Sciencemadness Discussion Board

Some old English patents appertaining to mixtures intended to substitute primary explosives

Blasty - 20-1-2010 at 05:46

In the section about explosives in Thorpe's A dictionary of applied chemistry, there is mention of several patents regarding mixtures that are intended as replacements for primary explosives, like mercury fulminate, in blasting caps/detonators, an interesting but relatively little known or talked about subject:

http://books.google.com/books?id=MgA5AAAAIAAJ&pg=PA84&am...

"Mixtures, without fulminate, containing aluminium, have been proposed by Führer (Eng. Pat. 2755, 1901, and 24812, 1902), Bielefeldt (Eng. Pat. 7148, 1901), and von Dahmen (U.S. Pat. 702357, 1902), but these mixtures require very strong confinement to be effective; the Westfälisch - Anhaltischc Sprengstoff Actien-Gesellschaft have patented mixtures without fulminate, containing potassium chlorate with mono-, di-, or tri-nitrocresol, &c.; and Bielefeldt (Eng. Pat. 23889, 1901) suggests a mixture of potassium chlorate with trinitronaphthalene." (volume 3, page 84, 1922 edition)

I have been able to locate the von Dahmen U.S. patent mentioned by Thorpe:

http://www.google.com/patents?id=qnoPAAAAEBAJ&printsec=a...

Unfortunately, the patent omits a few important details, such as:

1) What's the container to be used for the mixture? A metal tube or capsule, such as used in ordinary blasting caps, or can it also be made out of other materials? (the age of the patent seems to rule out such things as plastics, so I assume he was likely using copper tubes or capsules.)

2) Is it necessary to apply any pressure to the mixture after loading it into the container?

3) Perhaps I am interpreting the inventor's words too literally here, but how is a "hermetically sealed space" achieved in such a device that can be set off by means of a "strong powder fuse" (a black powder fuse, I suppose)? It will leave an orifice of some kind, no matter how small the diameter of the fuse is. Thorpe says that "these mixtures require very strong confinement to be effective", but "very strong confinement" does not necessarily mean "hermetically sealed".

Jahred Ledgar, in The Preparatory Manual of Black Powder and Pyrotechnics, page 256, after giving more specific instructions on how to prepare a batch of this mixture, says:

"To use, it simply needs to be pressed into any blasting cap or detonator housing under the usual means."

Not sure if this is a very reliable source, though, particularly on a subject as comparatively little known as this. If anyone around here has actual experience with this mixture perhaps he/she could clarify some of these points.

Incidentally, I found another patent of von Dahmen, also about the topic of detonating high explosives without using fulminates, that is not mentioned by Thorpe:

http://www.google.com/patents?id=5B1QAAAAEBAJ&printsec=a...

It's a different mixture and method, which apparently consists of combining a mixture of ammonium nitrate, di or tri nitrotoluene and aluminum with a mixture that looks like a sort of modified black powder (sulfur, carbon, potassium nitrate and lead peroxide), then strongly confining it and setting it off with a black powder fuse.


I have not been able to find any of the English patents mentioned by Thorpe. I was only able to find bits of information about some of them in several places.

Regarding Eng. Pat. 20755 (not 2755, as is misprinted in Thorpe's Dictionary) I found this:

"Detonating Composition To Replace Fulminate Of Mercury.— This composition is the invention of Herr J. Fuhrer of Vienna, and it is intended for use in place of fulminate of mercury for producing the initial detonation necessary for firing a charge of high explosive. It is very much safer to handle than fulminate of mercury and the inventor claims it will satisfactorily detonate the high explosives. If so, the gain will be very great. One of the great dangers in handling high explosives has been the sensitiveness of the fulminate fuze or detonator, and no satisfactory detonator not containing fulminate of mercury has (unless this proves to be the long sought article) been obtained. The materials used are copper, ammonium nitrate, potassium nitrate, sulphur and aluminum. One formula specifies 30 to 40 parts of copper-ammonium nitrate, 42 to 25 parts of nitrate of potassium, 10 to 7 parts of sulphur, and 18 to 28 parts of metallic aluminum. The date of acceptance of the British patent (No. 20,755) is December 31, 1901." (Proceedings of the United States Naval Institute, Volume XXVIII, Part 1, page 145.)

Thus it appears to be the same mixture, or at least very similar, as U.S. Pat. 702357.

Regarding patent 24812, I found this in a German book:

Die Erfindung betrifft einen Zundstoff fur Sprengkapseln und Zwischenladungen, bestehend aus 45.5 Teilen Kaliumnitrat, 30 Teilen Kaliumbikarbonat, 16 Teilen Schwefel und 8.5 Teilen Aluminum.(Dr. Alfred Stettbacher, Dr. Richard Escales, Initialexplosivstoffe, 2002 reprint. pp. 214-215.)

Loosely translated (with the aid of Systran 6):

"The invention concerns an explosive for blasting caps and intermediate loads (?), consisting of 45.5 parts potassium nitrate, 30 parts potassium bicarbonate, 16 parts sulfur and 8,5 parts aluminum."

So it appears to be a sort of modified "pulvis fulminans". Unfortunately, the book does not give any information of how is the mixture of the above substances made and employed in blasting caps.

I couldn't find anything about Eng. Pat. 7148 (this number is very likely a misprint) by Bielefeldt.

Regarding Eng. Pat. 23889, by the same inventor (Bielefeldt), I was able to find this:

"Patent 23889 vom gleichen Jahre verwendet statt Knallquecksilber Mischungen aus Trinitronaphthalin und Kaliumchlorat." (Dr. Alfred Stettbacher, Dr. Richard Escales, Initialexplosivstoffe, 2002 reprint. Page 204.)

Which loosely translated (again with the aid of Systran 6) is:

"Patent 23889 from the same year uses mixtures of trinitronaphthalene and potassium chlorate instead of mercury fulminate."

The following from another source was a bit more informative:

"Percussion Caps and Detonators; Priming Compositions or Charges for . M. Bielefeldt, Berlin. Eng. Pat. 23,889, Nov. 25, 1901.
Finely pulverised trinitronaphthalene (70 per cent, to 85 per cent.) is mixed with finely pulverised potassium chlorate (15 per cent, to 30 percent.) and sufficient gum solution to form a paste of the desired consistency." (Journal of the Society of Chemical Industry, Volume 21, Oct. 15, 1902. Page 1246.)

This gives the proportions of the materials, but it does not give details of how is it used in detonators.

If anyone around here has access to these English patents, please let me know.

ScienceSquirrel - 20-1-2010 at 05:58

I would be very cautious of potassium chlorate mixtures.
They can be quite sensitive and unstable with mixtures with sulphur being particularly nasty.
Chlorates have caused a lot of lab accidents over the years.
At one time it was commonly heated with managanese dioxide to produce oxygen. Normally the reaction would proceed without problems but contamination of the manganese dioxide or the molten chlorate coming into contact with the rubber stopper or tubing could result in disaster.

Blasty - 20-1-2010 at 06:11

Quote: Originally posted by ScienceSquirrel  
I would be very cautious of potassium chlorate mixtures.
They can be quite sensitive and unstable with mixtures with sulphur being particularly nasty.
Chlorates have caused a lot of lab accidents over the years.
At one time it was commonly heated with managanese dioxide to produce oxygen. Normally the reaction would proceed without problems but contamination of the manganese dioxide or the molten chlorate coming into contact with the rubber stopper or tubing could result in disaster.


Only one of the mixtures in the patents described above uses a chlorate, and there is no sulphur in it.

I have handled several chlorate mixtures before. One that never gave me any trouble and is easy to make is Berge's blasting powder:

http://books.google.com/books?id=qJHhhBwf5H8C&pg=PA330&dq=%22berge's+blasting+powder%22&cd=1#v=onepage&q=%22berge's%20blasting%20powde r%22&f=false

No sulfur involved, just sugar, a chromate (speeds up the reaction), some wax (paraffin works) and the chlorate. Just don't get too cocky and think it's 100% safe. Given a blow strong enough it can detonate.

Rosco Bodine - 20-1-2010 at 09:49

Here's two of the old British patents

Attachment: GB23889 Detonating composition, Bielefeldt circa 1901.pdf (131kB)
This file has been downloaded 1477 times

Attachment: GB24812 Detonating Composition , circa 1902 Fuhrer.pdf (183kB)
This file has been downloaded 1208 times

Blasty - 20-1-2010 at 10:08

Quote: Originally posted by Rosco Bodine  
Here's two of the old British patents


Thanks!

Just out of curiosity, where did you find them? I looked on the net quite a bit but with no results.

Rosco Bodine - 20-1-2010 at 10:23

ESPACENET using a name search, the indexing for the older patents sometimes uses an archival number having the year as prefix and a letter added as suffix to the actual patent file number. Therefore a straight number search won't bring it up, but a name of inventor search may get a search hit.

