Method for electrolyzing and regenerating alkaline etching liquid

Abstract

The invention discloses a method for electrolyzing and regenerating an alkaline etching liquid. The method comprises the steps of: injecting an alkaline etching waste liquid into an anode liquid storage tank and a cathode liquid storage tank before electrolyzing; in an electrolyzing process, carrying out circular flowing on the alkaline etching waste liquid in the anode liquid storage tank between an anode chamber and the anode liquid storage tank through an anticorrosion pump, carrying out circular flowing on the alkaline etching waste liquid in the cathode liquid storage tank between a cathode chamber and the cathode liquid storage tank, wherein after electrolyzing, the alkaline etching waste liquids in the anode liquid storage tank and the cathode liquid storage tank are respectively electrolyzed to form anode liquor and cathode liquor; and regenerating the etching liquid by using the anode liquor as a material and preparing cuprous chloride by using the cathode liquor as the material. According to the invention, the electric energy of the anode can be fully utilized; the etching quality is greatly improved; the copper resource is fully utilized simultaneously, and no pollution or waste is generated.

Description

technical field [0001] The invention relates to a treatment method for etching waste liquid, in particular to a method for electrolytically regenerating alkaline etching waste liquid used for etching printed circuit boards. Background technique [0002] During the manufacturing process of printed circuit boards, when the etching ability of the etching solution is weakened, it must be replaced in time, so the etching process will produce a large amount of copper-containing alkaline etching waste solution, which contains copper ions, C1 - , NH 3 , NH 4 + and other useful substances. Research shows that every ton of etching waste liquid contains C1 - More than 250kg, copper ion more than 120kg, NH 3 -NH 4 + About 80kg and various other valuable ions, with an average production of 1m 2 The PCB board will produce about 2.5L of waste etching solution. Therefore, if it is not disposed of properly, it will easily cause serious waste of resources and environmental pollution....

AI Technical Summary

Problems solved by technology

[0006] (1) It is difficult to accurately control the concentration of copper in the etching solution at 80-90g / L after extraction, which will affect the regeneration and reuse of the etching solution;

[0007] (2) It is difficult to prevent a part of the extractant from entering the etching solution, affecting the etching effect, and even destroying the etching solution after a long time, so that the etching solution must be completely replaced;

[0008] (3) Some substances cannot be reused, and the effect of completely closed circuit cannot be achieved;

[0009] (4) After adding ammonia water, the volume of the etching solution increases, so that the production line cannot fully accommodate it, and part of the etching solution must be discarded, resulting in high-concentration sewage;

[0010] (5) Long stripping time and large volume

This method requires the CuCl in the alkaline etching solution 2 Change to CuSO 4 , after producing etching waste liquid, since there is no Cl in the waste liquid - Partial copper can be directly electrolyzed without extraction, so as to reduce the concentration of copper ions in the etching solution and achieve the purpose of regeneration and recovery of copper, but this technology will seriously reduce the speed and quality of the etching line, which is difficult for most manufacturers to accept

The Chinese patent with the publication number CN 102206823A discloses a direct electrolytic copper extraction process of etching waste liquid, which adopts a special electrode connection method and matching current and voltage supply, which can not only handle alkaline etching waste liquid, but also acid etching waste liquid, but the electrolysis method has the disadvantage of low current efficiency

[0012] The Chinese patent with the publication number CN 1966773A discloses a method for electrolyzing acidic etching solution and microetching solution at the same time. The method uses cationic membrane technology and can fully utilize the anode electric energy, but the disadvantage is that it cannot be applied to alkaline etching waste solution

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