Would it be possible to remove slight impurity of close to pure silver or gold using a sodium carbonate and sodium nitrate flux? Even if I refine my gold and silver in electrolityc cell I sometime end up with traces of impurity in the metal, probably due to a lack of washing before drying and melting, probably it would be possible to oxidise those impurity with sodium nitrate and lock these in borax?
Smelting slightly impure silver and gold
- Thread starter elfixx
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Barren Realms 007
In Remembrance
Not completely.
Depending on how much impurity is there it is possible to clean it up. Melt the metal in a clean crucible and when molten add a pinch of borax to form a sticky spot on the crucible wall. Then sprinkle on sparingly a few prills of potassium nitrate (niter). The niter will dance around on the surface and will oxidize out small amounts of base metals which will stick to the borax.
It's an art to develop the right quantity of borax to collect all of the oxides from the pool of molten metal.
With gold I have also seen ammonium chloride dumped on the mold as soon as the metal has been poured. This smokes a nasty thick white smoke so do in under a hood with good exhaust.
You may be better served rinsing your sponge with ammonium hydroxide before melting. If the water turns blue, keep rinsing and filtering until the blue is gone and the filtrate runs clear.
Whatever you do,it is just a band aid for having been sloppy with your original refining process.
It's an art to develop the right quantity of borax to collect all of the oxides from the pool of molten metal.
With gold I have also seen ammonium chloride dumped on the mold as soon as the metal has been poured. This smokes a nasty thick white smoke so do in under a hood with good exhaust.
You may be better served rinsing your sponge with ammonium hydroxide before melting. If the water turns blue, keep rinsing and filtering until the blue is gone and the filtrate runs clear.
Whatever you do,it is just a band aid for having been sloppy with your original refining process.
As 4metals alluded to, if you've done everything else right and, especially if the AR solution was made crystal clear before precipitating the gold, the main source of contamination in the final gold is from not enough, or improper, rinsing.
