"Jon Elson" wrote in message
ervers.com...
Harold and Susan Vordos wrote:


It comes as no surprise to me that folks on a jewelry group wouldn't be
much
help in refining. Rarely do you find a jeweler that knows anything about
the
subject. They generally don't do their own, although I know one that
does.

I can't imagine what you're accomplishing. For starters, a cupel won't
give you gold of any quality when you start with low grade
material-----not
unless it is a huge cupel, capable of absorbing a lot of lead, and you
have
a proper muffle furnace. Are you using a cupel, or a melting dish?
They're not the same critter.

As far as I know, these are cupels. A soft, friable refractory, with no
glaze on it.

Clay melting dishes have a similar appearance, although they're not very
soft. If you purchased them from a reputable firm that represented them
as cupels, they probably are. Cupels are typically made of bone meal, are
typically quite thick (so they can absorb litharge), and have a light tan
coloration.

Fluxes help in absorbing some of the crud, but melting and fluxing won't
give you gold of any quality. Unless you're prepared to work with
acids,
you're not going to be very happy with your outcome.

Well, there shouldn't be any other metal in there but gold.

Chuckle! What do you think the discoloration is coming from? You're
seeing traces of oxides of base metals in your flux, otherwise it wouldn't
be colored as it is. The idea that you can extract gold in a pure state
is interesting, but it simply doesn't work that way, in spite of the claims
you may have read.

Do you have any experience in gold refining? Would you like to share
with
me exactly what you're doing, so I can provide some pointers on what to
abandon, and how to accomplish your mission?

I am using Technic's Techni-Strip AU, a gold salvage compound based on
the cyanide process. it is VERY effective at leaving all base metals
alone, and only removing Au and platinum group metals. But, there
should be only gold on the scrap.

It's highly unlikely it's *very* effective at leaving base metals behind,
although it will limit their dissolution. All it takes is too much cyanide
in solution and it will dissolve copper.

Unfortunately, you made no mention of the fact that you had dissolved the
gold with a cyanide compound, so I had no clue what you were attempting to
do.

Recent scrap has very thin gold plating. But, a lot of this stuff is
from the 1960's, and the gold is VERY thick, up to .0005" or so! There
may be some measurement error here, but I weighed a loss of 200 mg from
ONE 4" long piece of card edge! I later doubted my measurement, and so
did a bunch of card edges, and got about 50 mg per piece as the average.
With gold running at roughly $13/gram, that works out to $0.65 per card
edge, at 50 mg each.

You really should hear the (true) story of a guy that came to me after a
summer of mining placer gold. His story was much like yours, but in his
case, his father-in-law died while they were extracting their values.

One bit of advice. Don't let gold take over your good sense. If you do
so, you're going to be unhappy with everything you do in the process of
extracting it, having unreasonable expectations being the chief cause.

The problem with your calculations is you're basing your findings on the
idea that you're taking off nothing but gold. I seriously doubt you are.
Been there, done that, got the T shirt. Before I closed the doors on my
machine shop, I was refining on the side, for pleasure. One of the
products I produced in the shop was a wire wrap connector for Univac. I
purchased a standard connector from Cinch, then modified it, making three
from one. Granted, this was in the late '70's, but the amount of gold on
the pins was known, and it was about .000080". While I don't doubt you
may be finding higher levels of deposition, unless you go back to wave-guide
assemblies, very early (when gold was still $35/oz) , it's pretty hard to
find gold that is plated very thick.


The Techni-Strip AU removes only the gold, and it works like a charm.
The problem I am having is precipitating the gold back out of the
solution.

Or, you're getting a good recovery, but you aren't getting as much gold off
as you think you are. It's also entirely possible you are unwittingly
tossing the gold out with the sludge, having self precipitated. That's not
uncommon, either. As long as you haven't discarded any of your waste
materials, you haven't lost anything, however. Are you titrating your
solution so you know the concentration level of free cyanide?

I've seen all sorts of schemes, such as adsorbing it onto
activated carbon, ion exchange precipitation with Zinc (but that
contaminates the gold), electrowinning, ion exchange resins, etc.
I haven't tried the carbon yet, but the rest work, but are a lot of
effort, and I'm only getting a small part of the gold back out of
the solution. I'm a little afraid of systems to break down the cyanide,
as I don't want to gas the neighborhood!

Forget all the *schemes* and use zinc flower, particularly at the level
you're working. Your gold is already contaminated, like it or not. Zinc
is virtually 100% effective, and very inexpensive to use. Getting rid of
excess zinc is no trouble, and can be as simple as distilling it off,
although it's very easy to remove with acid. Do you have a fume hood in
which you can work safely?


I have gotten several grams of gold, some of it looking VERY pure, in my
pilot experiments with this stuff before I go into full-scale
production. I'm pretty sure I can burn the Zinc out of this with acid,
if that proves to be the best process.

Looks can be VERY deceiving where gold is concerned. Gold, in the pure
state, melts with NO oxides on the surface, and stays bright yellow with a
glistening surface when cooled. It has a green luminescence in the molten
state, and is free of surface scum. It also pulls a deep pipe as it cools.
If your gold doesn't pull the pipe, or it's dull, or frosty looking, it's
hardly pure, although it could be quite good. If you'd like to see pic
of a dish of (pure---9995+ purity) gold pellets, ask and I'll send it to you
for comparison as to color and appearance.


As for the bulk of the waste, that has been discarded years ago. I have
crushed connector shells, pushed pins out of backplanes, cut card edges
off, etc. over the years, packing the gold-bearing parts into a fairly
small pile of ~ 100 Lbs.

Cool! It helps a lot to have information. I've recovered gold from
almost anything you can imagine, including carpets, but providing good
guidance is difficult without knowing the circumstances at hand.


Thanks for any insight into what I'm doing right and wrong, here!

I won't bull**** you, Jon. I had countless people laugh in my face when I
started playing with precious metals, but my "hobby" turned into a full time
job and a business that I sold when I retired. You can do it, just as I
did, but you'll have to learn to walk before you run. Take it slow and
easy, until you clearly understand what the reactions are, and how to
control your losses.

What might be best for you to do is contact me on the side, and give me more
details on what you're doing. Frankly, I think you're going about it
wrong, but I'm not sure. One thing I am sure of is you won't be able to
achieve a high degree of purity without actually dissolving the gold and
precipitating it after you've recovered it-------or running it through a
gold cell. It should be of high quality to do that, though, and you must
have several ounces of pure gold just for the electrolyte. Chemical
refining is much easier. If you don't adhere to this, you'll end up
selling your gold as scrap, when it can be sold to jewelers at spot prices
or slightly above if you provide good quality.

Harold