Sciencemadness Discussion Board - Oxygen balance neutral

Oxygen balance neutral

rot - 1-3-2006 at 08:55

Hi all,
Ik now that mixing an explosive with a negative oyxgen balance (TNT for example) With an explosive with a positive oxygen belance (ammonium nitrate for example), Increases the power of the explosive.
I know there is a mixture, called amatol. It's 80% AN and 20% TNT, and it has more power than pure TNT. Well I don't have TNT, so I did the math for TNP (Picric Acid):

TNP Detonation + Extra oxygen
4(NO2)3C6H2OH + 13O2 --> 24CO2 + 6N2 + 6H2O

Ammonium Nitrate detonation:
2NH4NO3 --> 2N2 + O2 + 4H2O

So we get:
2(NO2)3C6H2OH + 13NH4NO3 --> 16N2 + 12CO2 + 29H2O

2 Moles TNP = 458.212g
13 Moles AN = 1040.56g

That's 31% TNP and 69% AN.
Can anyone tell me if this is correct? and is it more powerful than pure TNP?

[Edited on 1-3-2006 by rot]

[Edited on 1-3-2006 by rot]

PHILOU Zrealone - 1-3-2006 at 10:02

Also good to work with lower amounts

or other equations

...

HO-C6H2(NO2)3 --> H2O + 3 CO2 + 3/2 N2 + 3 C + 1/2 H2
and
NH4NO3 --> N2O + 2 H2O
so
6 N2O + 3 C --> 3 CO2 + 6 N2
1/2 N2O + 1/2 H2 --> 1/2 H2O + 1/2 N2

Summing everything and after simplification:
HO-C6H2(NO2)3 + 13/2 NH4NO3 --> 8 N2 + 6 CO2 +29/2 H2O

Your equations for zero balanced equation is correct!
Note that there exists also equations for unbalanced mix where outputs products are CO and H2O.
In that case:
HO-C6H2(NO2)3 --> H2O + 6 CO + 3/2 N2 + 1/2 H2
and
NH4NO3 --> N2O + 2 H2O
so
1/2 N2O + 1/2 H2 --> 1/2 H2O + 1/2 N2
Finally:
HO-C6H2(NO2)3 + 1/2 NH4NO3--> 5/2 H2O + 6CO + 3/2 N2

Energy output is indeed improved for TNT and for TNP in such mixes....energy output would be even better with NH4ClO4...

Boomer - 1-3-2006 at 10:21

Now would you mind to tell him that picric acid is an ACID (duh) and with even the slightest bit of water (which you can never exclude with AN) they can react to form AP and nitric acid....

I know nitric is stronger, but a test batch developed smell and corroded the fuck out of things that AN and TNP separately did not.

It is not that bad, unlike AN/chlorate or AN/Mg, but I prefer mixes that dont react before I wont them to

rot - 1-3-2006 at 12:09

I don't think picric acid is strong enough to displace the nitric acid from AN.
Only really strong mineral acids such as sulfuric and phosphoric acid will do that,
I don't think there is even one organic acid strong enough.

@PHILOU Zrealone.
Your equations are actually not correct, there is no such thing as 3/2th of a molecule.

pdb - 1-3-2006 at 12:23

Quote:

Your equations are actually not correct, there is no such thing as 3/2th of a molecule.

The cutest reply ever ?!...

lacrima97 - 1-3-2006 at 13:50

I think the 3/2 just means he didn't feel like raising everything else, and he just wanted you to do that yourself???

I think he is a pretty smart guy, so I don't think it would be very wise to doubt him....

DeAdFX - 1-3-2006 at 18:51

Quote:

Originally posted by Boomer
Now would you mind to tell him that picric acid is an ACID (duh) and with even the slightest bit of water (which you can never exclude with AN) they can react to form AP and nitric acid....

I know nitric is stronger, but a test batch developed smell and corroded the fuck out of things that AN and TNP separately did not.

It is not that bad, unlike AN/chlorate or AN/Mg, but I prefer mixes that dont react before I wont them to

I find solutions of Nitrates or Nitrates (inorganic to my knowledge) to be very corrosive on metals. However I have this interesting blender blade that seems to resist nitrate (potassium and ammonium) corrosion pretty damn well.

