Non-Chemical Recovering precious metals from polishing sweeps(for silver)

[goldnugget77]

Recovering precious metals from polishing sweeps
We all know this thread and it has some valuable information thanks to a few people and particularly to Harold
Harold was saying in this thread that there was a way of doing this process that was suitable for silver sweeps.
I have read this thread a few time and I didn't notice anything like that.
Harold if you could write the process for recovering sweeps with silver that would be a big help.
Thanks

 

[Harold_V]

Use the same process, but substitute a dilute nitric digest instead of an HCl digest after incineration and screening.

You would not rely on filtration when recovering the silver nitrate. Filtration would be difficult, if possible at all. Allow it to settle well, then decant using a small hose (I used a 3/8" vinyl with 1/8" wall). Rinse the mud a few times, using distilled water unless you don't mind a little silver chloride forming, in which case you could use tap water.

If the material contains both silver and gold, there should be further processing to insure that the gold, once dissolved, can be filtered easily. It generally can't be. You would incinerate the solids after removal of the silver with nitric, which would insure that you had eliminated all traces of nitric. Heat until the brown fumes no longer are emitted. You would then give the solids a boil in HCl and water, which would remove substances that complicate filtering. After a rinse (tap water is fine), you would then dissolve the remaining values with AR.

Harold