# PCI slots processing



## kjavanb123 (Sep 18, 2012)

All,

Just wanted to start a threat regarding PCI slots. As I noticed in my batch they consisted 10.9% of the motherboard weight. So after depopulating 2 Chinese made motherboards ( colorful boards ). Here is the scope;




Motherboards combined weight = 1100 grams
PCI slots weight ( 10 pieces of them from 2 boards ) = 120.39 grams
Pins weight removed from 10 PCI slots = 31.57 grams

Therefore,
PCI slots weight percentage to the boards weight = 120.39 / 1100 x 100 = 10.94%

Also it took me 6 mins to remove the pins from each of the PCI slots. So time spent 1 hr.

Now, I have used the following methods on a trial batch and was wondering which one would be recommended on such a small scale amount of pins.

1. Hcl method, where pins are heated in muratic acid for 2 hrs, decant, rinse with water, then incinerate, follow by dilute nitric leach to remove the remaining base metals, filter, and proceed to HCL/Cl leach for gold and drop.

2. Dilute sulfuric acid method, where pins are put into a 1:10 sulfuric: water solution for few hrs to completely dissolves tin / leads, incinerate, follow by dilute nitric bath.

Tried the HCl method, and after incineration and dilute nitric bath still some white powder remained, using sulfuric method, all the tin were dissolved prior to incineration and further leaching.

Regards,
Kevin


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## maynman1751 (Sep 18, 2012)

Actually a sulfuric cell would be best. I wouldn't waste nitric on such low grade scrap.


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## mjgraham (Sep 18, 2012)

I don't exactly remember who's post it was but the fellow yanked the plastic off the PCI slots while still soldered on the board then turned it upside down and heated the area whith the pins on there and pecked it and they fell out. I know you can rip the plastic off but I was using a wood chisel just to shear them off. Either way there is a little cleanup sometimes with extra parts getting removed but it might be faster than pulling the pins out of the socket after you unsolder them.


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## patnor1011 (Sep 18, 2012)

Another person just did nearly the same. They removed plastic housing, cut out piece of board with chips attached and applied extra solder on other side, to make them all to be connected together. Then deplated in cell and after that melted solder from bottom part again to be used on another one.


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## Marcel (Sep 18, 2012)

mjgraham said:


> I don't exactly remember who's post it was but the fellow yanked the plastic off the PCI slots while still soldered on the board then turned it upside down and heated the area whith the pins on there and pecked it and they fell out. I



Hehe, maybe I was that one?

This is how I usually do it:
Part 1 : Preparation
[youtube]http://www.youtube.com/watch?v=2M08A1Eexo4&feature=plcp[/youtube]

Part2: Desoldering the pins
[youtube]http://www.youtube.com/watch?v=IzpZKSEwefc&feature=plcp[/youtube]

It goes very fast. As you can see, these are uncut real time vids. And It takes me about 15 Minutes to strip that board completely including the seperated pins from the PCI slots.


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## jimdoc (Sep 18, 2012)

http://www.youtube.com/watch?v=2M08A1Eexo4&feature=youtu.be

http://www.youtube.com/watch?v=IzpZKSEwefc&feature=youtu.be


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## ericrm (Sep 18, 2012)

sorry to ask but... any kind of yield on that material?

or if there is no already tested number, i have 389g of those pins availlable(removed by heat and plyers) ,that i dont have a way to test miself in my curent situation (i dont have acces to clean nitric yet)or they could be sended to a trusted member who has acces to nitric acid and is willing to work basicaly for free?


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## samuel-a (Sep 18, 2012)

ericrm said:


> sorry to ask but... any kind of yield on that material?



0.05% or less..


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## patnor1011 (Sep 19, 2012)

I was told 1/2g from a kilogram. When I harvest them I try to cut them as close to area which is plated as possible. Normal scissors work just fine, well for a while at least


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## Marcel (Sep 19, 2012)

ericrm said:


> sorry to ask but... any kind of yield on that material?



Sorry to say that, but I have removed several kilos of this stuff (Looks like pins from slots and memory sockets), I used AP and even had it tested in lab. The 
gold and palladium content was 0,5%. This complies with my observations from AP tests.
3XXg is really nothing concerning yield.
Here in europe/germany you can put it up on ebay and sell it for around 30€/25 USD.
..to someone who has not read this thread and still believes he would get out more.
Other than that, you need enourmous amounts of material and the best way to process would be a reverse electroplating cell as shown here on this forum.
I have not tested this yet, but due to the amount of +98% base metals, nothing else makes sense to me.
If you are fast you can harved around 500g a day of these pins. 
But if you are using a cell, you could also just desolder the sockets without prior removal of the plastic. Then maybe you can harvest 1-2Kg a day.


