removing solder from pins HCI

TEB · Jan 27, 2011

Hello.

I stripped around 20 motherboards to play with, I removed all the pins with a blow torch and other various parts.
As a test i pried out around a handfull of pins from the plastic surrounds, There was still a fair amount of solder left on them. I read the the solder could be removed with HCI so i got a glass jar and pored in some HCI about 20min later ild say most near all the solder was gone. Though the pins look greay with no gold left. So i pulled out a few pins and gave them a rub to see if this was just a surface coating of solder and other metals.
Ild say that it was tarnished with the other metals, though what gets me is it seams that near all the gold has also been stripped, as i can see through it in most places and its nowhere near as shiney.

i dont get it how do i process these pins off the motherboard, and can they be processed in the plastic casings.
Sorry i know this would bound to be on the site though i can find it and am confused.

thanks

patnor1011 · Jan 27, 2011

Not a lot of people process them. It is because all that you encountered in your experiment. It is very labor intensive to cut them off board but it saves you time and chemicals later when you process them. If you use heat gun and desolder them from boards you get a lot of tin on them.
I would try to separate them in two types. You can see that here: http://www.goldrefiningforum.com/phpBB3/viewtopic.php?f=33&t=6169
They are cut out to minimise amount of solder. I can think about two types of extraction. One is gold cell where they will be stripped in copper basket and second is (good for small pins which may not be good for basket) crock pot whith HCl. Your test just showed you how to do that but in order to get values, you need to leave them in HCl for considerable amount of time to have them completelly dissolved. You can speed up that process little bit by using crock pot, and small very small amount of oxidizer like peroxide.
You can use Nitric for dissolving base metals too, do not add HCl as you may create AR and dissolve everything. When you dissolve base metals proceed to incinerate foils and powder to get rid of traces of Nitric and wash with HCl.
Lot of chemicals and time involved but it can be done.
Do not try to process pins with plastic holders in acids as you may end up with big mess as some plastics do not like acid baths :mrgreen:

patnor1011 · Jan 27, 2011

All this is on forum already so if you want to see processes or some yields or problems encountered please do yourself a favor and try to explore this forum. All your future questions were answered at some points and everything is perfectly explained in Hokes book you can download that from my signature. You need to sit down and invest your time in gaining knowledge first if you want to be successfull in this field. There are too many variables involved in processes and you need to gain knowledge to be able to choose the right path to solve any problem which you may encounter.

TEB · Jan 27, 2011

Thankyou for the informaion and the links, i will read it all.
I put them back in the HCI and it is still removing metals showing the gold more, though like you say its a lot of effot for little return.

though im not about to quit, just need more information i guess, cheers for the links again.

lazersteve · Jan 27, 2011

What type of motherboards did you strip? The pins off of PIII and newer motherboards are most likely only flash plated and hence a total waste of your time.

You should look at processing a few hundred grams of fingers as your first test batch, not motherboard header pins.

Steve

TEB · Jan 27, 2011

roughly
1 x 486
4 x p2
5 x p3
8 x p4

after a good look at it today,it seams that like you said its mostly flash plated and very thin. there are a few good ones in there i guess they are from the 486 and p2, i have just over 100gms of these pins so i will just put them aside to i get a lot more and a better understanding.

I have about 100gms of clean fingers of slot cards and if i clean up some of the ram i guess 150gms, though some of the older ram i had is gold printed under the green mask. and the rest is like any other still with a few spots and gold solder for the chips. so i look into these more today.

i tryed to read some of the things that patnor1011 has in his signature though i lost intrest quickley without pictures. I like to get my hands dirty 1st and lean as i go. Steve i think they are you videos i wached and they where great. Vidoes and pictures and good

i might wait to i strip another dozen or two computer before i get anthink worth refining. Ill keep trying though.

lazersteve · Jan 27, 2011

As a learning process you can process a few hundred grams of finger boards in a quart sized mason jar. Make sure the fingers are trimmed close with minimal green board along the cut edge and no tiny spare parts or pins on the boards!

Do this in a well ventilated area away from metals items that can corrode easily.

