# Purify bars of electrical gold alloy scrap



## Capitalmind (Jun 8, 2015)

Hi all, new to the forum and see lots of good reading ahead. I've done a few searches and not sure I've found exactly the right info so probably not searching for the right phrase.

I spend most of my time refining silver due to the availability and price. Regarding gold, I have a few small bars that are reclaimed electrical scrap and probably contain very little gold. I'd be lucky to find 2g per 100g. I'm not sure how to process this? Is it worth trying to extract the copper or other metals?

Current thoughts are dissolve everything in nitric acid and see what comes out. I get a green colour using 18k purity test so it reads as plated, only it's a weak alloy. All suggestions and links (if this topic has come up already) greatly appreciated.


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## Lou (Jun 8, 2015)

Welcome!

For low grade material like that, you might consider granulating it into shot and separating the copper from the gold with 15% nitric acid. Filter that solution and dissolve the gold up (search forum) for refining.

Alternatively, if you have much to process, you can buy copper sulfate (pentahydrate I believe) root killer at Home Depot and make a plating bath solution that is 5 wt % sulfuric acid and 60-100 g/L in copper ion. You can then plate the copper out onto stainless steel sheet at 3-4V. The gold will report as an anode slime. So the game plan is make an anode bar, as thin as possible, put it in a muslin cloth to hold the gold slime, alligator clamp it all up (perhaps use a large deep HDPE kitty litter container) and run it til the anode is a stub (a butt, in plating parlance). No fumes aside from hydrogen, so best done in well ventilated area (Saran wrap over it to keep misting down).


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## nickvc (Jun 8, 2015)

The one thought that comes to mind to me is if you have more material,gold plated, then use the bars you melted for cementing values such as in your stock pot, this becomes a win win situation as you get whatever gold you already have melted into uneconomic recovery bars into a process to recover the values for free plus any values left in your solutions.


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## Capitalmind (Jun 9, 2015)

Thanks for the replies. Nickvc, I'm not sure I fully understand what you mean?

Lou thanks for the suggestion and the voltage level! I might pour the bars as shot to reduce unit size then try your electrolysis idea. I'll read up on refining the copper caught and the gold slime.


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## nickvc (Jun 9, 2015)

If you intend to process more e scrap or any gold scrap you will have what we call a stock pot, old solutions from refining or recoveries that may contain gold,to recover this gold we use cementation, the copper goes into solution any values come out, this means that you do not have to use fresh expensive acids but will recover any values by using the bars for cementation, you get the gold back for free.
If you intend to use AP to recover values from e scrap and if they prove to have gold in solution same applies, use your bars to recover those values.
If none of this makes sense then you need to do some studying so you can learn how to recover and refine your good bearing scrap in an economic and safe way.


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## Tomd (Mar 29, 2016)

nickvc said:


> If you intend to process more e scrap or any gold scrap you will have what we call a stock pot, old solutions from refining or recoveries that may contain gold,to recover this gold we use cementation, the copper goes into solution any values come out, this means that you do not have to use fresh expensive acids but will recover any values by using the bars for cementation, you get the gold back for free.
> If you intend to use AP to recover values from e scrap and if they prove to have gold in solution same applies, use your bars to recover those values.
> If none of this makes sense then you need to do some studying so you can learn how to recover and refine your good bearing scrap in an economic and safe way.



Thats a great idea cant belive id never thought of that! i have bought a few bars off an aparently reputable ebay seller but not yet found time(too busy running good stuff) to see what i acctually get from them so into the stockpot they go. thanks for the idea!


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## patnor1011 (Mar 30, 2016)

Bars made from electronic scrap like from pins we do call them gold drops, they are common on ebay and most of them do not contain gold at all. Even those which do have any gold in them are extremely low yield material and most of people avoid them like plague. You never know what is included in that melt but as for gold is concerned most of them will be not 1-2% but rather like 0.1-0.2%.


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## goldsilverpro (Mar 30, 2016)

These drops or bars, if made from fully plated pins, probably do not contain more than 0.4 grams of gold per 100 grams total weight, at best. More likely is that the pins used were only partially gold plated. If so, the value could be as low as 0.1g/100g, or even worse. Also, the fatter the pins, the lower the value. 

Buying those bars or drops is always a pig in a poke.


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