Sciencemadness Discussion Board - Xylene vs. NM vs. Methanol

Xylene vs. NM vs. Methanol

holmes1880 - 1-3-2011 at 22:53

The AN activation patent talks about using xylene as a sensitizer for activated AN. 2% is said to be sensitive to #6 cap(I have doubts since their tests charges are rather immense at 1kg so a smaller sample will likely fail).

So, I have three interesting topics:

1. Can xylene match NM in sesitizing the AN in small percentages?
2. Why did Hurst use methanol if it is so desensitizing to begin with
3. Is ANNM with small NM ratio (say 5%) substantially more sensitive than ANNM @ 15% ratio?

We're not talking OB and maximum power, just the mixes' ability to detonate with a small cap.

Swing away.

[Edited on 2-3-2011 by holmes1880]

hissingnoise - 2-3-2011 at 04:21

These mixtures, adjusted for neutral OB will generally be more cap-sensitive than lean or fuel-rich binaries . . .

quicksilver - 2-3-2011 at 07:29

Hurst placed few "how's & why's" in patent literature or discussion due to the patent protect agenda and some of the changes made in "trade secret" agenda in patent procedure during the time when the KineStik & KinePak products were actually being marketed. They were truly his products and many of the issues surrounding ammonium nitrate's "activation" were kept close to the vest.
A very important issue, should you re-read the "cap sensitive" patents dealt with density and maintaining a water-free product. Prill tower design that produced a dense product were less desirable than those that lowered the density as this worked hand in hand with keeping the product water free when exposed to a warm dry environment. Prills were not easy to work with & (IMO) it was a production issue that kept this from issue around for as long as it has. Many time the same plants that made a solid nitrate also produced various forms of nitrogen, acid, etc.

The real KinePak formula is much more powerful than a "ANFO type" (HN4NO3 + hydrocarbon fuel). The following is just my opinion.....
Why Hurst experimented w/ methanol (1) is a question based in the context of his experiments. Much of his actual experimentation was directed toward packaging of the KineStik/Pak product and the displacement of water was a very important issue. Much of this was not made public as it was part of patents.
The ratio of 185ml per was based upon a great deal of "side issues". He had a product that needed to be mixed when used. Would more have a greater effect? There was a "sensitizer" of aluminum that brought the heat way up. However it also could have been a very important step in making sure that the product was consistent in it's release of energy. Note that many ANFO-type products (very often) did not detonate completely. leaving a great deal of unused nitrate around the borehole, etc as evidence that the explosion was inefficient. This did NOT occur with aluminumized "Kine-products".

Nitromethane has a hygroscopic nature that is often over looked. I am fairly sure that the OB issue and the potential for maintaining a dry product kept the level of NM at what it was and not greater. There was a great deal of experimentation with prill density levels.
What functioned well at a certain level may have a greater attraction for water at a higher level, etc, etc, etc. One of the reasons for attempts at "blending" of nitromethane and hydrocarbons or other fuels has been used to reduce or eliminate any possibility of water contamination*.
Methanol(1) is also used as a common dilution in commercial NM. This was not done to reduce hygrocopicity but as a production issue. The product had a design similarity to water-gels in that it's a delicate balance that makes if efficient. It's efficiency & safety was what sold it.

*model fuels (Castor Oil), etc.
One of the problems in seeking answers to questions via patents was the "trade secrets" ruling that started becoming very prevalent in many patents.

[Edited on 2-3-2011 by quicksilver]

holmes1880 - 2-3-2011 at 15:37

Quick,

So what you're saying is that NM is hygroscopic and so low ratio NM are more sensitive because they grab on to less water.

Xylene is not know for its hygroscopy, so methinks it could be a good sensitizer in small percentage for AN.

simply RED - 3-3-2011 at 01:03

Also quite good fuel for ANFO is pine turpentine, which contains isolated double bonds. These doble bonds C=C brake easily and make the mix sensitive.
Even better will be a hydrocarbon with isolated tripple CC bonds.
Anyway, I have not made comparison between turpentine and xylene - which one is better.

Both xylene and turpentine work much much better if 2-5% Al powder is added to the mix. Like 4-5% xylene/turpentine and 3% Al powder.

Do not expect these mixtures to be cap sensitive. Even if they are - never use a single cap but at least 20 grams brisant booster.

[Edited on 3-3-2011 by simply RED]

quicksilver - 3-3-2011 at 07:16

Quote: Originally posted by holmes1880

Quick,

So what you're saying is that NM is hygroscopic and so low ratio NM are more sensitive because they grab on to less water.

Xylene is not know for its hygroscopy, so methinks it could be a good sensitizer in small percentage for AN.

I did want to be clear that I was offering opinions on certain things as Hurst played a great deal of his lengthy research close to the vest. He was supporting a patent that was the corner-stone of his financial stability, so a lot of the material I wish I could quote from; I do not think he made public.
So what I believe is that the low ratio is what worked. It presented a delicate balance & mixed very well. It was dyed & so it had a visual que to determine if it spread evenly the product would be a CONSISTENT pink.. Even aluminized products showed a clear pink. The red dye of the day was generally the very compact Sudan Red. Instructions on mixing was always to be carried out to the letter. "Disperse Red" has also used Sudan Red coloration for it's tenacious ability: I would imagine it should work with Xylene as well.

