Best way to refine sterling?

[thesillym]

Hi,

If you already melted the stuff and made flakes, i guess to avoid large quantities of metastannic and acid waste, I would recommend cupellation first and silver cell after. This way you will minimize the acid usage thus waste creation, and can get rid of the tin and lead as well.

Pete.

I’ve seen small cupels for sale, but I have hundreds of ounces to process. I saw a method of making cupels using dry Portland cement and forming by compression into a bowl shape. Will that work? Or another diy or source for cheap cupels of larger size?

 

[Yggdrasil]

I’ve seen small cupels for sale, but I have hundreds of ounces to process. I saw a method of making cupels using dry Portland cement and forming by compression into a bowl shape. Will that work? Or another diy or source for cheap cupels of larger size?

The Portland cupels work.
But you still need a suitable furnace for them.

 

[Martijn]

Hi,

If you already melted the stuff and made flakes, i guess to avoid large quantities of metastannic and acid waste, I would recommend cupellation first and silver cell after. This way you will minimize the acid usage thus waste creation, and can get rid of the tin and lead as well.

Pete.

Or the parkes process to get pm's out of the lead with zinc. Depending on the amount of lead.