Recently I posted a question about rdx synthesis without acetic anhydride and someone pointed out it could be done with unusually highly concentrated
hno3. Can Anyone point me to such a synthesis? I can't find it for the life of me. Also would hno3 condensed from no2 be pure enough(h2So4+ Kno3
heated with vapors "pushed" through a graham or liebig condenser)? Thanks guys...hissingnoise - 15-11-2010 at 04:04
Here's the original 1922 von Herz patent for cyclonite!
Thanks abunch, this should do it.hissingnoise - 15-11-2010 at 09:24
Quote:
Also would hno3 condensed from no2 be pure enough(h2So4+ Kno3 heated with vapors "pushed" through a graham or liebig condenser)?
Ideally your acid should be free of dissolved NO2 to minimise the likelihood of a runaway . . .
prometheus1970 - 15-11-2010 at 13:37
Adding urea will remove dissolved No2 won't it?prometheus1970 - 15-11-2010 at 13:40
I assumed that when you heat up a mixture of h2So4 and a nitrate salt that the reddish vapors released into the condenser are no2 these vapors
condense into nitric acid, and that was the best way to high purity hno3 am I wrong?hissingnoise - 16-11-2010 at 02:21
Quote:
Adding urea will remove dissolved No2 won't it?
It's better to re-oxidise the NO2 as far as possible by blowing dry air or oxygen through the acid.
Any colour that remains can then be removed by adding a pinch of urea.
The reaction of urea with nitrous acid is a loss of fixed nitrogen and shouldn't be a first resort.
Microtek - 16-11-2010 at 08:51
XNO3 + H2SO4 liberates highly concentrated nitric acid. When this is distilled (particularly at atmospheric pressure), some of the nitric decomposes
into NOx and water. When the nitric acid vapours condense, some of the NOx and most of the water is absorbed in the liquid nitric acid (and some of
the water and NOx may possibly form HNO3 and HNO2).
The reaction of urea with NOx produces water, so using urea to remove excessive amounts of NOx will dilute your acid.
IMO, the best method is to heat the distilled acid to 50 C and then bubble dried air through it until it is as colorless as water. This takes about 10
minutes depending on factors such as bubble size, air volume per unit time and residence time of the bubbles in the acid.
The primary mechanism of NOx removal using this method is stripping; due to the high concentration of NOx in the acid and the low concentration in the
air (bubbles), NOx will cross the liquid/gas interface until an equilibrium is reached (given enough time).
Don't panic when the acid becomes very dark red or brown when you heat it to 50 C. This is just because the NOx converts reversibly to N2O4 or N2O3 at
lower temps. Since it's the NOx that is red-brown, you get that colour change as a matter of course. quicksilver - 29-11-2010 at 10:32
The point Microtek made is very important and I discovered this myself when measuring the density of some acid that I had "cleaned up" via urea. I had
thought that some dilution was attained via exposure to the air but the time period was too short for this to take place realistically. However, to
the best of my knowledge the synthesis will function at a level of 90+% of HNO3 so that totally anhydrous acid is not a necessity. The yield may
suffer however if it reaches the lower 90% mark depending upon the dynamics of the synthesis.Rosco Bodine - 29-11-2010 at 12:23
@prometheus1970 Read quicksilver's earlier thread Neglected RDX Process http://www.sciencemadness.org/talk/viewthread.php?tid=4701 There was a series of experiments done which sheds some light on the nitrolysis and
suggests some ideas for future experiments.
