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Author: Subject: Ammonium nitrate detonation through oxypropane
DHT420
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[*] posted on 24-6-2011 at 08:43
Ammonium nitrate detonation through oxypropane


I found this post on another forum:

"My uncle used an interesting method to detonate ammonium nitrate for making farm ponds. He would fill a 10lb propane tank with unmodified prills, tap in a spark plug (sealing with superglue), and overpressurize the tank with 2/1 air/propane until just before the relief valve popped. He then let the tank sit 24 hours to mix.
The tank's propane was ignited with an ordinary ignition coil wired to the sparkplug as per usual. Detonation was achieved from the heat of combustion in the air gaps between the prills."

Now was it possible the man's uncle was actually detonating AN, or that the "detonation" was just a confined explosion of air/propane? Ammonium nitrate is notoriously insensitive and low order explosives are not enough to detonate it, I don't understand how a compressed fuel/air mixture could do the trick.

Anyone willing to try this out?
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holmes1880
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[*] posted on 24-6-2011 at 10:06


Bahahahaha. Hid uncle wad a red neck, I recken' . He shouda tried dat tanneeeerite.
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AndersHoveland
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[*] posted on 24-6-2011 at 10:40


First, it is illegal to refill propane tanks. Second, doing what you described is extremely dangerous, pressurizing a mixture of air with a flammable gas into a big tank under high pressure is likely to result in an explosion, as the gas is very vulnerable to ignition from an ambient static discharge. I also doubt that the superglue seal would hold under such pressure.

But, theoretically the idea would work. Pressurized propane tanks contain both propane gas floating over propane in its liquid form. I you shake a half-full tank, you can hear the liquid swishing around. The AN probably would form a fuel mixture with the liquid propane at the bottom, while the spark would ignite the pressurized air-propane gas mixture above. It may be possible that the pressurized propane-air mixture may be powerful enough to detonate the AN-liquid propane mixture.

I do not even know how one would place the AN into the tank to begin with.




I'm not saying let's go kill all the stupid people...I'm just saying lets remove all the warning labels and let the problem sort itself out.
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The WiZard is In
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[*] posted on 24-6-2011 at 11:29


Quote: Originally posted by AndersHoveland  


But, theoretically the idea would work. Pressurized propane tanks contain both propane gas floating over propane in its liquid form. I you shake a half-full tank, you can hear the liquid swishing around. The AN probably would form a fuel mixture with the liquid propane at the bottom, while the spark would ignite the pressurized air-propane gas mixture above. It may be possible that the pressurized propane-air mixture may be powerful enough to detonate the AN-liquid propane mixture.

I do not even know how one would place the AN into the tank to begin with.


I really shouldn't feed the trolls [Sherlock]...

There is NO air in a propane tank for obvious safety reason(s).

As you have noted - how did he get the valve out to fill la tank
with AN?

NB - I rang up Superman and he denies all knowledge.
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Rogeryermaw
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[*] posted on 24-6-2011 at 11:55


it can be quite the bitch to turn the valve out of a bbq tank but it can be done. i cranked the valve out of one and welded a 3/4 rigid coupler in its place to make a large scale phosphorus retort. ya this sounds like a horribly unsafe practice but that's some of the retarded things we rednecks do out in secluded properties. sort of like loading the AK to shoot at propane tanks looking for a boom. it never works, is inherently dangerous, but is fun as hell!



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Rosco Bodine
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[*] posted on 24-6-2011 at 11:57


All the larger refillable propane tanks I have seen have the valve screwed into pipe threads. So if follows pretty likely that to remove the valve a wrench would be applied and the valve unscrewed, with reassembly in reverse order :P
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[*] posted on 24-6-2011 at 12:03


Quote: Originally posted by Rosco Bodine  
All the larger refillable propane tanks I have seen have the valve screwed into pipe threads. So if follows pretty likely that to remove the valve a wrench would be applied and the valve unscrewed, with reassembly in reverse order :P


those valves are cranked in by a machine who does not care about torque, but is programmed to run them in a certain depth, same as the safety relief valves on water heaters. often a cheater bar or additional set of hands is required. if the valve is to be sacrificed it can be cut off and the threads removed by drilling the soft brass, but in the op's case, the valve was being reused.




