Mixed Pins With Acid Peroxide

[Tzoax]

I just wanted to share my experience with processing computer/laptop/telecom pins with A/P method as this is my first time doing it. this is 400 grams of mixed pins. They are all barely magnetic - copper / brass / bronze based pins. As the matter of fact i haven't found ever kovar based pins in computers (not including CPU pins). There are also jumper pins. AUGAT pins are not included.

This is my setup - aquarium air pump (Tetra APS 150) with aquarium air curtain, 5l basket, HCl concentration 16 percents and 3 percent H2O2.

I added total of 300ml of H2O2 (not at once), i started with small amount with HCl and H2O2 and when Copper II chloride formed i added more HCl (which diluted solution color) then i added more H2O2, and so on.
The Copper II chloride slowly started to paint the solution in green color. This is the progress by days.




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[Tzoax]

I filtered the foils several times so far (just for curiosity)...


And i started to accumulate the foils in a beaker.

Pisture of what was left in a filtered basket after 10 days.


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[Tzoax]

Some more pictures of filtering...




Picture of remaining pins...


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[Tzoax]

Magnified view of foils.

I filtered once again...


And i saved foils again in a beaker.



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[Tzoax]

I decided to refine the gold foils that i have so far...




After washing a gold powder...

It is 0.3g of gold so far. Now it is day 16 and there are a lot more visible foils floating in a solution. I like this process, i haven't got any problems so far (considering there are all types of mixed pins (not including kovar based)). I hope you like the pictures.

 

[kernels]

I really love your posts, always very interesting to see what you are doing !

I've just processed about 400g or so of pins from PCI sockets from motherboards, they are a bronze pin with nickel plating and a bit of gold where they make contact with the PCI card. I found that just leaving them in HCl for a few days worked great. The HCl attacked the nickel which then separated the gold from the pins. It was then just a matter of filtering the gold from the pins using a standard kitchen sieve. I haven't refined the gold yet, but it was nice that I could get the gold by using a comparatively small amount of acid.

I also now have many kgs of BGA packages from RAM modules, looking forward to getting an incinerator built to run them!

 

[Tzoax]

Thank you kernels!

I haven't tried to process that kind of pins, but in my case i will dissolve all base metals to make sure i got all the values since it is possible that some of the gold cemented back (because of H2O2 addition). And the second reason is that there are many kind of pins still having visible gold plating on many of them. Don't forget to soak small BGA chips in HCl to remove tin before / if you are using nitric acid or AR later to avoid loss of gold.

 

[upcyclist]

Looks good!

Two things to consider. First, consider letting the bubbler do it's magic after you kickstart the reaction with hydrogen peroxide. That will cut down on dissolution/cementation of gold. We don't use starter fluid after the car is running Not as important for pins, but can be important later on with chips, where the gold might cement inside the chip. Second, consider incinerating your filter papers--that way you'll use less acid (none needed to consume the filter paper).

 

[Tzoax]

Thank you upcyclist!

I started with a small volume of HCl and H2O2. When copper II chloride formed, i added more HCl - the green solution becomes barely colorless , so i added some more H2O2, and so on, until the color was like on the picture above (barely green, the first picture of basket with solution). That was because i needed at least 3 liters of HCl (because it was not concentrated). I could done it at once, but i decided to do it this way, gradually adding HCl and H2O2. So, for better understanding, my car didn't startup at once, it needed several attempts to kick off. :lol:

I could burned the filter papers, but i didn't because there was possibility that wind would blow away the ash containing the gold foils, and because there must be all burned to white ash, carbon would absorb some gold later in AR (i don't have experience wit torch). This way, i used a little more of acid but i'm sure i washed (with water) and squeezed any little solution left (in the remaining of the filters/pulp).

 

[kernels]

Thank you kernels!

I haven't tried to process that kind of pins, but in my case i will dissolve all base metals to make sure i got all the values since it is possible that some of the gold cemented back (because of H2O2 addition). And the second reason is that there are many kind of pins still having visible gold plating on many of them. Don't forget to soak small BGA chips in HCl to remove tin before / if you are using nitric acid or AR later to avoid loss of gold.

