Rickthenewb said:
Hey guys, I usually don't mess around with silver but I was just offered around 5000 lbs of powder containing
Ag – 7.21%
Mo – 1.18%
Zr – 0.07%
Zn – 8.72%
Cu – 8.28%
Ni – 73.02%
Fe – 0.29%
Cr – 0.46%
Ti – 0.78%
Now I am not sure if this is the full contents or if its mixed with some sort of silicon.
I am getting a small sample and was wondering the best way to isolate the silver.
I was thinking HCl will dissolve the Zn and the Nickel, after that I'm not sure how to proceed.
Good luck!! Sounds like you have a white elephant, as it is called in the scrap metal trade. It's something huge that looks neat and profitable, but what do you really do with it? What is the source of this stuff, anyway. Is the silver
ON it, as in your title, or is it
IN it. This could make a big difference
HCl will dissolve 73% Ni, but, I think it would have to be hot and concentrated. Even then, it's slow, especially when the powder is not very fine. The fumes coming off of hot conc. HCl are very intense, there are a lot of them, and they will rust anything even slightly close - cars, tools, buildings, etc.
Peroxide and diluted sulfuric might work and would produce very little fumes - the mix must be right, however, or it could be dangerous. Experimentation in small quantities is required.
Nitric would certainly work and then you could cement the silver with copper. Nitric also produces lots of corrosive fumes and it would take about a gallon to dissolve 2 pounds of material. Two pounds of your material is worth about $80 in silver. Unless you can buy nitric in drum quantities, it could chew up any profits especially when you consider waste disposal.
If the powder is fine enough, you may be able to oxidize the surface of the particles and then leach the base metal oxides with weak sulfuric. This may take several cycles.
That's a lot of material to dissolve. If you can somehow use weak sulfuric, it would be safer and less expensive. Lots of waste solution, however.
If you dissolve it with any acid, figure that you'll need about 50 to 75 drums, depending on the acid used. After dilutions, etc., you would generate from 2 to 5 times this volume in waste.
With that much weight, I would approach the nickel smelters. Maybe, they don't want it, though.