Learning how to recover gold from garbage

Here is a .5 ozt solid pure gold button that I made by recovering/refining gold from some junk computer scrap.

How did you recover/refine the gold from the scrap? I have a lot of computer scrap laying around here.

Well, that is a topic that would fill an entire forum itself... I will try to post some "basics", but there is alot to info to digest.

This gold was recovered from trimmed contacts on old PC cards (old sound, video cards, etc.) I used the "AP" method as described at a gold refining forum.

You can recover gold from just about anything that has gold plating on it. Computer junk is a great place to look.

In a worst case scenario of economic collapse I plan on doing alot of "urban mining". I have spent the last 15 years learning this as a means to trade small amounts of PMs for basic good and services (in the event off...)
Here is a video showing how to recover silver from keyboards with content data...
Maybe it doesn't make much sense with silver at $32, but what about $50, $100, $1000, etc.?

How do you remove the silver/gold from the alloys/plastic and refine it?

I can say this - older and more specialized stuff has more gold. There's been a lot of effort put into getting things to work with ever-thinner plating layers. The really old stuff (pre PC) can have quite a bit of gold on the contacts, the new stuff it's only a couple of atoms thick. Older industrial control boards are usually "over done" with gold too. New PC type boards - you're going to need a really big amount of to get a lump of gold you could hold in your hand.

Quite a few coax connectors have thick silver plate. Again, the older the better.

Another source is older low volume ceramic chips - such as those found in old DEC Alpha boards. They really spared none there. Even the metal chip covers have thick gold on both sides, and medium thick gold bonding wires inside between the chip and the pins. Stuff like that was going for such a high price the gold content was in the noise, so they didn't bother to cut it to the minimum.


I've been working on extracting the Pt group from old catalytic converters which I sometimes run across. The older the better there too. In that case, just getting the stuff is fairly easy - aqua regia gets both Pt and Pd which are then not too hard to selectively precipitate. Or you can use just nitric to get the Pd, then add the HCl to get the Pt, but this doesn't give great separation by itself. You can also just plate them out from the solution.

There was enough worry about people doing this that for a long time you couldn't even buy a catcon from a junkyard without turning in a core. I think that's over with now. The new ones use quite a bit less, so they're not as useful for this - you want the old kind with the alumina beads from right when they started with them, before they learned to put it on one atomic layer thick.

PMBug said:

How do you remove the silver/gold from the alloys/plastic and refine it?

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Here is a YouTube video (slide show) describing the process.

Kind of left out how the AgCl got reduced.

For those who haven't done this, his warnings about nitric fumes aren't even strong enough. I presume he's starting with normal lab grade stuff - around 70% purity which is about the most concentrated you can have it and it be stable at all. I make 100% pure (and fuming) here and it's wicked stuff and very unstable.

The danger is the nitric fumes aren't like chlorine or ammonia where you'll reflexively stop breathing and get away before any real damage is done to you. They smell kind of not-so-bad, but one cc of that crap in your lungs and you'll be coughing up nitrated lung tissue for weeks - I know this from experience and now I do this under fume hood or even under some vacuum, with the fumes blowing through a bucket of alkaline solution to get them before they get me.

Note, nitric acid is "on the list" for terrorism and drug manufacture. You can make it, but it's not easy or quick or safe. I can show how if anyone is interested. You can still buy the stuff around the 'net, but buying a lot is going to get you some attention, and it's not cheap, which is why miners don't use this technique much, it's just not cost effective on low grade ore.

Note that indium and gallium are quickly becoming precious metals themselves, and are present in modern tech in larger amounts than the more conventional PMs.
Indium is used for the semi-transparent conductive traces in nearly all displays to "talk to" the pixels, as indium-tin oxide. Gallium is a major component of most leds, and some high frequency transistors.
http://www.rotometals.com/Indium-Ingot-s/7.htm
I use a fair amount of indium here in the lab, it's pretty neat stuff. It wets glass used in a solder alloy, makes great gaskets for vacuum systems (and is reusable).
It's used in various low melting alloys, which is why those are expensive.

