# 486's Where's the GOLD?



## cytek (Mar 5, 2008)

Interesting, a new experiment with twelve 486's CPU"s , I opened the lids and added them to the AP mix. Only used HCL and peroxide. Let them set in a bucket for three days, mix periodically.

All pins are gone, dissolved and gold flake visible, but where did the gold go from the pins? Still in the AP mix? See both pics. 1 is the 12 CPUs and ther other the filtered AP and chips. 

I haven't added the pins and flake to a nictric mix yet. 

Cytek


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## cytek (Mar 5, 2008)

I forgot to add, if the Gold went into the AP, then how do i get it out?


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## skyline27 (Mar 5, 2008)

You can use SMB to push it out of AP. 12 cpu's won't yield very much gold.
I hope somone more knowledgable than myself can comment on this because I am having the same problem with cpus in AP.


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## cytek (Mar 5, 2008)

Thanks Skyline, i'm new to refining , i find it very interesting. I remember Steve saying that there was .33g in the 486's. I'll post what the yield is on the 12.
I know Steve said to take the spent CPU's and add them to a batch of Nitric to get the rest of the gold out.


cytek


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## skyline27 (Mar 5, 2008)

I was under the impression that a pentium pro has .33g and 386/486 something less.


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## cytek (Mar 5, 2008)

your right Skyline it was the pentium pro's. So i am going out of town right now but when i get back i will test for gold in the hcl-H202 if it's in there i will precipitate with smb. You don't have to dissolve wiht HCL- CL because it looks like it's been dissolved. Will post back in two days.

This is my first experiment with CPU's, i have some pro's and some fiber cpu that need extraction i also have about 100 PII's, and PIII"s. Not sure there anything in the PIII's. They have a smal squre on the chip that is shinny and looks like platinum or palladium. Not sure which, 

Cytek


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## skyline27 (Mar 5, 2008)

"They have a smal squre on the chip that is shinny and looks like platinum or palladium. Not sure which"

It's neither. I would be happy to be proven wrong.


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## lazersteve (Mar 5, 2008)

The tops are nickel plated copper.

AP works fine on certain types of cpus and has problems with others. If the base metal in the CPU is an iron alloy or if the lids are left on the AP will stop working. This is why I sort all my scrap and test a small batch of each type to determine the best way to dissolve out the base metals from each type. This goes for cpus too.

You can test your AP with stannous for dissolved gold. Generally speaking if the AP shows a bright yellow ring around the top of the liquid level, small amounts of dissolved of gold are present. The precipitated gold will be very dirty and require cleanup and redissolving to purify.

AR will definitely strip the cpus in record time compared to AP or even FeCl3. With the added speed you will also have the added dangers of NOx fumes. 

Don't forget that part of the ceramic cpu yield is in the form of wires embedded in the ceramic housing.

Steve


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## skyline27 (Mar 5, 2008)

Steve,

Which cpus would you recommend for AP? Do you have any tips on the cleanup process? I've tried a few things but I always end up with a gnarly mess like the above photos.


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## lazersteve (Mar 5, 2008)

Sky,

For one I don't mix cpu types (no fiber with 486, no 486 with pentium, etc). I have mixed AMD and Intel 486's with no problems.

Secondly, I never break apart my cpus. Just remove the lids and toss in the AP for a few weeks. 

I check the cpus every so often and give then a little prodding with a long shish-ka-bob stick or piece of plastic and a toothbrush to see if I can help any of the gold along. As the cores loosen up and fall off they come out and get rinsed. I save them to be added to a piece of art work I'm working on. It's a mosaic collage of cpu cores. 

If the cpus are really stacked thick I move them about so each gets a fair amount of exposure to the AP.

I keep the AP mix strong on the HCl so it maintains more of a clear brown color also. I add peroxide only if I don't see any loosening of the foils after a few days of soaking. Check each day of the soak and test each leg to see if it's ready to flake off.

If you run cpus that have the iron or steel legs they should be treated with hot HCl in a crockpot to remove the foils.

The sludge you see is a result of including the fiber cpus or cpus with solder on the legs. The solder that connects them to the legs is a mix of base metals that don't mix well with AP. That gray sludge is a sign of possible tin, lead, or silver in the mix (or all three). Generally silver will show purple silver chloride if in a lighted area. 

The legs of most fiber cpus are also kovar which is another alloy AP has trouble with. CPUs with kovar legs should be processed with AR.

Overall the mash of gold foils in the photo looks very similar to what I have when I do ceramic cpus (aside from the gray sludge). Wash the foils just like you would finger foils from AP. Start with HCl until the wash is clean. Then dissolve the foils in HCl-Cl to get the gold into solution. My cpus don't come out of the AP until all of the legs are gone and all of the cores are free from the ceramic housing. The toothbrush helps this process complete. The shish-ka-bob stick is very handy to remove the cores once they loosen.

The housings are saved to be crushed very fine and leached with AR or HCl-Cl.

The above works fine on small 1 pound batches. If you process more than that at one time either set up several small flat dishes with a small batch in each or use AR to process them all at once. Keeping the cpus fairly exposed to the solution helps a lot.

Steve


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## skyline27 (Mar 5, 2008)

Ok. That clears up alot of my questions. I can do that!

I hope you post a photo of your "scrap art". I'm often struck by the beauty of old electronics and strange chemical reactions. 

Salud!


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## viacin (Oct 31, 2008)

cytek, if you ever come back to the forum I'de like to know how much gold you ended up with.


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## NobleMetalsRecovery (Dec 25, 2008)

lazersteve said:


> The housings are saved to be crushed very fine and leached with AR or HCl-Cl.
> 
> 
> 
> Steve



I guess this answers my earlier question to you. Have you or anyone you know of done this? Any results?

Thanks, Steve


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## butcher (Dec 25, 2008)

a big prtion of gold is inside them, crushing and HCL/Cl or Aqua regia to disolve fine gold is how we get it out of the processors.


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