# About CPU yield data



## Roberto Aleman

Hi everyone, 

As i wrote on my presentation post, i am working on e-waste precious metals recovery, i`ve been doing several tests to get some yield data of gold in CPU. So far, these are some avarage 24k gold yield i have obtained: 

Green, yellow, brown Fiber (big ones AMD, Intel PIII) : 0.63 g/kg 0.29 g/lb	
Green Fiber (small ones P4, AMD Athlon etc) or with soldered cu heatskin: 0.76g/kg 0.34g/lb
Black fiber with soldered copper heatskin (Intel celeron): working on	-	
Simple Ceramic (AMD): 1.78 g/kg 0.81g/lb
Ceramic black bottom (Intel pemtium):	1.78g/kg 0.81g/lb
Ceramic gold bottom - black top: 3.59g/kg 1.63g/lb
Ceramic black bottom - gold top:	2.53g/kg 1.15g/lb
Ceramic gold bottom - gold top:	4.24/kg 1.92g/lb
Slot processors (PII, etc):	0.47/kg 0.21g/lb
RAM memories: 0.4g/kg 0.18g/lb

These yields are caulculated without Cu or Al heatskin. What do you think about them? are they good or bad yields?. Do anyone know if there is gold inside the ceramic processors? i mean between the ceramic layers?. I did hot cyanide leaching on this tests. what yield should i expect from 1 kilogram or pound of motherboard? 

Best regards!


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## Geo

did you mean to double post?


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## lazersteve

Have you read the thread on ceramic cpus?

Ceramic CPU Discussion

Great work, did you track the silver content in the cpus? 

Steve


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## ericrm

wow im happy that someone gave a tested list. good job
but i think your a bit low on the gold brazed cpu(the one with the square gold under), i think you could think 2-3 g per lbs, i dont have tested yield but i sell them between 125 et 150$lbs 
keep on the good work


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## cnbarr

I agree with ericrm your yields seem a bit low on some of the ceramic cpu's. The cpu's with gold plated lid's, did you process the plated lids separately, or are they included in your yield totals?



> Do anyone know if there is gold inside the ceramic processors? i mean between the ceramic layers?



Some believe there is gold bonding wires in ceramic, I don't believe there is though. Read through the link steve posted above, there is a lot of great info on ceramic cpu's.

Other then that I think your list is a really good starting point for what you've done, good job.


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## Roberto Aleman

Thanks for yours answers, 


> did you mean to double post?


I didnt mean it, sorry, i didnt realize i double posted, but i deleted one post. thanks.



> Have you read the thread on ceramic cpus?


I read it, honestly i got lost, i`ll read it again carefully.



> ... did you track the silver content in the cpus?


I have not tracked it, with cyanide leaching i only get metals on the surface, i get 20k - 23k gold that i refine later, most of the impurities seems to be copper and just a little bit of silver. Silver is in the solder right?, i`ll begin working on silver. 



> Some believe there is gold bonding wires in ceramic..


That´s what i was thinking, rigth now i`m running some tests with pownder ceramic in AR, i`ll post the result. 

I`ll keep working on cpu's with gold plated lid's because i included them in yields totals. By the way, i have already received Hoke`s book that i ordered in US, i havent read it totally, but it seems to be a very good source of information.


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## patnor1011

Can cyanide effectively leach gold braze which is used on lids?


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## a_bab

No cyanide based leach will attack the gold braze.


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## Roberto Aleman

patnor1011 said:


> Can cyanide effectively leach gold braze which is used on lids?


That`s a very good question, i think it can, but it will take much more time. i think thats why i`m not getting good yields on those processors. 

Would you recommend me to process plated lids separately with AR?


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## lazersteve

To recover the silver you must acidify your cemented zinc/gold/silver residues (if you used zinc powder to precipitate) with nitric acid instead of muriatic acid. If you use muriatic your silver will convert to the chloride (silver chloride) and cause filtering issues as well as trap gold in the chloride's structure. 

Many cpus have a high silver content and the cholride can lead to many issues down stream when using cyanide if not properly treated as explained above. I speak from experience when I tell you that if you have a lot of silver in your zinc precipitate along with the gold, you'll have a real headache getting all of your gold out unless you acidify with nitric acid before refining the recovered gold powder. This will be evident as a dark purple soild in your filter papers if using muriatic to acidify the zinc/gold/silver precipitate.

