# Why not aqua regia from the start



## boutselis (Jun 17, 2012)

Now at page 43 Hole says to further refine the gold that we place it in aqu regia. Why the nitric acid? Why couldn't you just place all the metals in the aqua regia to begin with?


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## jimdoc (Jun 17, 2012)

boutselis said:


> Now at page 43 Hole says to further refine the gold that we place it in aqu regia. Why the nitric acid? Why couldn't you just place all the metals in the aqua regia to begin with?



Because you want to remove the base metals first, or you just end up with a mess.

Jim


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## boutselis (Jun 17, 2012)

jimdoc said:


> boutselis said:
> 
> 
> > Now at page 43 Hole says to further refine the gold that we place it in aqu regia. Why the nitric acid? Why couldn't you just place all the metals in the aqua regia to begin with?
> ...




But from what I read, after the nitric treatment you still have base metals. Are you saying there are far less base metals after using nitric acid than there would be if you only used aqua regia?


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## qst42know (Jun 17, 2012)

The more metals in the mix the more complications, and the dirtier the result.

The cleaner it is the better. Clean gold is a treat to work with.


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## maynman1751 (Jun 17, 2012)

You almost always try to remove the base metals before dissolving the gold. Nitric will do that. You are then left with still contaminated gold, but much cleaner and easier to refine than if you were to dissolve everything with AR.


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## NobleMetalWorks (Jun 17, 2012)

I made this rule for myself.

Each step in my process should improve or at least maintain the purity and quality of my solution. If this is not so, if any step in my process does not maintain or improve the quality of my solution, then it shouldn't be in my process, alternatively if there is a step I should be taking in my process, that does produce the desired results, then I should include it as part of my process. 

Different acids act upon different metals, differently. This is why a combination is required to dissolve Au into solution, only one or the other will not do it. Also consider this, a drop or two, at the correct step in your process, of sulfuric acid, will precipitate lead sulfate, removing it and promoting your desired end result.

Reading Hoke is the best possible thing you can do with your time, if you are just starting to learn about all this.

Scott


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## Geo (Jun 17, 2012)

Scotts right, for instance, if you wanted to process some Escrap or gold filled, both of these materials contain tin (among other base metals). tin in an AR solution is a nightmare to deal with. tin in nitric acid will create metastannic acid. this substance is insoluble in water or acids. it is a sticky, gooey mess that will trap your values.it has to be removed before it is introduced to the nitric containing solution.

this is just one example. there are other more serious problems that will haunt you if you do not learn the correct way to process this material before you attempt it.


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## friendz708 (Aug 7, 2012)

CAN ANYONE GIVE ME THE BOOK Hoke's book "refining precious metal waste".PLZ PLZ PLZ THANKS


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## maynman1751 (Aug 7, 2012)

friendz708 said:


> CAN ANYONE GIVE ME THE BOOK Hoke's book "refining precious metal waste".PLZ PLZ PLZ THANKS


http://tinyurl.com/mfnyhs


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## butcher (Aug 9, 2012)

Wow a book with a tutorial of how to refine and recover gold.
 

What a great find thanks.


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