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[*] posted on 24-6-2011 at 12:11


Quote: Originally posted by AndersHoveland  
First, it is illegal to refill propane tanks. Second, doing what you described is extremely dangerous, pressurizing a mixture of air with a flammable gas into a big tank under high pressure is likely to result in an explosion, as the gas is very vulnerable to ignition from an ambient static discharge. I also doubt that the superglue seal would hold under such pressure.


This is a good point, Any oxy/gas mix under pressure is a huge danger and death wish IMO. !!
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[*] posted on 24-6-2011 at 13:03


Quote: Originally posted by Rosco Bodine  
All the larger refillable propane tanks I have seen have the valve screwed into pipe threads. So if follows pretty likely that to remove the valve a wrench would be applied and the valve unscrewed, with reassembly in reverse order :P


The problem I have found with 32 lb tanks dobe -- the shield
that protects the valve is welded onto the tank in a position
that makes getting a wrench on the valve impossible. Even
if you cut the shield off which would make the tank un-refillable
unless your the local propane dealers drug dealer.

Then how do you hold the tank while you apply a wrench to the
valve? A chain wrench would work... how do you hold the chain
wrench.

Yes you can brake/cut the valve off and .... well using a Ridgid®
plumber's stud remover didn't work for me. Me thinks
they use a very-very good thread sealer. You can drill it out,
however, then you have to re-thread it and find a new valve.

Comes now the question — why would propane react with ammonium nitrate?

You cannot get it to burn without oxygen. So.........!?!
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pjig
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[*] posted on 24-6-2011 at 13:37


This subject should be moved to the detritus thread IMO.:P
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dann2
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[*] posted on 24-6-2011 at 15:24
Kewl!


Had to laugh at some of the answers. The original poster asked such and such. The subject then turned to: How to screw out a valve from a tank? LOL
The original question may be a bit off limits as it is asking 'Will this bom work?

The original question is this. Can Ammonium Nitrate (prills) be made to explode (in metal tank) if they are impregnated with a 2 to 1 gas mixture of air/propane under pressure(all gas, no liquid propane mentioned). Pressure of gas mixture not mentioned.

The total mixture would be deficient in fuel. Add some diesel first?

Dann2's question. Would it work if a stioc. ratio of (pure) Oxygen/Propane were used.

I'll try this in the morning. Mother in law is expected on a visit..........

Dann2
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pjig
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[*] posted on 24-6-2011 at 16:35


LOL ... sounds like some kewl bullshit out of the anarchist cookbook, from the Q. of his first post.

[Edited on 25-6-2011 by pjig]
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DHT420
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[*] posted on 24-6-2011 at 16:58


Quote: Originally posted by pjig  
LOL ... sounds like some kewl bullshit out of the anarchist cookbook, from the Q. of his first post.

[Edited on 25-6-2011 by pjig]


Anarchist Cookbook is good stuff, don't know why you're knocking it. It has longevity and charisma, and is scientifically accurate.

Seriously though, I'm asking questions about the veracity of an anecdotal story I found on a chemistry enthusiasts forum. If that makes ME a kewl then I have a pretty good start here.
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[*] posted on 24-6-2011 at 17:02


Quote: Originally posted by dann2  
Had to laugh at some of the answers. The original poster asked such and such. The subject then turned to: How to screw out a valve from a tank? LOL



Actually. This reminds me of the old adage 'bout bear stew...
First you have to kill the bear. Here - First you have
to remove the valve.
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[*] posted on 24-6-2011 at 18:14


Quote: Originally posted by DHT420  


Anarchist Cookbook is good stuff, don't know why you're knocking it. It has longevity and charisma, and is scientifically accurate.


what cookbook did you read? The one I read a lot of BS in it. Bananadine... Lol

[Edited on 25-6-2011 by Bot0nist]




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Mr. Wizard
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[*] posted on 24-6-2011 at 18:19


Quote: Originally posted by AndersHoveland  
First, it is illegal to refill propane tanks. Second, doing what you described is extremely dangerous, pressurizing a mixture of air with a flammable gas into a big tank under high pressure is likely to result in an explosion, as the gas is very vulnerable to ignition from an ambient static discharge..