Oxygen and output!

Sickman - 1-3-2006 at 23:51

Unfortunatly, when we add an oxidizer to a high explosive with a negative oxygen balance we are trading detonation velocity for overall output.
Say we have 20% TNT with 80% AN, with TNT's VoD aroung 6900 M/sec, you will end up, when all is said in done, in probably the low 4000 M/sec bracket.
So if you're cutting steel I would stay with straight TNT or TNP. When you dilute it with any oxidiser you will be loosing brisance and thus cutting power. Blasting rocks and earth however the advantage is obvious, but then you can just use anfo and not bother with the TNT or TNP except to get the anfo going. In just looking at military use, they tend to resort to such mixtures not because they are more desirable, but because TNT is scarce towards the end of a long war, Amatol is also much cheaper, which is likely the greater factor$.

Chris The Great - 2-3-2006 at 01:09

Depends, much more exotic oxydizers would even increase the VoD. Say if your oxydizer is hydrazine nitrate, VoD 8600m/s, or tetranitromethane.

Now, those are of course exceptions, in 90% of cases your losing VoD.

jpsmith123 - 2-3-2006 at 02:44

Quote:

Originally posted by Sickman
Say we have 20% TNT with 80% AN, with TNT's VoD aroung 6900 M/sec, you will end up, when all is said in done, in probably the low 4000 M/sec bracket.

According to the following table, it's more like the low 5 Km/sec range for 80/20 amatol: http://mihailru.freeservers.com/shopping_page.html

PHILOU Zrealone - 2-3-2006 at 11:32

Actually most cases of explosives oxydisers have higher or equal VODs then TNT!

VOD is only a part of the energy image of a HE but not all the picture!

NH4NO3 is acidic in presence of water pKa is arround 4.5
Quite effective to dissolve and corrode usual metals.

HNO3 is acidic pKa is arround -1.5
Picric acid is also acidic pKa is arround 0.5
So there is an order of magnitude pKa 2 betwen the two...this means equilibrium is 99% shifted on the side TNP/AN and 1% on the side ATNP/NA...
HO-TNB + NH4NO3 --> NH4O-TNB + HNO3 (1% of reliability)
NH4O-TNB + HNO3 --> HO-TNB + NH4NO3 (99% of reliability)
The mix is thus truely more corroding than the apart components!

Rod,
You are right on the molecular point of view...if you wrote molecular equations but then you can only use integer and of course you can multiply your equations by integer.
On my side I'm right on the molar point of view...because 1 mole is 6*10E23 molecules...so I can divide it by 6*10E23, by two, by 100 or multiply it by as much non integer as I want to...that's the magic of stoechiometric equations...

So stoechiometric equations are a larger view of the more specific molecular equations...are you really able to work with a few molecules and manipulate them? Not easy to weight 2 molecules of TNP and 13 molecules of AN...isn't it?

that's why chemists invented the mole ...as for shoes we have pairs.

:cool:

6*10E23 shoes would be far then enough to allow everybody to walk without naked feet...I must admit I own about that number...and damn I love lether boots

but it takes too much place says my grilfriend

...

So there is no problem we look in the same direction, I'm just a few steps behind you.

[Edited on 2-3-2006 by PHILOU Zrealone]

[Edited on 2-3-2006 by PHILOU Zrealone]

Axt - 2-3-2006 at 14:32

Quote:

Originally posted by PHILOU Zrealone
Actually most cases of explosives oxydisers have higher or equal VODs then TNT!

Right, but in practice its not realised. Theres nothing obviously wrong with AN, its quite dense @ 1.72g/cm3 containing only energetic oxygen, and all N2 & H2O products.

Its problem is that for all practical purposes its in a constant LVD, thats the reason we never see definate VOD figures for ANFO its given as a range of anywhere from 1000 to 6000m/s as its more related to initiation strength, charge diametre and confinement then it is to density as you see with "ideal" explosives. VOD calculation of AN based comps is near impossible because of this, as its always overstated in calculations.

