2-ethylene thiourea; the leveling agent is sodium polydithio-dipropyl sulfonate.

Wherein the surfactant is one or more of cetyl betaine, methylene naphthalene disulfonate and cetyl trimethyl ammonium chloride.

After the additive is added into the alkaline etching solution, the 1, 2-ethylene thiourea and the sodium polydithio-propane sulfonate can be adsorbed on the surface of a cathode, such as a high current density area of the cathode, to form a compact adsorption layer to prevent copper ion discharge, so that the overpotential of cathode reaction is increased, the electrode reaction rate is slowed down, and finally a bright copper coating with fine grains is obtained. The hexadecane-betaine can reduce the surface tension of the electrolyte, form a double electric layer by directional adsorption at an electrode-electrolyte interface, improve the overpotential of cathode reduction reaction, increase polarization, refine electrolytic copper crystals and improve purity. Therefore, by adding the additive containing the brightener, the leveling agent and the surfactant into the alkaline etching solution, the copper layer with bright and smooth surface, high purity, compact structure and high ductility can be recovered.

The method for preparing copper by using the additive for recovering copper from the electrolytic alkaline etching solution comprises the following steps:

1) carrying out micropore precision filtration on the alkaline etching solution waste liquid;

2) diluting the alkaline etching solution waste liquid filtered in the step 1), and adding the additive into the alkaline etching solution waste liquid to prepare electrolyte;

3) pumping the electrolyte into an ion membrane electrolytic cell for direct electrolytic treatment;

4) in the electrolytic process, stripping copper dendrite on the cathode every 12 hours, and scraping the copper dendrite on the surface of the coating to obtain copper;

5) and blending the residual liquid after electrolysis to prepare alkaline etching liquid regeneration liquid, and returning the alkaline etching liquid to the etching production line for utilization.

Wherein, the step 2) is specifically as follows: diluting the alkaline etching solution waste liquid filtered in the step 1) to the concentration of copper ions of 30-50g/L, the concentration of chloride ions of 180-200g/L and the pH value of 8-9, and adding 20-70ml/L of additive into the alkaline etching solution waste liquid to prepare the electrolyte.

Wherein, the anode in the electrolytic cell in the step 3) is any one of a titanium-based manganese dioxide electrode, a titanium-based iridium tantalum coating electrode and a titanium-based iridium ruthenium coating electrode, and the cathode is a stainless steel electrode or a copper electrode.

Wherein, the temperature of the electrolyte in the step 3) is controlled to be 25-50 ℃, and the current density is 200-400A/m²The electrolysis time is 20-24 h.

Wherein, the ionic membrane in the electrolysis process in the step 3) is a cation exchange membrane.

The invention has the beneficial effects that: the additive for recovering copper from the electrolytic alkaline etching solution can improve overpotential, increase polarization, slow down electrode reaction rate and finally obtain a copper coating with fine and bright grains by adding the additive containing a brightening agent, a leveling agent and a surfactant into the alkaline etching solution, so that a copper layer with bright and smooth surface, high purity, compact structure and high ductility can be recovered.

Detailed Description

The present invention will be further described with reference to the following examples.