A method for in-situ electrolytic regeneration of acidic copper chloride etching solution and copper recovery

Abstract

The invention belongs to the technical field of printed circuit board etching machining and discloses an acidic copper chloride etching liquid in-situ electrolytic regeneration and copper recycling method. An anode liquid feeding stream flows into an anode chamber of an electrolytic tank, and an anode liquid discharging stream flows out of the anode chamber of the electrolytic tank; a cathode liquid feeding stream flows into a cathode chamber of an electrolytic tank, and a cathode liquid discharging stream flows out of the cathode chamber of the electrolytic tank; the anode liquid dischargingstream is divided into a regeneration etching liquid stream and a regeneration etching liquid branch stream; the cathode liquid feeding stream and the cathode liquid discharging stream form a cathodeoutdoor circulation stream to circulate outside the cathode chamber; the regeneration etching liquid branch stream is gathered into a cathode outdoor circulating stream; the cathode outdoor circulating stream is split to form a cathode liquid branch stream; and the cathode liquid branch stream is gathered into an etching liquid stream to serve as the anode liquid feeding stream to enter the anodechamber for regeneration. The acidic copper chloride etching liquid is regenerated through a simple single electrolytic tank process, gas precipitation and consumption of hydrochloric acid are avoidedin the electrolytic process, copper is recycled in a high-purity copper board mode, the production efficiency is improved, resources are fully used, and the environment is protected.

Description

technical field [0001] The invention belongs to the technical field of printed circuit board etching processing, and specifically relates to a method for electrolytic regeneration of acidic copper chloride etching solution and copper recovery. Background technique [0002] Printed circuit boards are the basic components of various electronic products. An important part of the production process is to use chemical etching to etch away the excess copper (generally 60-70%) that is not required by the circuit on the copper foil board. Acidic copper chloride etchant and alkaline copper chloride etchant are currently the most used etchant, among which acidic copper chloride etchant is especially suitable for printed circuit board products with high etching precision requirements due to its characteristics of small side etching, and is used by a large number of Printed circuit board factories are increasingly used. The chemical reaction that occurs during the etching process is th...

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Problems solved by technology

Jiang Yusi and others [8] Using a cation exchange membrane electrolytic cell with a small cathode and a large anode and distributing the etching waste liquid to the anode chamber and the cathode chamber respectively to process the acidic copper chloride etching solution can successfully regenerate the etching solution and recover copper powder, but chlorine gas is precipitated in the electrolysis and hydrochloric acid consumption

Xu Haiqing and others [9] An anion exchange membrane electrolytic cell with a small cathode and a large anode is used to process the acidic copper chloride etching solution in a manner of intermittent operation and four-step current reduction, which can regenerate the etching solution and recover copper plates, but chlorine and hydrogen gas are still precipitated and the operation is complicated.

[0006] The reported method of electrolytic treatment of acidic copper chloride etching solution may cause harmful and dangerous gases such as chlorine and hydrogen to be precipitated, or the recovery of copper in the form of copper powder is easy to entrain impurities and requires centrifugal dehydration, or the technical process and operation are complicated

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