Its believed that this is due to a relatively low critical diametre, but an exceedingly high ideal diametre for HVD to occur. The same thing is seen in NG where its critical diametre is small, but in thin tubes it has a very low VOD, for all practical purposes AN is stuck in a "thin tube" as its ideal diametre is so great.

This susceptablity to LVD is explained by the "relatively low decomposition rate of AN, which cause a wide reaction zone, in combination with lateral heat losses and rarefaction waves which extinguish the decomposition reactions".

BTW, hexanitroethane mixed with benzotrifuroxan (hexanitrosobenzene) to OB has a VOD of 9440m/s & det pressure of 44.9GPa, thats the highest "fuel/oxidiser" figures that I can find.

[Edited on 2-3-2006 by Axt]

artem - 3-3-2006 at 00:54

Quote:

Originally posted by Axt

Right, but in practice its not realised. Theres nothing obviously wrong with AN, its quite dense @ 1.72g/cm3 containing only energetic oxygen, and all N2 & H2O products.
...
BTW, hexanitroethane mixed with benzotrifuroxan (hexanitrosobenzene) to OB has a VOD of 9440m/s & det pressure of 44.9GPa, thats the highest "fuel/oxidiser" figures that I can find.

[Edited on 2-3-2006 by Axt]

The main problem to get the "ideal" detonation for "fuel/oxidiser" is to obtain needfull degree of mixing vs charge diameter. When all the components are high-sensitive to shock, it's enough ~0.001mm for 1cm charge, and as for nonexplosive components or AN, for the same homogeneity you need about 10cm or more charge diameter.

For "fuel/oxidiser" good results were obtained, for example, in the case of BTNEN+HE-fuel (ultra-fine composite, 20-40mm charges) with the impulse ~106%HMX, and for its NF2-analogue (~110-112%) .
The best results for specially-made AN-based explosives (VoD~7-8km/s) are close to theoretic predictions for 100-200mm charges in steel casing.
As for HNE+BTF mix, such figures were only calculated (by Finger, Lee, based on BKW-R EOS). Some "predictions" gives more than 50GPa for NF4(+)oxidiser/HEfuel.

Chris The Great - 3-3-2006 at 03:21

And those calculations also give 166GPa for DTTO

I'd like to know what method they're using, the Kamlet/Jacobs method only gives 65GPa. Still though

To bad it has yet to be synthesized.

Interesting stuff on the diameters Axt, I always thought it was just because ammonium nitrate just didn't want to detonate. Makes a lot more sense now.

Boomer - 6-3-2006 at 04:11

"... because ammonium nitrate just didn't want to detonate"

That's another way of saying the same. It does not want to, and if it does you the favour at all, it's not willing to hurry.

BTW Axt, is the VoD given in Cooper correct, i.e. 5.27 km/s at d=1.3? I know it's not a practical velocity for pure AN, but it could be the calculated velocity. Re-calculating it to TMD gives 6.48 km/s (!). I still suspect a typo, namely 2.57 at 1.3!

And Artem, what are those 7-8 km/s AN mixes composed of? HNIW/AN 80/20 or what?

Axt - 6-3-2006 at 17:30

Quote:

Originally posted by Boomer
BTW Axt, is the VoD given in Cooper correct, i.e. 5.27 km/s at d=1.3?

Thats the same number thats given in LLNL handbook, but following its reference back to J. Phys. Chem. 59, 675-680 (1955) [attached] it shows that that its a calculated number for its "ideal" velocity. The article also shows some actual measured VOD figures for AN at various diametres.

Heres some measured vs calculated figures for ANFO, fired in 42.7mm steel tubes with "emulsion" booster:

<center><img src="http://www.sciencemadness.org/scipics/axt/anfo-vod.jpg"></center>

ref. Miyake, A & Terushige, O; 24th Int. Pyro. Sem, 383-390 (1998)

Attachment: reaction rates of AN in detonation.pdf (696kB)
This file has been downloaded 1028 times

artem - 8-3-2006 at 05:44

Quote:

Originally posted by Boomer
...And Artem, what are those 7-8 km/s AN mixes composed of? HNIW/AN 80/20 or what?

