Jon Elson wrote:
Martin wrote:

Over the years I've accumulated a bunch of electronic surplus, much of
it gold-plated (edge connectors, PC boards, etc).

I was wondering whether anyone has a simple process for using this
scrap as the sacrifical electrode to perhaps "plate" all the gold onto
another object, from which it may be easily scraped off and
recovered? My only experience with similar processes is electrolytic
de-rusting.

Is it possible to plate the gold without also transporting the base
metal to the plated electrode?

Kind of. There's a guy who has come up with a new process. It doesn't
actually plate the gold onto anything, but it does remove the gold and
it precipitates out. It doesn't work on non-conductive substrates like
PC board edge fingers, though.

You could actually de-plate the gold onto something like graphite, but
it is very slow and you still get base metals.

See http://www.goldrefiningforum.com/for a new forum discussing this.
They've just moved the forum to new servers, and so I'm not sure where
everything is now. You have to "join", but it will be WELL worth your
while to do it. This is one of the best resources I've ever seen on the
net!

I have been salvaging gold from connector edge fingers with a highly
toxic solution sold for this purpose (cyanide). The company that makes
it wants to do the recovery from solution for you, but you'd need a
hazmat license to ship the stuff back to them, so I couldn't if I wanted
to! I have been fooling around with this and have recovered about 3/4
Troy Oz of gold so far. I have no idea how much I may be losing in the
process.

The process the above web forum describes looks very good, it is all
done with drain cleaners and such from the hardware store, and the
amount of gold these guys are getting out just about has me drooling!
Just so you know which one I am talking about, I think it is
"LazerSteve" has a process where he uses sulfuric drain cleaner plus
glycerine to deplate the gold. Another guy figured out you could put a
layer of the pins on a stainless steel screen and the pins would deplate
just the same, with much less handling. He uses a lead anode on the
bottom of the jar.
When the solution is full of the "black" colloidal gold, he then dilutes
the solution and filters out the gold with coffee filters. He then
purifies the result with another process to remove the small amount of
base metal.

Jon

Just so you'll know, Jon, the link comes back "Not found". rats, I was
hoping to be ble to read it.

Jim