Telecom board in solution

[Joeyc118]

Hi all,
Just wondering if and how I should remove gold from these telecom boards. The reason I ask is on one picture it looks as if the gold is super thick and in a perfect world just completely solid all the way through.
I would think that I just chop out sections of gold and put in aqua regia and if something else comes out then I just refine but I’m very much open to suggestions.
Thank you!

 

[Martijn]

You never put whole boards in AR.
You use AP for that, which requires no H2O2 by twe way.
The gold plating on these boards seem very thin.

 

[Darkthirty]

You never put whole boards in AR.
You use AP for that, which requires no H2O2 by twe way.
The gold plating on these boards seem very thin.

Acid / peroxide, without the peroxide?

 

[Martijn]

Yes!!
I realize I will not get away with only that answer, so:

We should have called it CC2 leach or something in stead of Acid Peroxide.
Hard to get rid of things like this, like the use of urea in refining.

The Peroxide is used to oxidize the first bit of copper to make Copper 1 Chloride (CuCl), which will turn into copper 2 chloride (CuCl2) with the aid of a little air (oxygen)
CuCL2 can dissolve copper, HCl alone can not.
HCl + H2O2 is a refining tool, used to dissolve gold!

You do not want to dissolve gold in your AP, you want foils to filter out, not cemented gold dust, imo.
To avoid the "help questions", I recommend making CuCl2 by putting a piece of corroded copper or copper carbonate (that green layer) in HCL, and voila, you're done, without the risk of dissolving gold.

If the HCl is 'depleted' and can not convert CuCl to CuCl2 anymore, H2O2 can also help convert the CuCl into CuCL2, but again, not without it's side notes.

So technically, you can make the AP with H2O2, but it's less fool proof as this method.
Beginners tend to add more and more if they don't see results within 10 milliseconds.
That's why I recommend it to beginners, and really no-one should need to buy chemicals they don't really need if they have the time (hobbyists)

Martijn.

 

[Darkthirty]

Yes!!
I realize I will not get away with only that answer, so:

We should have called it CC2 leach or something in stead of Acid Peroxide.
Hard to get rid of things like this, like the use of urea in refining.

The Peroxide is used to oxidize the first bit of copper to make Copper 1 Chloride (CuCl), which will turn into copper 2 chloride (CuCl2) with the aid of a little air (oxygen)
CuCL2 can dissolve copper, HCl alone can not.
HCl + H2O2 is a refining tool, used to dissolve gold!

You do not want to dissolve gold in your AP, you want foils to filter out, not cemented gold dust, imo.
To avoid the "help questions", I recommend making CuCl2 by putting a piece of corroded copper or copper carbonate (that green layer) in HCL, and voila, you're done, without the risk of dissolving gold.

If the HCl is 'depleted' and can not convert CuCl to CuCl2 anymore, H2O2 can also help convert the CuCl into CuCL2, but again, not without it's side notes.

So technically, you can make the AP with H2O2, but it's less fool proof as this method.
Beginners tend to add more and more if they don't see results within 10 milliseconds.
That's why I recommend it to beginners, and really no-one should need to buy chemicals they don't really need if they have the time (hobbyists)

Martijn.

Thanks for the reply. I've just read all the posts that came up after searching AP. Sounds like selective depopulation, HCL leach to remove Sn/Pb, then AP (CC2) leach is the proper order.

 

[Martijn]

It may be a bit too obvious, but only spend HCl leach on those parts worth leaching!
Collect the high yield parts and sell the rest as scrap. If you go for each tiny trace of gold, you'll be losing money fast!