AN / Xylene - #6 Cap Sensitive

[HVD]

Nitromethane is expensive and quite hard to get in some parts of the world. I was looking into alternative cap sensitive AN mixtures that do not use Nitromethane.

US Patent 4 093 478 "Activated Ammonium Nitrate Explosive Composition" details many cap sensitive AN compositions, however almost all of the fuel compositions tested in the patent contain some part Nitromethane, making them unsuitable.

However, page 9, lines 6 to 32 detail that 1000 grams Activated Ammonium Nitrate and 25 grams Xylene make a relatively powerful number 6 cap sensitive mixture.

To paraphrase the patent:

"The charge, when placed on a 1 cubic yard limestone boulder, shatters it into pieces of a mean diameter of about 10 inches."

The mixture seems attractive for 2 reasons:

1) Xylene is cheaper and less restricted/high profile than Nitromethane
2) The Ammonium Nitrate can be agricultural grade and does NOT need to be powdered.
3)Minimal preparation (see below).

The only step than must be taken is to Activate the AN prills, which is simply wetting them with 5% by weight water and drying them in an oven at 60 degrees C for 30 minutes.

Has anyone any experience of this mixture or can compare it to regular AN / NM?

[Kleng]

I was just thinking of the activation of AN. I got a drying box giving 40 degrees temperature. This is stable temperature. Could this one be used?

[KrIsPy]

Thanks HDV for this information...

I have been looking into various cap sensitive AN mixture which have comparable power to that of ANNM.

AN/Xylene has come up in other threads on this forum as a possibility, but always with the addition of NM.

While standard ANFO, with a low enough density, can also be cap sensitive, its power in this form is quite low, not to mention the difficulty of keeping the density low enough for cap sensitivity.

At some point, I intend to test various solvents and fuels for ANFO to compare power and sensitivity...
For now, after bringing up this patent which mentions Xylene specifically, I think I am going to compare AN/Xylene with AN/Turpentine (mentioned in the ANFO-k thread) and see which one performs better, as in what ratios are best, required confinement and what size cap is necessary for detonation.

Just out of curiosity, prior to this thread, I was under the impression that both AN/Xylene and AN/Turpentine were similar to ANNM in that the percentage of fuel, Xylene or Turpentine, should be around 20-30%...so, is this false and should the fuel percentage rather be closer to that of standard ANFO or ANWAX?

[High Density]

A percentage of 6% Xylene is a good ratio for AN/Xylene I think, And some confinement to achieve full detonation.

20-30% is way too much overfuelled.

Mayby ANNM-Xylene 90/5/5 are good ratio's for a cap sensitive, powerful mix.

[Charles Owlen Picket]

This issue gets back to when there were intelligent postings on alt.eng.explosives. YES, it does shoot. And YES the prep of the AN is paramount (as is ratio of xylene). This was going to be Gerald Hurst's baby, as it were. As he was doing a lot of research in that area. Health issues interceded.

(OT warning)
And on that note, it seems that a Hell of a lot of folks who were fine research chemists started getting serious health issues in their 50's - 70's. We lost a lot of people to preventable illnesses.....I'm not going to whine about that shit but it really took it's toll on a lot of folks.

[Bert]

(OT)
Yep. A whole crop of people I used to work with at the Physical Sciences Labs of the U of * took a similar hit. Worked around a lot of chemicals, a lot of different RF frequencies and enough radiation so we all wore rad badges if we worked in the buildings with various particle accelerators, beam lines and/or targets. Add to that the exposures in the WWII thru Vietnam military that a large number of the technicians and staff had, and we had our own cancer cluster going.

[Rbick]

I recently found some Xylene back in my storage room, so I think I may try this out. 6% is the proper amount of Xylene to be used with AN, 20-30% is far too much. Well actually 5.9%, but I'll round up to be safe. I think I may add some Al to further sensitize the charge.

Xylene is C8H10, so in order for fully oxidize you need 21 mols of O (I'm aware O is a diatom, this is just to make it easier to understand) to make 8CO2 + 5H2O. Since AN releases 1 mol of O we need 21 mols of AN. The molecular mass of AN is 80

80(21) = 1680.