I mean, for example, well-known class of melt-cast eutectic-AN HE, such as Formit, EAK(VoD 7.5),NEAK(VoD 8.02), DAG and so on. There are also examples of AN-unexpl.fuel eutectics with good VoD and impulse.

PHILOU Zrealone - 8-3-2006 at 10:21

NH2-NH2/AN

Glycine As A Sensitizer For AN

jpsmith123 - 9-3-2006 at 03:05

Speaking of AN mixtures, attached is an interesting patent.

(BTW, thanks for that AN paper, Axt).

Attachment: 4746380.pdf (397kB)
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rot - 9-3-2006 at 11:17

Glycine is not the same is glycerine or is it?

PHILOU Zrealone - 10-3-2006 at 05:56

Glycerine is propantriol trivial name.
So CH2OH-CHOH-CH2OH

Glycine is NH2-CH2-CO2H...the simplest of the aminoacid.
(alfa )amino acetic acid...

The sensitisation comes from the presence in the mix of

Free HNO3 (tiny %)
NH2-CH2-CO2NH4
HO2C-CH2-NH3NO3
NH4O2C-CH2-NH3NO3

Expected VOD in the range of between plain CH3-NH2.HNO3... and AN!

DeAdFX - 10-3-2006 at 07:45

Is it safe to assume that any Ammonium compound with an oxidizing cation (dinitramide, perchlorate, trinitromethane etc) would work in place of the Nitrate of Ammonia?

PHILOU Zrealone - 10-3-2006 at 09:58

Quote:

Originally posted by DeAdFX
Is it safe to assume that any Ammonium compound with an oxidizing cation (dinitramide, perchlorate, trinitromethane etc) would work in place of the Nitrate of Ammonia?

YEP

artem - 19-3-2006 at 08:35

Quote:

Originally posted by Axt
BTW Axt, is the VoD given in Cooper correct, i.e. 5.27 km/s at d=1.3?-Thats the same number thats given in LLNL handbook, but following its reference back to J. Phys. Chem. 59, 675-680 (1955) it shows that that its a calculated number for its "ideal" velocity. The article also shows some actual measured VOD figures for AN at various diametres.

For pure AN (1.05g/cm3) Mader gives the calculating value VoD=5.262km/s and cites value ~4.5km/s as the experimental, [J. Phys. Chem. 61, 194 (1957) -also M.A.Cook]. Is this value also some type of "approximation"( I have no this reference)?

For pure AN 4.5-5km/s seems not fantastic, as at density ~0.85 the measured VoD=3.95 vs calculating 4.0 (see attachment). But the charge seems too large

[Edited on 19-3-2006 by artem]

Attachment: DS8-560.djvu (398kB)
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Axt - 19-3-2006 at 22:24

Quote:

Originally posted by artem
For pure AN (1.05g/cm3) Mader gives the calculating value VoD=5.262km/s and cites value ~4.5km/s as the experimental, [J. Phys. Chem. 61, 194 (1957) -also M.A.Cook]. Is this value also some type of "approximation"( I have no this reference)?

Unless I'm reading it wrong, the 4.5km/s is also a calculated number, with the actual considerably lower. Thats the "aluminized explosives" article I attached into another thread. Here 'tis again:

http://scipic2.ft100.net/banners/aluminized%20explosives.pdf

JohnWW - 19-3-2006 at 22:46

Quote:

Originally posted by artem
For pure AN (1.05g/cm3) Mader gives the calculating value VoD=5.262km/s and cites value ~4.5km/s as the experimental, [J. Phys. Chem. 61, 194 (1957) -also M.A.Cook].
(cut) Thats the "aluminized explosives" article I attached into another thread. Here 'tis again:
http://scipic2.ft100.net/banners/aluminized%20explosives.pdf

That link is broken already.

Axt - 19-3-2006 at 23:01

Yeh, host is down.. again.

Attachment: aluminized explosives.pdf (853kB)
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rot - 25-3-2006 at 03:36

When you choose a fuel for a mixture, e.g. adding carbon or aluminum to ammonia dynamite to use up the oxygen, how do I determine what the best fuel is? is heat of combustion and gas output all that matters?