HCL Leach

[rich_2137]

Hi all

Iv'e managed to collect around 350 grams of gold plated pins mostly from CPU's but was wondering if this method can be use on normal header pins, mother board pins, well any sort of pins really? :roll:
The reason i ask is iv'e read and seen a video on the Gold-N-Scrap website but he only uses CPU pins

Thanks
Rich

 

[samuel-a]

rich_2137

Hot/boiling HCl alone is effective for ferrous based pins (CPU's, header... basically anything that stick tightly to a magnet), can loosen the foils in few hours or in even in one, depends on temperature used.

For copper/brass based pins you probably be better using the "crock pot" methode using AP, you can use the AP at ratio of 3-5 parts HCl to 1 part H2O2 3%.
Within several days the foils will come loose. Use the search button to find more info on crock pot method.

Good luck.

 

[rich_2137]

Hi Sam

Thanks for that, your videos are very helpful 8)

Rich

 

[rich_2137]

Hi all
I've just put my first batch on for 3 hours at a low boil and have removed the heat to get the solution back to room temp, will all the foils float? As there is probably only half floating and the other pins I see are on the bottom of the beaker, would they be foils too as the base metals were dissolved?

Sorry for all the questions

Rich

 

[maynman1751]

No, not all the foils will float. Most will be at the bottom of the vessel. Can you tell if ALL the pins are dissolved? What process are you using? The HCl or the AP? Are you working with the CPU pins or the header etc. pins? ( ferrous or non ferrous base metal)

 

[rich_2137]

Hi
Yeah I can see pins at the bottom but not sure if there just foils I'll check them again tomorrow as the solution should of cooled by then.
They were CPU pins in HCL at a mix of 10ml per gram of pins
Thanks
Rich

 

[rich_2137]

Think I've messed up on this one! I drained both solutions through some filters leaving the unresolved pins at the bottom, I then washed the foils and black powder with water until clear.
Then I desided to separate some of the foils from the black powder into another beaker and desolved with HCL/CL which turned green and not yellow, could this be traces of copper???
So after that I also desided to do the same with the foils and the black powder which also turned a darker green, but here's the part that went wrong not sure why I did it I desided to add the darker green solution to another beaker that I had desolved some foils from RAM fingers in which was! a nice yellow colour but as soon as I added the solutions together it went brown and merky and when I came home from work it looks like it has precipitated the gold??
I'll post pics as soon as I can

Thanks
Rich

 

[rich_2137]

This was just the foils green not yellow like the next pic

This was my nice yellow solution from Ram fingers

and this is what happened to the solution when mixed

If anyone can shed some light into what has happened would be much appreciated
Thanks
Rich

 

[nickvc]

Rich the green is from base metal contamination, don't worry you can still precipitate your gold it might not be as clean as you would like but Harolds rinsing process will work wonders or else re refine your gold.

 

[maynman1751]

As long as there is base metal (pins) not all gold will be dissolved. It will cement to the base metal, so don't throw away the undissolved pins just yet. Like Nick said, you can still drop the gold from solution, but it will probably need refined a second time. Your just having the same problems we all have at the start. Nothing that can't be fixed. Stick with it and you'll learn and if you need help along the way your at the right place.

 

[Geo]

i work with solution that is much more green than that many times. it is preached on the forum, and rightly so, remove base metal first. after you become more experienced and know how to deal with contaminated solutions you will find it a helpful tool to be able to take some shortcuts sometimes.

 

[rich_2137]

Thanks guys hopefully I'll get the hang of it soon, I tried precipitating the green solution in the 1000 ml beaker with SMB but the solution didn't turn clear and then darken it seems to stayed the same colour I'm guess it will take longer to drop the gold as it's dirty solution?

Rich

 

[maynman1751]

Important! Make sure that you test any solutions with stannous. That will tell you what is or what is not there.

 

[rich_2137]

What do you think the brown sediments are in the bottom of the beaker? As there was only small amounts of black powder that went in with the clear solutions?

Rich

 

[Geo]

i didnt see any in either the green or yellow solution. did it precipitate out when you combined the two or did you add it separately? it could be just about anything. do not precipitate your gold in the container with these solids. decant solution of the solids and lightly rinse with a spray bottle and decant to your solution leaving solids behind. now filter your solution in another beaker and rinse your filter into the beaker. you can test the solids by trying to dissolve a little in hcl/Cl and test it with stannous chloride. after you precipitate your gold from solution and test to be sure no gold remains, add a pinch of salt to see if any silver precipitates.

 

[rich_2137]

Hi Geo
There was another beaker with some foils in but it also had the black powder from the CPU pins, not actual pins but little black deposits, so I desolved the foils using hcl/cl and it went a really dark green but as soon as I added the dark green solution to the yellow one thats when it turned murky brown and when I returned from work it was like it is in the picture :|
Rich

 

[Geo]

im not going to say it is, but the way it reacted sounds like it could be silver. like i said, try to redissolve it and see what happens.if it doesnt dissolve in hcl/Cl then incinerate and try a little nitric acid.

 

[maynman1751]

Geo, would high levels of base metal in solution cause gold to cement out of solution?

 

[Geo]

only if there are solids present. base metal already in solution will not normally cause gold to precipitate like that.

 

[Harold_V]

Hi Geo
There was another beaker with some foils in but it also had the black powder from the CPU pins, not actual pins but little black deposits, so I desolved the foils using hcl/cl and it went a really dark green but as soon as I added the dark green solution to the yellow one thats when it turned murky brown and when I returned from work it was like it is in the picture :|
Rich

It is my opinion that you are seeing gold. It often comes down quite dark and fine from a dirty solution. If one of your solutions had SO2 introduced, the residual gas (dissolved in water) precipitated the gold from the second solution.

Before jumping to any conclusions, start by testing the solution, to see if gold is still contained within. If not, allow the solution to settle well, then decant, separating the solution from the solids. That's a good start at getting to the gold, even if there's something else included. I would then give the solids a hard boil in HCl, which does wonders for removing contaminants that are soluble. If the solids are gold, you should witness a change of color as it boils, with the solution darkening. Boil for some time, then add a little water. Allow the solids to settle well, then decant. Give a boiling rinse, decant, then do a wash with ammonium hydroxide, followed by another water rinse. Finally, give a last HCl wash and rinse, boiling for some time. If the solution doesn't darken, you can feel confident that you have removed the bulk of the contaminants. What remains, if it's gold, should agglomerate, but there are instances when it does not.

At this point, it is a good idea to re-dissolve the solids, for a second precipitation. That will ensure that you end up with pure gold.

Test everything before discarding. If you suspect that you have silver present, the ammonium hydroxide wash can be introduced to the stock pot, where any dissolved silver will be recovered.

Harold