1. Place the clean fingers in the jar so they stand upright (long ways) and fit loosely (not tightly packed).
2. Fill the jar up to the top of the fingers with 31.45% HCl (muriatic acid) from Lowes.
3. Add two caps full of 3% Hydrogen peroxide from Walmart or your local drug store.
4. Stir the solution with a glass rod to mix in the peroxide.
5. Wait one hour and observe the color of the solution.
6. If the solution is pale light blue repeat steps 3 through 5.
7. If the solution is emerald green, let it sit covered overnight (24hours), stirring occasionally if desired.
8. Using plastic tweezers, remove any finger boards that become 100% stripped of all copper (and gold foils) during the next 24 hours, spraying them off into the solution as you remove them. The foils all should be settling to the bottom of the jar, fight the urge to try to pull them out until you are done. Too much water is not desirable, so keep your rinsing to a minimum.
9. When all of the boards have been stripped, let everything settle and siphon off the liquid.
10. Wash the foils with several rinses of HCl, stirring, settling, and siphoning with each rinse, until the rinse acid is free of color.
11. Wash the foils with two flushes of clean water, stir, settle, and siphon with each rinse.
12. Process the foils with HCl-Cl in the same jar for highest purity.

Post some photos of your experiments and results!

Steve

TEB · Jan 29, 2011

Steve, I have done what you has sugested and run the small batch of finger i had.

There are a few things in the process that i used that i think need changing for future batches, more along the lines of what you have in your video.

Its been about 36hrs and about half of the fingers are 90-100% stripped. There are a few that have not seem to be affected at all though time will run its course and prove everything out for me.

What is happening here?
The solution at 1st turns a pale yellow colour, Knowing that nothing is what it seams when in dulute solutions. Im not ready to jump on saying this is gold though it well could be.
A few of the Pcb's have had the green solder mask removed. so this leads be to thinking that the solutions is at least at a very small scale breaking the surface layers of the Pcb itself, at very least attacking a component used in the mask construction.
(And what reminds me of a plating solution i done with vinagar and hydrogen proxide prity much the same as here. )
The solution is attacking the copper though this is where i kind of start questining everything, Part of this looks as a simple answer where the gold is printed onto a copper layer and the solution is either leaching through the poures of the gold of the pcb or somewhere attacking this layer of copper when this copper enters the solutions the gold simpley flakes away.
The second theory is the gold is in the relm of 70-80% pure and copper is used as the buffing material. the solution is pulling at the copper and each time it pulls a bit of copper it rejects some of the surounding gold from it bond to the metal allowing it to flot away.
Time will show the next questing more though ill put it up now.
if the pbc has the gold directly printed on the pcb with some kind of glue flux and the gold is closer to the 100% pure, the solution has no copper to pull so this does not allow the top two theorys to hold and the gold should stay attached to the pcb, unless it is attacking some type of flux layer. this or the lack of time could explain why some of the fingers look to not be affected.

i havenot documented the experement very well, though will post a few images where the process is finished.

thanks again.

Barren Realms 007 · Jan 29, 2011

TEB said:
Steve, I have done what you has sugested and run the small batch of finger i had.

There are a few things in the process that i used that i think need changing for future batches, more along the lines of what you have in your video.

Its been about 36hrs and about half of the fingers are 90-100% stripped. There are a few that have not seem to be affected at all though time will run its course and prove everything out for me.

What is happening here?
The solution at 1st turns a pale yellow colour, Knowing that nothing is what it seams when in dulute solutions. Im not ready to jump on saying this is gold though it well could be.
A few of the Pcb's have had the green solder mask removed. so this leads be to thinking that the solutions is at least at a very small scale breaking the surface layers of the Pcb itself, at very least attacking a component used in the mask construction.
(And what reminds me of a plating solution i done with vinagar and hydrogen proxide prity much the same as here. )
The solution is attacking the copper though this is where i kind of start questining everything, Part of this looks as a simple answer where the gold is printed onto a copper layer and the solution is either leaching through the poures of the gold of the pcb or somewhere attacking this layer of copper when this copper enters the solutions the gold simpley flakes away.
The second theory is the gold is in the relm of 70-80% pure and copper is used as the buffing material. the solution is pulling at the copper and each time it pulls a bit of copper it rejects some of the surounding gold from it bond to the metal allowing it to flot away.
Time will show the next questing more though ill put it up now.
if the pbc has the gold directly printed on the pcb with some kind of glue flux and the gold is closer to the 100% pure, the solution has no copper to pull so this does not allow the top two theorys to hold and the gold should stay attached to the pcb, unless it is attacking some type of flux layer. this or the lack of time could explain why some of the fingers look to not be affected.

i havenot documented the experement very well, though will post a few images where the process is finished.

thanks again.

HCL will turn yellow when introduced to air. It dosen't mean you have gold in your solution.

The pin's that you seen no reaction on are likely kovar.

