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Copper Recovery and Effluent Purification

IP.com Disclosure Number: IPCOM000095341D
Original Publication Date: 1965-Dec-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Murphy, FD: AUTHOR

Abstract

This system enables recovery of ammonium persulfate and copper from spent copper-bearing solutions used to etch copper-clad printed circuit boards. At the same time it purifies the effluent waste so that it can be discharged into public sewage facilities without toxic effect on the watershed.

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Copper Recovery and Effluent Purification

This system enables recovery of ammonium persulfate and copper from spent copper-bearing solutions used to etch copper-clad printed circuit boards. At the same time it purifies the effluent waste so that it can be discharged into public sewage facilities without toxic effect on the watershed.

Copper-bearing rinses are mixed with soft water in collection tank 1 and pumped by pump 2 into pipe 3 to which sulphur dioxide is added to treat the waste oxidants. Educators 4 spaced along pipe 3 pick up various waste concentrates such as spent ammonium persulfate etchant, spent nitric acid strip and other copper-bearing solutions. The combined liquors are discharged from pipe 3 into ion exchange unit 5 with which is associated electrowin unit 6. Unit 6 uses insoluble anodes so that, as copper is being recovered the sulfuric acid eluent is automatically regenerated and expenditure of sulfuric acid is minimized. The liquor from pipe 3 is picked up on an ion exchange resin using a lead and scavenge system. This is in such a way that the effluent discharged via pipe 7 consists of a dilute solution of ammonium sulfate and sulfuric acid which can be discharged into public sewage facilities. The eluted liquid is conveyed via pipe 8 to unit 6 from which copper is won at 9 and concentrated sulfuric acid is returned to unit 5 via pipe 10.

Ammonium persulfate etchant preferably is recovered by unit 11. Ammonium persulfate is highly soluble ev...