Digging for GOLD

[Christoph Alpermann]

Well, errh, yes sort of...

 

I´m running a small Computershop in Trier and finally have found the time to get my storage room (aka explosive testing site of vile messiness) sorted.

There I came across a whole pile of old ISA cards and mainboards with what I thought were gilded pins.

Being a little gaga-headed from all the dust I inhaled throughout my cleaning efforts I thought "those pins be small - maybe enough gold (4-5%) there for shakudo, let´s see the inner is made of copper".

 

So off went one of the pins and scraped it was with a sharp knife, but no copper there, scraped half the way through - still no copper!

 

Rationally thought I would say "brass, not gold" on the other hand there is no oxydation on even one of the pins.

 

Is this my personal Klondike (i have tons of that stuff) or am I just making a fool out of myself?

 

If there is any chance that these pins are solid gold, I have the possibility of testing it at one of my customers shops who has a aqua regia testing kit (I just don´t want to look too stupid with that stuff turning out to be anything else...)

 

Any opinions?

 

 

Regards,

 

 

Christoph

[Geoff Keyes]

Gold contacts used to be quite common, so it wouldn't surprise me. I worked for a shop that had a computer recycle shop on the side. They would tear down used machines and send the boards and cables off to a metals house. They would burn the boards (releasing who knows what kind of nasty stuff) and recover the metals, mostly copper and gold, and the company got a check.

 

On the down side, there is not much of either on any single board, on the up side, prices are way up.

 

Geoff

[Doug Lester]

There's a couple of guys around here who recover gold from computer boards down here in the Norfolk area. They gave me the formula for making aqua regia from muratic acid and potassium nitrate as long as I wouldn't give away the chemical process for recovering gold. It at least pays for their time and reagents and is not as poluting as the cyanide method.

 

Doug Lester

[Christoph Alpermann]

Allright, then next time when I work for that customer, I´ll take along some of those pins and see if they´re actually made of gold - now I only need his computer to break...well, Microsoft will take care of that in no time

 

Thanks a lot,

 

Christoph

[RedNeckLeftie]

Hi Christoph,

 

Electronics Industry standards for card-edge fingers (back to at least 15yrs ago) offer 2 options: 30 micro-inch of electrolytic (hard) gold over 80 micro-inch Nickel (0.76um Au over 2um Ni). A more recent alternative, they could be 0.05-0.75um Au ("flash" gold) over 2um Ni if an electronic contact grade corrosive lube is used.

 

Not much gold in there...good luck!

 

Thanks,

Brian K.

[Christoph Alpermann]

Hi Brian,

 

thanks a lot for the technical insight - and I was hopping around like ol´ Scrooge McDuck

 

No seriously, the card edge fingers are indeed plated, I´ve noticed that by scraping a little material off. They seem to be copper though (judging by the colour).

I was referring to the pins, that rise from the card, they show no change in colour however deep i scrape.

 

But maybe it´s just the fact that I want to work with shakudo (while not being able to afford the gold) so badly that makes me put my hopes higher than they´re supposed to.

 

Question: Would Gold take any colour from putting it into ferric? If not I could easily tell if they´re brass or any stuff other than gold...

 

 

Regards,

 

Christoph

[RedNeckLeftie]

No problem, I work with this kind of stuff in my day-job. Yeah, the card edge fingers start with 1 or 2-oz Cu (0.0007 or 0.0014-inch), are plated with Ni, then with Au. As for the "pins, that rise from the card," I believe these would be header pins--0.025-inch sq, with 0.100" spacing. Stop reading now if you don't want your buzz harshed...

 

 

According to 2 mfgs' datasheets, the pins are phosphor bronze, electroplated with 50 micro-inch Ni, then electroplated with 30 micro-inch hard Au. It's also possible (but unlikely) the base metal could be Beryllium Copper. I cut into a header pin today for fun, and yep, it cuts and looks just like gold all the way through. For fun, I dunked a complete pin in ferric, the color did not change except where plating was missing.

 

Regards,

Brian K.

[Christoph Alpermann]

Oh now that made my day - no gold for me then, I guess...unless I scrape very gently.

 

Thank you a lot for going through the trouble of finding that out for me - I´ll go and rob a jeweller now.

Edited July 1, 2008 by Christoph Alpermann

[Gungnir]

me and my dad have been jr. prospecting here in Manitoba since i was a kid. I remember when he found that out computer chips had some gold on them. He gather up as many as he could and extracted the gold. We learned that it is not worth it. The chemicals that are required to extract it cost more then the gold that you will get. It is also a very pain staking procedure. It was way more fun to hike around and find abandon mines and go through there left over ore, and if your lucky you can find a nice quartz vain that is hiding a gold vain in it.