Sciencemadness Discussion Board

Pressed Cast Explosivies?

sammac14 - 31-1-2011 at 05:16

I am looking at making cast explosives for a reliable base to detonate larger charges. I was thinking along the lines of about 120 grams (overpowered for guaranteed det) of potassium perchlorate with a wax type binder pressed into a casing with a large press. I was thinking of also adding aluminium powder maybe 2-3%, the cast ratio I was considering was 90/7/3 (pp/wax/al) is this a bad idea or is it feasible? The detonator is based on a 2 gram base charge of ETN or nitrocellulose. All in cardboard to stop fragmentation and shrapnel. I was curious to here from others opinions about the reliability of the casting process, the press can create a pressure upwards of 1 ton or more.

Thanks

-=HeX=- - 31-1-2011 at 05:55

Test fire it first, but perhaps using ammonium perchlorate instead? I know there is a way to convert the K into NH4 but it slips my mind...

Also, perhaps use more ETN...

hissingnoise - 31-1-2011 at 06:22

NH4ClO4 can't be produced from KClO4 by simple metathesis as KClO4 hasn't enough solubility in water.
Strong HCl, added to a sol. of KClO4 will precipitate KCl to leave dilute HClO4!
This can be concentrated by heating until heavy, white vapours appear.
A saturated sol. of HN4NO3 added to HClO4 will precipitate NH4ClO4 . . .
NC, BTW, isn't a good choice for a base-charge because it's very insensitive!

hissingnoise - 31-1-2011 at 06:42

Perchloric acid . . .

http://www.ask.com/wiki/Perchloric_acid?qsrc=3044

SB15 - 31-1-2011 at 07:28

Quote: Originally posted by sammac14  
I am looking at making cast explosives for a reliable base to detonate larger charges. I was thinking along the lines of about 120 grams (overpowered for guaranteed det) of potassium perchlorate with a wax type binder pressed into a casing with a large press. I was thinking of also adding aluminium powder maybe 2-3%, the cast ratio I was considering was 90/7/3 (pp/wax/al) is this a bad idea or is it feasible?


I very much doubt you'll be able to detonate the mixture. Alkali perchlorates do not decompose easily at all. You would be better off using potassium chlorate in a Cheddite type mixture.

-=HeX=- - 31-1-2011 at 08:21

Hissingnoise: That was what I was thinking of, just was trying to take physics notes at the same time. had I been in a chemistry lecture it would have been easier to think!

I recall some method involving SODIUM perchlorate, ammonia solution and CO2 as dry ice... IIRC it was on RS in the archives.

It entailed creating a soln. of NaClO4, adding NH4OH, and then CO2 as dry ice to convert NaOH to Na2CO3 or NaHCO3 or something. The exact process totally slips my mind so I will go find it!!


I doubt someone will have much luck using KClO4 in a blasting charge, unless perhaps mixed with mononitrotoluene and some other sensitizers...

I recall people had luck with potassium nitrate and nitromethane! So maybe there is hope.

sammac14 - 31-1-2011 at 15:06

I don't really really want to Alter the chemical structure to much I would rather us potassium perclhorate. I can us a bigger ETN charge Mabye 4-5 grams if this would help and a blasting grade aluminum powder. I have used potassium nitrate nitromethane mixtures along with PP in a base charge but I want a solid dry explosive. That can detonate easily.

franklyn - 1-2-2011 at 22:19

What a sad eclectic little thread this is when a perfectly relevant one is here
http://www.sciencemadness.org/talk/viewthread.php?tid=6334
@ sammac14
Welcome to the wonderful world of formulation explosives, as if there hasn't
been enough exploration and variations of this theme since the dawn of
explosives research in the 19 th century. See p.357 C.O.P.A.E. by T.L Davis
http://library.sciencemadness.org/library/books/the_chemistr...
Prefer what you want but realize accepting what works supercedes wishing for.
Paraffins or grease typically are used to de - sensitize mixtures prone to
flame from static electricity. As SB15 observes , there isn't enough percussion
in all of Christendom to detonate such a pyrotechnic mixture , why it makes
for an alright rocket fuel although more than 50 % by weight is KCl which
contributes nothing except its weight.
Attachment: NaClO4 Slurry explosive US5665935.pdf (470kB)
This file has been downloaded 744 times


