The perils of home refining

Jewelry Discussion
1

Home refining? OK for a graduate chemist but all others try this at
their peril! Amateur use of acids is dangerous and almost always
illegal from an EPA standpoint.

Regarding the widely advertised I-Shor refining system.

My first problem with this is that the company in their print ads
flat out lies about how much refiners typically charge . My proof?
Read on.

I quote in part from their print ad in Professional Jeweler
magazine, February 2004 issue-

“From those who did their own assay on the bench and carefully
calculated their cost both up front and hidden, the answer was always
the same: It cost $800 to have ten ounces of gold refined” You can
not truly assay on a bench.

Another very questionable claim-“100% return no losses (even if you
have no experience)” Ask a chemist about truly 100% return from a
chemical process.

I did the math and it is way off from what real refiners like us
Precious Metals West, Hoover & Strong, David Fell, or any of the
majors charge. You see advertised refining rates from 1% and up.
PMWest charges 2.5% and includes assay costs in that quote. The math
goes like this - at $400 gold 14kt is worth at most (58.5%) $234 per
ounce. Presume ten ounces of 14kt sent for refining. $2,340 value
less 2.5% in charges. We charge 2.5% or $58.50 for all ten ounces.
The refining cost per ounce is $5.85 per ounce. The I. Shor company
exaggerates refiners charges by more than ten fold in their print
ads.

If only the FTC took jewelry trade ads as seriously as consumer
oriented advertising from major companies…

The next paragraph in their ad is about polishing sweeps and is
laughable in its exaggerations and false claims about charges. Talk
about negative marketing! Still wondering about the process? Call the
major refiners and ask if they use the Simplicity system or anything
else based on salt bath solutions and electricity. Most of us use
Aqua Regia or chlorine.

To be fair the claim can be made that the refiner may not get all
the gold out of solution. TRUE! That is true of EVERY method of
refining. A person I used to know bought the “Simplicity Gold
refining System”, and lost his job when it failed to work well,
perhaps with operator error, perhaps not. Many ounces of gold got
tied up in solution and the stench emptied the room. Obviously
something went very wrong.

One more thing-Exaggerated claims on refiners taking too much gold
or stealing are often rooted in the practices of scrap buyers who
consolidate lots and then use a real refiner later. Most refiners
just like most jewelers are honest hard working people.

As admitted I work for a refiner. How did I get this job? When I had
my retail store and shop, I sent my refining to PMWest, and got to
know the owner. When my store failed during the Carter presidency and
amid the horrible economy I went to the people I learned to trust to
look for work.

My suggestions for Jewelers on refining

Do your homework. Learn about refining. AJM had a good article last
October. The World Gold Council has good info. So does the Santa Fe
Symposium book from last year, discussing platinum refining.

Hands on-Drag a magnet through filings to remove iron. Melt your
scrap into one bar well heated, fluxed and very well stirred. Drill
the top left and bottom right ends and keep the drillings. Send the
bar to an assay office that is unconnected to a refiner, there are
many just in Los Angeles. Pay them for their service and use the
assay to be your guide. Many refiners will actually accept a good
assay, subject to confirmation. Now what is wrong with this picture?
Can’t make a bar? Equip accordingly or call in a favor with a friend
who casts. They can make your bar for you!

I invite calls from concerned jewelers to fill in more detail about
refining strategies. After all, we can not be more successful than
our clients.

Finally, I would like to thank the many unhappy buyers of the
Simplicity System for their refining business. The few happy ones are
welcome to our alloys for karating. :slight_smile:

Daniel Ballard
Precious Metals West
WWW.Pmwest.us

2

I bought one of the refining systems several years ago. I used it
several times. Total waste of money. Now I reuse all my clean yellow
gold, using “re-cast-it” to clean up the melt. My sweeps go to a
scrap dealer who comes around once a year. If you’re still not
convinced, buy the detergent they sell to clean your buffing dust
and try to get the ounce of metal they claim from each pound of dust. R. H.

3 
 Hands on-Drag a magnet through filings to remove iron. Melt your
scrap into one bar well heated, fluxed and very well stirred.

Daniel, Can you recommend a good fluxing mix for melting filings?
How 'bout polishing dust? while melting down scrap in bits big
enough to handle, I’ve found bench sweeps and filings to be
difficult, perhaps due to the percentage of abrasive dusts and other
contaminants. It seems like when I try to melt down my own, often
with an electromelt so it can sit and 'cook" for a while longer than
reasonable with torch melting, I still end up with really junky
looking slag which appears to still retain significant little bits of
metal…

And I’ve never tried polishing dusts, which are much lower yield.
Does it pay to try to do smaller amounts?

Also, how about bench sweeps or better quality scrap where there are
undetermined, but likely significant, amounts of platinum. When you
melt this into a bar, does it mix in uniformly, so an assay would
properly show it, or does it tend to not fully dissolve, staying on
the bottom of the crucible? Seems like I think I’ve seen that
happen…

Also, given the fact that cobalt platinum is sufficiently magnetic
that filings of the stuff will stick to the same magnet one might
use to remove iron, should one save that removed material and submit
it separately?

thanks.
Peter

4

Hello All, I will address a few questions that came my way.

 Daniel, Can you recommend a good fluxing mix for melting filings?

Johnson Matthey is said to have such a thing, so did Handy & Harman.

How 'bout polishing dust?

