Sciencemadness Discussion Board

Effect of Water on Detonation

Trotsky - 19-4-2013 at 16:24

I have read here that while wet NC will not deflagrate (obviously), wet NC is actually far easier to detonate than dry material.

I am wondering if wet nitrostarch is also easier to detonate and if this is true at all?

The change from liquid water to water vapor produces an enormous change in volume, which I assume increases the damaging potential of an explosive.

What effect does the addition of water have on the detonate-ability of ammonium nitrate or ANFO? I know that water has been purposely added to AN-fuel blends for decades. Is this to increase stability (that hardly seems necessary) or to increase power?

I added some water to my ANNK blend and now wonder if this was a mistake. The NS and ANNS layer on top has of course absorbed some of this moisture and I'm wondering now if this will render it useless or increase it's usefulness (not that it has any use beyond the experiment, but of course I hope for a positive result).

Initiation will come from dry ETN or TATP.

thanks

trotsky


Edit: as the moisture absorbed into the ANNS layer the smell of ammonia is very present. I think perhaps some sodium carbonate was present in the NS. This would produce NaNO3 , NH4 and CO2, correct? NaNO3 isn't desired but still active at least.

[Edited on 20-4-2013 by Trotsky]

hissingnoise - 20-4-2013 at 03:38

What's "ANNK"?

AndersHoveland - 20-4-2013 at 12:19

Quote: Originally posted by Trotsky  
I have read here that while wet NC will not deflagrate (obviously), wet NC is actually far easier to detonate than dry material.

probably has more to do with physical properties. The reason NC is reluctant to detonate is its loose porous structure that can easily absorb impact.

Trotsky - 20-4-2013 at 17:23

Ammonium Nitrate / Nitro Kerosene

Sorry for the confusion. Just substituting the nitrated kerosene products for fuel oil, with the goal of producing a more energetic variant on ANFO.

Ral123 - 20-4-2013 at 22:03

Quote: Originally posted by AndersHoveland  
Quote: Originally posted by Trotsky  
I have read here that while wet NC will not deflagrate (obviously), wet NC is actually far easier to detonate than dry material.

probably has more to do with physical properties. The reason NC is reluctant to detonate is its loose porous structure that can easily absorb impact.

Loose porous material is much easier to go high order. 0.2g azide on a highly nitrated product and it's off. The density of plasticised NC is harder.
I haven't hear of soaking NC with water, I've heard of soaking with strong AN solution and using a booster to set off that mess. I have success with soaking AP with AN and getting good brisanse.

Fantasma4500 - 21-4-2013 at 04:25

about apan
i thought it was drymixed..?
ohwell makes it many times more safe (:
they did use under vietnam daisy cutters -- huge blocks as much as several tonnes AN to clear off trees and such
it was using several percentages of water to make it a dense slurry (perhaps to give better density???) and aluminium in it (5%?)
but NC with water thats pretty interesting

Ral123 - 21-4-2013 at 05:28

APAN is dry mixed. My tests showed wet mixture can be no less powerful. I think it lost some brisanse, but gained a little energy density.

chemcam - 23-4-2013 at 20:37

What is the proper way to dry mix a very sensitive HE like AP? I would think it would be extremely dangerous unless one was wet. Or does "dry mix" have a different meaning than mixing the two HE's totally dry?

Trotsky - 23-4-2013 at 21:28

I think here ap refers to ammonium perchlorate.


Really my question is a) how much will water added to an ammonium nitrate based explosive diminish its sensitivity to initiation

And b) how much will the incredible change in volume from liquid to vapor add to the power of detonation of an ammonium nitrate based explosive with added water?

Is there a known optimum level of water in Anfo-like explosives?

Would you expect the nitrated kerosene to increase the brisance of ANFO?

[Edited on 24-4-2013 by Trotsky]

golfpro - 28-7-2013 at 17:53

Quote: Originally posted by Trotsky  



Really my question is a) how much will water added to an ammonium nitrate based explosive diminish its sensitivity to initiation

And b) how much will the incredible change in volume from liquid to vapor add to the power of detonation of an ammonium nitrate based explosive with added water?

Is there a known optimum level of water in Anfo-like explosives?

Would you expect the nitrated kerosene to increase the brisance of ANFO?






[Edited on 29-7-2013 by golfpro]

AndersHoveland - 28-7-2013 at 23:56

Quote: Originally posted by Trotsky  
wet NC is actually far easier to detonate than dry material

That is probably just because the water causes the loose fibers to cling to each other, becoming more compact, and possibly because the water fills in the empty air space to better conduct the blast wave. In contrast, loose nitrocellulose tends to dissipate/cushion mechanical impact.

franklyn - 26-10-2013 at 21:53

I remembered this paper which specifically addresses this question.

About the Misuse of the Detonation Velocity for the Characterization of High Explosives
www.dtic.mil/dtic/tr/fulltext/u2/a293530.pdf

.

Ral123 - 26-10-2013 at 22:56

Very interesting I didn't know water is that much better then air. Certainly it decreases reliability. May be then even EGDN will beat as briance RDX pressed in a vice. That also kinda explains why TNP and Tetryl are not so far away as velocity.