# 18 Pentium I ceramic CPUs w/o gold caps - only 1 gr of Au



## Renaldas (Aug 8, 2010)

Is it normal to get about 50 mg of Au from this CPU?


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## samuel-a (Aug 8, 2010)

tell us how did you processed them?

and we'll go from there...


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## Renaldas (Aug 9, 2010)

samuel-a said:


> tell us how did you processed them?
> 
> and we'll go from there...



Put for several days in diluted nitric to loose pins and solder from core. Processed pins in AR, precipitated precious metals with copper. Cores and remaining ceramic corpuses of CPU put in hot AR. After all visible gold have been dissolved, add all have been precipitated with copper to the same solution. Neutralized nitric with urea and dropped gold with SMB. 
I see some gold remaining inside CPU cores, but I think this is tiny amount of them. I'll crush them and count the quantity of gold in them later, then will have them enough.


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## dtectr (Aug 9, 2010)

do you have a photo of PIN-side, for my inexperienced eyes?
thanks
jordan


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## Renaldas (Aug 9, 2010)

dtectr said:


> do you have a photo of PIN-side, for my inexperienced eyes?
> thanks
> jordan



Now all CPU of this type are processed. Nothing specials, standard ceramic Pentium, just no golden caps.


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## glorycloud (Aug 9, 2010)

OK - here is the answer to your question. The same website that you
used to get the picture of the pentium 1 cpu's will pay $1.57 each for them.
So, let's do the math. 8) 

You had (18) P1 cpus x $1.57 = $28.26 (from Thrifty bits)
If we divide their price by say $1,200.00 (a troy oz of gold)
you get:
$28.26 / $1,200 = .02355

If you multiply that # by the number of grams in a troy oz you get:
.02355 x 31.1 = 0.7324 grams

It Thrifty bits will pay you the value in dollars of your (18) P1's
of .7324 grams of gold, then the 1 gram you refined from the (18) P1's
could be a fairly good estimate. 8)


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## samuel-a (Aug 9, 2010)

glorycloud said:


> OK - here is the answer to your question. The same website that you
> used to get the picture of the pentium 1 cpu's will pay $1.57 each for them.
> So, let's do the math. 8)
> 
> ...



yup, i totally argee.

although, i have secund thoughts about cementing the gold (from pins) with copper... 
if you eliminated the base metals from the pins with nitric and then dissolved in AR, you have a fairly clean gold solution that you can drop with SMB.
i can see how cementation can cause losses...


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## Renaldas (Aug 10, 2010)

samuel-a said:


> glorycloud said:
> 
> 
> > OK - here is the answer to your question. The same website that you
> ...



No, metals in my pins do not dissolve in nitric, they only loosen from CPU. So, I need to process them in AR, after this step I cemented gold with copper.


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## samuel-a (Aug 10, 2010)

Renaldas said:


> No, metals in my pins do not dissolve in nitric, they only loosen from CPU



well... they should.



Renaldas said:


> So, I need to process them in AR, after this step I cemented gold with copper.



do you know whay the good folks around suggest ayllways to get rid of base metals first?


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## Chumbawamba (Aug 10, 2010)

Did you crush the CPUs so the acids could get into the inner core?


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## Renaldas (Aug 10, 2010)

samuel-a said:


> Renaldas said:
> 
> 
> > No, metals in my pins do not dissolve in nitric, they only loosen from CPU
> ...



But they dont dissolve, I dont know why ... BTW, they were magnetic.


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## Renaldas (Aug 10, 2010)

Chumbawamba said:


> Did you crush the CPUs so the acids could get into the inner core?



What is "inner core"?


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## samuel-a (Aug 10, 2010)

Renaldas said:


> But they dont dissolve, I dont know why ... BTW, they were magnetic.



well, that might be dou to acid exhaustion.
next time try to give time and if needed replacing the diluted acid with new one... adding heat might profe beneficiary...

magnetic pins is most likely made of Kovar which is readly dissolve in dilute hot nitric.



Renaldas said:


> What is "inner core"?



by that i suppose he ment for the gold brazing between the Si waffer anf the ceramics


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## Chumbawamba (Aug 11, 2010)

Basically, the inside of the CPU, where the gold bonding wires and additional gold plating is. You should see it when you pop the lid, or when you break open the CPU. There's probably as much or even more gold inside than out.


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