Process for regenerating and for recovering metallic copper from chloride-containing etching solutions

Claim 1

A process for recovering copper values in metallic form from an aqueous, ammoniacal, etching solution containing the copper values along with chloride ions, said etching solution being derived from the etching of printed electronic circuit boards with a mixture of ammonium hydroxide and ammonium chloride, comprising the steps of: a. intimately mixing the etching solution with an organic medium containing an exchange reagent which is capable of selectively extracting copper and chloride ions from said solution, thereby producing a dispersion comprising an aqueous phase and an organic phase, the organic phase containing the exchange reagent, the copper ions, and the chloride ions; b. separating the phases of step (a); c. intimately mixing the organic phase of step (b) with an aqueous, weakly acidic, scrubbing solution which is capable of selectively stripping the chloride ions from the organic phase to produce a dispersion comprising an aqueous acidic phase containing the chlorides, and an organic phase containing the exchange reagent and copper ions substantially free of chloride ions; d. separating the phases of step (c); e. intimately mixing the organic phase of step (d) with an aqueous acidic stripping solution which is capable of stripping copper ions from the organic phase, thereby producing a dispersion comprising an aqueous phase containing the copper ions substantially free of chloride ions, and an organic phase containing the exchange reagent; f. separating the phases of step (e); and g. electrowinning metallic copper from the aqueous phase containing the copper ions substantially free of chloride ions.