Problems with gold plated computer pins

[Maggies1dad]

Good morning to all !

I am a new member to your forum and my user name is Maggies1dad. I am a 71 year old senior who has recently gotten interested in recovering gold from scrapped computer components. After going through open heart surgery this past February to have my defective aortic heart valve replaced with an organic pig valve, I am no longer to be as active as I once was which is why I have decided to get myself involved in a hobby that will not require any extreme exertion upon my heart, but a new hobby that will keep the old brain active.

Recently, I had purchased several computer panels from scrapped military computers and the panels or boards were loaded with gold plated pins. Several days ago, I spent several hours pulling the pins out of the board and once done, I had realized that I ended up pulling a total of 4800 pins ! Anyway, when carefully looking at the gold plated pins, I could see a thin layer of silver solder upon each pin and the solder was located half way into the length of each pin where the pins had been affixed to the top side of the panel as well as the pins had passed through small holes in the board so that the pins could project out of the back side of the board.

Realizing that the gold plated pins are partially coated with silver solder, I am wondering if any of you fine gentlemen can give me a helping hand by passing on some good information to me about how I can chemically remove or recover the gold from the gold plated pins, perhaps by using a chemical electrolyte with a 12 volt power source, that will remove the gold plating that is on the pins without the silver solder getting into the gold solution ? In other words, is there a method to recover the gold without the silver solder interfering with the process ?

In closing, I thank you a million in advance for any helpful information that you may pass onto me ! With this said, I send my best regards to all and wish for you all a great day !

 

[jason_recliner]

Welcome to the forum.

Do you know the solder is actually silver, or it is just silver in colour?

 

[lanfear]

If this is high yielding pins you should dissolve the solder. Molten tin will absorb some of the gold from the pins.

Jon

 

[etack]

Welcome to the forum.

Do you know the solder is actually silver, or it is just silver in colour?

Also is it solder at all it could be a non plated part. That was done in Nortel back planes and in AT&T back planes. I have a 2' reel of pins from AT&T that are plated only on the ends.

Eric

 

[patnor1011]

What is total weight of your pins?

 

[Maggies1dad]

At this time, I cannot guarantee that the solder is silver solder, however; it has a raised area toward the center of the pin whereby that area of the pin isn't simply bare uncoated metal, but I remain to think that it is silver solder.

 

[Maggies1dad]

Lanfear, thank you for your reply. Actually, I thank all of you for your replies, but I am trying to figure out how to respond to each one of you individually ?

Anyway, Lanfear, how can I dissolve the solder without dissolving the gold or altering the gold plate upon the pins ?

 

[lanfear]

The gold will be trapped or alloyed with the tin. Not shure about that so feel free to correct me. But the solution is simple. Dissolve the tin in HCl and the gold will drop as fine powder. The rest of the gold plating will be intact. But make shure that there really is gold plating under the solder. Can you see any plating under the solder point?

Jon

 

[4metals]

The gold plating will partially or completely alloy with the tin depending of the gold thickness. The gold forms Gold Stannate Au4(SnO4)3 with the tin and you will never get to the smooth gold underplate that you see on the rest of the pins, the gold is alloyed in the tin.

Hydrochloric treatment will remove the tin and leave you with a fine gold colloid which may take a long time to settle. Plus it will not respond to stannous chloride to indicate the presence of gold because it already did when it alloyed. The gold on the balance of the pins will be unaffected by the Hydrochloric treatment and will be recoverable by your method of choice.

Gold was a common contaminant of solder pots used in the soldering of gold plated connectors and when it built up high enough there were problems with brittle solder joints. Years ago we used to get in blocks of solid, gold contaminated solder for refining. We made it into fine shot and dissolved it in hydrochloric acid and cheated and spun the liquid in a centrifuge to "help" the gold settle quickly. If I remember correctly there were only a few ounces in a 15 pound block of solder, and God knows how many connectors were soldered to get it up to that level.

So what I'm saying is 4800 pins may not even have a gram of gold contained in the colloidal suspension from dissolving the solder layer. Most of your gold is on the remainder of the pins.

 

[patnor1011]

What is the weight of them? 1 pound, or more?

 

[macfixer01]

Lanfear, thank you for your reply. Actually, I thank all of you for your replies, but I am trying to figure out how to respond to each one of you individually ?

Anyway, Lanfear, how can I dissolve the solder without dissolving the gold or altering the gold plate upon the pins ?

Maybe to start with... If you still have a board you haven't pulled pins from yet, can you post a picture showing where the pins go through the board? Or if nothing else post a close up picture of some of the pulled pins? If these are wire-wrap pins that were only press fit into the board, then you are looking at a non gold-plated area of the pins and it's not solder. If the pins were soldered into the board you'd see a filleted area right where the solder flowed in between the pin and the pad on the circuit board. Also you couldn't likely just pull them all out, either many would break in the process or you'd probably have to cut them off above and below the board.

 

[Maggies1dad]

Gentlemen, being that I am not certain about properly replying to you for your kind, helpful messages, I am sending this message with hopes that all of you who have helped me will receive this message of mine !