What may occur with some of these old "fulminating powder" type of detonating compositions is that only a low order detonation is achieved, especially for the smaller charges. There really is no substitute pyrotechnic mixture which can do the same job as a bona fide primary detonating explosive which has a far greater self-acceleration and ultimate velocity from a very small distance and time requirement from ignition to "run-up" to full velocity and output. A pyrotechnic
composition which may marginally be able to do the job is a curiosity more than being any genuine equivalent substitute in terms of performance.

(by weight) KClO3 5 parts and potassium ferricyanide 3 parts is a fulminating mixture.

[Edited on 20-1-2010 by Rosco Bodine]

Blasty - 20-1-2010 at 21:25

Quote: Originally posted by Rosco Bodine  
ESPACENET using a name search, the indexing for the older patents sometimes uses an archival number having the year as prefix and a letter added as suffix to the actual patent file number. Therefore a straight number search won't bring it up, but a name of inventor search may get a search hit.


Thanks for the tip. I had stumbled upon that site before. Their indexing is a bit awkward. I was searching for the patent numbers in question (as quoted by Thorpe and the other sources above), so I got no results.


Quote:

What may occur with some of these old "fulminating powder" type of detonating compositions is that only a low order detonation is achieved, especially for the smaller charges. There really is no substitute pyrotechnic mixture which can do the same job as a bona fide primary detonating explosive which has a far greater self-acceleration and ultimate velocity from a very small distance and time requirement from ignition to "run-up" to full velocity and output. A pyrotechnic composition which may marginally be able to do the job is a curiosity more than being any genuine equivalent substitute in terms of performance.


Even though the subject is rather "arcane" and comparatively little known, the number of inventors claiming success in detonating at least several types of high explosives or explosive mixtures without using primary explosives is rather interesting and, in my opinion, worthy of further inquiry as a possible alternative. It is also interesting that at least as early as the early 1870s, less than 10 years after Nobel introduced the fulminate blasting cap, we already have inventors trying to do away with it by using mixtures that, they claim, were more or as effective and less dangerous to handle.

Quote:
(by weight) KClO3 5 parts and potassium ferricyanide 3 parts is a fulminating mixture.


Yes, a similar mixture, but with potassium picrate added in (invented earlier by Designoble and Casthelaz, but who apparently had not fully realized its potential use as an initiator) was already used by Prudencio Castellanos in the 1870s to detonate dynamites:

http://www.google.com/patents?id=2C9tAAAAEBAJ&printsec=a...

He called his devices "percussive petards". He made them both out of metal capsules as well as of cardboard tubes. The percussive mixtures he used do not require pressure after being loaded in the containers, and seem to work best granulated.

Something that Castellanos says in his patent also struck me as curious: even black powder charges were apparently being used to attempt to detonate dynamites. It doesn't seem that the fulminate blasting cap was as universally accepted as one would think from reading most history books on the subject.

a_bab - 20-1-2010 at 22:59

Probably MF was quite expensive; there were some terrible accidents asociated with it's manufacture, and they must have been trying to find new alternatives. After all, dynamite can go off even with BP. With the development of new explosives they must have realised that a real primary is needed for reliable work, and not some fart-fulminating mixtures.

The caps for the gun cartridges are a different story; all it's needed there is a flame to ignite the propellant, so chlorate based mixture were used, till the bore corrosion was observed.

Blasty - 20-1-2010 at 23:40

Quote: Originally posted by a_bab  
Probably MF was quite expensive; there were some terrible accidents asociated with it's manufacture, and they must have been trying to find new alternatives. After all, dynamite can go off even with BP. With the development of new explosives they must have realised that a real primary is needed for reliable work, and not some fart-fulminating mixtures.


It does not seem to be as simple as that. According to Castellanos' statements, black powder charges seem to have been very little reliable, igniting the dynamites rather than making them explode. Plus back then other explosives were already known. That didn't seem to stop these inventors from seeking a safer alternative to mercury fulminate compressed in a cap. Some of these patents are even from the early 1900s, and specifically mention explosives like guncotton, picric acid, and ammonium nitrate mixtures, and such detonating/fulminating/percussive mixtures were still being tinkered with and used. The increasing variety of explosives does not seem to have deterred such investigations.

hissingnoise - 21-1-2010 at 09:28

HNM is almost a primary explosive!
It will detonate from a hot flame (hmmm, sense of déja vu here) and was used as a base charge, initiated by a suitably hot flash powder.
AFAIK, this type of detonator used a steel tube as containment.
while HNM is much less shock-sensitive than fulminate or azide it still needs some care in handling.


Rosco Bodine - 21-1-2010 at 11:37

There are progressive density and diameter loading schemes using strong confinement to cause a shortened runup DDT distance for PETN, probably also adaptable to other near primary explosives like nitromannite and nitroinositol,
all three of which are also detonable by pyrotechnic initiators via a combination
of cookoff and impulse, communicated directly or via flyer plates across a short airgap. Regular 60/40 perchlorate/aluminum flash will initiate sensitive explosives
with confinement, but so will the snap of a good electrical arc which will cookoff
NG nicely. There are a few ways around having to use a primary explosive as the means of initiation, which are alternatives to the more conventional use of a primary to get the job done. However it still remains true that using a primary which is best suited for the task is the simplest, surest, and most economical solution.

Blasty - 21-1-2010 at 20:56

Quote: Originally posted by hissingnoise  
HNM is almost a primary explosive!
It will detonate from a hot flame (hmmm, sense of déja vu here) and was used as a base charge, initiated by a suitably hot flash powder.
AFAIK, this type of detonator used a steel tube as containment.
while HNM is much less shock-sensitive than fulminate or azide it still needs some care in handling.


I once exchanged personal messages with a guy who used similar methods but with erythritol tetranitrate.

Tri and tetra-nitronaphthalene also can detonate with heat. The patent by Bielefeldt seems to use this method but with a mixture of potassium chlorate.

[Edited on 22-1-2010 by Blasty]

gregxy - 22-1-2010 at 11:59

It would be interesting to see how chlorate+X compares to various primary explosives in the drop test. If an explosive is sensitive to impact it should be able to detonate and if it is
easy to ignite it might be a primary.

chlorate+fulminate is less sensitive than straight fulminate,
the same likely applies to ones like HMTD.

chlorate+TNT is probably more sensitive than TNT but
how much? Its difficult to see chlorate and nitrated napthalene doing much.

To make a primary the mixture should also be easy to ignite,
so the melting points of the ingrediants should be high
or else the heat of melting will absorb too much of the energy.

Someting like chlorate + phosphorus is quite
sensitive and can work in percussion primers like fulminate
it is probably a primary.

An interesting one to try would be chlorate+picrate salts
so see if it works any better than the straight picrate.

Rosco Bodine - 22-1-2010 at 14:47

The simple clathrate of basic lead picrate/lead nitrate/lead chlorate is more energetic on detonation than anhydrous lead picrate or basic lead picrate alone.

Possibly in mixture with nitromannite or some other sensitive and near primary sensitivity nitroester or similarly sensitive
HE, the binary mixture composition with a relatively mild primary would basically become a fuse sensitive HE binary capable of rapid DDT for high order and high output.

However the danger, potential instability, and sensitivity is usually greater for mixtures of chlorate or perchlorate or other oxidizers with ordinary fuels or energetic oxygen deficient explsoive fuels, than is comparable for other compounds used in mixture to achieve a synergistic effect.

Blasty - 22-1-2010 at 22:36

Quote: Originally posted by gregxy  
Its difficult to see chlorate and nitrated napthalene doing much.


Tri and tetra-nitronaphthalene can detonate with sudden heat:

"Trinitronaphthalene... is insoluble in water, only slightly soluble in alcohol and ether; precipitated in flocks from solution in fuming nitric acid. The crystals decrepitate when heated, melt at 214° with partial sublimation, and detonate at a higher temperature.

Tetranitronaphthalene... is produced by heating a solution of trinitronaphthalene in fuming nitric acid for four days in closed vessels, and crystallises from hot alcohol in long asbestos-like needles, which melt at 200°, detonate violently at a higher temperature, and are coloured deep red by alcoholic ammonia." (Henry Watts, A dictionary of chemistry, Volume 6, 1879 edition. pp. 848-849)

"M. Berthelot has shown that substances, which, by gradual increase of temperature, are not explosive, such as picric acid, trinitronaphthalene, potassium chlorate, etc., can nevertheless be caused to explode if they are suddenly heated to a much higher temperature than is necessary to bring about decomposition." (Heinrich Brunswig, Explosives: a synoptic and critical treatment of the literature of the subject as gathered from various sources, 1912. page 33.)

This seems to be the property that Bielefeldt was using by mixing it with potassium chlorate and setting it off in a confined space.
Quote:
It would be interesting to see how chlorate+X compares to various primary explosives in the drop test. If an explosive is sensitive to impact it should be able to detonate and if it is
easy to ignite it might be a primary.

An interesting one to try would be chlorate+picrate salts so see if it works any better than the straight picrate.


