Suface mount caps on the CPU

[zamistro]

I'm about to process a bunch of these CPUs with the poor mans AR method.

Yes, I will crush them up good first.

Do I need to worry about the little surface mount capactiors? How about the residual glue that held an aluminum lid on?
What about the silicon chip in the center?

 

[lazersteve]

The glue may cause some headaches with nitric.

I wouldn't crush them at all. The fine ceramic powder is difficult to filter.

The glue and caps come off easily with a torch.

Steve

 

[oldtimmer]

Why the AR route? I use an exacto knife or box cutter to remove the glue and it has not been an issue.

I have done several batches of these in Muratic Acid on a warm hot plate with good success. After 8 to 10 hours, I will remove them (entire CPUs), light rinse in water and the pins will usuall come off very easily. It is then back into the Muratic Acid, again on a warm hot plate until the pins stop floating around with bubbles coming out. I then use a maginet to see if any iron is still left in the pins. If so I will let them cook for a few more hours.

Rinse with hot water, back into a small amout of Muratic acid as a final check to make sure that any last base metal is gone then into HCl +Cl to dislove the gold.

 

[zamistro]

Thanks guys. A few more questions...

If I leave the chips whole won't I miss the gold inside?

Will the dust really go through 3 or 4 coffee filters?

Do the caps have PMs?

 

[butcher]

my sugestion, process whole at first, getting gold from pins, then break them up not powder, process to get more gold from wires, last powder them and get a lil more, as steve says the powder is hard to deal with. get as much base metals from pins as you can before trying to dissolve the gold.

 

[Harold_V]

Rinse with hot water, back into a small amout of Muratic acid as a final check to make sure that any last base metal is gone then into HCl +Cl to dislove the gold.

I'm impressed! Someone actually dealing with the base metal first! My hat's off to you, oldtimer. 8)

Harold

 

[DNIndustry]

So let me ask before trying,

if you try this with ceramics that have been de-lidded and still have 80/20 solder on them, will it make a mess?

 

[zamistro]

So let me ask before trying,

if you try this with ceramics that have been de-lidded and still have 80/20 solder on them, will it make a mess?

Good question!

 

[butcher]

Tin and nitric is trouble. if going nitric route remove solder first.

with Acid Peroxide (muratic and H2O2) tin from the solder will go into solution, as long as not saturated (too little solution for metals), it wont be much trouble, the lead chloride is not soluble, will settle, with the gold foils, after base metals are dissolved, a boiling water can remove lead from gold, lead chloride is slightly soluble in boiling water, silver chloride is also insoluble (slightly soluble in acidic solution), silver chloride is not soluble in boiling water, this is how we can seperate silver and lead chloride powders,

I know your not too concerned with silver here, but little more info for later:

If seperating lead and silver chlorides, (a note here), silver chloride will take time to settle in a solution that is agitated (stirred up), and as boiling water creates agitation the silver chloride takes time to settle, keeping the solution hot for period of time after boiling to allow as much silver to settle, and hot enough to keep lead from cooling and crystalizing in solution helps, if alot of chlorides, I repeat this process several times. then silver can be cleaned with household ammonia, (caution here never let ammoniacal silver solutions dry out, they are unstable temperature & shock sensitive DANGEROUS when dry, acid will make them safe),
silver will dissolve, in solution lead will not, after decanting (removing liquid from lead solids, adding HCL to acidify silver solution (makes it safe), precipitates silver as a chloride, without the lead (I usually add few drops of HCl to lead also just for good measure ( I save my lead for later uses). silver can be converted with sodium hydroxide and kayro light corn syrup and water, well I am getting so far off subject I'll stop here.

 

[DNIndustry]

who cares about base metals...?

(harold's head starts steaming)


1.2 Liter column. + 1 Liter XAD-7 Resin
Disolve everything Hcl+clo
Match the following details
(2.5 - 4 N free clorine / 80C /-900mV AgCl Vs. KCL/ max 5g Au per L solution/ max 20g Au per L Resin)
turn on the pump
watch TV...
Elute (wash gold off resin
Hcl:acetone-9:1)
Watch TV...
Precipitate (Organic reducer)
Wash
Melt
Sell
Repeat...alot

The details become your standard when the process is setup



Yes I over simplified

 

[qst42know]

who cares about base metals...?

(harold's head starts steaming)


1.2 Liter column. + 1 Liter XAD-7 Resin
Disolve everything Hcl+clo
Match the following details
(2.5 - 4 N free clorine / 80C /-900mV AgCl Vs. KCL/ max 5g Au per L solution/ max 20g Au per L Resin)
turn on the pump
watch TV...
Elute (wash gold off resin
Hcl:acetone-9:1)
Watch TV...
Precipitate (Organic reducer)
Wash
Melt
Sell
Repeat...alot

The details become your standard when the process is setup



Yes I over simplified

Would you mind elaborating on this process you summarized?

A tutorial perhaps?

 

[zamistro]

Ok, I put these in AP until the reaction settled down, then moved it all to a hot plate for a few hours, then let it sit for a few days. Here is the poured off liquid:

Here are the (mostly) stripped pins:

Why didn't the pins come off? They are fimly attached. They are magnetic. Shouldn't they dissovle first?

Does the green mean copper? Do I neutralize and SMB now?

 

[Oz]

If you had to let a cold AP solution settle down you used too much/strong H2O2.

Where did you put the black/brown powder that was in your AP and covering the CPUs that you have washed so well?

 

[lazersteve]

AP reaction takes a few days to complete, not a few hours.


Magnetic legs is a sign of iron and will be slow going with AP.

Iron dissolves well is straight hot HCl or battery acid (35% H2SO4).


Steve

 

[zamistro]

Thank you. As for the green liquid, should I now use urea then drop with SMB?

 

[Oz]

Your stannous chloride test will tell you if there are even PMs to be had. Based on the color I would continue to use it instead of wasting chemicals. Have you read the AP document on lasersteves site? If not, do nothing until you have.

You sound a bit like you are shooting in the dark hoping to hit your target.