Merged Topics on Ceramic CPU Recovery with Yields

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I read through most if this thread and got a fair idea of the 'spot value' for a PP chip. concluding that the collectors value of these far outstrips the value of gold content (price around $1700/£1000 at time of writing)

Not only are theses items a rare piece of history - but a working unit (particularly the dual core models) are sought after by collectors (at least in the UK). Even the crazy ebay prices of late are a good investment... but only if you build them into a working machine.

DIY refining in the UK is out of the question, but a couple of large outfits pay good money on the weighbridge. That said, this board has been enlightening - thank you all for the contributions and I hope my perspective as a vintage computer nerd adds to the community.
 
Ok, i think this is the place, i made a test on a single AMD K6 and got 0.03g and a K5 gold top and get 0.22g. Is this right?
 
lazersteve said:
Electrolytic cell with sulfuric acid electrolyte.

Steve
i have been looking for this for a while now, right i got my ceramic cpu lids, i cant use electrolytic, what shall i do, should i hlc then ap. or strait in with the ar, if ar should i take the nitric route or the poor mans route hypochlorite ( which still seems expensive )
 
What looks simple in writing is not always as easy as it looks on paper. You must follow each step through to completion or your results and yields will suffer. Do not base your reactions on time, but instead on completeness of each step in the process. You can also get visual clues form the reactions themselves (eg: color, vapors, bubbles, etc.). You biggest mistake will be rushing the process.

Steve
 
I incinerate any material that I suspect contains trace organics prior to treatment of any kind.

I rinse loose foils with hot water until the rinse water tests neutral to pH paper to confirm removal of traces of HCl. I try to avoid incinerating foils as the heat tends to fuse the foils into larger blobs which are much harder to later dissolve unless using AR. There is nothing wrong with incineration after HCl as long as you do not melt the material making further dissolution of the foils more difficult. If you are not using AR to dissolve the foils you will find fused foils are much more difficult to dissolve using the work around reagents like AP and HCl-Cl.

Steve
 
Pentium Pro value This has to be accurate for the high end, imo, Bidder Bid Amount Bid Time
0***2( 5072) US $2,659.00
Feb-19-13 07:54:36 PST
http://www.ebay.com/itm/Lot-of-129-Scrap-Pentium-Pro-CPUs-Processors-Computer-Gold-Recovery-24-9-lbs-/300864064154?pt=LH_DefaultDomain_0&hash=item460ce54a9a


k***2( 15) US $2,609.00
Feb-21-13 11:15:24 PST

s***a( 146) US $2,509.00
Feb-18-13 18:55:21 PST

k***2( 15) US $2,250.00
Feb-18-13 21:47:02 PST

t***t( 330) US $2,200.00
Feb-18-13 18:04:10 PST

s***a( 199) US $1,501.00
Feb-18-13 17:31:08 PST

m***m( 141) US $1,300.00
Feb-18-13 17:53:50 PST

m***m( 141) US $1,050.00
Feb-18-13 17:53:38 PST

m***m( 141) US $850.00
Feb-18-13 17:53:22 PST

1***o( 4 ) US $200.00
Feb-18-13 17:47:32 PST

1***o( 4 ) US $100.00
Feb-18-13 17:47:24 PST

1***o( 4 ) US $2.00
Feb-18-13 17:47:13 PST

Starting Price US $0.99
Feb-18-13 17:07:57 PST
 
Somebody somewhere is saying " That's a 129 grams of gold". That's over 4oz of gold! Man that's worth $6,300!!!!!
If i can get them at $3,000 dollars i can double my money. What a deal !!!!
 
Wow!!! $33 a piece.

1/3 gram per chip = $17 per chip gold value before refining, shipping, selling. He only lost $16 a chip X 129 chips=$2064.

:shock:
 
I've read this entire thread & searched. I haven't had access to my copy of Hoke most of the last week or so due to my hard drive dieing. I'm working from a borrowed laptop right now & don't always have access to it so I'll have to check for responses as I'm able.

I have a few Pentium Pros I'd like to process. In 1 of his replies in this thread, lazersteve mentions preprocessing with a 35% nitric bath to remove the tungsten/copper heat spreader. In another he mentions complete digestion of base metals & continuing the nitric bath until the die falls out. I'm wondering if a 50/50 solution of water & 67% nitric acid produces the 35% nitric bath he calls for. (33.5% actually. I know. I figure someone will tell me if this is close enough.) Steve mentions tungsten turning into a yellow powder. My understanding of "complete digestion" is that all the metal is dissolved into solution. Someone please correct me if I'm mistaken.

So, my questions are:

1 - Is my understanding of the 50/50 nitric acid/water solution correct?
2 - How much nitric acid should it take to digest this tungsten heat spreader? (I remember seeing such formulas for PMs but not for base metals. Hoke says newbies usually use too much of everything. I have a limited supply on hand so I don't want to be wasteful.)
3 - Should I use heat or just let it soak cold?
4 - Any idea how long it should take to digest a given amount of tungsten?

I'll check back as soon as I'm able for any replies. This thread has a LOT of good info. Thanks to everyone who contributed & to everyone who has helped me along the way. (I still have a long way to go. I might even enroll in a Chem 101 course this Spring or Summer.)
 
Mix the 67% nitric acid with an equal volume of distilled water and you will be fine.

Digest at room temperature or higher (more heat = faster), the hotter you go the more likely you will form the yellow tungsten compound which is undesirable. Go room temperature for a few days and the lids will slide off with zero yellow tungsten compound. Get everything hot and you could be done in a few hours with a little yellow compound to deal with in your filter cycles.

Don't try to digest the tungsten, just get the copper and silver out. You'll know your done when everything falls apart, like a well cooked piece of meat, it 'falls right off the bone' :) .

Trying to digest tungsten will be a lifelong venture, well maybe not that long, but you get the idea.

The goal is to remove the copper, silver, and other base metals, not to digest the tungsten.

Steve
 
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