There is some conflicting info about this in old books and patents. Some, like Designoble, Castellanos, etc., seem to have been very convinced that such mixtures were safer to prepare and use than mercury fulminate. I have found others who claim these mixtures of picrate + oxidizers are too sensitive to be useful. However, the critics of these mixtures usually refer to the manufacture and use of them as the main charge in artillery shells, torpedos, etc. which require larger quantities. The only class of such mixtures that met with general approval were the ammonium picrate + potassium nitrate mixtures.

According to the following statements, some mixtures of picrates and chlorates are not only more powerful than the picrates alone, but more powerful than mercury fulminate, and almost like nitroglycerine:

"About 35 parts of carbozotate of potassa (potassium picrate)
18 parts of ferrocyanide of potassium
47 parts of chlorate of potassa

This last powder is nearly three times as powerful as the fulminate of mercury." (Designoble and Casthelaz, U.S. Pat. 76173)

The above mixture is the one that Castellanos preferred to use in his "percussive petards". Unfortunately, none of these inventors gives details of how exactly did they mix and granulate these materials (it goes without saying that they must have been worked wet.) Designoble & Casthelaz just say that these mixtures are prepared pretty much like black powder.


"Potasium Picrate.—Most violently explosive of the picrates. Potassium picrate and potassium chlorate form a mixture nearly as powerful as nitro-glycerine, but it is so sensitive to friction or percussion as to render it practically useless. With potassium nitrate instead of chlorate a less violent mixture is obtained, but one still too liable to accidental explosion." (Walter Nickerson Hill, Notes on certain explosive agents , 1875. Page 49.)

"The potassium salt is that most easily prepared, on account of its very slight solubility in water. It is also one of the most highly explosive. When mixed with oxidising agents, and especially with potassium-chlorate, it furnishes very powerful explosive materials; indeed, the chlorate mixture approaches nitro-glycerine and gun-cotton nearly in violence of action than any other explosive agent produceable on a practical scale. This mixture is, however, so susceptible of detonation by friction or concussion as not merely to render its employment in shells impossible, but also to preclude its application to any purpose without the adoption of very special precautions." (Professor Abel on Explosive Agents, The Chemical news and journal of industrial science, V. 24 , 1871, pp. 127-128)

I wonder if perchlorates, instead of chlorates, could be used in such mixtures to make them safer? I haven' t found anything on the subject yet.



[Edited on 23-1-2010 by Blasty]

Rosco Bodine - 23-1-2010 at 02:42

You will be able to confirm by experiment that those early references are not reliable. The power described for such mixtures is an exaggeration. One of the real disadvantages which will be encountered is that the critical mass required for the transition from low order to high order detonation will be excessive, so that the physical dimensions of what would become a useful device reliable as a blasting cap is more like the dimensions of a booster, for example in the range of tens of grams of the mixture being required for some of these contemplated schemes. Perchlorate would probably be safer than chlorates. There is probably an inherent risk of spontaneous decomposition and perhaps spontaneous ignition
which is a real concern for such mixtures.

There is a significant difference between "explosion" and "detonation" just like there is a significant difference between a low order detonation and a high order detonation. Bona fide primary explosive compounds having small critical mass and diameter are exponentially more effective and are safer and more practical
than any pyrotechnic mixtures.

Blasty - 23-1-2010 at 04:47

Quote: Originally posted by Rosco Bodine  
You will be able to confirm by experiment that those early references are not reliable. The power described for such mixtures is an exaggeration.


Are you aware of anyone who has tested them more recently?
Quote:
One of the real disadvantages which will be encountered is that the critical mass required for the transition from low order to high order detonation will be excessive, so that the physical dimensions of what would become a useful device reliable as a blasting cap is more like the dimensions of a booster, for example in the range of tens of grams of the mixture being required for some of these contemplated schemes.


Unfortunately, these inventors often do not specify how much of their mixtures are supposed to be used when employed as detonators. In other cases some of these detonating mixtures were stated to be used in quantities that range from less than a gram to about 2 or 3 grams. Von Dahmen, for example, claims that 2 to 3 grams of his copper-ammonium nitrate mix are enough to detonate dynamites, picric acid explosives and ammonium nitrate mixtures.

Rosco Bodine - 23-1-2010 at 08:14

No I don't know of any tests being done for these pyrotechnic mixtures.

Patent claims do not necessarily tell the whole true story and all of the
explosives mentioned are capable of low order detonation schemes,
which is likely what would be the result from their inititiation by
one of these alternative detonators.

argyrium - 23-1-2010 at 14:02

Michael Swisher wrote a short monograph entitled "Brisantly Explosive Pyrotechnic Compositions" in Pyrotechnica XVI. He covers a number of different mixtures used throughout time; from various "flash" powders to dark report comps as well as those based on K4Fe(CN)6 and K3Fe(CN)6 mixed with KClO4.

An interesting reference is to co-precipitated (from mixed warm aqueous solutions dropped out by addition of 2-propanol) intimate mixtures. A patent secured by John W. Fronabarger (per Unidynamics/Phoenix, Inc.) is attached below.

A strong word of caution. Co-precipitation of an oxidiser and fuel often leads to unexpectedly sensitive mixtures, some even while "wet". Speaking from personal experience, should one desire to play in this area, start out with very small quantities with efficient agitation, protected by appropriate safety gear and a shield.


Attachment: 3793100_IGNITER_COMPOSITION_COMPRISING.pdf (121kB)
This file has been downloaded 1147 times

Blasty - 23-1-2010 at 21:31

Quote: Originally posted by argyrium  
Michael Swisher wrote a short monograph entitled "Brisantly Explosive Pyrotechnic Compositions" in Pyrotechnica XVI. He covers a number of different mixtures used throughout time; from various "flash" powders to dark report comps as well as those based on K4Fe(CN)6 and K3Fe(CN)6 mixed with KClO4.


You wouldn't happen to have a scan of that article, would you?
Quote:
An interesting reference is to co-precipitated (from mixed warm aqueous solutions dropped out by addition of 2-propanol) intimate mixtures. A patent secured by John W. Fronabarger (per Unidynamics/Phoenix, Inc.) is attached below.


Thanks. It's an interesting piece. I notice, however, that the mixtures of ferricyanide containing perchlorate instead of chlorate do not seem to be detonating (by adding potassium picrate they very likely would, though.) I have noticed this more "tame" behavior of perchlorates before when dealing with sugar mixtures. Earlier in the thread I mentioned Berge's blasting powder, which burns very fast, in a flash. Even though that mixture is relatively safe to make and handle, a while back I thought about coming up with an even safer updated version using potassium perchlorate, but it was rather difficult to achieve even a decent approximation to the performance of the original chlorate mix. For starters, chromates do not seem to speed up the reaction between perchlorates and sugar. Using dichromates seems to speed up things a bit, but the combustion is still too slow. By replacing some of the sugar with finely pulverized charcoal I was able to get a more decent deflagration speed, but still inferior to the original Berge's powder. Perchlorates are safer, but they come at a price in speed.


Quote:
A strong word of caution. Co-precipitation of an oxidiser and fuel often leads to unexpectedly sensitive mixtures, some even while "wet". Speaking from personal experience, should one desire to play in this area, start out with very small quantities with efficient agitation, protected by appropriate safety gear and a shield.


Care to elaborate on which of these precipitated mixtures you've found particularly dangerous to deal with?

Two Component Instant Detonator

franklyn - 24-1-2010 at 03:45

Whatever the application of secondary explosives may be , the use of
a primary explosive detonation initiator is unavoidable without invoking
exploding bridgewires. For military applications the search for what are
termed insensitive explosives remains compromised by the properties
of the primary explosive initiator. In civilian use the work around has
been to segregate detonators from the main charge until just before
setting off the explosion. Fuzes are similarly only attached to ordnance
before actual use and the two are never stored assembled.

I had thought that the binary gas artillery shell design could be applied
to binary or Sprengel type explosives. The mixing to be done during flight
thus there is no risk from recoil and setback upon firing. Such a munition
would be safer for transport and storage than anything in use now.
Explosives for civilian use such as mining are not amenable to such
techniques. Precedents of the use of binary explosive mixtures as a main
charge are ill conceived , the components are invariably reactive liquids
which introduce additional problems in place of the issue of sensitivity. A
consideration which is not dealt with is what to do with the mixture once
it is made , since it cannot readily be deactivated , it's disposal becomes
very problematic.

It has subsequently occurred to me that this is actually quite perverse in
its conception since it is a contrived solution to the primary issue , the
sensitivity of the initiating explosive. Primary explosives whatever their
merits are always a compound made for the purpose , which is then
distributed for it's intended use just as it is. It may seem an oxymoron to
have an insensitive primary explosive since that then transcends into the
realm of secondary explosives. Why not have instead a detonator
comprising a two component primary explosive that is mixed in the act
of arming or priming. For electric detonators this could certainly even be
done remotely. This idea is surely not original and must have been
addressed many times although no mention of the topic or investigation
of it can be found. Compositions that have seen limited application as a
main charge , although shock sensitive are not primary initiating explosives.