Do not try to process polishing dust. People get hurt physically and
or in the wallet when they try too often. This may be a California
thing but polishing dust is a Haz Mat, and illegal to process without
a huge investment in time and equipment. The best strategy there is
to minimize what goes into that collector. NO FILINGS OR LAPPING
MATERIAL. Those should be held separate as should silver and platinum
group metals.

It seems like when I try to melt down my own, often with an
electromelt so it can sit and 'cook" for a while longer than
reasonable with torch melting, I still end up with really junky
looking slag which appears to still retain significant little bits
of metal...

Just scoop the slag off and set it aside. Go with a bar poured from
the clean molten material. Contact me offline for details on how to
further work the slag. In short, higher temperatures and added metals
like copper can capture the metals into a much lower yield bar. There
is always some lower yield junk that you get down to that you cannot
glean good metal from. Even us refiners have junk to dispose of in
the end, perhaps with gold content down to parts per million.

And I've never tried polishing dusts, which are much lower
yield.

Don’t do it. For the overwhelming majority of jewelers it is either
dangerous and or illegal to try. In California (try not to laugh)
polishing dust is a haz mat. Processing Haz mat can incur HUGE fines.

Does it pay to try to do smaller amounts?

No

Also, given the fact that cobalt platinum is sufficiently magnetic
that filings of the stuff will stick to the same magnet one might
use to remove iron, should one save that removed material and
submit it separately?

Keep all magnetic materials aside. They are valuable. You are
absolutely right about cobalt and get this- In certain circumstances
our pt plumb solder can be magnetic. Perhaps the heat treatable Pt
can be slightly magnetic if rolled out just right… or wrong as it
were.

My opinion is your strategies are right on the money, just be
careful of the law of diminishing returns. Its tempting to try too
hard. Do not worry about the slag and magnetics, once you have gotten
the big easy part out to bar gold out for assay. You are already
ahead of the game, perhaps just let your refiner do the slag and the
magnetics. Always track your historical returns, this is crucial to
catching any errors.

One note to you all about refining vs. assaying or accounting. When
we make a bar it has nothing to do with refining and everything to do
with assaying or accounting for the used gold. The bars are
ultimately remelted into a form that dissolves well. It’s not
refining until it’s going into the acid. This is especially true of
the polishing sweeps. They get baked, then ground for sampling, and
then made into a big bar for assay then remelted for the acid. Whew!
Different refiners modify the above process but the basics remain.
More detail could be addressed on the phone or offline.
Daniel@preciousmetalswest.com

Daniel Ballard
WWW.Pmwest.us

5 
It seems like when I try to melt down my own, often with an
electromelt so it can sit and 'cook" for a while longer than
reasonable with torch melting, I still end up with really junky
looking slag which appears to still retain significant little bits
of metal...

I’ve experimented a bit with reclaiming gold from sweeps. I first
cook my sweeps in a mixture of sodium hydroxide and water. I use a
pyrex measuring cup. Put approx. 3/4 inch sodium hydroxide to 5
inches water. Simmer this for a couple of hours. There will be a lot
of scum on the top of the liquid. Skim this off and carefully drain
the container and refill with water several times. I usually put a
small amount of detergent in with the water to break the surface
tension. Some of the particles of gold are extremely tiny and easy
to wash out with the waste water. Next, I thoroughly dry the dust
and then remove iron with magnets. I use the small rare earth
magnets. Just put them in with the powder and swirl the mixture
around.Take the magnets out and clean them repeating this process
until there is no longer any filings being picked up. I then mix the
filings with a 50/50 mix of boric acid and borax. Mix one part of
this boric acid/borax mixture to four or five parts of sweeps.You
might have to experiment with this a bit. I put the mixture in my
melting furnace and crank her up. I usually put an ounce of other
gold scrap on the top of the mixture. When the top scrap has melted I
start stiring the top of the mix playing with the molten gold on the
top. The gold in the mixture below will start coming together in
small balls and as you work the mixture these balls slowly join the
larger melted metal. Gravity will drag the gold to the bottom of the
crucible. The slag is very viscous so you need to play with this
stuff for a while. I put some re-cast-it in the mixture also. Seems
to make the melt flow better.Use your stirring rod to open a channel
for the molten gold and pour into a mold. I keep the slag. Some day
when I have enough to bother, I’ll grind it up and pan whatever gold
is left in the slag. There isn’t a lot left in the slag when I’m
finished. I’ve tried this with a torch but found it too tedious. You
might wonder why I go to this trouble. I didn’t think I was getting
enough for my sweeps. The metal I reclaim usually tests a little
better than 12 karat. I think it’s worth the bother. If your scrap
dealer offers less than you expect for your melted sweeps, you can
do what I have done. I check the karat of the scrap bar and then add
alloy enough to bring it down to 10K. I made a mold of one of my
casting trees and pour the 10K metal into that.Clean the casting
with nitric acid and water if you have it. Now I have no argument
with the scrap dealer. I get a certain amount of pleasure out of
doing this but it isn’t nearly as tedious as it sounds. R. Hood

6

Hi Robert,

Next, I thoroughly dry the dust and then remove iron  with
magnets. I use the small rare earth magnets. Just put them in with
the powder and swirl the mixture round. Take the magnets out  and
clean them repeating this process until there is no longer any
filings being picked up.

If the magnets & container holding the mix is large enough, you
might save yourself some time in cleaning the magnets by putting
them in plastic bags before placing them in the mix. Then all that
is necessary is to remove the bag from the magnet will be clean. The
ferrous material will stay in the bag.

Dave