Ceramic CPU Expert WANTED!

[etam]

First let me say sorry for this new topic, but after a lot of searching, readning and asking here on the board I still not really get the answers for my questions and I tend to be more confused and more lost and that's why I need somebody's help who is much experienced than me at processing ceramic CPUs.I almost read all of the informations I found here with the use of the search function and pearhaps this could be the reason of my confusion.

As I know it exist two ways of how to get the gold out the CPU;
dissolution all of the metallic parts->denoxing->precipitate or (AR/ PM's AR) Problem: presence of base metals and NOx in solution, harmful fumes, difficulties could occure at precipitation, doubtful purity of gold powder Advantage: fast, eats everything (small pieces of gold foils inside a CPU->hard to collect when float)

dissolution of the base metals only->dissolution of foils->precipitate (AP) Problem: some kind of ceramic CPU legs are made of indigestible alloys, not as fast as AR or PM's AR, Advantage: no "baby-sitting needed", less fumes, easy accessible chemicals, "gold always remains visible during the recovery process" (copyright: lazersteve in http://www.goldrefiningforum.com/phpBB3/viewtopic.php?f=49&t=423&hilit)

I really don't know wich method would be suitable for me and for my CPUs. I read some posts where guys got in trouble during processing ceramics in AP and read others where everything went right.... but what this depends on? My experiment with the PM's AR was successful (I think) because after percipitation I got a deep grayish/purple powder. What do you advise? Which way is workable only for ceramics and what experiencies do you have with different processes related to CPUs? (The only thing I "scared" of those nasty alloy legs)

Thank you in advance,
Matt

 

[stihl88]

Some people go straight to the AR process but i like to eliminate the base metals wherever possible at first.
To eliminate the base metals Ive experimented with Nitric and AP, what i found is that the AP method although slow has worked for me so far.
The AP solution should have a fish tank Air Bubbler with an Air Stone blowing Air through the AP solution, the idea of the Bubbler is to re introduce oxygen back into the solution for the HCL to utilize, we can introduce more oxygen back into the AP solution by adding more Peroxide but although fast reacting it becomes expensive to do it this way. The air bubbler works just as fine and would cost a few cents total to run once we've kick started the process with some Peroxide.

The AP solution will attack the base metals Copper, Tungsten etc leaving the gold foils behind but this takes some time to completely dissolve the lid so you can heat the lids off first and just add the ceramic CPU's to the AP solution and etch the tin, lead solder etc away which should render fairly clean Gold solder and plated components in the heart of the CPU > Now the cleaned CPU can be processed in AR.

The lids can then be processed in a Sulfuric Gold stripping cell.

 

[lazersteve]

For all types of ceramic cpus:

Modified Poorman's AR

Steve

 

[etam]

Thank you very much for your replies!
Yesterday I started my first AP test with a CPU hopefully it'll have a good outcome! The Poor Man's AR is very enticing for me and my first test with it ended successfully (0.05 gold button from 1 CPU) but the only thing I worry about is the purity of that tiny button. I belive it contains a lot of base metals, because PM's AR isn't the purest procedure, sure?

Matt

 

[glondor]

A question about torching off the lids. I tried one yesterday,(pentium pro). The torch seemed to vaporise the gold on the plate and the solder never did let go even after 5 minutes of heat. The ceramics did shatter and the back ceramic plate fell off in pieces however the main plate just changed colour and stayed put. I tried to pry a bit while torching, however this did not work either. (not enough hands)

Did I vaporise the gold on the heat sink?

Mapp gas torch. This is not the first time I have tried with out success. What am I doing wrong?

I may just try a hammer. 8)

 

[lazersteve]

There is no reason to remove the top 'lids'. It is a plate of tungsten copper alloy that is gold plated on the surface.

You can remove them using an oxy/act torch and extreme heat. The lid will fall right off once the cpu is glowing red hot. You won't find any hidden treasure under the top lid. The top piece is more accurately called the 'heat spreader'.

All previous general discussions about removing lids with a torch referred to the bottom 'lid' only.

Steve

 

[glondor]

Thanks for the explanation Steve.