Does Nitric Acid dissolved Gold powder?

[Palladium]

I have heard from some of the old-timer gold refiner locally that is still using traditional ways to refine gold says when they recover the gold by smelting the material they wish to refine in a crucible with borax<Only Borax> and use lead bar and a small portion of Copper wire as a collector they say there are some gold dissolved in the nitric acid and they are losing some gold.

:roll: I forgot to mention about the process about how they do above, Ok, First after smelting the material in a very big furnaces with borax, Lead Bar and some copper wire<if the material does not contain copper> for about 2 1/2Hr they set aside and give it some time to cool and use a solid sharp iron rod with a hammer and slowly chip out the borax until it reach the bottom of the crucible and it will left with a piece of at least few Kgs of Lead metal.

They then remove the big piece of lead from the bottom of the crucible, Melt it again in a big homemade melting dish until the whole piece reach its boiling point then slowly remove the impurity by using a thin steel rod to tuck it out bit by bit until it became a nice boiling metal with no trace of any impurity or any trace of borax.

Lastly use a big stainless steel spoon to tuck it and pour in pail of water to make Shot.
After rinsed 1-2 times, Finally soft boil it with nitric acid in a Big Stainless steel mixing bowl.
Without using AR method, The result is 99.95up.

But however using this method I have never see them recover any PGMs before even the material has high PGMs in Content.

:lol: :lol: :lol: I am just trying to share with you guys that in my country most of them process this way and this is the way they do it.


Francis

I would love to hear more about your experiences Francis. Please continue.

 

[stardust18]

In addition to my first post: When soldering the gold dissolves in the solder, the solder is dissolved in nitric acid - together with the gold located there. It can also be your loss. Thank you for your attention.

 

[Franciz]

I would love to hear more about your experiences Francis. Please continue.

Dear Palladium,

I am willing and happy to share all of my experience. Please let me know what you would like to hear from me.

Best Regs
Francis

 

[Palladium]

Anything that has to do with gold refining in your culture. Or anything about your life in general you want to share. I think its cool to learn how others live and function aside from the normal BS we go through everyday in our culture. Makes my wants and complaints I have seem small in comparison. You seem like an interesting person.

 

[Franciz]

Anything that has to do with gold refining in your culture. Or anything about your life in general you want to share. I think its cool to learn how others live and function aside from the normal BS we go through everyday in our culture. Makes my wants and complaints I have seem small in comparison. You seem like an interesting person.

My family has no chemical knowledge at all but my father was a refiner here :lol: I saw them refine gold since i was a boy :lol: But there is nothing much i can share about their process because no matter what material they wish to refine, The just smelt it with lead and copper into a button.
The only thing i know lately is they are losing gold in their used borax, I know because i send it for assay. I have many tons of this borax, :lol: :lol: :lol:

The story start since mid last year When i saw a post on my local website teaching how to recover gold using chemical. I called up and go to the person place which took me 12hours to reach there who agree to teach me with a fee of about USD2000/-.
All i learn from him is using electrolysis method with cyanide solution. I bring there 2pounds of P.Pro CPU and recovered 2.5g of Gold but it took him 8Hr for the process :x < I know the gold is not fully recovered but the person who teach me insist>
After paying the USD2000/- i feel that i should find another way to learn and should try my best to make it success :lol: :lol:

I have never think my father method is the best in fact i am think his method is the lousy as each time he process he are throw away some amount of gold and had never seen any PGM from him even some of his material like goldsmiths dust, sweep which contain PGM.

There is only 1 time i am proud of him is few years back ago he came back home with 30L of unknown solution and he is able to recover 300g of gold and 44KG of silver in 30L solution :shock: :shock: :shock: But that is the only time. :lol:

Now i am consider full time of this project doing research and reading and the most beautiful part is i am a member of this forum as there is so many ''real'' experience refiner who i can ask and learn and it is FREE :lol: :lol: :lol:
After asking so many stupid question here and some reading today i have ordered a few hundreds dollar of the chemical require for gold and PGM :lol:

I will not stop until i success:lol: :lol: :lol:

Francis

 

[Palladium]

If you need any help just ask Francis.
The name francis, is that like your real name or just a screen name? The reason i ask is because of the country your from francis just seems like a strange name from there.

 

[Franciz]

If you need any help just ask Francis.
The name francis, is that like your real name or just a screen name? The reason i ask is because of the country your from francis just seems like a strange name from there.