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## ericrm (Sep 19, 2012)

samuel-a said:


> ericrm said:
> 
> 
> > sorry to ask but... any kind of yield on that material?
> ...



samuel-a, do you mean 0.0005 x 454g = 0.227g by lbs?

that would make them worth about 15$ lbs minus time and chamical...



kjavanb123 said:


> All,
> Motherboards combined weight = 1100 grams
> PCI slots weight ( 10 pieces of them from 2 boards ) = 120.39 grams
> Pins weight removed from 10 PCI slots = 31.57 grams
> Kevin



that would make a value of 0.40$ by mobo...... that is very disapointing once again it shows that mobo are for professionnal refiner...


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## patnor1011 (Sep 19, 2012)

They are Eric. We just cherry pick best parts from there.


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## kjavanb123 (Sep 19, 2012)

All,

Great seeing so many responds.



> The
> gold and palladium content was 0,5%. This complies with my observations from AP tests



vs.


> Samuel 0.05% or less by weight



so which one is correct? I mean it makes a big difference. Please confirm. As I was trying to find an estimate of gold on each components from a Chinese made board which they claim use as much as 1/3 of the precious metals used in green mobo.

If there are not enough precious metal inside the mobo then why are being traded? So I presume there is some profit that they are being traded even without the CPUs and memory cards and etc. I guess 0.1 grams of gold can be extracted from all components on mobo without the CPU and cards. 

Marcel,

Thanks for your videos, great help.

Regards,
Kevin


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## Marcel (Sep 19, 2012)

I have to correct myself, sorry. It is not 0,5% !
0,05% return is more realistic.
I melted some ingots made of these contacts.
The volume will shrink by around 10%-20%.
XRF showed 0,1% -0,2% Au and Pt.
So let´s say a theoretical average is 0,15%.
But from 0,15% to 0,05% is not really that far, remember, the figure is from an XRF. If you recover, there are losses.

Btw. I used notebook motherboards. Those contacts yield slighly higher than PC mobos. But the total weight is also lower.
PC mobo: 70g (including contacts from all interfaces)
notebook: 30g

One funny thing:
Here a scrap motherboard costs around 6 €.
0,15g of gold are worth ---- 6€!

So it´s only worth the trouble if you collect the tantals, the MLCCs, the northbridge and some other stuff and process or sell it later. Just for the gold it would not pay off.


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## samuel-a (Sep 19, 2012)

Eric,
you got your answer


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## kjavanb123 (Sep 20, 2012)

The boards tested here costs $4 / kg so they are like $2 per piece of motherboards. I would assume each board would have at least 0.1 grams of gold in all components combined. so that is $5.6 of gold alone in each board. I just cut all components for 2 Chinese made boards, and try to find out total gold values using a sulfuric cell, will post results.

Regards,
Kevin


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## ericrm (Sep 20, 2012)

kjavanb123 said:


> The boards tested here costs $4 / kg so they are like $2 per piece of motherboards. I would assume each board would have at least 0.1 grams of gold in all components combined. so that is $5.6 of gold alone in each board. I just cut all components for 2 Chinese made boards, and try to find out total gold values using a sulfuric cell, will post results.
> 
> Regards,
> Kevin


what lead you to get that conclusion about the 0.1g of gold in a motherboard? do you have proof to back it up?
if you have that would be awsome :mrgreen:


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## kjavanb123 (Sep 20, 2012)

ericrm said:


> kjavanb123 said:
> 
> 
> > The boards tested here costs $4 / kg so they are like $2 per piece of motherboards. I would assume each board would have at least 0.1 grams of gold in all components combined. so that is $5.6 of gold alone in each board. I just cut all components for 2 Chinese made boards, and try to find out total gold values using a sulfuric cell, will post results.
> ...



I have collected all the pins with some gold plating from 2 motherboards, waiting for my sulfuric cell components to be assembled and used to process each individual batch containing gold plated pins from slots. will post pictures and estimates once is completed.

Regards,
Kevin


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## Chirou (May 13, 2019)

Hello everyone. I got few older motherboards. And i'm trying to get everything with gold i can from them but i have to admit that if there's gold in PCI and memory/AMD CPU sockets i can't see it no matter how hard i look. I appreciate your knowledge and i'm grateful that you guys are sharing your experience with beginners like me who got only 1.65g so far. 
I decided to just junk these pins back and forth until they break ^^ it seems like theres no gold plating down near the solder (if i'm wrong please correct me). I guess i will have to boil them in HCL anyway to get away some potentional tin. But it should be ok i think. But i'm not sure after reading abot yelds that you guys mention.


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