A detonating cap should also not present any greater risk or special
handling than existing types when there is a need to remove it from
a secondary charge. Procedures providing an instant explosive on
demand for such a device , comprised of safe components which if
mixed remain stable , requiring only ordinary cap safety handling if it
is not immediately used , have certainly been known but dismissed as
curiosities and their potential application has remained unrecognized.

A likely candidate would be a Metal salt of Nitromethane , which are
described in references as powerful detonating primary explosives. The
requirement for absolute anhydrous conditions has doubtlessly relegated
their synthesis and consideration for practical use to obscurity.
Nitromethane reacts with Calcium Hydride producing Calcium Nitromethanide
http://gallica.bnf.fr/ark:/12148/bpt6k3133k.image.f1034.lang... - translated below
on demand evolving only Hydrogen gas. The notion of applying this synthesis
in situ becomes viable since the reaction remains encapsulated , dispensing
with the main detraction , this primary's reactivity to moisture and air.
http://membership.acs.org/c/chas/jchas_archives/1995/2(1)/1995-2-1urben-blast.pdf
In a related thread see Quote( By Vorion )
https://www.sciencemadness.org/whisper/viewthread.php?tid=50...

In a previous post I outlined some mixtures which suggest another
approach , to have a volatile component of a Sprengel explosive
which can be vented to deactivate the explosive potential.
http://www.sciencemadness.org/talk/viewthread.php?tid=5777#p...
Fashioning a workable detonator is just a matter of engineering. Whether
these later ingredients are able to produce a high order detonation is
not personally known to me , but that some similar combination can
I have no doubt.


Comptes Rendus de Académie des sciences 1925, 180, 1034-1036

ACADEMIE DES SCIENCES

Organic Chemistry - Reduction of Nitro Compounds by Calcium Hydride
Note (4) J. F. DURAND , S. HOUGHTON

(4) Science 23 Mar 1925

Nitro derivatives of the Acyl series. - Nitromethane dissolved in cold
Ether and treated with powdered CaH2 gives a vigorous evolution of
hydrogen. Exactly 1 molecule of hydrogen is gathered for every
molecule of nitromethane; this last body becomes a salt of calcium.

2 CH3.NO2 + CaH2 -> (CH2NO2)2Ca + 2 H2

.

Rosco Bodine - 24-1-2010 at 04:12

The use of actual compounds which contain the desired functional groups in each molecule can eliminate variables which can cause more unpredictability about the potential behavior of physical mixtures. You cannot achieve a more intimate mixture than to include the oxidizer at the molecular level within the structure of the explosive fuel component,
where the two are married as a compound. Mixtures certainly can have their usefulness. However, in my experience the performance is better if the properties for which a synergy is being sought can be achieved by combining the desired properties by embodiment within an actual compound at the molecular level, or at the next closest state of microscopic subdivision, such as inclusion by microcrystalline lattice structure entrapment, where a quasi-molecular electrostatically bonded complex crystal inclusion compound known as a clathrate, nearly as intimately combines the separate materials as if they were a conventional compound. Basic lead salts of polynitrophenolic compounds are capable of forming complex multiple salts and clathrates. I have experimented with a few of the many different possible multiple salts and clathrates all of which are primary explosives which behave more or less like
lead styphnate. They are almost, but not quite there in
terms of self-accelleration, to be useful as initiating explosives, close enough to being what is desired that it
remains interesting to investigate by experiment predicted
complex salts of these types which have not been reported in the known literature.

I have made the tertiary clathrate [basic lead picrate - lead nitrate - lead chlorate]

And it was my observation that it would be interesting to experiment further and see if a binary clathrate or double salt complex was possible for the nitrate, and for the chlorate, possibly for a perchlorate as well. Only the binary for the nitrate variant was investigated by experiment, which was a confirmation of an already published compound.
See attached patent US2175249 example #2.

The chlorate variant and the perchlorate variant may also be possible as analogues of the nitrate variant of example #2.

A styphnate based material of similar composition may be possible also.

A double salt of lead styphnate and lead picrate may be possible.

Complex derivative variants of a basic form of that possible double salt may also exist, as is hypothesized for the basic lead picrate variant above, and the chlorate and perchlorate analogues for example #2 of the patent.

Nickel Styphnate - Potassium Styphnate double salt should be investigated, as well as the possible? Nickel Styphnate - Lead Styphnate double salt.

The chemistry and potential value for such unreported potential compounds, along with some of the double fulminates, is more intriguing to me anyway, than is the
physical blending of pyrotechnic mixtures......which somehow only seems like so much effort at putting more flash and crack
in a glorified flashcracker :D

Attachment: US2175249 Lead Nitrato-Bis Basic Lead Picrate ex.2 .pdf (177kB)
This file has been downloaded 1525 times

Animaniacs Bad idea son.

Liedenfrost - 20-2-2010 at 09:33

Quote: Originally posted by Blasty  


"Detonating Composition To Replace Fulminate Of Mercury.— This composition is the invention of Herr J. Fuhrer of Vienna, and it is intended for use in place of fulminate of mercury for producing the initial detonation necessary for firing a charge of high explosive. It is very much safer to handle than fulminate of mercury and the inventor claims it will satisfactorily detonate the high explosives. If so, the gain will be very great. One of the great dangers in handling high explosives has been the sensitiveness of the fulminate fuze or detonator, and no satisfactory detonator not containing fulminate of mercury has (unless this proves to be the long sought article) been obtained. The materials used are copper, ammonium nitrate, potassium nitrate, sulphur and aluminum. One formula specifies 30 to 40 parts of copper-ammonium nitrate, 42 to 25 parts of nitrate of potassium, 10 to 7 parts of sulphur, and 18 to 28 parts of metallic aluminum. The date of acceptance of the British patent (No. 20,755) is December 31, 1901." (Proceedings of the United States Naval Institute, Volume XXVIII, Part 1, page 145.)




Can you say damn sensitive Tetramminecopper(II) nitrate, often lazily and exasperately acronymised as TACN?

http://www.sciencemadness.org/talk/viewthread.php?tid=1778&a...

http://mihailru.freeservers.com/shopping_page.html

http://www.ab.ust.hk/hseo/sftywise/199302/page3.htm

Bad idea, even before we come upon the Al and nitrate dangers.

gregxy - 20-2-2010 at 12:04

I doubt that these compositions work.

Here is a simple way to test primaries,

Wrap a 1.5" square piece of Al foil around a 0.25" glass rod to form a tube.

Crimp over the bottom end.

Place about 250mg of the compound in the tube and pack
lightly with the glass rod. (avoid holding the tube in your hands for this step).

Insert a fuse and close the top.

Tape the little cracker on a block of pine, light the fuse and
get away.

Most "flash" mixtures will simply burn since the confinement
is not strong enough.

A primary like fulminate or HMTD will explode and the explosion will cut a deep grove (about 1" deep) into the
wood block.

argyrium - 21-2-2010 at 11:53


Quote: Originally posted by Blasty "Care to elaborate on which of these precipitated mixtures you've found particularly dangerous to deal with?"

Notes unavailable, another lifetime. Same procedure had been done once before on a smaller scale.
A solution of K2CrO4 dripped into a solution of Ba(NO3)2 with fine B suspended therein. Don't recall concentrations or T other than it was warm (preheated), w/ strong mechanical (overhead) stirring. Sometime after completion of rxn the 600mL beaker "exploded". The noise was like a very loud 'click' and nothing like the sound of glass that just fails thermally. The beaker broke into many small pieces, some being projected across a wide bench. Addition funnel did not break.
No light or flash was noticed. Stirrer had not touched the glass and rate was a nice vortex to a near the bottom of the vessel.
Nasty mess to clean-up and gave someone quite a scare.

hissingnoise - 21-2-2010 at 13:00

Quote:

Place about 250mg of the compound in the tube and pack
lightly with the glass rod. (avoid holding the tube in your hands for this step).


A wooden dowel would be safer than a glass rod but even holding a dowel while tamping HMTD seems pretty iffy.
Mounting it on a drill-press with a protective screen between you and the detonator should be the way to go!

Blasty - 22-2-2010 at 06:51

Quote: Originally posted by Liedenfrost  
Quote: Originally posted by Blasty  


"Detonating Composition To Replace Fulminate Of Mercury.— This composition is the invention of Herr J. Fuhrer of Vienna, and it is intended for use in place of fulminate of mercury for producing the initial detonation necessary for firing a charge of high explosive. It is very much safer to handle than fulminate of mercury and the inventor claims it will satisfactorily detonate the high explosives. If so, the gain will be very great. One of the great dangers in handling high explosives has been the sensitiveness of the fulminate fuze or detonator, and no satisfactory detonator not containing fulminate of mercury has (unless this proves to be the long sought article) been obtained. The materials used are copper, ammonium nitrate, potassium nitrate, sulphur and aluminum. One formula specifies 30 to 40 parts of copper-ammonium nitrate, 42 to 25 parts of nitrate of potassium, 10 to 7 parts of sulphur, and 18 to 28 parts of metallic aluminum. The date of acceptance of the British patent (No. 20,755) is December 31, 1901." (Proceedings of the United States Naval Institute, Volume XXVIII, Part 1, page 145.)