Most likely your solution will attack the copper base metal before it attacks the gold plating. And gold is not painted on it is plated onto items.

lazersteve · Jan 29, 2011

If the solution turns dark chocolate brown or black or you see a sediment of gray powder let me know.

Be sure you don't have the finger boards packed too tightly in the jar. The boards tend to shield each other.

If your solution is dark brown, add a 10-20 mL of HCl. Followed by two more caps of 3% H2O2.

I purposely instructed you to use a minimal amount of peroxide to keep you from over doing it and dissolving the gold.

A light blue to emerald green solution is optimal.

Copper chloride can appear yellow in dilute solutions. You need to have stannous on hand to be certain you are not dissolving gold.

Could you post a photo of the results so far?

Steve

TEB · Jan 29, 2011

I think its all working alright. i have another image of the weigh-in though its on the cameras memory and i need the cable. though its just a kitchen scale in increments of 29gms

i dont have any stannous on hand, unless i can make some. ill look into this more. so i will not dispose of anything as yet.

its a dark emerald green colour, i was thinking that some of the fingers where not releasing at all. though after lots of agitation they are comming off. up untill this point i was just stiring every hour as they are tightly packed.

i know everything is crude. though a good test i think.
thinking that at this point i can get my hands on 15-30 computer a week without trying though it would be great to get some good scrap. Ebay seams like its all overpriced and slim pickings. i see most auctions, people wanting around the same price as recovered gold for their wares. so ill probley stick to the computers and wait to i get a good stock pile.

///
colour

everything in the jar

removing and washing the stripped pices

The striped pices there is a flake or two that are not 100% removed though what the hell good enough for this test

the fallen gold of the washed pices

cheers

edit.
if the Tin(II) fluoride show that there is gold in solution, am i correct in thinking if a few small pices of copper are placed in the solution will edventually become staurated with copper sulfide and push out the gold.

lazersteve · Jan 29, 2011

Looks like you are ready for the final clean up with HCl and onto dissolving with HCl-Cl to make the gold chloride solution and precipitate with SMB.

Very good!

Let me know if you want more details on the final steps to your first BB.

Steve

TEB · Jan 29, 2011

i have had to dump a handfull back in to the solution.

Steve thanks for your help, you rock for being so dedicated and helping so many folks out.

Ill watch your video again so it shold be good.

lazersteve · Jan 29, 2011

TEB said:
if the Tin(II) fluoride show that there is gold in solution, am i correct in thinking if a few small pices of copper are placed in the solution will edventually become staurated with copper sulfide and push out the gold.

You were doing so well until you posted this, but I understand your enthusiasm with all this new excitement :lol: .

Please follow along as directed so that you will meet with success and have your first gold BB to show for you devotion and patience. Going through the paces slowly on a small scale will give the insight and confidence to move on to the more complicated scrap types and to apply what you have learned from your earlier observations to succeed with them.

Tin Chloride (aka Stannous Chloride) is what we use to test for gold dissolved in a solution. There is a link to a recipe in my signature line below, we will get to that in due time. No need to think of saturating the solution with copper chloride anytime soon as the emerald green solution you have is reusable as it is with a little additional air.

If you get antsy please take the time to read the Guided Tour Link below to occupy yourself before jumping ahead.

Steve

TEB · Feb 7, 2011

removed to new thread

voeckel · Oct 7, 2012

We are talking about 30+% of HCl concentration. Is there a point where the acid would be too weak to work? I could get here 5L bottles of 20% HCl very cheap (fre of any other ingredients, only HCl and H2O) but i am not sure if it could be used?

If i would multiply the amount of 20% HCl by 1,5, i would get the same amount of substances as the 30% HCl, but what about the excess H2O?

Beginner's question, i know...

Thanks in advance!

Geo · Oct 7, 2012

many members can only get 15% hcl where they live and from what ive read, it seems to work just fine.

patnor1011 · Oct 7, 2012

I can confirm that. Even only 10% and it worked charm.
I try to get at least 15% one and I boil it down to 50% of volume and use it in AR, also without slight problem.

voeckel · Oct 7, 2012

Thanks gents. Any experience with time values? I.e. half the concentration needs three times as long, etc?

just curious but it would complete my picture of what to expect.

By the way, patnor, i saw a thread somewhere where you should two CD/movie download links regarding PMs in Ireland but they were not working anymore. Are these still available somewhere? Can't find the post anymore.

patnor1011 · Oct 7, 2012

You probably mean gold in ireland cd, I do have it somewhere and when I find it I will upload it somewhere.

removing solder from pins HCI

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