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Abstract

An etching and recovery method is described, wherein articles made of copper are etched with an acid aqueous solution of etching chemicals containing Cu²⁺ for oxidizing Cu⁰ to Cu⁺, chloride ions, oxidizing agent which oxidizes Cu⁺ to Cu²⁺, and pH-adjusting hydrochloric acid. The technical problem to be solved is to make it possible to circulate the etching solution between the etching process and the recovery process during the recovery of used etching solution in such a manner that a closed circuit can be maintained between the processes. This is effected in that a regenerated etching solution containing a lower quantity of Cu²⁺ than the used etching solution is produced and in that the recovery process has an extraction step in which removed etching solution is mixed with an organic extraction solution of a complexing compound with which Cu²⁺ forms a copper complex which can be extracted in the organic extraction solution, after which the two mixed liquids are separated once again in order to obtain an organic extraction solution containing said copper complex, and regenerated etching solution. The method is carried out with an etching solution having a pH above 1.5 and a high copper content.

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