# HCl + H2O2 + NaCl?



## NuggetHuntingFool (Jan 9, 2008)

Will this help me recover Pt and Au effectively by concentrating the values?


Why is the salt added?



Thanks


----------



## NuggetHuntingFool (Jan 10, 2008)

So nobody knows why the salt is added to this solution??

I'm curious as to what the salt's effect is. :mrgreen:


----------



## skyline27 (Jan 10, 2008)

Be sure to take a pinch of salt when Ron Paul starts talking!


----------



## NuggetHuntingFool (Jan 10, 2008)

Why?

He speaks only the truth... but that's for another topic Mr. Smarty Pants.


----------



## lazersteve (Jan 10, 2008)

NHF,

Who instructed you to add salt to the AP solution?

Steve


----------



## NuggetHuntingFool (Jan 11, 2008)

I saw it somewhere on The Internet for gold recovery processes...


I'm curious as to what effect the salt adds to base metals, or Pt and Au...


I think this mix should be heated as well...


----------



## arthur kierski (Feb 23, 2008)

the salt helps to produce more clorine to dissolve totally pt and au---it must be hot


----------



## NuggetHuntingFool (Feb 27, 2008)

What happens with the Sodium then? I've read that Na is a highly reactive element!


----------



## peter i (Feb 28, 2008)

NuggetHuntingFool said:


> What happens with the Sodium then? I've read that Na is a highly reactive element!



Yes, metallic sodium is a reactive element, sodium ions are not that reactive.
(Remember, you sprinkle sodium chloride on your egg, and very little happens) 

In contact with a acid thats stronger than hydrochloric, NaCl will give you elemental chlorine and the sodium salt of the stronger acid.


----------



## eagle2 (Feb 29, 2008)

NHF
I only use the AP process to leach away the base metals.

The simplified equation is: 2HCl + H2O2 + Cu = CuCl2 + 2H2O

The cupric ions in solution will now do the work of leaching more Copper (and Nickel). Basically the peroxide is there just to get the Copper leach started. I start with a dilute HCl solution, not concentrated.

You can add salt. the reason it is added is so you can use less HCL. The salt will supply the necessary Chlorine ions. In fact with a large amount of salt, you only need to keep the mix slightly acid. You can keep the solution near boiling and covered to speed up the process. 

Now the equation is complex, but basically You get Cu + Cl2 and Na + OH ions, (Sodium hydroxide). This tries to make the solution less acid. 

Because, NaOH + HCl = NaCl + H2O. 

Using up HCl, so you need to keep an excess of HCl or the leach will stop. And the Salt is never used up!! 

The whole point of using salt is so you don`t need to have concd. HCl as a starting solution. Also, if you want to boil the solution, you will have less trouble with this more dilute mix. 

I like to use concd. HCl and H2O2 to re-dissolve a gold precip. that I want to purify. Its very quick and clean. Also it will eventually dissolve the thin gold foils obtained from a Copper leach. I use it this way in preference to HCl + Bleach, because its also cleaner.

Al


----------



## NuggetHuntingFool (Feb 29, 2008)

Man. I think I should take basic chemistry again. I've forgotten so much about the subject that this is all Greek to me now. Especially the mathematical formulas involving chemical changes.

Thanks for the replies though.


----------



## Platdigger (Feb 29, 2008)

Yes, Eagle, that was a great post!

Let me ask you this.

When using concentrated HCL/peroxide, do you need to remove the excess oxygen before adding smb to get a good drop?
Randy


----------



## eagle2 (Feb 29, 2008)

Welcome. 

Its important to know what your doing so its easier to be safe.

NHF, You could find a basic chemistry book anywhere, try the library! 

Platdigger, Thanks. I heat my solutions to near boiling before preciping anything. This will decompose any left over H2O2. Or if you used HCl + bleach some easy heating will drive off the Cl2. I think you will get a much better and more complete precip with a hot solution anyway. With Gold and PMG`s going higher and higher, it really gets important to get all your value out! 

Hey, check out Lazersteve`s tutorials. There loaded with info. 

Al


----------