I have read all of your messages and I will go back to look at another board that I have which has not had pins removed from it. As for the pins that I have already pulled, I am going to place them into a glass container with sulfuric acid in it and my anode and cathode will be copper and stainless steel. Once that I make the electrical connections, I will see if the process will take the gold plating off the pins, followed by getting back to you to give you the results.

Thanks a million, guys !

~Doug~ (Maggies1dad)

 

[kurtak]

As for the pins that I have already pulled, I am going to place them into a glass container with sulfuric acid in it and my anode and cathode will be copper and stainless steel.

You don't just put the pins in a glass container & than add a piece of copper (for the anode) & a piece of SS (for the cathode)

It needs to be set up as a "cell" meaning you have an anode & a cathode in an electrolyte with a "give" space between the anode & the cathode - concentration of the electrolyte plays a part as well

In a "parting cell" - metal parts from the anode to the cathode - meaning the metal you want to take away from needs to be your anode - in this case that means your pins need to be the anode

In a sulfuric cell this is done by making an anode "basket" with a copper mesh screen which you then put you pins in & then make your positive connection to the copper mesh basket

You need to do A LOT more research before you go jumping in to doing this --- Start by using "sulfuric cell" as search words & read all you can before going any further

As a beginner I suggest that you start by using the AP (acidic peroxide) method to recover your gold as foils & then HCl/Cl to refine the foils --- there is a ton of info on this forum about AP recovery & HCl/Cl refinement & those processes are much safer for the beginner --- you have MUCH to learn before you start processing --- research is your friend here - start by putting A LOT of time into that before you start doing anything

Have you down loaded & read Hokes book yet :?: --- if not you will find it in FrugalRefiners signature line (bottom of ALL his postings) --- it is a MUST READ

Kurt

 

[patnor1011]

Gentlemen, being that I am not certain about properly replying to you for your kind, helpful messages, I am sending this message with hopes that all of you who have helped me will receive this message of mine !

I have read all of your messages and I will go back to look at another board that I have which has not had pins removed from it. As for the pins that I have already pulled, I am going to place them into a glass container with sulfuric acid in it and my anode and cathode will be copper and stainless steel. Once that I make the electrical connections, I will see if the process will take the gold plating off the pins, followed by getting back to you to give you the results.

Thanks a million, guys !

~Doug~ (Maggies1dad)

You may want to reconsider your decision. It is not worth to start messing with concentrated sulfuric acid without a clue of what is going on. Mainly for a handful or 2 of pins which will return significantly less than you expect.
It is not a "hobby" what you are going to do. You are talking about hardcore adrenaline "sport" where without proper training accidents are guaranteed.

 

[DC Willi]

You may want to reconsider your decision. It is not worth to start messing with concentrated sulfuric acid without a clue of what is going on. Mainly for a handful or 2 of pins which will return significantly less than you expect.
It is not a "hobby" what you are going to do. You are talking about hardcore adrenaline "sport" where without proper training accidents are guaranteed.

Absolutely correct! I"JUMPED" into wet ashing IC chips and it went horribly wrong in every way possible! After several small burns and a sore throat I did recover some gold bond wires that I proceeded to lose somewhere in my backyard🤦🏼‍♂️. Definitely do your research and most definitely use proper protective equipment.

 

[Yggdrasil]

Absolutely correct! I"JUMPED" into wet ashing IC chips and it went horribly wrong in every way possible! After several small burns and a sore throat I did recover some gold bond wires that I proceeded to lose somewhere in my backyard🤦🏼‍♂️. Definitely do your research and most definitely use proper protective equipment.

Welcome to us.

So you can continue your studies, I add some links.
Pay especially attention to safety, waste treatment an C.M. Hokes book.

We ask our new members to do 3 things.
1. Read C.M. Hokes book on refining jewelers scrap, it gives an easy introduction to the most important chemistry regarding refining.
It is free here on the forum: https://goldrefiningforum.com/phpBB3/viewtopic.php?f=54&t=19798
2. Then read the safety section of the forum: https://goldrefiningforum.com/forums/safety.47/
3. And then read about "Dealing with waste" in the forum: https://goldrefiningforum.com/threads/dealing-with-waste.10539/

Suggested reading:
https://goldrefiningforum.com/forums/the-library.101/
https://goldrefiningforum.com/threads/when-in-doubt-cement-it-out.30236/
https://goldrefiningforum.com/threa...le-read-this-before-you-post-about-ore.33333/


Forum rules is here.
https://goldrefiningforum.com/threads/gold-refining-forum-rules.31182/

 

[Shark]

Wet ashing without proper lab set up is a death wish. With a proper lab setup it is just extremely risky.

 

[MvK]

Yes, read up on the topics @Yggdrasil provided you. Collect your safety gear before you even think of a sulfuric cell and make sure you dont expose skin while handling it.

I also like to 'play' with the sulfuric cell but while in operation i treat it like a bomb that can go off any time. Slow movements, no splashing, no overloading. Face mask, gloves, coat and fume hood where i hide my face behind glass. Also a emergency spill kit so you can clean up fast IF it goes sideways. Dont play around because you will find out! Sulfuric is nasty stuff, but the cell is worth it to run if you have enough material to process.
I like it because it creates less waste to deal with and you can run it for a long time until you get to the refining part.

Anyone can toss metal in acid and create a mess. Dont be that guy and take your time to learn. But i think you are on the right track