Denox was not done after Aqua Regia

[OroMontalban]

Best regards to all I'm new to the group and refining and would like to seek your valuable comment in the following or direct me to where I can find my answer to what I think is a typical problem.
I performed Aqua Regia in a soil sample and got positive result with Stennous Chloride on cooling. I continue with electrolysis to precipitate the gold and the process was stopped at 20 minutes with 5 Volts and 1 Amp producing a good amount of the dark brown/black precipitate. After about an hour or two I noticed that the amount of particles at the bottom of the beakers were disappearing and the dark cloud was changing from being opaque to clear. At that time I realized that I did not denox the solution so the gold went back into solution again. My question is do I denox and re perform electrolysis or denox and start again with Aqua Regia or denox and reduce the 200 mls with heat and then start the Aqua Regia process followed by denox and then electrolysis. The second question is since I'm dealing with small quantities once the precipitate is formed how long can the precipitate be saved in liquid form or do I need to dry it first then save
Thank you so much

 

[Yggdrasil]

Best regards to all I'm new to the group and refining and would like to seek your valuable comment in the following or direct me to where I can find my answer to what I think is a typical problem.
I performed Aqua Regia in a soil sample and got positive result with Stennous Chloride on cooling. I continue with electrolysis to precipitate the gold and the process was stopped at 20 minutes with 5 Volts and 1 Amp producing a good amount of the dark brown/black precipitate. After about an hour or two I noticed that the amount of particles at the bottom of the beakers were disappearing and the dark cloud was changing from being opaque to clear. At that time I realized that I did not denox the solution so the gold went back into solution again. My question is do I denox and re perform electrolysis or denox and start again with Aqua Regia or denox and reduce the 200 mls with heat and then start the Aqua Regia process followed by denox and then electrolysis. The second question is since I'm dealing with small quantities once the precipitate is formed how long can the precipitate be saved in liquid form or do I need to dry it first then save
Thank you so much

First:
Do you have an assay of the "Soil"?
Soil is a very wide and little specific term.
Next why have you chosen electrolysis (electro winning) to get your Gold out in stead of the proven SMB, Ascorbic acid, Ferrous Sulfate or Oxalic acid route?
Electro winning is not straight forward and will drop more or less all metals.

So I suggest deNOx and precipitate with SMB or Cement on Copper.

 

[4metals]

Did you do any pre-treatment of your soil sample, crushing or roasting? Do you know anything about the soil in terms of mineralization? Unless you are seeing physical gold that can be separated by density usually the gangue is panned off and then one method could be aqua regia. But on a larger scale some type of leach procedure is typically used because aqua regia is not practical on large quantities of soil that have not been concentrated in some way.

In terms of your concerns about de-noxing, when the excess nitric dissolves the metal you have electrowinned from solution it is actually consuming some of the excess nitric in the process and eventually it will de-NOx itself. Of course if you used way too much nitric, it will repeat itself for some time before the free nitric is consumed.