Sodium Metabisulfite

[gem3]

Hi, I am new here and have read already alot to refine gold and silver.

On one topic I've read to use SMB to precipitate gold.

But how much SMB in how much H2O do I need to precipitate the gold in a solution of 0.53 gallon (1,6+0,4=2 Liters) Aqua Regia ?
Is there a kind of mathematic formule to know that ?

 

[Geo]

it depends on the amount of gold in solution. estimate how much weight in gold you have and add 1.5 times the weight of SMB in a clean container and add enough water to dissolve it all. add the SMB and water to your solution and stir.

 

[donnybrook]

I use the following formula/mixture to precipitate gold using SMB. For every sixty grams of gold you wish to recover (sorry I don't have the American weights and measures) you add 110 grams of SMB to 1 litre of water.
donnybrook