Plus the mass of one Xylene mol to be oxidized is 1786.

106/1786 = .059 or 5.9%.

The interesting thing about adding Al to this is the way Al acts in the reaction. Instead of taking Oxygen from the AN, it strips it away from the formed gasses of the above reaction. So if Al where to be added in the proper amounts, the 5H2O would become 5H2 and the 8CO2 would become 8CO while the "stolen" Oxygen reacts with the Al to produce Aluminum Oxide (Al2O3). The great thing about this is you will get more thermal energy output without reducing the gas output (as far as # of mols) of your charge! If too much Al is added however, it will strip the O away from the CO and leave you with just C, reducing your gas output. Al also decreases VoD as more is added, but increases energy output. We also have to remember that the 21 mols of AN releases 2H2O per mol as well.

From the resulting gasses, 55 mols of O can be exchanged without reducing the gas output. The 21 mols AN give out 2H2O each, and the oxidized Xylene leaves 13 available Oxygen mols.

It would take about 36 mols of Al to be oxidized by the 55 Oxygen, giving you about 18Al2O3 (This is approx, so its not right on). Mass of Al is 27.

27(36) = 972 + weight of AN and Xylene = 2758

So overall weight percentage would be

35% Al
4% Xylene
61% AN

This was kind of a random off shoot of the thread, but I think it applies. While 6% is the right amound for O balance with AN/Xylene, that doesn't exactly mean 20-30% Xylene wouldn't work. I'll have to find out... But Adding Al helps sensitize the charge, and sensitivity could be an issue with Xylene/AN mixtures. Although the above would give the most effecient use of the added Al, it isn't exactly nessecary as any Al not oxidized will do so via taking O from the air (hence the use of Al in thermobaric charges), and adding something like 10% Al would work fine too. I'll do some tests with ANNM and AN/Xylene and post the results. :)

[TreverSlyFox]

Hmmm, I hope this works out as it's much harder to obtain Nitromethane plus the cost with Hazmat shipping. Now Xylene I can buy at the Farm Store or Hardware for about $9-$11 a gallon which would make my pocket a lot more happy.

Is my thinking correct that density will still be an issue, the same as ANFO? The cost of micro balloons isn't an issue but it sure would be nice to know they were needed before hand.

[Charles Owlen Picket]

I recently found some Xylene back in my storage room,


I think you know this stuff but I'll pop it in here for completions sake..... make sure you prep the AN properly, use a minimum 6" diam containment (needs a lot of area). The Al is an interesting idea and you MAY get it to shoot at smaller than 6".

Hurst used a variety of tools to determine the specifics of the AN. As I remember, he used a lab oven and always placed emphasis on the absolute dryness of the AN & it's density.

I have seen real DuPont blasting grade AN and it's a very valuable thing to actually see, feel, and weigh it....it's not like the prills we get accustomed to seeing with fertilizer, etc. Phase stabilization was something that Jerry debated (in terms of it's actual impact on the finished product as well as it's validity). Phase stabilize a standard fertilizer prill and you will get a hard little rock. Oven dry them gently with a bit of water wash as in the patent and you will get a very dense but easily crushed little pearl.....there is a difference.

If we extrapolate from the patent: Al should be last addition. So prep the AN, add the xylene; wait, then finally add the Al and seal. I'm pretty sure it will shoot strong but at 1st I would consider a booster or det cord priming to establish a starting point.

[Hinckleyforpresident]

Earlier tonight I successfully detonated 1/2 kilo of AN / Xylene.

The ratio that I used was 20:1 AN:Xylene. It was set off by a 50 gram APAN (1:10) booster which was in turn set off by a copper pipe blasting cap (1.5 grams 1:4 APAN and .5 grams acetone peroxide). The whole thing was confined in a bent coffee can.

It was quite powerful. It was placed under about 2 feet of sand in a sand dune. The next day I went back and measured the crater, it was four feet wide and two feet deep.