Can you say damn sensitive Tetramminecopper(II) nitrate, often lazily and exasperately acronymised as TACN?

http://www.sciencemadness.org/talk/viewthread.php?tid=1778&a...

http://mihailru.freeservers.com/shopping_page.html

http://www.ab.ust.hk/hseo/sftywise/199302/page3.htm

Bad idea, even before we come upon the Al and nitrate dangers.


I haven't tinkered with that compound (yet) but in this very forum I have read several differing opinions about how sensitive (or even if useful at all) it is:

http://www.sciencemadness.org/talk/viewthread.php?tid=2187

Blasty - 22-2-2010 at 06:55

Quote: Originally posted by gregxy  
I doubt that these compositions work.

Here is a simple way to test primaries,

Wrap a 1.5" square piece of Al foil around a 0.25" glass rod to form a tube.

Crimp over the bottom end.

Place about 250mg of the compound in the tube and pack
lightly with the glass rod. (avoid holding the tube in your hands for this step).

Insert a fuse and close the top.

Tape the little cracker on a block of pine, light the fuse and
get away.

Most "flash" mixtures will simply burn since the confinement
is not strong enough.

A primary like fulminate or HMTD will explode and the explosion will cut a deep grove (about 1" deep) into the
wood block.



Some of these mixtures are meant to work under strong confinement only, otherwise they either do not explode at all or not with sufficient force to be useful. Such a method of testing would not work for them. Stronger containers would need to be used.

Blasty - 22-2-2010 at 06:59

Quote: Originally posted by argyrium  

Quote: Originally posted by Blasty "Care to elaborate on which of these precipitated mixtures you've found particularly dangerous to deal with?"

Notes unavailable, another lifetime. Same procedure had been done once before on a smaller scale.
A solution of K2CrO4 dripped into a solution of Ba(NO3)2 with fine B suspended therein. Don't recall concentrations or T other than it was warm (preheated), w/ strong mechanical (overhead) stirring. Sometime after completion of rxn the 600mL beaker "exploded". The noise was like a very loud 'click' and nothing like the sound of glass that just fails thermally. The beaker broke into many small pieces, some being projected across a wide bench. Addition funnel did not break.
No light or flash was noticed. Stirrer had not touched the glass and rate was a nice vortex to a near the bottom of the vessel.
Nasty mess to clean-up and gave someone quite a scare.


Messy stuff! Now care to elaborate on any safer ones you might have tinkered with in "another lifetime"?

Blasty - 22-2-2010 at 07:06

Quote: Originally posted by hissingnoise  
Quote:

Place about 250mg of the compound in the tube and pack
lightly with the glass rod. (avoid holding the tube in your hands for this step).


A wooden dowel would be safer than a glass rod but even holding a dowel while tamping HMTD seems pretty iffy.
Mounting it on a drill-press with a protective screen between you and the detonator should be the way to go!



I once had an aluminum tube with some HMTD go off while pressing it in such a set up. I had placed lead ingots surrounding the tube, so they absorbed most of the shock and shrapnel. My ears were ringing for a couple of days, though. The wooden dowel "vaporized".



[Edited on 22-2-2010 by Blasty]

hissingnoise - 22-2-2010 at 09:05

Quote:

I once had an aluminum tube with some HMTD go off while pressing it in such a set up.

I can see how that would make one look for safer primaries.
But HMTD detonating during pressing into Al should be a very rare occurrence.
Do you have any idea why it happened?

I once pressed incompletely (smelling as fishy as the hexamine used to prepare it) washed HMTD in a Al tube over a base-charge of RDX while holding tube and dowel in my hand (hope this doesn't upset argyrium?).
My senses were heightened while I did it but no digits or organs were damaged!




[Edited on 22-2-2010 by hissingnoise]

gregxy - 22-2-2010 at 11:19

The point of my experiment is that a real primary does not
need confinement. It will also show what a tiny amount
it takes to remove your fingers.

Black powder will go boom if you put it in a steel pipe simply
because the presssure builds up and ruptures the pipe.
But the peak pressure is just a few hundred PSI. A detonating explosive will generate 100X more pressure.

You can also try taping an M80 to a wood 4X4. What
happens to the wood? Not much.


Quote: Originally posted by Blasty  

Some of these mixtures are meant to work under strong confinement only, otherwise they either do not explode at all or not with sufficient force to be useful. Such a method of testing would not work for them. Stronger containers would need to be used.


[Edited on 3-1-2013 by Polverone]

Blasty - 22-2-2010 at 11:24

Quote: Originally posted by hissingnoise  
Quote:

I once had an aluminum tube with some HMTD go off while pressing it in such a set up.

I can see how that would make one look for safer primaries.
But HMTD detonating during pressing into Al should be a very rare occurrence.
Do you have any idea why it happened?

I once pressed incompletely (smelling as fishy as the hexamine used to prepare it) washed HMTD in a Al tube over a base-charge of RDX while holding tube and dowel in my hand (hope this doesn't upset argyrium?).
My senses were heightened while I did it but no digits or organs were damaged!
[Edited on 22-2-2010 by hissingnoise]


I suspect it was because the bottom of the tube had not been as flattened as I thought it was. You see, I was trying to make an improvised "capsule", rather than just shut one of the ends of the tube by drawing the ends together. I tried flattening the bottom of the imrovised "capsule" by inserting an iron rod in the open end and hammering over an anvil, but I guess some rough and/or uneven surfaces remained. When I pressed the HMTD some friction with the rough/uneven surfaces at the bottom of the tube must have happened and BOOOOM!!!

Blasty - 22-2-2010 at 11:38

Quote: Originally posted by gregxy  
The point of my experiment is that a real primary does not
need confinement. It will also show what a tiny amount
it takes to remove your fingers.

Black powder will go boom if you put it in a steel pipe simply
because the presssure builds up and ruptures the pipe.
But the peak pressure is just a few hundred PSI. A detonating explosive will generate 100X more pressure.

You can also try taping an M80 to a wood 4X4. What
happens to the wood? Not much.


Quote: Originally posted by Blasty  

Some of these mixtures are meant to work under strong confinement only, otherwise they either do not explode at all or not with sufficient force to be useful. Such a method of testing would not work for them. Stronger containers would need to be used.


These mixtures however are claimed to explode so violently when confined that they allegedly can initiate at least some types of high explosives. The claims of their inventors are not merely those of a firecracker-like explosion (Castellanos' patent from the 1870s even contrasts the much stronger concussion of his "percussive petards" with that of black powder firecracker-like charges, which he points out could not reliably detonate dynamites.)

[Edited on 3-1-2013 by Polverone]

hissingnoise - 22-2-2010 at 13:01

Pressing HMTD into a crimped Al tube could be dodgy too.
Pressing onto a base-charge like RDX or PETN should generate less friction but the consequences if it did go off would be more considerable than using HMTD alone.
A small tissue plug in the crimped end of the tube might be another idea?

Lambda - 23-2-2010 at 10:16

HMTD is exceptionally hazardous to press, it explodes, if pressed too hard. Too hard is really not hard at all, no Machines are allowed! Pressing by Hand (with proper safety precautions) is OK. Also, the cap should never be made of Metals other than Aluminum, since HMTD is totally incompatible with most Metals. If the Cap does not explode during manufacture, then it will deteriorate in a few hours/days due to the catalytic action of the Metal. Copper and it's Alloys are particularly efficient in this respect.

Pink Floyd - Comfortably Numb - Pulse 1994 (HD Live):
http://www.youtube.com/watch?v=iJZYG5qwHHI

Lambda

Some old English patents appertaining to mixtures intended to substitute primary explosives

dts - 24-2-2010 at 09:59

The described mixtures are interesting but largely too sensitive ( because of the chlorate ) to be useful. Does anyone know if replacing a proportion of the chlorate with perchlorate :- a makes them safer and b retains their explosive properties?

hissingnoise - 24-2-2010 at 11:00

Chlorate mixtures with red P or sulphur are certainly too sensitive to friction and shock to be trusted but in any case, replacing chlorate with the per-salt, if you can, is always a good idea.

chlorate perchlorate ratio in mixtures

dts - 26-2-2010 at 06:23

My above post was perhaps not clear enough so ...
One of the mixtures described in Roscos post above is for trinitronaphthalene ( unspecified isomer ) and potassium chlorate. My question was how much chlorate can be replaced with perchlorate to leave the mixture much safer but still retain the interesting explosive properties ( apparently able to function as a primary ). ?

hissingnoise - 26-2-2010 at 06:45

It's possible that replacing all the chlorate with perchlorate would make the mixture insensitive to the spit of a fuse.
A small quantity of perchlorate flash-powder pressed lightly on top should correct this.

quicksilver - 27-2-2010 at 08:28

IMO there is no "safe" or "safer" w/ Energetic Peroxides. Use powdered Al always as a dry lubricant when materials that are friction sensitive are pressed. Avoid glass or seemingly smooth surfaces, as these actually contact the material harder on a microscopic level, etc. The pores of wood allow Al or graphite to fill with a dry lube.
When viewing a film of a loading machine, one thing I noticed right away was the thing went very slowly. So slowly in fact that at first it appeared to not be functioning.
Sometime back there was a thread somewhere about accidents and HMTD was right up there with suspicious consistency.

hissingnoise - 1-3-2010 at 04:42

Thanks for the heads up on glass quicksilver - I have been considering glass tubes for HMTD.
But when I hear of HMTD accidents I'm inclined to assume some kind of careless handling, energetic pressing, incompatible metal or insufficiently-washed product.


quicksilver - 2-3-2010 at 10:53

It's (HMTD) the only energetic peroxide that the US Bureau of Mines (USBoM) ever considered and tested. At that time (1912 + or -) plastic and polymers were really unavailable but they did have bake-a-Lite and that was what they used for testing initiation. They found that from that standpoint HMTD was quite respectable in initiation however the shelf life was much lower than Hg Fulminate. And that was exactly what they were attempting to try and move from. this was the first time that azides were examined commercially & by a gov't testing agency. Scores of material are available from the USBoM (now defunct) but reprinted in both white papers and a book specifically dealing with the subject. Detonators for High Explosives; Hall, Howell, & Taylor - ISBN 1-4276-1460-1. The book is where most of the material is re-printed. I searched for quite a long time to get the originals in their entire length.

