Process for directly electrolyzing waste etching solution to extract copper

Abstract

The invention discloses a process for directly electrolyzing waste etching solution to extract copper; a special electrode connecting mode and matched current and voltage supply are adopted, that is, an acid electrolytic cell and a corresponding current and voltage are adopted for an acid waste etching solution, and a parallel connection for electrodes in the acid electrolytic cell is adopted; an alkaline electrolytic cell and a corresponding current and voltage are adopted for an alkaline waste etching solution, and a series connection for electrodes in the alkaline electrolytic cell is adopted; therefore, the acid waste etching solution and the alkaline waste etching solution can be electrolyzed respectively; when the current decreases to a controlled range, a cathode is removed and electrolytic copper is stripped; the residual waste etching solution is blended to become a regenerated sub-liquid for recycling use in a production line; no substance with other components is mixed into the waste etching solution during the whole process, so the components of the waste etching solution are not destroyed; therefore the regenerated sub-liquid has more stable performance and can be recycled all along, and the cost for the whole process is lower; on the other hand, the invention also solves the problem that currently no effective processing technology exists for acid waste etching solutions.

Description

[0001] technical field [0002] The invention relates to a process for recovering copper from etching waste liquid. Background technique [0003] The etching process in the PCB board (circuit board) manufacturing process is an important process in the circuit board manufacturing process. The etching waste liquid generated in the etching process contains a large amount of copper ions. If it is discharged directly, it will not only waste a large amount of copper, but also seriously pollute the environment. Therefore, the etching waste liquid must first be recycled for copper, and then discharged or reused . At present, some manufacturers use the acid etching process, while others use the alkaline etching process. The acid and alkali etching processes have their own advantages and disadvantages. Acid etching is suitable for the inner layer, allegro, and ordinary single- and double-sided panels, and its etching speed is relatively slow; Permanent etching is suitable for high...

AI Technical Summary

Problems solved by technology

The advantage is that the quality of electrolytic copper is high, the price is high, and the waste etching solution can be recycled and recycled; the disadvantage is that the extraction agent is used, the cost is high, the process is more cumbersome, and the extraction agent will be mixed into the regeneration solution, which will affect the etching. The rate and the cycle life of the etching waste liquid lead to the need for regular replacement of the etching waste liquid. In addition, the expensive extraction agent needs to be replaced regularly, and the expensive anode also needs to be replaced regularly; in addition, sulfuric acid needs to be added to convert the alkaline etching waste liquid into acidic etching waste. liquid, and replace the copper sulfate, and then electrolyze the copper sulfate solution with the common electrolysis method to obtain copper.

[0005] As for the acidic etching waste liquid, there is no good treatment process so far that can solve its regeneration problem well. The reason is that the sodium ions in the acidic etching waste liquid are difficult to react with other substances, causing sodium ion deposition, and sodium ions are difficult to separate from the etching waste liquid, so the regeneration of acidic etching waste liquid is currently a difficult problem at home and abroad

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