Firing the Iron Sulfate Precipitate

[Gold Lady]

Hi! Its me again the Gold Lady. Can anyone give me a fluxing formula to fire my brown powder from usin iron sufate as a precipitate? I have a muffle furnace as well as an electric one. I love the forum. Its great with a lot of good info. I live in Tucson Arizona and would love to hear from any one that lives here as well.
Joyce

 

[4metals]

Ferrous sulfate drops the gold nicely but it doesn't drop the highest purity gold, no problem, using the proper flux and you can clean up the gold by scavenging the silver and base metals and trapping them in the slag. Make some flux up as follows;

2 parts Anhydrous borax glass
1 part soda ash
1 part silica sand
1 part manganese dioxide

mix all the ingredients and store it in a sealed container until you use it.

mix equal parts gold sponge and this flux mixture and heat in a crucible at 2000 degrees for half an hour. Sometimes this flux will be thick and stick to the bar tenaciously. If that's the case mix up 1 part flourospar and 1 part calcium oxide and use it to thin the flux above. Use this mix sparingly, it is tough on crucibles start with 1/2 part in the mix above.

 

[Lino1406]

I suppose you boiled it beforehand with HCl? Then water
Then washing with ammoniac?

 

[Harold_V]

I suppose you boiled it beforehand with HCl? Then water
Then washing with ammoniac?

That sure would be my advice. I melted gold without flux, and did so routinely. The only flux was that which lined the melting dish, and that was so thin none could pour out if the dish was tilted.

I hate to beat this to death, but if you do your work properly at the outset, even using ferrous sulfate, you can produce gold of such quality that it needs no flux for melting. It is VERY important that you follow strict washing procedures.

Harold