Fiber CPU's - That's how i do them

[joubjonn]

BUMP

Good thread. I was searching around, I have 100 green fiber various intel cpu's. Mostly the Xeon's from 2005 era. Small pins, some MLCC's. Also had a dozen or so P3 with big pins and some older Xeon (2001 era) on those the pins do not seem to want to come off at all. I'm using a small propane torch with a box fan sucking the air as I do this. 1 hour and I have 40 grams of CPU pins (nice pile of MLCC's) and still have 70 cpu's to go. I will incinerate the pins after I remove all of them as they are dirty with grease. Then I'll do a quick HCl bath to remove some tin, decant, top off with new HCl and add small amounts of Nitric until they dissolve. This seems like the best method for kovar.

 

[saadat68]

Hi
Why many members here advise add pins to AP?
These pins have tin and it isn't good even in AP solution

What do you think about this process
1- Add pins (mixed pins) to hcl for couple of weeks to dissolve kovar pins and tin then decant and wash

2- Add residue to AP solution to dissolve copper pins then decant and wash

3- Boil residue in hcl then filter gold foils

 

[saadat68]

Also we can do this process. It is faster
1- Boil mixed pins in hcl for 3 hours then decant and wash
2- Add AP to pins
3- filter gold foils

 

[Geo]

Some people just doesn't have enough time to wait. Tin is not a problem in the copper(II) chloride leeching process. The tin does cement copper while it is dissolving but is overcome by having a highly acidic solution. The tin does not remain in solution for long. Simply by the nature of the process, the highly oxidized solution will oxidize the tin(II) chloride much faster that stannous chloride test solution. The tin oxide is a white, non-soluble powder that gives little to no problem when dissolving the foils. In the instance that the pins have a higher amount of tin than normal for whatever reason, the oxidized tin can be treated hydroxide and rinsed from the foils before dissolving the foils.

 

[saadat68]

Thanks Geo
-------
Sam doesn't explain how recovery foils in his process
Because these foils have base metals and some undissolved pins do we must add them to aqua regia? Or just hcl-cl do the job?
Is it better first recovery gold with hcl-cl and then add residue to aqua regia?
Thanks

 

[Geo]

If there is any other solid metal besides gold foils, HCl and bleach will cause you to lose some gold. I recommend aqua regia. If you know there is still base metal, the HCl/Cl will dissolve some foils but any metal from the pins will start cementing the gold as soon as it dissolves. You will have a finely divided black gold powder that will be very easy to rinse out. When you dissolve the foils, you should make sure that ALL of the metals dissolves.