On 4/02/2010 13:39, James wrote:
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> --- In Homebrew_PCBs@yahoogroups.com
> <mailto:Homebrew_PCBs%40yahoogroups.com>, "nathan_h_tna"
> <nathan_h_tna@...> wrote:
> >
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> As someone else said, the dissolved copper is the problem with disposal,
> it's highly toxic to marine life even in very dilute quantities. Either
> solution can be neutralized and/or evaporated and the solids disposed of
> in the trash.
CuCl2 is hygroscopic and difficult to evaporate. Garden or builders lime
is a cheap source of impure calcium hydroxide and is good way to
nutralize (i.e -> copper hydroxide and calcium cloride) followed by
evaporation to a solid. Another way is to not neutralise and throw in
excess scrap aluminium, in a closed container. After a few days you
should have crystal clear liquid with a brown sediment of copper metal
sludge plus some unreacted aluminium.
Adam