Silver + Base metal ore

[Blakey]

Hi All,

I have an ore stockpile which I assayed and it contains:

• 843ppm Ag
• 5.2% Zn
• 1.3% Cu
• 9000ppm Sb
• 1520 Pb
• 2.7% As
• 5% Sulphur

I haven't tried roasting yet and have tried smelting the concentrate using fluxes. The first attempt I added an Iron rod to the crucible to help reduce the sulphur but the metal in the cone mold was hard and my magnet stuck to it so likely mostly iron.
The second and third attempt using limited and then no iron and only fluxes did produce a metal cone which had a lead tip and a zinc base. I cupelled the lead and there was no silver so I dissolved the zinc in nitric and then attempted to precipitate silver and got no silver. The fluxes I was using was a combination of Silica, soda ash, niter, borax.
So I can only assume the silver is in the slag.
Any ideas why my silver is not coming out?

Cheers!

 

[Yggdrasil]

Hi All,

I have an ore stockpile which I assayed and it contains:

• 843ppm Ag
• 5.2% Zn
• 1.3% Cu
• 9000ppm Sb
• 1520 Pb
• 2.7% As
• 5% Sulphur

I haven't tried roasting yet and have tried smelting the concentrate using fluxes. The first attempt I added an Iron rod to the crucible to help reduce the sulphur but the metal in the cone mold was hard and my magnet stuck to it so likely mostly iron.
The second and third attempt using limited and then no iron and only fluxes did produce a metal cone which had a lead tip and a zinc base. I cupelled the lead and there was no silver so I dissolved the zinc in nitric and then attempted to precipitate silver and got no silver. The fluxes I was using was a combination of Silica, soda ash, niter, borax.
So I can only assume the silver is in the slag.
Any ideas why my silver is not coming out?

Cheers!

There are 0.0843% Silver so which is 84 0.8 grams in a Kilogram.
Anyway there are significant amounts of Arsenic so I'd be careful with the out-gassing/smoke.
How much are you smelting at a time?

Edit to add.
Slight calculation error.
0.843 grams of Silver per Kilogram
Which amounts to slightly below 1 USD per kg or per 2.2 pounds
I'm not sure it is worth it.