I had seen several of the packaged products & there was a great deal of instruction. They were not shipped in a manner than could readily bring them together, etc.

TTBoMK the very light Xylene mixture functioned certainly as well or better than a 4-6% fuel oil / ANFO product as it was more brisant & consistent. The major consideration with many of these is the need for dye in the fuel component. If you read the Xylene material over several times, one thing was barely touched upon; result of the prill configuration (density levels) may be a distinct issue.

The visual que shows how consistent the mix was made: this issue can be critical. - Certainly it was in a commercial product.
From a first impression in-so-far as the use of Xylene from his materiel on the subject, it seems an addition of aluminum (@10% overall weight or less) would be appropriate with a "Xylene-ANFO" if the agenda were to strive for cap sensitivity & consistency in detonation Even in such a seemingly simple thing, the variables can interact. Many industrial setting (bore-holes) the use of a det-cord traveling the length of the hole was not excluded from a material being sold as "cap sensitive". The issue of "critical diameter" is another issue that should always be addressed in studying why a blasting technique would function in a certain manner.

Since Xylene is a non-polar solvent I agree, the chance for water introduction isn't great however it would be a very good idea to test (an OTC product) or perhaps dry the Xylene via distillation for reasons of purity, etc. Many failures in chemistry have their roots in the impurities from a reagent's unknown background.

[Edited on 3-3-2011 by quicksilver]

holmes1880 - 3-3-2011 at 22:09

Well, I tried xylene 2% with no success. Turpentine I did not try, nor will try it. It is impossible to work with the stuff because of the toxic fumes and aroma that stays even in a well-ventilated room. It is horribly toxic, both xylene and turpentine. I need something more natural and non-toxic. Gosh, even methanol and NM seem like harmless liquids compared to those two. I am not surprised xylene hasn't caught on.

So, I figure methanol might not be that bad of an idea for prilled mixes. It may desensitize, but its still more sensitive than diesel fuel.

simply RED - 4-3-2011 at 01:31

Hm... You put 1, 2 kilos milled and dried AN in those 10 liters plastic water bottles and then add the turpentine and Al powder. Mix well with the cap of the bottle closed and then discharge the mix in the container of your choice...

holmes1880 - 4-3-2011 at 08:56

Red,

Just mixing that way will get you high or give a headache. You have to have mask, gloves, and actually doing all the mixing outside. Working with big quantities is extra bad...

SB15 - 4-3-2011 at 11:27

I'm wondering if a higher xylene % would result in a more sensitive mix, especially when dealing with smaller charge diameters. 2% is very little fuel, and it may have problems spreading uniformly throughout the prills, even with the help of AN activation and the resultant capillary action that comes into play.

Some quick stoichiometry puts the optimum mixture (Assuming CO2, H2O, and N2

at around 92.5% AN and 7.5% Xylene. Maybe test that out and see if you get better results.

I understand your toxicity concerns, but while volatile hydrocarbon vapours are very irritating, I'd be more concerned with handling methanol, as its metabolic products are particularly nasty. Methanol -> formaldehyde -> formic acid. The latter attacks the optic nerve and can cause permanent blindness with as little as 10-20mL absorbed methanol. Aromatics are typically only dangerous when the exposure is significant and long term.

That said, it's a good idea to wear a good quality respirator and gloves when handling most of the materials that are relevant to this hobby. I know you work with ETN, so you must already have the PPE to deal with fuming nitric acid, oxides of nitrogen, hot alcohol vapours, etc. Xylene seems pretty tame in comparison to many of those.

Quote:

Also quite good fuel for ANFO is pine turpentine, which contains isolated double bonds. These doble bonds C=C brake easily and make the mix sensitive.
Even better will be a hydrocarbon with isolated tripple CC bonds.

There's definitely a lot of energy to be had in carbon-carbon pi bonding, or electron delocalization as in benzene ring derivatives. Turpentine is a decent OTC source of unsaturated hydrocarbons, but I'd certainly love to be able to experiment with liquid alkynes like diethylacetylene. Dicyanoacetylene with AN might yield an interesting explosive as well, given the tremendous amounts of energy stored in the C-C and C-N triple bonds. Ah, we can dream...

[Edited on 3-4-2011 by SB15]

simply RED - 5-3-2011 at 14:48

One winter I was shooting alomost every day charges larger than 600 grams containing ammonium nitrate, Al powder and turpentine. I happened to live near a forest that days and it proved to be a good testing ground. Not even once I had misfire or partial detonation. Boosters were always 100+ grams TNT equivalent. Not even once I noticed any excessive smell (this may be because of the cold weather).

SB15, yes alkynes and nitriles should be tried for sure!

Fulmen - 6-3-2011 at 00:58

Quote: Originally posted by SB15

... handling methanol, ... can cause permanent blindness with as little as 10-20mL absorbed methanol.

I wouldn't worry about it. The RC-guys use methanol all the time, never heard of this being an issue. 10-20ml might not be a big drink, but to absorb that much through the skin or form vapor you'd probably have to pour a quart over yourself.