It is my nick name, My name is Pornsak. I got the nick name Francis when i study oversea for my O-level :lol:
I prefer Francis because it sounds more international :lol: :lol: :lol: :lol: :lol: :lol: :lol:

 

[Oz]

I prefer Francis because it sounds more international :lol: :lol: :lol: :lol: :lol: :lol: :lol:

I understand completely, there is much prejudice in this world and while living in Europe I saw many do the same in picking a generic name when dealing with others in a different country. Tell us which you prefer to be called by, as I will not allow country or ethnic prejudices on this forum.

Glad to meet you …….

 

[Franciz]

I prefer Francis because it sounds more international :lol: :lol: :lol: :lol: :lol: :lol: :lol:

I understand completely, there is much prejudice in this world and while living in Europe I saw many do the same in picking a generic name when dealing with others in a different country. Tell us which you prefer to be called by, as I will not allow country or ethnic prejudices on this forum.

Glad to meet you …….

I will prefer to be called Francis :lol: More international,,, Haha...

 

[Westerngs]

I vaguely remember that Bugbee mentions nitric acid dissolving small amounts of finely divided gold. I will dig out my old copy of Bugbee and see if I can find that again.

Funny thing. Just yesterday I received samples of silver dissolved in 1:1 nitric acid and was asked to determine if any gold went into solution when dissolving the silver (trace gold content in silver being dissolved). I will post findings later.

 

[Westerngs]

Found where Bugbee mentions gold dissolving in nitric acid.

Pg. 132 "IF the parting acid contains impurities, particularly chlorine in any form, some of the gold is sure to be dissolved. Even pure nitric acid, if concentrated and boiling, dissolves a small, but for ore analysis a negligible, amount. According to F.P. Dewey this loss does not exceed 0.005 part per 1000 parts of gold."

Now the samples I received (mentioned in my post above). I checked the solution, did not find any gold at 1 ppm detection limit. Unfortunately, it is difficult to matrix match the standards to the samples, so the samples are in 1:1 nitric acid and the standards are in 2% HCl.

Then I filtered the samples and digested the filters in aqua regia. Easy to matrix match samples and standards here. Again, did not find any gold with 1 ppm DL.

So... As far as I can tell, gold will not dissolve in nitric acid.

 

[butcher]

Nice work Westerngs thanks for spending time on this,
There was no doubt some of the tiny gold atoms may get passed through the processes, if not dissolved then in some fine powers suspended in solution at some point.

When we make our own nitric acid the nitrate salts can very well have some chlorides as contaminates, which can dissolve a little bit of gold when we use the homemade nitric acid.

I keep a stockpot or reuse my spent nitric solutions, in hopes of capturing what may go through my processes.

 

[Geo]

Francis, you said you have many tons of borax with gold trapped. has anyone tried to address this? borax can be dissolved with dilute sulfuric acid, im sure of that because thats what i use to clean my melting dishes. the little borax thats left after boiling in dilute sulfuric acid is very soft and can be rubbed off with your finger. is there some way to use this to dissolve the borax you have to recover the gold thats locked up in the borax glass?

 

[nickvc]

Geo I believe this has been discussed earlier in another thread and I think 4metals gave him some advice on what mix of fluxes to try but Franciz was having problems sourcing some of the chemicals.
I know what would work but I hesitate to say as it's the one acid I really hate and would rather crawl over hot broken salted glass than use it or advise anyone else to.

 

[Franciz]

Francis, you said you have many tons of borax with gold trapped. has anyone tried to address this? borax can be dissolved with dilute sulfuric acid, im sure of that because thats what i use to clean my melting dishes. the little borax thats left after boiling in dilute sulfuric acid is very soft and can be rubbed off with your finger. is there some way to use this to dissolve the borax you have to recover the gold thats locked up in the borax glass?

Dear Geo,

I have already try to dissolved in hot dilute sulfuric acid. It did not works. :lol:
I have also tried 4metal flux receipe it also don't work.
For the borax, I have already give up and selling to a Taiwanese :lol:

Best Regs
Francis

 

[Lino1406]

I do not agree with cyanide "turns gold+1
to gold+3" If cyanide changes valence,
which it does not, is by reduction, not
oxidation
Lino1406, author of "25 recovery procedures..."