Method for electrolyzing circuit board acidic etching waste liquid

Abstract

The invention discloses a method for electrolyzing a circuit board acidic etching waste liquid. The method comprises the following steps of adding an organic acid solution or a nitric acid solution which does not contain chloride ions and sulfur ions into an anode chamber; adding the circuit board acidic etching waste liquid to a cathode chamber and a middle separation chamber; applying a power source to an anode plate of the anode chamber and a cathode plate of the cathode chamber so as to carry out electrolysis; and carrying out hydrochloric acid regeneration in the middle separation chamber. Compared with the prior art, through the electrolysis method, anolyte does not generate chlorine in the electrolysis reaction process, so that the production cost of absorbing chlorine is reduced, and the environmental pollution caused by chlorine leakage can be avoided; the hydrochloric acid anode chamber regenerated in the middle separation chamber an the oxygen generated in the anode chamberare used for regenerating the etching waste liquid into an etching solution for recycling; in addition, after part of the anode liquid enters the middle chamber or the cathode chamber through a cationexchange membrane, the etching speed and the etching factor of the etching solution regenerated by the middle chamber are not reduced; and meanwhile, the waste liquid after electrolysis of the cathode chamber cannot pollute the environment.

Description

technical field [0001] The invention relates to the technical field of electrolysis, in particular to a method for electrolyzing circuit board acidic etching waste liquid. Background technique [0002] Acid etching refers to the use of etching solution to dissolve and remove the exposed copper other than the line protection layer on the workpiece. During the etching process, when the concentration of monovalent copper ions in the etching solution reaches saturation, the etching solution loses its etching ability and forms an etching waste solution. Except that the waste liquid contains a large amount of monovalent copper ions, the remaining components are similar to the etching solution; so the usual method of regenerating the etching waste liquid is to oxidize the monovalent copper to divalent copper; in the prior art, the acidic etching waste liquid of the circuit board is electrolytically extracted The anode of the copper process will produce chlorine gas, which not only ...

AI Technical Summary

Problems solved by technology

[0002] Acid etching refers to the use of etching solution to dissolve and remove the exposed copper other than the line protection layer on the workpiece. During the etching process, when the concentration of monovalent copper ions in the etching solution reaches saturation, the etching solution loses its etching ability and forms an etching waste solution. Except that the waste liquid contains a large amount of monovalent copper ions, the remaining components are similar to the etching solution; so the usual method of regenerating the etching waste liquid is to oxidize the monovalent copper to divalent copper; in the prior art, the acidic etching waste liquid of the circuit board is electrolytically extracted The anode of the copper process will produce chlorine gas, which not only requires a large amount of caustic soda to absorb chlorine gas, but also increases the cost of electrolysis; in addition, chlorine gas leakage may occur during the electrolysis process, which is not only harmful to the environment and human beings, but also generates chlorine gas with the cathode during electrolysis. When the hydrogen mixture reaches a certain ratio, it will cause an explosion and an accident; in order to solve the problem of chlorine gas produced by the anode during the electrolysis process, the solution adopted in the prior art is to replace the electrolyte of the anode with an inert electrolyte that does not contain chloride ions, such as sulfuric acid, such as Sulfamic acid; sulfuric acid or sulfamic acid can be used to solve the problem of chlorine gas production at the anode; but because the selectivity of the ion exchange membrane is usually only 95%, 5% of anions in the anolyte or 5% of the cations in the catholyte leak through the ion membrane to the cathode In the catholyte or anolyte, the concentration of sulfuric acid or sulfamic acid in the catholyte gradually increases, which will lead to a decrease in the etching rate of the regenerated etching waste liquid; and the waste liquid generated after the electrolysis reaction pollutes the environment and generates environmental loads

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