ATENTION AT GOLD PLATED BOARDS!

[Alondro]

Thank you. Follow up question: Can I draw any conclusions when I process them (after depopulating of course) in copper (ll) chloride (AP) with respect to how easily the plating peeled up and did not adhere to the PC board?

If you're sure the base metals are completely dissolved, then that foil is gold. To check, you can always wash a piece very well in distilled water (to make sure no chlorides remain) and then drop it in 50% nitric. If it sits there for a day and nothing happens, GOLD!

 

[Yggdrasil]

Thank you. Follow up question: Can I draw any conclusions when I process them (after depopulating of course) in copper (ll) chloride (AP) with respect to how easily the plating peeled up and did not adhere to the PC board?

There are situations when plating has been covered by some kind of coating.
So one of the good advice practice by some of our gurus and present members is to roast/heat anything to be refined to red glow.
This will take care of oils and such.

 

[Ag and Au]

The scrape and peel method on the surface of old HP boards produced 30.4 grams of foils. There are still some base metal(s) visable on the underside of the foils that need to be dealt with. Next? ... Hot distilled water wash, followed by hot HCL wash then to AR?

 

[BlackLabel]

The scrape and peel method on the surface of old HP boards produced 30.4 grams of foils. There are still some base metal(s) visable on the underside of the foils that need to be dealt with. Next? ... Hot distilled water wash, followed by hot HCL wash then to AR?

The base metals will consume a lot of nitric and you'll get a dirty solution.
I'd start with AP. This will leave nice clean gold foils.

 

[Ag and Au]

So the copper II chloride will dissolve the nickel and copper, thereby leaving an easier and cleaner AR process. Thank you.

 

[rickbb]

Yes, it will remove the base metals allowing you to either melt the foils as is or refine further with an AR process.

edit to add, you realize that 30g of copper backed foils will not yield very much gold

 

[Ag and Au]

edit to add, you realize that 30g of copper backed foils will not yield very much gold

Unfortunately yes. I am bracing myself for the actual final yield; but this gives me the opportunity to hone my beginner skills. I will post the final yield to this thread in a few weeks. Thank you for your input.

 

[Martijn]

Use very littlte acid. Just cover the foils, apply low heat and add drops of nitric.
Chill, filter and then test with stannous. If it's a nice faint purple reaction, save a bit as reference solution to test your stannous.

 

[Ag and Au]

Will do, thanks.