Hi Tzoax, for soaking the BGA packages prior to incineration, will cold HCl work, or will it be better to heat / boil ?

 

[Tzoax]

Thank you kernels!

I haven't tried to process that kind of pins, but in my case i will dissolve all base metals to make sure i got all the values since it is possible that some of the gold cemented back (because of H2O2 addition). And the second reason is that there are many kind of pins still having visible gold plating on many of them. Don't forget to soak small BGA chips in HCl to remove tin before / if you are using nitric acid or AR later to avoid loss of gold.

Hi Tzoax, for soaking the BGA packages prior to incineration, will cold HCl work, or will it be better to heat / boil ?

it will be faster if you boil, if you are not in a hurry you can soak them in HCl. Either way, it is done when tin from solder balls disolves in HCl solution. You can observe and conclude when it is done. Also, there will be some silver and gold in this solder balls, so expect some of the powders settled on the bottom, and save them with filtering, after that, I would incinerate everything -chips + filter paper with values and continue the procedure.

 

[Barren Realms 007]

Thank you kernels!

I haven't tried to process that kind of pins, but in my case i will dissolve all base metals to make sure i got all the values since it is possible that some of the gold cemented back (because of H2O2 addition). And the second reason is that there are many kind of pins still having visible gold plating on many of them. Don't forget to soak small BGA chips in HCl to remove tin before / if you are using nitric acid or AR later to avoid loss of gold.

Hi Tzoax, for soaking the BGA packages prior to incineration, will cold HCl work, or will it be better to heat / boil ?

it will be faster if you boil, if you are not in a hurry you can soak them in HCl. Either way, it is done when tin from solder balls disolves in HCl solution. You can observe and conclude when it is done. Also, there will be some silver and gold in this solder balls, so expect some of the powders settled on the bottom, and save them with filtering, after that, I would incinerate everything -chips + filter paper with values and continue the procedure.

Boiling does not really help.

 

[Tzoax]

Thank you kernels!

I haven't tried to process that kind of pins, but in my case i will dissolve all base metals to make sure i got all the values since it is possible that some of the gold cemented back (because of H2O2 addition). And the second reason is that there are many kind of pins still having visible gold plating on many of them. Don't forget to soak small BGA chips in HCl to remove tin before / if you are using nitric acid or AR later to avoid loss of gold.

Hi Tzoax, for soaking the BGA packages prior to incineration, will cold HCl work, or will it be better to heat / boil ?

it will be faster if you boil, if you are not in a hurry you can soak them in HCl. Either way, it is done when tin from solder balls disolves in HCl solution. You can observe and conclude when it is done. Also, there will be some silver and gold in this solder balls, so expect some of the powders settled on the bottom, and save them with filtering, after that, I would incinerate everything -chips + filter paper with values and continue the procedure.

Boiling does not really help.

Thank you. Heating the solution of HCl (when disolving tin) would work about the same when heating to point just below boiling then. Plus that way is a bit safer way. Kernels, If you don't have much experience I suggest that you just soak the chips in cold HCl, it works well either, it just needs more time.

 

[kernels]

Absolutely, I've got a small sample soaking in cold HCl in a beaker now. When my heat pad is free, I will run a second sample heated to about 60 degrees C or so to compare the speed. I know that when making Stannous the reaction is much faster with a bit of heat, so I assume it will be similar for the solder balls.

 

[Barren Realms 007]

Absolutely, I've got a small sample soaking in cold HCl in a beaker now. When my heat pad is free, I will run a second sample heated to about 60 degrees C or so to compare the speed. I know that when making Stannous the reaction is much faster with a bit of heat, so I assume it will be similar for the solder balls.

Heating is fine but boiling is totally uncalled for and not necessary and dangerous.

 

[kernels]

Hi Tzoax, have sent you a pm :mrgreen: