Recovery of Copper from Spent Solid Printed-Circuit-Board (PCB) Wastes of a PCB Manufacturing Facility by Two-Step Sequential Acid Extraction and Electrochemical Deposition


Monet Concepcion C Maguyon, Catalino G Alfafara, Veronica P Migo, Jovita L Movillon, Carmelita M Rebancos
Vol 15 No 1 (2012), pp. 17-27

 

Abstract:

 

The recovery of copper from solid printed circuit board (PCB) waste, by sequential acid dissolution and electrochemical deposition, was investigated as a resource recovery strategy for a local PCB-manufacturing facility. The fi rst stage acid dissolution process extracts the embedded copper metal from the solid PCB matrix in the form of copper ions, and the second-step electrolysis converts the copper ions back to its purer metal form. The copper metal can then be processed for possible reuse, or sold for income generation. For the acid treatment, the best extractant was found to be concentrated nitric acid added at a waste loading ratio of 120 mg PCB waste per mL of acid, and 4 hr contact time. Six-hour electrochemical deposition experiments (of the acid extracts from the best dissolution conditions) showed that a copper removal effi ciency of 98% (from the acid extract) could be achieved. The charge dose of the electrochemical deposition process was computed to be 11.987 coulombs mg-1 of copper removed from the acid extract. From preliminary cost estimates, the reuse of the spent nitric acid from the acid treatment step is recommended to minimize the total copper recovery cost.

 

Keywords: copper, printed circuit board, electrodeposition, semiconductor, electronics


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