Refilling propane tanks isn't illegal in the US. Do you throw your tanks away when you are done with them? The smaller 1 pound tanks say it is against DOT regulations to transport refilled tanks, which is a regulation on commerce, not on the act of refilling the tank. Even the small tanks are easily refillable from the bigger 20# ones with a minimum of equipment and effort.

I agree it would be stupid and dangerous to add air or an oxidizer to the pressure.

[Edited on 25-6-2011 by Mr. Wizard]

[Edited on 25-6-2011 by Mr. Wizard]
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freedompyro
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[*] posted on 24-6-2011 at 21:58


Quote: Originally posted by DHT420  

Now was it possible the man's uncle was actually detonating AN, or that the "detonation" was just a confined explosion of air/propane? Ammonium nitrate is notoriously insensitive and low order explosives are not enough to detonate it, I don't understand how a compressed fuel/air mixture could do the trick.


Most explosives that use liquid oxygen detonate just fine... Compressed air and propane? Yep... That should detonate AN just fine... Would be real tricky to get the ratio's correct though.
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dann2
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[*] posted on 25-6-2011 at 03:58




It is simple enough to get the valve out of a Propane tank. Just unscrew the valve with a wrench. The tank will of course be empty (leave the valve fully open for a few days).
I have done it several times to use tanks for other purposes (not packing with exp's!).

In order to help impregnate the prills with the air/Propane (or much better Oxygen/Propane) you could stick a vacuum on tank filled with AN prills for some time and then commence adding gasses.
You would need flow meters etc to get amounts roughly correct. Not terribly simple.
There would be little chance of a static discharge inside a metal tank (no electric field (I think)).
I would be somewhat nervous though.

The question is: Would the AN actually detonate? (successful pond project)
Freedonpyro votes yes.
Dann2 has no idea.

This subject is legitimate on Sci.Mad. I have read the rules and NOWHERE has it stated that a discussion regarding the making of ponds* is prohibited.

Dann2

*duck or otherwise


propane.jpg - 18kB



[Edited on 25-6-2011 by dann2]
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[*] posted on 25-6-2011 at 04:41


It is really dodgy* to be filling up a tank of propane with AN, with oxygen.

For a start we do not know if the autoignition temperature of propane would be lowered below room temperature in the presence of high partial pressures of O<sub>2</sub>, effectively meaning that at some point in the filling process the tank will blow up.

Oxyliquit which is a coal-liquid oxygen explosive has already been described as temperamental under room conditions (actually refridgerated by the cryogenic liquid O<sub>2</sub>;) and can spontaneously ignite. Autoignition is activation energy driven and for propane this can only be lower than with solid graphite, which has a high activation energy.

The OP doesn't even bother to state at which partial pressures he thinks the propane tanks should be filled with oxygen, and why he thinks it is safe to do so. There is grave risk someone filling it will just keep filling until the autoignition temperature of the propane-oxygen mix is reached, and then explode. A propane-oxygen explosion in a metal tank is bad enough. Having AN there just makes it absolutely lethal.

And don't forget we do not know if AN will affect the autoignition temperature of propane, or if there will be the slightest impurity in the valves (e.g. lubricant oil) which will have their own autoignition temperature. Just the smallest flame will set the mixture off.

IMO the OP is just trolling for a kid to try this out and blow themselves up. A pre-mixed propane-oxygen tank has no role in a professional military or civilian arsenal and its sole function is to give posthumous Darwin awards to people dumb enough to try :mad:

http://en.wikipedia.org/wiki/Autoignition_temperature

Quote:

Factors which may cause variation include partial pressure of oxygen, altitude, humidity, and amount of time required for ignition.