And outstanding experiment was making dinitrohexamine as one were to make RDX but instead, use that to make HMTD. The resultant appeared to have perhaps one of the most interesting properties. It appeared stronger than HMTD yet the yield was somewhat less! The material appeared to be longer lasting (shelf life) and popped when exposed to flame instead of burn on a sample of tens of milligrams level. It appears granular instead of somewhat "soft" and in all likelihood is more sensitive if mishandled.

Another very interesting paper was written on the development of a "sealant" for fuse caps. This is the first time I had read of the commercial use of nitro-cellulose lacquer. The material was made to instantly transmit the spit of a flame and drive a very hot deflagration into the cap. The material was made thick (25% NC) mixed with coal dust and K Chlorate. The transmission of flame becomes a "pop" but it is also waterproof. This material was patented by the Austin Powder Company. Not only did it hold up to time but the material because it was so high in NC was pliable even when aged. This made for consistent water proofing and had been used in Hg Fulminate fuse caps for many years. In cold climates the seal was sufficient to allow the caps to last longer than the previous standard which was very high sulfur ratio BP seal (this was also warmed prior to mixing forming a tar-like mass) pressed with the same pressure as the rest of the cap.
The BP seal often crumbled over time and was rather thin so as to maintain immediate ignition.

We all know that sulfur was used for plugs in both types of caps, as was tar. This continued despite better sealants because the tooling for warming and delivery into caps made alteration of this, cost prohibitive.

[Edited on 2-3-2010 by quicksilver]

hissingnoise - 3-3-2010 at 06:04

Naoum thought highly enough of HMTD to suggest its use in explosive rivets in a 1938 patent.
Presumably the explosive wouldn't be safe if pressed directly into the bare rivet but into some kind of protective capsule which could be placed in the rivet's shank.
The patent however, made no mention of protective containment!
Whether the rivets were manufactured in number is doubtful too, considering HMTD's thermal stability.
Once loaded though, caps containing HMTD should be safe and fairly stable as long as they're properly stored and handled.






Rosco Bodine - 3-3-2010 at 09:51

Not all that glitters is gold, and that often holds true for what may seem at first to be sparkling bright ideas :D

[Edited on 3-3-2010 by Rosco Bodine]

hissingnoise - 3-3-2010 at 10:35

A single mishap will put me firmly in Blasty's camp.
If I do come a cropper I hope not to see any glistering in the hands area.
FLW?
No, but seriously, I've heard of HMTD going off while being pressed or from being left in sunlight (or was that AP?) but not from normal handling of finished detonators.


[Edited on 3-3-2010 by hissingnoise]

quicksilver - 3-3-2010 at 14:33

Actually safety would be a damn good thing to start a thread about. There are people who really don't understand static's impact on energetic materials and often use the term "unstable" when the materiel was poorly synthesized or handled / stored inappropriately. That's one thing I despise about AP; it's simplicity of mfg.


I once read a poster that actually didn't understand static ignition in relation to primaries. Again, only my opinion but I believe that static ignition is responsible for some people calling some materials "unstable". Properly synthesized and maintained very few things are actually unstable. If a material requires neutral ph, low temp, dry or moist environment, no UV - that does not make that material unstable. Way too many people want to race through a synthesis so they have "run-a-ways" (when lucky) or the result is a shit-blob of wasted chemicals. When unlucky they feel that time distorted sickly weak feeling and can't seem to hear or catch their breath as they feel nauseated with fear as they look at their extremities & can't seem to focus on what just occurred.....


There used to be a quite lengthy thread on (UseNet) Rec.Pyrotechnics of "accidents". There are VERY few accidents with energetics: just as with firearms, there is negligence. That's why I've not used the term accidental discharge -the damn thing was a negligent discharge. An accident is actually tough to find if you think about it. However it could just be a question of semantics. Many people say "unstable" when what they really mean is "sensitive" or demanding or certain protocols.... :P

One serious problem is that few people READ (study) a hobby anymore. They want to race when they should be learning how to crawl without skinning their knees.

[Edited on 3-3-2010 by quicksilver]

nitro-genes - 3-3-2010 at 18:04

Over the past 10 years I've probably pressed well over a hundered blasting caps, never had a premature detonation while pressing the primary. Mostly used Ag2C2*AgNO3, Pb(N3)2 and AgN3 for very small detonators, but ALWAYS in combination with a basecharge that is very sensitive to initiation, like PETN, MHN or RDX! Never liked pressing the primary over the basecharge though, so I usually pressed the basecharge and primary seperately. The primary was pressed in a somewhat smaller diameter tubing, that fits precisely in a somewhat larger tubing, in which the basecharge was pressed. This allows you to press (and store) the primary (20-100 mg), attach fuse mechanism, etc without any risk of prematurely detonating the basecharge. To decrease the amount of primary needed I also pressed about 100 mg of the basecharge by hand (~1 g/cm3) on top of the lever-pressed or plasticized basecharge, (>1.6 g/cm3) for easy initiation...

Usually used STRONG plastic tubing as the casing (you dont want it to flex with the primary inside!!!!) and a large length of it. Adding some length to your detonator casing not only makes pressing of the basecharge easier but also provides sufficient distance between your fingertips and the basecharge when handling the finished detonator. (When plastic is used)

[Edited on 4-3-2010 by nitro-genes]

Rosco Bodine - 13-3-2010 at 16:00

With regards to fulminating mixtures containing KClO3, I have wondered about
the possible use of manganese ferricyanide as a combination fuel and catalyst,
as the MnO2 byproduct is a known catalyst for the heat driven decomposition and release of oxygen by KClO3. Reportedly the addition of potassium ferricyanide
to a solution of a soluble manganese salt results in the precipitation of the
manganese ferricyanide Mn3[Fe(CN)6]3 as a brown substance insoluble in HCl,
also insoluble in NH4OH. I almost hesitate to speculate about such materials possible usefulness with KClO3 because there is an inherent danger associated with KClO3 mixtures which have a reputation for instability which is unpredictable,
and some of the KClO3 containing mixtures have even reportedly undergone spontaneous ignition or detonation, without the helpfulness in that regard which
would be supplied by any catalyst deliberately added. Therefore I would include a caveat with my suggestion about the possible usefulness of manganese ferricyanide as a catalyst, that such mixtures conceivably could experience storage instability, including the risk of spontaneous ignition or spontaneous detonation. Any experiments with such mixtures should involve small quantitites
and provisions for safety that allow for such a variable as that unknown control
introduced by the uncertainty of whether the energetic material will initiate
from a deliberately applied stimulus, or equally well at any other time it pleases.

It is precisely that uncertainty about such mixtures which causes my lack of enthusiasm for these types of pyrotechnic mixtures, and encourages my interest in chemical compounds
which tend to be more predictable.

[Edited on 14-3-2010 by Rosco Bodine]

Rosco Bodine - 17-3-2010 at 11:23

A related idea which I have been considering as a possibly worthwhile experiment regarding the energetic combination of ferricyanide and chlorate, involves a possible means of compounding the materials as a clathrate rather than as a physical mixture.

Referencing the attached file, Lead ferricyanide exists, and forms also a basic salt, and a double with lead nitrate.

Lead nitrate is also known to form complex multiple salts including combinations with lead chlorate and basic lead picrate, which may also contain organic salts of lead such as lead acetate or formate or glycinate ......therefore it would seem possible that lead ferricyanide may be included in that scheme as well. If my postulate hold true, then it should be possible to form a basic lead picrate - lead nitrate - lead chlorate - lead ferricyanide multiple salt or clathrate with
the idea being of course to achieve an intimate mixture at the molecular level which brings together the chlorate and ferricyanide in an energetic matrix of basic lead picrate - lead nitrate. It is probable that such a multiple salt would have energetic properties. And it is also possible that such a composition if it exists is novel and unreported.