Basic know how :
1. Expecting detonation from a mixture of fuel and oxidizer with the exception
of Sprengel explosives p.353 C.O.P.A.E , requires that at least one constituent
be capable of explosion on it's own. Most notably such as Ammonium Nitrate and
Ammonium Perchlorate.
2. Exceptions to this under special circumstances are peroxide or chlorate salts
=> KClO3 + vaseline will detonate.
3. To achieve the necessary molecular level combination of ingredients at least
one of the constituents must be liquid at some point ( subsequent to blending
it may solidify )
4. Alkali and Alkaline Perchlorates to be sensitized need the mixture to be acid.
This pretty much limits you to organic acids as fuel candidates.
Marsh relates that in this post _
http://www.sciencemadness.org/talk/viewthread.php?tid=6334&a...
Acetic acid + NH4NO3 does not detonate as fast as claimed for Acetic acid + NH4ClO4
I am dubious this is achievable even over the critical charge diameter. I could
be wrong, I don't know and references are wanting. Substitution of Lactic acid
being 20% denser may contribute improvement. Mixing Aluminum into any acid
makes no sense at all.
Lactic acid is 4 times more expensive than Acetic acid. It is a yellow syrup the
best available product is 88 to 90 % solution with water. A solid form 50 to 60 %
the balance usually Calcium Lactate may be treated with sulfuric acid to free
all the lactic acid.
http://www.bacchus-barleycorn.com/catalog/product_info.php?c...
http://www.bacchus-barleycorn.com/catalog/lactic-acid-powder...
Attachment: Detonation failure diameters & detonation velocities of Nitric acid, Acetic acid, water mixtures .pdf (647kB)
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@ hissingnoise " NH4ClO4 can't be produced from KClO4 by simple metathesis "
Ammonium Perchlorate from K or Ba Perchlorate
http://www.oxidizing.110mb.com/chlorate/ammper5.html
http://www.oxidizing.110mb.com/chlorate/chlorate.html

.



sammac14 - 2-2-2011 at 00:07

So what you are basically saying is that that PP cannot be detonated at all? What types of explosive liquid do you suggest? Nitro methane, MEKP? And I cannot see why Potassium Chlorate can be detonated and PP cannot?

hissingnoise - 2-2-2011 at 03:22

By itself, KClO4 is practically undetonable - mixed with a fuel it is close to dynamite in strength but a strong cap is needed for full detonation.
Mixed with Al powder it can detonate from ignition when closely confined.
Sodium and ammonium perchlorate have higher oxygen contents than KClO4!

pjig - 2-2-2011 at 09:24

[Quote]"I recall people had luck with potassium nitrate and nitromethane! So maybe there is hope. "[quote/]

I wonder what power diff there is between the NH4NO3 and Kno3, as a oxidizing agent in the nitro. I know that the Nh4no3 is the easier one to det, but wonder if the Vod is effected much by the use of another nitrate. For that reason, would it be too unstable to use a chlorate with nitro methane, like a form of rack-a-rock?

[Edited on 2-2-2011 by pjig]

Zinc - 2-2-2011 at 14:15

I belive that the ANNM is more "powerfull" than KNO3/NM as AN is itself an explosive, and all the decomposition products are gasses. KNO3 is not explosive and creates solid decomposition products.

sammac14 - 2-2-2011 at 15:17

I am pretty sure ANNM is stronger than PNNM but I don't know for sure as I have only detonate PNNM before I am pretty sure that they have about the same power as NM is extremely strong and levels out the power. But in large quntities I don't think it really maters because they are pretty strong. That is why I wanted to make cast explosives to detonate large PNNM as it is extremely hard to detonate.

franklyn - 3-2-2011 at 16:01

http://www.economypoint.org/a/annm.html

Attachment: Blasting Explosives 1883 English Patent 5624.pdf (99kB)
This file has been downloaded 733 times

As described you only really need a small amount of nitroparaffin with
aromatic liquor or else sensitize the liquor with a bit of strong nitric acid.

- IMPORTANT -
This is for immediate use and N O T to be stored.
Perchloric acid is readily displaced from its salt and mixed
in with combustibles is very dangerous. Why milder organic
acids are preferable.

.

AndersHoveland - 31-3-2012 at 22:48

#6 commercial blasting cap can initiate the chlorate-wax explosive mixture.

This video used 1.5g HMTD to detonate a mixture of potassium chlorate and kerosene, and claims "about 1 gram of any primary will propogate a detonation in this explosive".
http://www.youtube.com/watch?v=ah4m6zd008U

9 parts chlorate to 1 part wax was used as an explosive filler in grenades during the first world war, when there was not enough TNT available.

Another explosive composition mixed TNT, wax, and chlorate together. This was not only cheaper than pure TNT, but also had lower brissance, which was desirable for producing scrapnel in bombs. Of course, dinitronapthalene could be used instead of the TNT and wax.

Another comment, although kerosene and petrol are much more flammable, the use of these fuels does not result in any increase in explosive performance over using wax or petroleum jelly. In fact, the last two are actually better because the chlorate particles will not settle to the bottom and separate out. The "flammability" of the fuel matters much less within an explosive that contains its own oxygen supply.

toluene and napthalene are both aromatic compounds that can be nitrated to nitro compounds. dinitronapthalene has a poor oxygen balance, an cannot be detonated by itself. Might want to mix it with chlorate, to form a "cheddite" -type explosive mixture.

DPT would probably be a good ingredient:
http://www.sciencemadness.org/talk/viewthread.php?tid=19103

[Edited on 1-4-2012 by AndersHoveland]

caterpillar - 1-4-2012 at 14:02

It would be interesting idea to mix trinitronaftalene with KClO3. Trinitronaftalene can be obtained without HNO3 (metal salts of nitric acide + H2SO4 instead). KClO3 can be readily prepared from Ca(OCl)2. In hot water Ca(OCl)2 -> CaCl2 + Ca(ClO3)2. Addition of KCl causes precipitation of KClO3.