Global NEST Journal, Vol 11, No 2, pp 241-247, 2009
Copyright© 2009 Global NEST
Printed in Greece. All rights reserved
PRODUCTION OF COPPER POWDER FROM PRINTED CIRCUIT BOARDS BY
ELECTRODEPOSITION
I. MASAVETAS
1 1
Laboratory of Inorganic and Analytical Chemistry
A. MOUTSATSOU
1,* 2
General Chemistry Laboratory
E. NIKOLAOU
1
School of Chemical Engineering,
S. SPANOU
2
National Technical University of Athens
A. ZOIKIS–KARATHANASIS
2
9, Iroon Polytechneinou str., Polytechnioupolis
E.A. PAVLATOU
2
157 73, Zografou, Athens, Greece
N. SPYRELLIS
2†
Received: 30/09/08 *to whom all correspondence should be addressed:
Accepted: 29/01/09 e-mail: angst@central.ntua.gr
ABSTRACT
During the last years, the waste electrical and electronic equipment (WEEE) are gathering
attention, as a very special section of waste. In fact, they have been proven to be source for
the recovery of metals. In the present study printed circuit boards (PCBs) were cut and
treated thermally at 500
o
C for 1 h in both air and nitrogen atmosphere. The obtained material
was dissolved in three different acid media HNO
3aq
, HCl
aq
and H
2
SO
4aq
, in order to extract
copper. The achieved Cu recovery percentages were 97.5, 65 and 76.5% respectively.
Electrodeposition technique was applied in order to recover copper in powder form. More than
98% of copper was recovered achieved by application of high current density resulting to
dendritic structure of copper. The applied process was characterised by a high current
efficiency and led to the production of copper powder of 80 µm mean diameter appropriate for
powder metallurgy applications.
KEYWORDS: Printed circuit boards, leaching, electrowinning, Cu recovery, Cu powder.
1. INTRODUCTION
Due to the rapid technological progress, the replacement of electronic equipment is very often
necessary, leading to huge amounts that end up as waste. In addition, waste electrical and
electronic equipment (WEEE) contains metals of high commercial value and others that are
supposed to be hazardous for the environment. Consequently, WEEE could be considered as
a significant source for recovery of non-ferrous metals. Among these waste, computers
appear to be distinctive, as far as further exploitation is concerned. According to studies
carried out, computers seem to be the only WEEE that could allow a system to be financially
beneficial (PriceWaterHouseCoopers, 2002). The most “useful” parts of the computers are the
printed circuit boards (PCBs) that contain many metals of interest. A typical weight distribution
indicates that PCBs represent approximately 13% of the weight of a desktop personal
computer unit (Menegaki et al., 2006). Statistics reveal that the amount of WEEE produced
per year in Europe is approximately 6.000.000 tn, with a growing rate of 3-5% per year
(Kirkitsos et al., 2002). In Greece, for the year 2007, the household WEEE produced is
estimated to be 100.000 tn (Polychronopoulou et al., 2006). Moreover, by taking into
consideration the so-called “historic waste” (waste that their owners, for various reasons, are
unwilling to discard), one comes up with a sum that would have fatal consequences if these
waste reach the current land-filling system.
The methods that can be used in order to recover metals from computers are basically the
physical/mechanical and the chemical separation. In Greece, during the last years the first
steps have been attempted, concerning mainly the physical/mechanical separation. As far as
concerning chemical separation, electrowinning, hydrometallurgy and pyrometallurgy are