Steve


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## Roberto Aleman

Thanks for the advice Steve. I precipitate metals with zinc powder, i have done two different proceses before melting it: 
1. I filter the precipitate, put it into a oven to incinerate taking care of no losing material, then i melt it with litharge base flux, i obtain a lead bullion and then i put it under cupellation. I enquart the obtained doré with 999 silver, i refine it with nitric, and finally i put it again under cupellation. This is the long way i learned in Starcore Ltd., but it works pretty well when analyzing gold. 
2. I decant the precipitate and i use muriatic as you described, then i do direct cuppellation, refine with nitric and copellation againg. I do this with proper precautions and lab scale. With this process i get 23.80 or 23.95 K gold, analizying it in a xray lab.
That`s why i have not measured or tracked silver, but you give an idea. 

I have not done tests with AR because i think there`s more troubles with managing wastes, but i`ll do some to compare results, especially in ceramic processor where i`m not getting good yields. I keep reading the forum and i have learned a lot.


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## lazersteve

*Safety Note: Adding any acid to cyanide solutions and/or precipitates will produce deadly hydrogen cyanide gas which can kill you in minutes!!! Never add acid to these solutions or precipitates without the proper fume control, safety equipment, cyanide training, and cyanide antidotes for everyone present on hand before beginning. You will likely die if you attempt this without the proper training and precautions.*

This is how I proceed after precipitating cyanide with zinc dust:

Cyanide Clean Up

My cyanide recovered gold after AR processing invaribly shoots a minimum of 999+ on XRF. Proper cooling/dilution and filtration of the AR digestion (until 100% transparent and free of sediment) is key to high purity.

It is very important to use nitric acid to remove the excess zinc dust prior to porcessing in AR.

I've never considered using cupellation for the cleanup of the zinc/gold precipitate due to my typical batch size. I have noticed that cyanide has problems completely stripping ceramic cpus, I've always assumed it was due to the iron (and/or kovar) under the plating on the legs. Silver is a major product of ceramic cpu processing, for this reason it must be dealt with as explained above.

Please keep us posted on your progress and welcome to the forum.

Steve


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## Roberto Aleman

Thats very interesting! Steve. Today i finished the black fiber processor test (cyanide), i got 1.2 g/kg, 0.54 g/lb, it`s almost double than green fiber ones, but still low compared with buying price, i`ll begin doing test with AR and i`ll post my progress.


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## Alentia

Roberto Aleman said:


> Hi everyone,
> 
> As i wrote on my presentation post, i am working on e-waste precious metals recovery, i`ve been doing several tests to get some yield data of gold in CPU. So far, these are some avarage 24k gold yield i have obtained:
> 
> Green, yellow, brown Fiber (big ones AMD, Intel PIII) : 0.63 g/kg 0.29 g/lb
> Green Fiber (small ones P4, AMD Athlon etc) or with soldered cu heatskin: 0.76g/kg 0.34g/lb
> Black fiber with soldered copper heatskin (Intel celeron): working on	-
> Simple Ceramic (AMD): 1.78 g/kg 0.81g/lb
> Ceramic black bottom (Intel pemtium):	1.78g/kg 0.81g/lb
> Ceramic gold bottom - black top: 3.59g/kg 1.63g/lb
> Ceramic black bottom - gold top:	2.53g/kg 1.15g/lb
> Ceramic gold bottom - gold top:	4.24/kg 1.92g/lb
> Slot processors (PII, etc):	0.47/kg 0.21g/lb
> RAM memories: 0.4g/kg 0.18g/lb
> 
> These yields are caulculated without Cu or Al heatskin. What do you think about them? are they good or bad yields?. Do anyone know if there is gold inside the ceramic processors? i mean between the ceramic layers?. I did hot cyanide leaching on this tests. what yield should i expect from 1 kilogram or pound of motherboard?
> 
> Best regards!



Thank you for data posted in a single post. 

Ceramic CPU Discussion is way too long without significant data http://goldrefiningforum.com/phpBB3/viewtopic.php?f=52&t=12845


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## Geo

Roberto Aleman said:


> Hi everyone,
> 
> As i wrote on my presentation post, i am working on e-waste precious metals recovery, i`ve been doing several tests to get some yield data of gold in CPU. So far, these are some avarage 24k gold yield i have obtained:
> 
> Green, yellow, brown Fiber (big ones AMD, Intel PIII) : 0.63 g/kg 0.29 g/lb
> Green Fiber (small ones P4, AMD Athlon etc) or with soldered cu heatskin: 0.76g/kg 0.34g/lb
> Black fiber with soldered copper heatskin (Intel celeron): working on	-
> Simple Ceramic (AMD): 1.78 g/kg 0.81g/lb
> Ceramic black bottom (Intel pemtium):	1.78g/kg 0.81g/lb
> Ceramic gold bottom - black top: 3.59g/kg 1.63g/lb
> Ceramic black bottom - gold top:	2.53g/kg 1.15g/lb
> Ceramic gold bottom - gold top:	4.24/kg 1.92g/lb
> Slot processors (PII, etc):	0.47/kg 0.21g/lb
> RAM memories: 0.4g/kg 0.18g/lb



the RAM yield seems a little low. is that just the foil weight from the fingers or does it include the chips as well? the last i ran was foils and chips, and it was a little better than 0.25g per pound, and i thought that was low.


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## Alentia

I did 100 Pentium CPU and came up with about the same about 0.8gr per pound.


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## CBentre

cnbarr said:


> I agree with ericrm your yields seem a bit low on some of the ceramic cpu's. The cpu's with gold plated lid's, did you process the plated lids separately, or are they included in your yield totals?
> 
> 
> 
> 
> Do anyone know if there is gold inside the ceramic processors? i mean between the ceramic layers?
> 
> 
> 
> 
> Some believe there is gold bonding wires in ceramic, I don't believe there is though. Read through the link steve posted above, there is a lot of great info on ceramic cpu's.
> 
> Other then that I think your list is a really good starting point for what you've done, good job.
Click to expand...


Removed photo because I can't find the article to go along with it. Don't want people to be misinformed.
Reposted with link to a site that explains about 24k soild gold wiring in ceramic chips. Enjoy. http://www.chipsetc.com/gold-value-in-computer-chips.html


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## NobleMetalWorks

CBentre said:


> cnbarr said:
> 
> 
> 
> I agree with ericrm your yields seem a bit low on some of the ceramic cpu's. The cpu's with gold plated lid's, did you process the plated lids separately, or are they included in your yield totals?
> 
> 
> 
> 
> Do anyone know if there is gold inside the ceramic processors? i mean between the ceramic layers?
> 
> 
> 
> 
> Some believe there is gold bonding wires in ceramic, I don't believe there is though. Read through the link steve posted above, there is a lot of great info on ceramic cpu's.
> 
> Other then that I think your list is a really good starting point for what you've done, good job.
> 
> Click to expand...
Click to expand...


Come on, that picture is not a fair representation at all. That material came from processors that were etched onto a polymer film, they did not come from ceramic processors. If you are going to post a picture like that, explain what it is we are looking at. Your picture is totally misleading. I have no idea if you did it on purpose, or just didn't know but a little more information would be nice so that people are not mislead into believing something about ceramic processors that simply is not true.

Scott


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## Roberto Aleman

I've been working on getting better yields, so far these are the best ones i have achieved after tests and reading several posts in the forum:

Green, yellow, brown Fiber (big ones AMD, Intel PIII) : 0.80 g/kg 
Green Fiber (small ones P4, AMD Athlon etc) or with soldered cu heatskin: 0.76g/kg 
Simple Ceramic : 2.06 g/kg 
Ceramic black bottom (Intel pemtium):	2.06 g/kg 
Ceramic gold bottom - black top: 5.82 g/kg 
Ceramic black bottom - gold top:	2.71 g/kg 
Ceramic gold bottom - gold top:	6.25/kg 
486/386: 7.3 g/kg
Slot processors (PII, etc):	0.50/kg 
RAM memories: 0.32g/kgRam (just from fingers)

I recovered about 80 gr of silver from aprox 7 kg of mixed ceramics cpus, but estimate i could get more. I got these cpu yields using both cyanide and AR proceses on differents parts of Cpu`s. In gold braze AR is definitely the best one.
Right now i'm trying to recover gold and silver from RAM and slot procesessor's flack packs and ICs. Any idea of how much gold and silver should i expect from those? I read that 0.7gAu/kg of RAM chips, but from slot processors? 

Best regards!


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## Alentia

Roberto,

Very valuable data, please keep posting your real outputs.


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## chambersjr

Didn't want to start a new thread as I wanted to compare to the photo posted above by 0T2BNLA. I was quite pleased when I finally popped the small tin/nickel cap on the center of these. I will post photo later of an intact chip if anyone is interested. In comparison to some higher yielding CPUs, am I crazy in thinking these look good?


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## CBentre

From a buyers perspective they look as good as the rest, wish I could help with a refining perspective but unfortunately i'm not the man in that field.


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