Gallium is going nowhere but up in price. The long liquid range is interesting, you can make thermometers with it that go from room temp to orange hot. Like water, it breaks containers when it freezes just below room temp. It dissolves aluminum and renders it extremely reactive with water, giving off hydrogen - there's a guy who has a patent on this as "hydrogen storage".

Back to silver, keyboards aren't the only place you see it - some lower volume PCB's used it for the tracks too. In that case it's mixed with a binder, so a solvent might be the preferred way to get it back - that *should* work with keyboard mylars too, and avoid some of the expense and chemical transformations required. Shouldn't be too hard to find a solvent that eats the glue and leaves the mylar behind.

Heck, I have a couple egg crates full of keyboards I've worn out. Gotta try this - just as soon as I remember which storage building they are in.

There is an entire forum for that. It is however technical. So our posts would be more helpful.

http://goldrefiningforum.com

Penn said:

There is an entire forum for that. It is however technical. So our posts would be more helpful.

http://goldrefiningforum.com

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Yes, I have been a member of the Gold Refining Forum for years. Nowhere can you find more data on the subject then there, but yes, a beginner would have alot of work to do before they would even know what anyone was talking about.
I do plan on posting some basic info for the beginners at the Precious Metals Marketplace forum (I am a co-founder of this company).
If you would like, I can post them here as well if the members are interested in the subject.

Why start a thread on the subject if you weren't planning to post the info?

PMBug said:

Why start a thread on the subject if you weren't planning to post the info?

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As I stated my reply to your PM.

I just simply did not know IF anyone would be interested in me posting "refining" info on this forum or not.
That is why I was open and honest about who I am and what I wanted to post!
I enjoy the discussion here that is not found in other forums, that is why I joined.
I'm NOT trying to "recruit" anyone.
I simply posed the question... "if anyone is interested"... If so, as I stated "I will post them here as well".

I'm interested. You could begin by finishing up the silver info with how you reduce the silver chloride and melt it without oxidizing the silver again.

DCFusor said:

I'm interested. You could begin by finishing up the silver info with how you reduce the silver chloride and melt it without oxidizing the silver again.

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Use Sodium Hydroxide (added to the silver chloride slowly) to convert the silver chloride to silver oxide, when exothermic reaction stops, start adding dextrose (corn syrup) which will convert silver oxide to metallic silver.
The result will be a silver colored cement which, needs to be dried into a lump or powder, then melted in a small melting dish with a torch into a solid piece of 99% (or better) pure silver.

I would recommend this process to precipitate the silver out of your solution instead.
Use copper to cement the silver out of your diluted silver nitrate solution. Simply suspend a piece of copper pipe into the solution. Silver will start precipitating out of your solution in metallic form (you will see it forming on the copper pipe). The results is still pure silver, but you save some steps as oppose to converting it to silver chloride first. The silver will still be very pure. Then dry and melt as stated above.

Very interesting thread.

I perform a tremendous amount of demolition of industrial structures, and have come across entire rooms stacked full of obsolete computers and assorted hardware. Please expound on this subject all you care to.

ancona said:

Very interesting thread.

I perform a tremendous amount of demolition of industrial structures, and have come across entire rooms stacked full of obsolete computers and assorted hardware. Please expound on this subject all you care to.

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This is becomeing VERY high value commodity! Grab this stuff (the older the better) where ever you find it. Stay away from any CRT monitors... they will cost you to dispose of, but enything else, grab it up.
You can collect this stuff up while you learn about Refining/Recycling and deside later if you want to refine some of the scrap into your own gold and silver, sell it as is, or a combination of.

I am way ahead of you there. I already shear boards and toss them in to gaylord boxes. When i have a few, I sell them locally. The money is fantastic and getting better all the time. Cell phones seem to have the highest density per kilogram, especially the older models.

If anyone wants some "hands on experiance" stop over to my shop and we will "run a batch"... all you have to do is dismantle this little pile of keyboards for me (SEE PHOTO) and we will split the silver 50/50.