Reportedly 3 grams of Potasssium Ferricyanide dissolved in 7 ml H2O when mixed with 3 grams of Lead Nitrate dissolved in 8 ml of H2O will after a few minutes yield more than a gram
of crystals of Lead Ferricyanide. These crystals could be obtained separately in advance by this method if necessary for use as a precursor. Only part of the ferricyanide is precipitated as Lead Ferricyanide and the residual solution
contains a double salt of Lead and Potassium.



:D Also of interest is something which I have never seen before from an old text circa 1891 reporting that Potassium Ferricyanide itself will detonate on heating with Ammonium Nitrate. Now that is an obscure and interesting bit of information.



Attached is a separate file which indicates that extreme caution should be observed for the inhalation hazard associated with some reactions involving ferricyanides because of the posible release of cyanide gas which can occur from these reactions. Also may be encountered a danger from the formation of cyanide salts.

The nitroferricyanides (nitroprussides) are also of potential interest.

Attachment: lead ferricyanide related.pdf (165kB)
This file has been downloaded 776 times


Attachment: ferricyanide reaction hazard warning.pdf (211kB)
This file has been downloaded 918 times

[Edited on 18-3-2010 by Rosco Bodine]

Attachment: Nitroprussides.pdf (259kB)
This file has been downloaded 1962 times

The WiZard is In - 6-4-2010 at 14:02

Quote: Originally posted by Blasty  
In the section about explosives in Thorpe's A dictionary of applied chemistry, there is mention of several patents regarding mixtures that are intended as replacements for primary explosives, like mercury fulminate, in blasting caps/detonators, an interesting but relatively little known or talked about subject:

[snip]

You may find Richard Escales und Alfred Stettbacher's
Die Explosivstoffe
Intitialexplosivstoffe
Verlag von Veit & Comp.
1917

Useful. It has been reprinted.

And —

Explosiv- und Züdstoffe in the yearly editions of —

Technicsh-Chemisches Jahrbuch
(1904 is volume 27.)

The WiZard is In - 7-4-2010 at 07:55

Quote: Originally posted by Blasty  
In the section about explosives in Thorpe's A dictionary of applied chemistry, there is mention of several patents regarding mixtures that are intended as replacements for primary explosives, like mercury fulminate, in blasting caps/detonators, an interesting but relatively little known or talked about subject:


-------
You could check :—

JP Cundill
Dictionary of Explosives
2nd Edition London 1895

It has been reprinted, or you can DL it from Google.com/books

JD Daniel
Dictionnaire Matiéres Explosives
Paris 1902
Google books again.

Patents for Inventions
Abridgments of Specifications
Class 9
Ammunition, Torpedoes, Explosives and Pyrotechnics
HMSO
Reprinted by Museum Restoration Service
Canada 1981

Various volumes.

I own
1855-1866
1867-1876
1877-1883
1884-1888
1889-1892
1893-1896
1897-1900

I do not know if there are earlier/latter volumes.




Blasty - 23-6-2010 at 15:51

I found some interesting old passages about the intricacies of detonating nitrocellulose using both primary explosives as well as non-primary explosives:

http://books.google.com/books?id=Y449AAAAYAAJ&pg=PA499&a...

"These effects are less marked in the case of loose gun-cotton, on account of the large quantity of air interspersed through its bulk. As compressed gun-cotton is less compact than nitroglycerin, it should follow that it is less easily detonated than nitroglyeerin ; and this is found to be the case. Nitroglycerin may be detonated by the fall of a weight from a moderate height, by a gun-cotton fuse, or by a mixture of potassium chlorate and fulminate of mercury. Gun-cotton detonates only with pure fulminate of mercury, and the best results are not obtained unless the fulminate be enclosed in a rather thick case of sheet-tin, and placed in contact with the gun-cotton, conditions which realise the greatest initial pressure. The quantity of force thus converted depends on the suddenness of the shock, and on the amount of work which it is capable of doing. These elements vary with the detonator, and Abel has found that chloride of nitrogen is not very efficacious, and that iodide of nitrogen, which explodes by the slightest friction, is incapable of exploding gun-cotton. But chloride of nitrogen develops lens heat than any other compound here treated of (see table), therefore a larger quantity of it must be employed, and judging by analogies drawn from other iodine substitution-substances, iodide of nitrogen should develop less heat and work than the same weight of chloride of nitrogen : hence its inactivity in this respect."

http://books.google.com/books?id=G1cmAQAAIAAJ&pg=PA725&a...

"The difference in the behaviour of such explosive substances as nitro-glycerine and its compounds, and gun-cotton when exposed to the influence of a source of heat, has been made the subject of careful investigation by many distinguished chemists in this and other countries. M. Nobel has shown that crude nitroglycerine can be detonated by contact with a small charge of confined gunpowder or by a large percussion cap.

It occurred to Mr. E. O. Brown, assistant-chemist of the War Department, that gun-cotton might also be ignited and exploded by detonation. Experiment proved this to be the case when the particles of the cotton were in a finely-divided state, and when its mass had been subjected to powerful pressure. Further trials, however, showed that gun-cotton is not nearly so sensitive or so susceptible to detonation as nitro-glycerine. The detonation of compressed guncotton cannot be accomplished by the explosion of ordinary fulminates. Nitro-glycerine can be detonated in contact with compressed gun-cotton without exploding the latter. An electric fuse, charged with 100 grains of a mixture of sulphide of antimony and chlorate of potash, has been fired on a disc of compressed guncotton without causing any explosion. The gun-cotton merely ignited and burnt away. A bottle, containing three-quarters of an ounce of pure nitro-glycerine has been detonated on the top of a disc of compressed guncotton without exploding the latter. The gun-cotton in this case was scattered by the violence of the explosion, and fragments of it inflamed. A detonating fuze containing ten grains of mercuric fulminate failed to explode a hank of gun-cotton thread, while half that amount of fulminate was sufficient to cause compressed gun-cotton to detonate violently.

These experiments support the views held by Mr. Abel:—

1. That gun-cotton, freely exposed, cannot be detonated by any explosive agent less sudden and violent in its action than mercuric fulminate.

2. That nitro-glycerine, which is more readily exploded by a blow than gun-cotton, may be detonated through the agency of explosive mixtures far less violent and sudden in their action than fulminate of mercury.

3. That the mechanical condition of the gun-cotton most materially influences the result, and that a considerable compactness or density, and a consequently great resistance to motion of the particles, is essential for the detonation of gun-cotton.

To what, then, is this remarkable action due? How comes it that the same substance is susceptible of a totally different metamorphosis into its gaseous products according to the manner in which fire is applied? Is it that the violence of explosion is proportionate to the amount of heat evolved in the disturbance of the chemical equilibrium of the particular substance used as a detonator? Is it due to the facility offered for the passage of heat throughout the material acted on? Is it owing to the suddenness or sharpness with which the detonating substance acts? Experiment does not support any one of these views. There is far more heat evolved in the combustion of 100 grains of sulphide of antimony and chlorate of potash than in the explosion of ten grains of mercuric fulminate; the latter, however, invariably detonates compressed gun-cotton, while the former fails to do so. It is impossible to detonate loose porous guncotton, so that the action cannot be due to the facility with which heat can permeate the mass. Both iodide and chloride of nitrogen, even in comparatively large charges, fail to detonate gun-cotton; yet the explosion of these substances is certainly far more sudden than mercuric fulminate. We must accordingly look elsewhere for an explanation of this extraordinary phenomenon, and recent experiments appear to favour the theory advanced by Mr. Abel, that the relative power of different explosive agents to accomplish the detonation of gun-cotton appears to be in direct proportion to the mechanical effects of their explosion ; in other words, to the blow they are capable of inflicting on whatever body they may be in contact with.

When iodide and chloride of nitrogen are fired on a thin sheet of copper, the indentation produced by the explosion is not nearly so marked as in the case of the mercury or silver fulminates. The indent produced by the former is not nearly so deep or sharply defined; indeed, a charge of two grains of chloride of nitrogen has been exploded on a watch-glass without fracturing it, whereas half that amount of silver fulminate was sufficient to shatter the glass to atoms. The mechanical effect of mercuric fulminate is much enhanced by confinement in a strong case, such as a tin tube, and under such conditions the violence of its action, as measured by work done, is in excess of either of the nitrogen compounds.

This may probably account for the fact that, although more instantaneous in its action, iodide of nitrogen fails to detonate gun-cotton, even in a charge twenty times greater than the usual charge of mercuric fulminate. Possibly, further investigation may throw more light on this remarkable explosive property. There may yet be some hidden peculiarity in the concussion or powerful vibration produced by some substances distinct from the mechanical force due to their explosion. There appears to be a species of entente cordiale between explosives of a certain class. They have a strange, undefined sympathy with one another. If one goes off, all the others in the immediate neighbourhood seem instantaneously to be en rapport. As the synchronous vibrations of a tuning-fork are taken up by other instruments, so the molecules of various explosives pulsate in unison. Thus, bodies in a state of high chemical tension may prove more susceptible to the operation of mechanical force chemically applied."

http://books.google.com/books?id=t-_mAAAAMAAJ&pg=PA179&a...


