Patent ID: 8236189

Claim:
An etching and recovery method comprising an etching process and a recovery process, said etching process comprising at least one etching step in which articles with exposed surfaces of metallic copper are etched with an aqueous, acid etching solution containing etching chemicals, wherein supply of solutions of said etching chemicals during the etching process is accompanied by a removal of an equivalent volume of etching solution, said etching chemicals including divalent copper ions for oxidizing metallic copper to monovalent copper ions, chloride ions, an oxidizing agent for oxidizing said monovalent copper ions to divalent copper ions so that there is no negative effect on the etching rate as a result of an increased concentration of monovalent copper ions, hydrochloric acid as a pH adjusting acid, and an aqueous solution, that contains divalent copper ions, and is added to the working etching solution as required when the divalent copper ion content of the working etching solution exceeds a predetermined interval, the divalent copper ion content of said aqueous solution being below said predetermined interval, characterized in that the etching process is carried out with a high copper content, which is within the range of 90 to 260 g copper/l, and with a chloride content within the range of 100-350 g C1-/l, the pH of the etching solution is maintained at a value above 1.5, and said recovery process is integrated with the etching process for receiving and treating said etching solution removed from the etching step in order to obtain a regenerated etching solution containing a reduced quantity of divalent copper ions in relation to the etching solution removed and forming at least a greater part of said aqueous solution that contains divalent copper ions and is supplied to the working etching solution in order to restore the divalent copper ion content to a value within said predetermined interval, that is within said range of 90 to 260 g copper/l, said recovery process including a first extraction step in which said etching solution removed is mixed with an organic extraction solution containing a complexing compound with which divalent copper ions form a copper complex, said copper complex being extractable by the organic extraction solution, after which the two mixed liquids are separated from one another once again in order to obtain an organic extraction solution containing said copper complex, and said regenerated etching solution.