Patent ID: 6821404
Filing Date: 2004-11-23
Classification: C22B,C23F,C25D,Y02P

Abstract:
A process for recovering copper from an alkaline etch bath from an etching process in which printed boards electroplated with copper are etched with the alkaline etch bath and then rinsed with water, comprising the steps of removing the copper from the alkaline etch bath by:extracting the alkaline etch bath with an organic solution containing a reagent, which forms with copper a complex compound, which is extracted by the organic solution, recirculating the alkaline etch bath to renewed etching, contacting the copper-containing organic solution in a re-extraction step with an aqueous solution of an acid so that copper passes from the organic solution to the aqueous solution to form a copper-containing solution, recirculating the organic solution from the re-extraction step to renewed extraction, passing the copper-containing acid solution obtained from the re-extraction step to a copper recovery operation, diverting a flow from the copper-containing acid solution before the operation for recovering copper from the copper-containing acid solution, adjusting the copper content of said flow so that it will be lower than the copper content of the acid solution which is used in the copper recovery operation, and recirculating said flow having an adjusted copper content to the operation for electroplating printed boards for use therein.