# Solution for Stripping Microscopic Gold--heat?



## Ferrell (Jun 28, 2011)

We're using saturated salt (7 parts) to one part nitric acid to strip/dissolve microscopic gold, then use butyl and oxalic to capture and turn to colloidal gold. We're just getting started with this, and the first batch we did worked great (other than not knowing we should do the cooking in a glass pot not metal....the gold rushed to the sides of the metal pot and stuck there). We mixed the crushed ore on that first batch (100 mesh) and soaked it for about 36 hrs in the SSN. It was a warm day and we left the bucket sitting in the sun. On the second batch, we thought maybe we shouldn't have let it get so warm (we didn't know for sure) and kept the bucket in the garage all day and overnight. Did the rest of the process today (same batch of ore so should've had the same results) with pretty much no recovery at all (used a glass pot this time). 

Can someone tell us if we're right in guessing the ore/SSN mix being too cool is the problem? Also, we'd been told to let it soak for 24 hrs...the first batch we went over and kept it in for about 40 hrs (we were told it's fine if you go over), this second batch was about 24-26 hrs. There were no other variables that we could figure out.....the only other one being that on the first batch we had just mixed the salt and nitric.... on the second batch we used the balance of the mix made up 2 days earlier and stored in a plastic bucket with a lid on it. But we understand that you can reuse or SSN solution after it's been filtered, so that shouldn't be a problem....or is it? 

Any help would be much appreciated. And remember, you're talking to novices, so please break down any instructions so we can understand (we don't know many of the abbreviations you all use here for various chemicals, etc). 

Allen and Miralee


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## Palladium (Jun 28, 2011)

:arrow: :arrow:


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## Ferrell (Jun 28, 2011)

Thank you. Unfortunately, I only have dial up rather than dsl, so the bigger files/books are difficult to load. I was able to load and read the one on SSN leach. It appears that the leach is more effective if at least 76 degrees, but not above 90 degrees (F)...?


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## Palladium (Jun 28, 2011)

The graph covers 10° C to 90° C. ( *Centigrade not Fahrenheit* ) 
Eighty degrees Centigrade (176° F) is the highest practical
temperature *due to volatilization of fluids*.


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## Ferrell (Jun 28, 2011)

Thanks. I could read most of the text, but can't get the graphs to load. Does it show (on that graph you referenced) the suggested/best temp during the leaching period? Between 10 and 80 C (50 F to 176 F) is a pretty wide range.


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## Wyndham (Jul 6, 2011)

Ferrel, I looked at the chart and the best temp is just below the 176 deg f at about 160-164 deg f.
I was wondering what metal bucket you used on the first batch, was it stainless steel or galvanized(zinc) metal or what? Did you ever figure out the amt of gold leached from any of your test?
I am interested because I have a source for micro gold in sediment that might be worthwhile testing with the equivalent of your SSN
Any others that want to chime in here on the idea that the gold in Ferrel's solution dropped out to a zinc coated bucket, please do.
BTW I have downloaded Hole's book and starting to read but it's like eating a plate of boiled greens, it takes some chewing and hard to get down with out a piece of fat back in there to help the taste :lol: 
Wyndham


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## jimdoc (Jul 6, 2011)

Wyndham said:


> BTW I have downloaded Hole's book and starting to read but it's like eating a plate of boiled greens, it takes some chewing and hard to get down with out a piece of fat back in there to help the taste :lol:
> Wyndham



You have been a member since 2007, and your just getting around to reading Hoke's book? Don't let Harold hear you say that.

Jim


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## Wyndham (Jul 6, 2011)

Jim, I think he already has.  
It takes me a looong time for some things to sink in. Have you ever been in a class that when you hear something it makes perfect sense but the moment you look at your notes, an hour later, you don't have a clue what's there, Chemistry it that boogieman for me. On the bright side, I'm only 64 so I have at least 100yrs to go to get all of this into the last 3 brain cells left active :lol: Wyndham


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## jimdoc (Jul 6, 2011)

Don't worry, Hoke leaves out a lot of the chemistry mumbo-jumbo and explains everything in easier to understand words. Sometimes it does take multiple reads, and taking notes to help it sink in. But if you stick with it until you understand it all, her book will help your refining skills greatly.

Jim


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