Gold foils disappear in solution and no gold after SMB (Please Help)

[Golden_Nugget]

Hello, I have followed all the usual steps, but this time the solution went wrong, the color looks good but nothing..., I have dissolved mobile circuits and processor pins with aqua regia, then added more nitric acid wait like 4 hours and add , urea (until there are no bubbles) and then SMB, leave it overnight, then nothing. no gold poder what have I done wrong??like one kilo of stuff, good stuff, anado fotos de la solucion.

 

[eaglekeeper]

Have you performed a stannous test on the solution.

I know you see it all over YouTube, but urea doesn't really denox your solutions very well. One excepted method is by using sulfamic acid for denoxing.

 

[Yggdrasil]

Hello, I have followed all the usual steps, but this time the solution went wrong, the color looks good but nothing..., I have dissolved mobile circuits and processor pins with aqua regia, then added more nitric acid wait like 4 hours and add , urea (until there are no bubbles) and then SMB, leave it overnight, then nothing. no gold poder what have I done wrong??like one kilo of stuff, good stuff, anado fotos de la solucion.

Eaglekeepers advice is good.
Stannous is our eyes in refining, it will tell us if there are PMs there and hint about concentration.

What have you done the time you have been a member?
You have clearly not studied much.
We usually dissolve the base metals first so we and up with relatively clean Gold foils.
And we add HCl to cover the foils and add small amounts of Nitric until all is dissolved.
This way we might not need to deNOx at all.
Urea is for the garden to deNOx we use Sulfamic acid.

Since this is your first post I will give you this advice.
Read C.M. Hokes book on refining jewelers scrap, it gives an easy introduction to the most important chemistry regarding refining.
It is free here on the forum:
https://goldrefiningforum.com/phpBB3/viewtopic.php?f=54&t=19798Then read the safety section of the forum
And then read about "Dealing with waste" in the forum

 

[sippingwithsocrates]

This may or may not be the correct thread to post my reactions to C.M. Hokes book, but reading the sage advice given I believe it worthwhile.

I read the posts for many months with each one a reminder for next month to read this book. To those who have not read the book, expecting a dry tome of years gone Chemistry you will be enriched, entertained and most of all educated.

The style of writing encompasses a teaching rubric rarely seen at the time period printed.

I am profoundly grateful to this site, members and the book.

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