We want the gold, but what about precious metals?

[AmateurGoldSeeker]

The work to do in order to collect electronics scraps and disassemble them would not be worth it if we were looking only for silver (since it is about 50 times cheaper than gold). But since the job is already done when we do it for gold, can we collect silver at the same time? I'm thinking, that the new batch could go first in a bath of nitric acid to dissolve all metals except gold (and perhaps palladium?). The gold flakes can then be collected and go in a second bath of aqua regia. But the waste from the first bath certainly contains silver. Can silver from this waste be precipitated by dissolving some extra copper in order to saturate the acid? Or is there another way of extracting the silver?

 

[rickbb]

In my experience there is less silver in e-scrap than gold, and it's harder to get. The low hanging fruit is the plated gold and in the BGA chips. There is no exposed silver on boards to my knowledge.

And other than exposed gold plating all the other values are locked up inside all the components and each component and its values, (precious metals), need different processes to get them out.

MLCC''s for instance are about 2% silver but 1% platinum group metals. Which are as, if not more, valuable than gold. But you have to remove them from boards, separate them out, crush them to a fine powder, roast them, then chemically leach them, then refine them into separate metals. And they are tiny, almost the smallest thing on a board so it takes thousands of them to make it worth the time and cost to work with.

You can't just throw the boards in whole and expect to get anything out. Everything has to be removed and sorted for most of us, or you could invest millions in a large-scale industrial grinding to dust operation and start various leaching processes like those using cyanide, etc. But you would need e-scrap stream of tonnage scale to make that profitable.