# Modern denox method in refining of PGM



## Mgnaing (Apr 12, 2014)

Today, I use ethanol absolute in denoxing excess nitric acid from AR solution in refining platinum . The effect is as same as traditional denox method but the modern denoxing method save me a lot of time in compare to traditional method. How about using this denox method ?


----------



## solar_plasma (Apr 12, 2014)

What is the equation? Does it form ethyl esters? Could those make trouble?

edit: http://en.wikipedia.org/wiki/Nitrate_ester ...I think I stay with the old, common and proven methods....

edit2: http://en.wikipedia.org/wiki/Ethyl_nitrate ...it decomposes in water, they say....

edit3: and you will get this one: http://en.wikipedia.org/wiki/Ethyl_chloride

edit4: interesting, last one could form traces of styling gel (ethyl cellulose) with the cellulose of a filter :lol:


----------



## necromancer (Apr 12, 2014)

Mgnaing said:


> Today, I use ethanol absolute in denoxing excess nitric acid from AR solution in refining platinum . The effect is as same as traditional denox method but the modern denoxing method save me a lot of time in compare to traditional method. How about using this denox method ?



Mgnaing, this was posted 3 times, i placed a link to this post in the other 2 copies of this post.
you only need to post one message, it will be seen and you will get help.


----------



## freechemist (Apr 23, 2014)

If you did not use highly excessive amounts of nitric acid to dissolve raw platinum-metal, denoxing before precipitation of a hexachloro-platinate(IV) salt is not necessary.

Dissolving raw Pt with Cl2/HCl; e.g. by generating Cl2 by oxydation with NaClO3, makes denoxing unnecessary.

Using ethanol for denoxing can be dangerous, because mixtures of AR with ethanol can decompose quite violently and in an unpredictable manner in a spontaneous boil-over, producing NOx and irritating gases/vapours with effects similar to tear-gas.

Ethanol is a reducing agent, capable to reduce dissolved Pt(IV) to Pt(II), which will not precipitate on adding ammonium- or potassium-salts, and finally to metallic platinum (Pt-black).


----------