*dodg·y: chancy: of uncertain outcome; especially fraught with risk

BTW the OP which the dht420 is copy/pasting from is here:
http://old.4hv.org/index.php?board=8;action=display;threadid...
See post by "Superkuh" on October 07, 2005, 08:00:39 AM.

[Edited on 25-6-2011 by IndependentBoffin]




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[*] posted on 25-6-2011 at 07:10


Quote: Originally posted by IndependentBoffin  
The OP doesn't even bother to state at which partial pressures he thinks the propane tanks should be filled with oxygen, and why he thinks it is safe to do so.
The stated gas ratio is 2:1, and the pressure given is "just before the relief valve popped". I don't recall exactly what the standard relief valve pressure is for a propane tank, but it's fairly low as pressure tanks go, since propane liquefies. I'd hazard it's something like 50 psi.

Also, nowhere did the OP say that this was safe.

What's most interesting to me is the "wait 24 hours" part. I'd presume that not waiting causes is not to work or to have poor yield, and that someone found this out through experience. What's happening in that day?
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[*] posted on 25-6-2011 at 08:10


Quote: Originally posted by watson.fawkes  
Quote: Originally posted by IndependentBoffin  
The OP doesn't even bother to state at which partial pressures he thinks the propane tanks should be filled with oxygen, and why he thinks it is safe to do so.
The stated gas ratio is 2:1, and the pressure given is "just before the relief valve popped". I don't recall exactly what the standard relief valve pressure is for a propane tank, but it's fairly low as pressure tanks go, since propane liquefies. I'd hazard it's something like 50 psi.

Also, nowhere did the OP say that this was safe.

What's most interesting to me is the "wait 24 hours" part. I'd presume that not waiting causes is not to work or to have poor yield, and that someone found this out through experience. What's happening in that day?


While it may be possible to infer his partial pressures from his statements, it is hardly as scientific as an actual number for the pressures. YMMV with propane tanks and relief valve pressures. It is highly irresponsible; some kid may take the value for propane tank A and try it on propane tank B, blow his hands off and then tell the hospital where he read how to do his trick.

Assuming you're pumping air into the tank with a compressor the air will go in hot because work will be done to compress it. I presume waiting for 24 hours is to let the gas cool down but the greatest hazard is obviously when you're pumping hot air into it.




I can sell the following:
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2) Alkex para-aramid Korean Kevlar analogue fabric (about 50% Du Pont's prices)
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[*] posted on 25-6-2011 at 08:36


I cannot believe you people are taking this seriously. The whole story doesn't make sense. Assuming the redneck uncle was able to stuff prills in there somehow, than nothing was ever detonating there except for the casing blowing open. And he was making "ponds" with it? How much prills can you fit in the propane tank... 15-20lbs? You're not making a pond with that.
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[*] posted on 25-6-2011 at 13:27


Honestly... I can't think of a way to do this safely except with 50ft gas lines welded into a propane tank for loading the propane/air or propane/oxygen. While hiding behind a bunker... That's the only way I would ever attempt that. Played with oxygen/acetylene enough as a kid...

I don't think you would have to worry about someone dumb enough to try this mentioning sciencemadness... If it was a five gallon propane tank everything within a five foot radius would be completely vaporized... Liquid Oxygen(Or pressurized air)/Fuel mixtures are VERY powerful.
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[*] posted on 25-6-2011 at 13:28


Quote: Originally posted by holmes1880  
I cannot believe you people are taking this seriously. The whole story doesn't make sense. Assuming the redneck uncle was able to stuff prills in there somehow, than nothing was ever detonating there except for the casing blowing open. And he was making "ponds" with it? How much prills can you fit in the propane tank... 15-20lbs? You're not making a pond with that.


Liquid/Pressurized Oxygen/Fuel mixtures readily detonate without the need for a detonator. ;)

[Edited on 25-6-2011 by freedompyro]
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[*] posted on 25-6-2011 at 14:06


I would not bet the cost of the propane tank and the time it takes to set it up, on its effectiveness. 1/100 or maybe even 1/1000 may work. Needless to say, you're not digging a pond with it. :P
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