I've got some old silver Solder, Stay Brite #8. I was wondering if anyone has done any refining with this before? Also, is it possible to dissolve with nitric acid and then cement the silver out of solution?
From what i could find the silver content is between 5.5-6% silver so it may a waste of hard to find nitric, I would try a small sample in hot HCl to see if you can dissolve the tin leaving silver chloride to convert.
Stay Brite has only 6% silver and 94% tin.
1lb = 453 grams x 6% = 27.18 grams of silver. 1 pound roll of this solder worth roughly $70 or more.
Its my opinion that it should be saved as a solder and has more value for use as solder.
You will have to use a lot of chemical and deal with all the waste.
If you are not going to use the solder, better to resell it.