It was also quite loud, it woke up my neighbors about 1.5 - 2 miles away (They described the noise as “Ba-Boom!”).

This seems like an awesome alternative to AN / nitromethane since xylene is dirt cheap in comparison.

Next time I try it I will post pics and video.

[Rbick]

Sounds pretty awesome. I know what its like to get calls from the neighbors :D. But I think we're trying to figure out whether an AN/Xylene mix is cap sensitive and doesn't have to be buried in hopes it will perform similar to ANNM. My personal opinion is that it may be sensitive, but considering NM is a high explosive nitro compound and Xylene is not, it won't be nearly as powerful. I've been wanting to try it, but with classes starting soon I've been rather busy...

When I do test it however, I'll probably start using a 1g AP and 1g ETN cap and see how it goes. I guess it would make sense to not add Al on these tests.

Thats cool you are secluded enough to call someone who lives 2 miles away your neighbor. I'm jealous :mad:

[Charles Owlen Picket]

Gerald Hurst's research may still be available as per past posts in UseNet & patents. He did some very interesting research on the subject. If you can grab those posts & patents DO IT as they may not be available in the future.

IF the AN is either prepped or is blast-grade then a variety of things are possible (fertilizer grade is NOT he same; Hurst made a point of emphasizing this!). Some of his research was ANFO using both Xylene and gasoline as substitutes for diesel. As well as KNO3 as substitute for AN.

The short answer is yes; given a booster. The complete answer is quite complex and does hinge on enclosure, preparation of the AN, initiation, & ratio.

Noting that ANFO is NOT ANNM (the latter being a much faster more brisant material) NM is not really a high explosive per se'. As experiments in shipping have proven (DOT 1971), it is not as vigorous as gasoline. Given an amine additive it's a whole different ball of wax of course.

HOWEVER....if a true HE like ETN were to be mixed with the AN there is a distinct possibility that a material such as the old-time AN-TNT comp is available (remember ETN is a real unknown as well as being a nitric ester as opposed to a nitro benzene!). The ratio could be VERY wide depending on the purpose.

Background study as to bursting charges used in WWII would guide the student to a variance that is so wide as to make even a single ounce of ETN produce a great deal of final product. AN (95.5%), Xylene (4.5%), ETN (+ or - 10% of total wight ratio)*, Al (not more than 15% total wight ratio)*
Extrapolated, this would be a typical example - AN and Xylene is 95.5% + 4.5%. This would be weighed and depending on that number the addition of an HE would be (n%) and if heat were desired the Al would be (n%) IIRC.

But do the background as I am really just pulling this from memory and it was just a patent of Hurst's that I remember....not something I witnessed, etc. However I'll bet I am damn close.

[Hinckleyforpresident]

The only reason that it was buried was to lessen the sound. However, I imagine that a similar composition would detonate above ground if contained in something else, such as PVC or a can.

I am not so sure about reliably detonating it without a booster. Once my 10 lbs of AN get here I will certainly try just using a cap.

And to Rbick regarding the AN/Xylene/Al ratio:

Are you sure that those numbers are right? I also calculated it for a complete burn of the xylene and the aluminum and the ratio that I got was something like 94:5:1 AN:Xylene:Al. I cannot actually find the paper that those numbers come from though, so they may be off by +/- 1 percent (I will post the actual ratio once I find the paper)

Am I simply incorrect or did I misunderstand your ratio?

[TreverSlyFox]

Gerald Hurst's Patent #4093478 " Activated ammonium nitrate explosive composition" is available at http://www.freepatentsonline.com/4093478.html

[Rbick]

Yeah my calculations are correct. It would be optimized to turn H2O into H2 and CO2 into CO, donating the stripped Oxygen to the Al. It may be off by .6 or something because I rounded. I have the calculations written down in my notes, I'll get them up later if I have time.

You have to remember that Al "strips" the Oxygen away from Water and CO2 during formation, every 2 Al mols taking 3 Oxygen. Its not all 1+1 ;). 1% Al wouldn't make much of an impact on the explosives overall performance.

