The best way to process the Pentium Pro cpu's is to use AR.
* First you must break the black glass underneath away from it. Remove as much as you can.
* Second, you should take a hammer and break the cpu into pieces. Normally when you break it in your hand with a hammer (WEARING GLOVES), I use welding gloves, you should get approximately 4 - 6 pieces.
* Third, put the pieces into AR and place it on the heat. While on the heat, regardless of the pins you see that have been dissolved, you should use a glass rod and stir the AR solution because you'll probably see the gold pins that have been shelled out floating around the solution. That means that your gold isn't all dissolved yet and you need to keep the heat going. Keep the heat on, and after using the stir rod to stir your solution and no gold floats to the top or swim around in the solution, you probably dissolved all the gold.
Stirring is the key. You MUST stir every so often (every half hour or so), to make sure you've dissolved all the pins and (or) you've exhausted all the nitric acid.
Once you know you've dissolved all the pins, then all you need to do is filter the solution and then drop the gold with SMB.
Just so you will know, I have done Pentium Pro's before and I can tell you from my own experience that with 10 of those cpu's, the most gold you will yield is approximately 3g tops.
If you break the cpu's into at least 4 - 6 pieces, and you recover gold near the amount I mentioned that you may get from at least 10 of them, there will be no more gold to recover. I've recovered gold from them and afterwards I crushed up the solid pieces to a powder and put that powder in AR and after testing it, there was no more gold.
So, don't waste your time and effort trying to recover gold from those cpu's because they're thicker than probably any ceramic cpu you'll work with because once you recover the gold from breaking them up into pieces, that's all you're going to get. Again, I tried it just to see if others were telling me something correct and for me to learn. I did learn. There is no more gold after they've been broken up good and put into AR and processed.
I didn't believe it, but, the AR WILL travel throughout the cpu and dissolve all the gold in there, regardless of how the wires are wired throughout the cpu. Break them up into 4 -6 pieces and there is no need to do any more breaking or even crushing afterwards. It's a waste of time.
Count the amount of Pentium Pro's you have and for every 10 you have, you should yield approximately 2.6g - 3g of gold. This is not exact, but this is an estimate I can rely on because of the other yields I've read about, and then my own experience processing them.
For your own experience and experiment, after you do the cpu's and you feel you've recovered all the gold there is in them, wash the cpu's very good with hot water and dish soap (I use Dawn)... let them dry out a few days or however you dry them and crush them up, and then put the crushed powder in some AR and process it. Although I'm saying you won't recover any more gold, you may very well recover some, plus you'll get the experience in doing so and knowing the yield data of those cpu's.
Hope that helps!
