cpu lids

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geonorts

Well-known member
Joined
Aug 18, 2009
Messages
92
Location
Australia
Just thought I would post this to see if anyone wants to do the math for me. These are the lids from the ceramic cpus, surface area is 16x25 cm (6.30x9.84 inches), double sided, thickness would vary a bit as they are from different years and modelsbut a rough estimate would be nice. So if there is someone that would enjoy doing the math could you let me know how much gold there would be on these that would be great. I would also be interested in seeing the calculations if you could post them.
Thanks in advance.
16x25cm.jpg
 
Those lids may vary in plating thickness anywhere from flash plating to 40 micro inch....
you can take an estimate at around 30 micro inch.

Assuming 30 micro inch at 124 sq.inch, you have there a tid less then 0.5 grams.


a simple search will help you find calculations
 
Last year I recieved a load of equipment that contained several hundred ceramic processors,mostly i860's.The average from all of the lids I processed came out to about $5.25 per lid,that was at $940/oz. spot.(82% paid out)
That equates to .202 grams per lid.However you should know that all 860's were mil-spec cpu's.
But if you extracted .15gr per lid(25% less) you are still looking at just over 12 grams of 24k.
I see a few 486 and K-7 lids in there,so you should be pleased with the result.
Please remember though I am only going on my yields.If these are "modern" or scraped up really bad,the yield will be significantly lower.
Let us know what you end up with.
 
:shock: This is quite a ballpark we're playing on here. I would be very curious to know the end results too!
 
Many years ago, we ran several hundred pounds of unused lids that had a Au/Sn solder preform attached. They ran close to 1 oz/pound. If you remove the lids with heat, about half of the solder stays on the package sealing ring

The value depends on how much, if any, Au/Sn solder is on the lid. The solder could be worth far more than the plating.
 
goldsilverpro said:
Many years ago, we ran several hundred pounds of unused lids that had a Au/Sn solder preform attached. They ran close to 1 oz/pound.
I think frank told me that is what he got also (per pound) from his,a couple of months ago.Unfortunately I don't have a weight from the ones I ran,so I couldn't give a yield based on weight.Sorry.
 
goldsilverpro said:
Many years ago, we ran several hundred pounds of unused lids that had a Au/Sn solder preform attached. They ran close to 1 oz/pound. If you remove the lids with heat, about half stays on the package sealing ring

The value depends on how much, if any, Au/Sn solder is on the lid. The solder could be worth far more than the plating.
Since it sounds like a lot of the values are in the solder/braze (thanks GSP)
To focus on getting ALL the solder from CPU's with attached lids:
1) if lids are removed from CPUs via torch & processed in the sulfuric cell, would the solder/braze de dissolved along with the gold plating?
2) If CPUs were broken, not crushed, with lids still attached, & processed with 50/50 nitric, would that dissolve the solder braze better?
 
Thanks steve, looks like they will be worth doing I might try your acid method as opposed to building the sulphuric cell, that was the main reason for my original question, (to see if it is worth building one for these)
 
Okay it took me a while to get round to doing it but I finally finished.
I processed using Steves acid method for lids, multiple soaks in HCL this lifted some of the foils but impatience got the better of me and after weeks sitting and changing the HCL I used H2SO4 (runaway reaction be careful) but it needs the heat, this lifted the rest of the foils and removed most of the base metals. Note: there was no solder on these lids. Twice refined with acid washes and fine filtration.

Lids:
81 various lids
133.83 grams of lids
124 square inches

Yield:
3.03 grams

That is 0.0374 grams per lid
22.64 grams per Kg
or $1.91 (Australian) $2 (US)

Steve this is similar to your yields for various lids with using your yields I was expecting 3.27 grams

untitled.jpg

mirror finish, first pure one i've done that had no pipe, but thats because it developed underneath

silversaddle1, looks like there wasn't more gold in my ring (3 grams at 9 ct makes only 1.1grams of gold)
 

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