[simply RED]

It should be more sensitive with pine turpentine since isolated double bonds are less stable than aromatic rings. Xylene (mineral turpentine) is also a very good alternative to NM. (No way to behave as good as ANNM or AN+IPN but still okay)

It is a waste of Al to add more than 10%. Actually, adding more than 5-8% is a waste, since more Al can not burn in these conditions (AN).

[Rbick]

Are you sure about the 10% of Al? From what I understand, thermobaric weapons use an excess amount of Al which burns by bonding with Oxygen in the air, creating the thermo (heat) baric (pressure) effect.

I shot this video (http://s164.photobucket.com/albums/u6/pudgedog69/?action=view&current=annmal.flv) last week. It was a 200g charge made up of 65% Al and 35% ANNM. I remember reading in the thermobaric thread here in RS, they discuss using 30% TNT to 70% Al in some weapons. If you don't want to make heat and pressure, adding a lot of Al wouldn't be a good idea. And Al does decrease gas output and VoD as more is added, but increases heat output. Depends on what you want I guess. If I'm not correctly understanding your point, I apologize.

[Charles Owlen Picket]

I'm pretty sure about 10% of overall weight. HOWEVER I don't think that oxygen balance was the thrust of the issue when it was proposed so there would be room for adjustment if that issue enters the equation.

I really need to dig that stuff up but have been so damn busy....I am guessing that it may have been an issue of a series of sensitizers used in that fashion.

[simply RED]

"Are you sure about the 10% of Al?"
Pretty sure from experimental data!

Take into consideration what are the conditions, maybe NM makes a difference. Maybe a bigger density makes difference too? Maybe AN is not the best "oxidizer" for thermobarics ?
Or Al is not the best fuel?

Schmel for example (one of the best thermobarics) uses 40% Mg powder and 60% IPN (and few % gel forming agent) as a main charge and at least 200g RDX as a detonator.

[nbk2000]

The IPN is used to act as an oxidizer/burn accelerant, to enhance the combustion of the magnesium.

[simply RED]

[50 : 50 - Propandioldinitrate : Mg powder] should be extra powerful (plus PGDN is thousand times easier to synthesize than IPN) !
Gelled with 5% DBSP or 3 ; 4 % NC.
Instead of clear PGDN, a mix of PGDN and EGDN could be used for additional brizance.
It is not a matter of dispersing a lot of fuel. The real aim is to disperse fast - an energetic fuel that will fully burn.

Booster - at least 200g EGDN, PETN, RDX etc - plastic (or liquid). The booster in a thin Al pipe inside the gelled main charge - through the whole length of the device.
Advantage will be to detonate the booster simultaneously from the both ends. Or detonate it from the geometry center.

Advantages: diameter of the whole charge - 3 times the diameter of the booster; length of the charge - 4 diameters; booster diameter - higher than 3cm; finer Mg powder; ultra fast, ultra strong booster

Advantages to the overall effect: Detonation in enclosed space; detonation near combustible materials; extra strong VS infantry and structures, (weak VS armor) .

[Hinckleyforpresident]

Just did about 2 kilos and taped it.

http://www.youtube.com/watch?v=z3weXPwNbuk

It did serious damage to the bolder hanging over it. Also it dug a nice hole.

[nbk2000]

I would suggest that, in the future, you use a tripod (or other solid object) to support the camera, because camera wobble just screams AMATEUR.

And it gets really bad when people are close to an explosion and they flinch from the noise, taping more of the ground than of the explosion.

[inventorgp]

Oh if only I had access to AN I would try it. AN in ice packs have been replaced with some diethyl something-a-rather-crap. Xylene is quite expensive here, AU$25/L.

To think that my bottle of it is just sitting on a shelf all alone, when it could be having fun with AN. :p

NBK, haha funny, I saw your post on youtube.. too bad I can't login at the moment

[W4RGASM]

I've always found aussie ice packs to be urea; which is useful in itself.

Furthermore, hardware store xylene is a mixtuer of isomers which I've found interferes with thigns like TNX.