Ceramic Cpu Process

[cbrux71]

Hi,

This is my first time posting on the forum after many hours of searching to get all the information I can myself before asking for some advice. I'm looking to process some ceramic cpu chip(pentium pro x 6) and have made a short step by step list of what I think I need to do. I'm looking to see if I have missed any steps in my list, any advice would be great.


1) remove legs & metal plates & process seperately
2) Crush pentium pro to minus 1/8" mesh
3) Place pentium pro into HCL & Peroxide to digest all base metals
4) Once all base metals have been digested, decant and save HCL & percoxide mix to test later
5) Wash all pieces in hot water to remove any residual HCL & peroxide
6) Use aqua regia with controlled nitric doses to leach gold and other PM(keep covered and heat, but don't boil)
7) Once all reactions stop, decant all liquid and ice the aqua regia
8) Wash all pentium pro pieces with distilled water to ensure all gold bearing liquid is saved
9) Filter the aqua regia solution to remover any traces of silver and other insoluble chlorides
10) Precipitate gold out of solution with SMB
11) Let the solution settle overnight
12) Filter all liquid to catch gold
13) Test filtered liquid for PM
14) Wash gold powder with hot HCL to remove any remaining base metals then wash with distilled water
15) Re-process through aqua regia to refine to .9995 gold

I hope I've gotten all the steps I need to process ceramic cpu's.

Please any advice on these steps would be great.

Thanks,
Chris

 

[butcher]

cbrux71.
Chris I do not see much wrong in your plans, here are some things you may wish to consider, I hope I do not confuse you with this post, as I am not always the best at putting my thoughts on paper.

Remove any heat sinks, but unless the pins are kovar not much reason to remove them.

You could Place Pentium pro into HCL & Peroxide to digest all base metals, the CPU’s usually do not have that much copper, or base metal compared to gold so the small amount of copper can usually be dissolved into solution with the gold, with the ceramic CPU.

If the pins magnetic (fiber type CPU) with the kovar pins the iron needs removed, before dissolving the gold.

There are several ways’ you can remove base metal, if you were going to use aqua regia later you could use nitric acid to remove the base metal.

The copper II chloride leach (HCl acid peroxide leach) for base metals may not work well here to get through the layers of gold, in some CPU’s the gold content compared to copper is so high that the acid may not be able to reach the copper through the layer of gold, so this may not be the approach I would take (unless the pins were Kovar then the acid peroxide works best).

You can dissolve the gold in HCl and bleach (much easier to deal with than aqua regia) especially If your not familiar with aqua regia.

Ceramic CPU’s (without the kovar pins) can be processed in the poor-mans aqua regia (no heat sinks or caps), it will dissolve some copper but if you can refine after you recover the gold, (see the general reaction list and poor mans aqua regia).

Testing your solutions with stannous chloride is how you tell where the gold is and is not when you cannot see it.

I would make sure the aqua regia was free of nitric acid (minimum nitric use and or evaporation method), I would also dilute the aqua regia, and this helps to lower the strong acid so the silver can precipitate from solution (some use Ice to help instead of dilution).

 

[maynman1751]

10) Precipitate gold out of solution with SMB
11) Let the solution settle overnight
12) Filter all liquid to catch gold

I would suggest that you do not filter after dropping your gold. You can lose some of your gold when you filter the powder. Simply decant or siphon off liquid from powders. Then do all of your washings in same vessel without any filtering.
Then, as Butcher said, re-dissolve in HCl/Cl.