| abstract |
The invention relates to a process for recovering copper from spent alkaline and acidic etching solutions used for fabricating printed circuit boards, in which the acidic CuCl2-containing etching solution is set to a pH of 1-2 with sulphuric acid, scrap iron is added and the precipitated copper is separated, and the remaining solution is admixed with alkaline, CuCl2.2NH4Cl-containing etching solution and is set to a pH of 1-2 with sulphuric acid, scrap iron is added, the precipitated copper is separated, and from the remaining solution ammonium sulphate and iron(III) chloride sulphate are recovered. |