Electrochemistry Anode Slimes = Free gold and PGMS GOt an XRF

[jewelerdave]

Is it normal for a lot of junk silver and scrap to contain gold and other PGMS

In the last couple months I have processed a few thousand oz of silver from scrap, Burned my anode bags and contained slimes and got a lot of tin gold and PGMS.
Nice bonus.

So the little more than an oz of gold was nice to get. and the traces of PT and PD...lot of Pd.

So I also just got an XRF and did some checking of things. Where is all this gold coming from? I know I get plated pieces and that accounts for some of it.
But it turns out some silver has traces of gold in it. Especially older stuff and jewelry.

Thus far I have found some coins before electrolytic refining have traces of gold in the alloy. One mexican coin from 1861 shows 1/10 of 1% gold.
Also some jewelry I have found is 1/4 % gold. All I can guess is it was not worth going after back in the day. or jewelers using the same crucible to melt both gold and silver for castings and cross contamination. OR the remelting of older stuff with gold in it.

In any case save the slimes, save anything that you get that is dark and settles to the bottom of your tanks. It may not be a lot but there is some values in that stuff. A lot of it is tin. But there is some fun stuff in there too.

Also now that I have an instant assay machine I can get answers to a lot of things that before were not worth checking out on small lots. how to better refine odd alloys by knowing the content before hand. Seriously cool
It was also refreshing to see that the product I am putting out is 999+ pure in both silver and gold especially when compared side by side with Government Mint products and other private mint companies.
Also found a silver bar that was only 993 with some copper...older pour bar the guy said he got in 1980 No marks as to who made it. just 10 ozt

And that leads me to something that everyone should be aware of if your making your own bullion. XRF is going to be more and more common as the tech gets less expensive, And that they are portable. If someone screws up its going to be easy to find and show its bad.


www.prospectorsgoldandgems.com

 

[nickvc]

I hate to tell you but I find it very unlikely that the coins contained gold, the jewellery possibly.
Xrf readings on low percentages tend to be junk and can show all sorts of metals so I wouldn't get too excited about gold or any other value showing in very low percentages. The gold you recovered is probably as you say from plated items and white gold that slipped through and the palladium could well be from the alloying of the white gold, another possibility is that modern silver jewellery is often plated and palladium was popular as it was cheaper than rhodium to get that tarnish free and white gold look.

 

[jewelerdave]

I hate to tell you but I find it very unlikely that the coins contained gold, the jewellery possibly.
Xrf readings on low percentages tend to be junk and can show all sorts of metals so I wouldn't get too excited about gold or any other value showing in very low percentages. The gold you recovered is probably as you say from plated items and white gold that slipped through and the palladium could well be from the alloying of the white gold, another possibility is that modern silver jewellery is often plated and palladium was popular as it was cheaper than rhodium to get that tarnish free and white gold look.

I will do a chemical assay on a few and disolve them in nitric and see how much gold is there. I get an alpha and a beta signal and this means its not a false read.
Other low gold items like a watch face that was silver with gold accents after a melt and xray showed a half % gold. And gold filled shows low gold.
this thing is specifically programed for dealing with only heavy metals, Au ag pt pd and a few dozen others. Its made for looking at allows.

It is also quite easy to get contamination from say using a gold crucible to melt silver, Any gold left behind will get mixed in, Also, before electric refining was common place All kinds of trace elements can get mixed in.

Each coin I found so far was made before the mid 1870s before electric refining was commonplace, So a trace here and there is not at all a shock.

Also, it was the job of mints to take peoples gold and silver and make it into coin. If you took in old spanish coins say made in Peru to the us mint, they would assay it and give it back too you as coin, what ever you ordered. Dimes, Dollars quarters halfs etc.
The thing is, its not at all consistant. The whole run made that year would not have that contamination. But batches I am sure did. Say some ship pulls into port in New Orleans in 1850 with the goods of the Carribean or from South America. If you were going to do business there or say were going to move there, and had a sack of spanish silver or bars you took in payment for say Rum or Sugar or for mining supplies, maybe the dore was not pure silver, maybe it had a trace of gold, maybe it as not worth enough in the size of the lot in its day to go after, it hardly is today. I just bring it up as it is interesting is all.

 

[Lobby]

Several of the karat gold batches I've refined have given me greater than 100% gold yield. Yep, more gold came out than I put in with the scrap. I've attributed ths to the presence of gold in the sterling jewelry I've used for inquarting.

This is one of the few advantages the home refiner has - capturing all the values (gold, silver, platinum, and Pd) in our karat gold.

 

[Geo]

some brazing contains gold. too as precious metals are refined and sold and then resold, some silver may be contaminated with gold but hey, whose going to complain about that?

 

[nickvc]

I must admit that using wet refining, acid dissolution, makes it very difficult to remove all the gold from silver so it's possible some gold, very small traces could be in old silver coins and fashioned items but remember that gold was always valued highly so every effort would have been taken to remove it. When I worked for one refiner we had loads of silver chlorides to convert which we then alloyed to sterling shot and sold and we had very small traces of gold in that well under Au 001 which eventually necessitated the setting up of banks of silver cells, it also meant we could process better. I still think the vast majority of the values in your anode bags is coming from plating and missed gold items slipping through in the silver scrap so I wouldn't spend too much time on the coins but you may prove me wrong..