Non-Chemical Degassing AR as an alternative..

[slouma37]

Part of the function of denoxxing PGM solutions is to replace the NO2 bound to the metals with chlorine, forming chlorides of the metals. I don't think this can be accomplished with decreased pressure alone, but I could be wrong.

Steve

Hi Master Steve,
no the denoxing doesen't replace the NO to Cl, this reaction took place before any denoxing, the heat just liberate the free NOx in solution (liberated from the replacment process), to eliminate them definitly.

Pressure Can do the Job very well if we study the Diagram curve of NOx wish reflates the states of gaz, pressure, liquid phases of NOx with it's triple point. We call that "Diagramme d'état des oxydes d'azotes" in french dunno what is in english. but it's related in the first principe of thermodynamic(the enthalpy).

Yes this process can be less troublesome if well done, and the idea is just genius and to be tryed and perfectioned.

Salim

 

[Lou]

Pressure alone can remove all of the nitrogen oxides, but the solution must be strongly acidic (hence the additions of HCl) to break down the normally stable nitrate anion into NOx. Heat and vacuum make it go very quick. It is more useful for the PGMs rather than gold, mainly because you're usually left with a strong aqua regia solution of platinum and the ol' gold button in the flask trick doesn't parallel with platinum, at least not on a commercial timescale.


Lou