Homebrew PCBs

Smilingcat,

I bought a 50 pound bag of calcium carbonate a few years ago so tried using
that. Seemed to foam up brown like the baking soda. 

I will keep adding calcium carbonate until it stops foaming. Don't want to
do too much at once or it will overflow. Once it is stable, I will mix in
some old cement and see if I can get something solid.

Thanks,

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
On Behalf Of smilingcat90254
Sent: Tuesday, March 12, 2013 10:32 AM
To: Homebrew_PCBs@yahoogroups.com
Subject: [Homebrew_PCBs] Re: trying to do the right thing

Easiest disposal of CuCl2 solution.

Since you don't know how much HCl is left in the solution, the best thing to
do is to use Sodium carbonate. It can be easily obtained from a pottery
supply stores. Cheap. Ask a high school ceramic instructor on where to get
it or ask any self respecting potter or ceramics artist. Cost is around
$2-$4 per pound I think... You don't need much more than a pound for a very
long time.

Pour sodium carbonate crystals into your "spent" solution. Excess sodium
carbonate is fine. CuCl2 will react and precipitate out as Copper carbonate.
Filter it out using coffee filter. Liquid should be excess sodium carbonate,
regular table salt and water.

Dump the liquid down a drain.

Dump the Copper carbonate precipitate into trash.

If you really want to be safe!! You can reduce the copper carbonate in a
furnace/kiln and heat the copper carbonate to around 200C. And it will turn
black. You are decomposing the carbonate to release CO2 and what remains is
Copper oxide. black powder. At this point its, very safe. But it can stain
clothing.

Dumping Copper chloride solution into a bucket of wood chips makes more
toxic waste, so stop it!!

Follow the directions on this post and all is well.

BTW, same procedure works for Ferric Chloride etchant. If it is used on
Ferric chloride solution, I would decompose the precipitate in a furnace. to
create iron oxide, (rust).




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