"Among several other interesting results furnished by an examination into the conditions governing and results attending the transmission of detonation by tubes, a remarkable want of reciprocity was found to exist between mercuric fulminate and gun-cotton. The latter substance is more susceptible to the detonative power of mercuric fulminate than of any other substance, as will presently be further shown. The quality of fulminate required to detonate gun-cotton is regulated by the degree to which the sharpness of its own detonation is increased by the amount of resistance to rupture offered by the envelope in which the fulminate is confined. From 20 to 30 grains are required if the detonative agent is confined in a thin case of wood or in several wrappings of paper; but as small a quantity as 2 grains of the fulminate suffices to effect the detonation of compressed gun-cotton, provided the fulminate be confined in a case of stout metal (sheet tin), and be closely surrounded by being tightly imbedded in the mass of gun-cotton. If there be no close contact between the two, the quantity of fulminate must be very considerably increased to ensure the detonation of the gun-cotton; and, in attempting to transmit detonation from mercuric fulminate to gun-cotton by means of tubes, it was found necessary to employ comparatively very large quantities of fulminate in order to accomplish this, even through short lengths of tubes. But when the quantity of fulminate used reaches certain limits, the detonation may be transmitted from it to gun-cotton through very long lengths of tube. In applying gun-cotton, on the other hand, to accomplish the detonation of mercuric fulminate, it was found that this result could be attained, and through considerable lengths of tube (7 feet and upwards), by means of very much smaller quantities of guncotton than is needed of fulminate to induce the detonation of gun-cotton through the corresponding distances.
This want of reciprocity between two detonating agents corresponds to one even more remarkable, which was observed by the lecturer in his earlier investigations on this subject. In the first place it was found that the detonation of 1/4 oz. of gun-cotton (the smallest quantity that can be thus applied) induced the simultaneous detonation of nitro-glycerin, enclosed in a vessel of sheet-tin, and placed at a distance of 1 inch from the gun-cotton ; while with 1/3 oz of the latter the same effect was produced with an intervening space of 3 inches between the two substances. But on attempting to apply nitro-glycerin to the detonation of gun-cotton, the quantity of the former, which was detonated in close contact with compressed gun-cotton, was gradually increased in the first instance to 3/4 oz., and subsequently even to 2 ozs., without accomplishing the detonation of the latter, which was simply dispersed in a fine state of division, in all instances but one, in a large number of experiments.
The force developed by the detonation of nitro-glycerin was found, by careful comparison of the relative destructive effects of corresponding quantities, to be decidedly greater than that of the fulminate, of which from 2 to 5 grains suffice for developing the detonation of gun-cotton, when it is in close contact with them. The non-susceptibility of gun-cotton to detonation by nitro-glycerin is therefore, it need scarcely be said, not ascribable to any deficiency in mechanical force suddenly applied when the nitro-glycerin is detonated.
That the power possessed by different very highly explosive substances, of inducing the detonation of such bodies as gun-cotton and nitro-glycerin is not solely ascribable to the operation of mechanical force very suddenly developed, is indicated not only by the singular inertness of guncotton to the influence of nitro-glycerin as a detonating agent, but also by a comparison of the behaviour of other detonating substances with that of the mercuric fulminate, when applied to the detonation of gun-cotton. Thus, the detonation of silver fulminate is very decidedly sharper than that of the mercury compound, yet it is in no way superior to the latter in its power as an initiative detonating agent; indeed, a somewhat larger amount of it appeared to be required than of the mercury salt to induce detonation of gun-cotton with certainty. Again, the iodide and chloride of nitrogen are far more susceptible of sudden detonation than the silver fulminate ; yet while 5 grains of the latter, confined in a stout metal envelope, suffice to detonate gun-cotton, 50 grains of chloride of nitrogen confined by water, appeared to be the minimum amount with which the detonation of gun-cotton could be accomplished with certainty, while no success attended the employment of confined iodide of nitrogen in quantities ranging up to 100 grains.
The incompatibility of these results with the general conclusion, based upon numerous and greatly varied experiments, that the facility with which the detonation of gun-cotton and nitro-glycerin, and bodies of a similar character as explosives, is induced by an initiative detonation, is proportionate to the mechanical force aided by the heat developed by the latter, led the lecturer to the conclusion that a synchronism or similarity in character or quality of the vibrations developed by the detonation of particular substances, operates in favouring the detonation of one such substance by the initiative detonation of a small quantity of another, while in the absence of such synchronism, a much more powerful detonation, or the application of much greater force, would be needed to effect the detonation of the material operated upon. This view has received considerable support from results since obtained by other experimenters, especially by MM. Champion and Pellet; but the subject is one which still needs further experimental elucidation.”


http://books.google.com/books?id=4Z08AAAAYAAJ&pg=PA140&a...

"The explosives such as the dynamites, nitroglycerin, dry gun-cotton, and the picrates detonate with extreme violence when a relatively small quantity of fulminate of mercury or chlorate of potash is detonated in close contact with them. These small primers are generally of 0.4 gramme to each 50 gr. of charge. In practice 1.5 gr. of fulminate will explode any ordinary charge.
Dry gun-cotton will not explode by the use of iodid or chlorid of nitrogen: fulminate of silver as violent as that of mercury fails also unless a large quantity is used; whilst chlorate of potash and sulphuret of antimony accomplish it easily ."


It is interesting to notice the contradiction between the last statement above (viz. that gun-cotton can be set off by a charge composed of a mixture of potassium chlorate and antimony sulfide) and the one given in the second source (viz. that 100 grains of such a mixture failed to explode gun-cotton.)

One of the Von Dahmen patents specifically mentions that one of his mixtures can detonate gun-cotton:

http://www.google.com/patents?id=5B1QAAAAEBAJ&printsec=a...

[Edited on 23-6-2010 by Blasty]

Rosco Bodine - 16-9-2010 at 00:05

Quote: Originally posted by Blasty  
Quote: Originally posted by Rosco Bodine  
(by weight) KClO3 5 parts and potassium ferricyanide 3 parts is a fulminating mixture.


Yes, a similar mixture, but with potassium picrate added in (invented earlier by Designoble and Casthelaz, but who apparently had not fully realized its potential use as an initiator) was already used by Prudencio Castellanos in the 1870s to detonate dynamites:

http://www.google.com/patents?id=2C9tAAAAEBAJ&printsec=a...

He called his devices "percussive petards". He made them both out of metal capsules as well as of cardboard tubes. The percussive mixtures he used do not require pressure after being loaded in the containers, and seem to work best granulated.

Something that Castellanos says in his patent also struck me as curious: even black powder charges were apparently being used to attempt to detonate dynamites. It doesn't seem that the fulminate blasting cap was as universally accepted as one would think from reading most history books on the subject.


Attached is the Designoble and Casthelaz patent US76173 which lists potassium ferrocyanide (not ferricyanide) in mixture with potassium chlorate and potassium picrate, describing the mixture as being "three times as powerful as mercury fulminate", probably an exaggeration, but such an anomaly could I suppose be possible. I wonder also about the energy difference which may be manifested dependant upon whether the ferrocyanide or the ferricyanide is used, or what difference may be realized by use of different metal ferricyanide salts or double salts. It may be possible to improve such mixtures.

Attachment: US76173 chlorate - picrate detonating mixture.pdf (174kB)
This file has been downloaded 789 times

Blasty - 18-9-2010 at 22:13

Quote: Originally posted by Rosco Bodine  


Attached is the Designoble and Casthelaz patent US76173 which lists potassium ferrocyanide (not ferricyanide) in mixture with potassium chlorate and potassium picrate, describing the mixture as being "three times as powerful as mercury fulminate", probably an exaggeration, but such an anomaly could I suppose be possible. I wonder also about the energy difference which may be manifested dependant upon whether the ferrocyanide or the ferricyanide is used, or what difference may be realized by use of different metal ferricyanide salts or double salts. It may be possible to improve such mixtures.


Those are good questions, which I wish I had better conditions to investigate myself. Unfortunately, my ability to perform such experiments is pretty limited (only during two seasons a year can I make any "loud" experiments, when everyone around here is discharging all sorts of fireworks.) If we could count with the cooperation of someone who is located in a more suitable environment to test such things many of these interesting questions could be settled once and for all.

Here is an obscure composition

Rosco Bodine - 23-10-2010 at 21:13

Here is a mixture which I found in PATR, a chlorate mixture which is reportedly brisant.

Blasty - 25-10-2010 at 21:20

Quote: Originally posted by Rosco Bodine  
Here is a mixture which I found in PATR, a chlorate mixture which is reportedly brisant.



Thanks for the info on this yet another mixture intended to substitute primary explosives. I don't suppose you have been able to find information on how it was intended to be deployed (strong containment required or not?, pressed or loosely packed?, granular or powder form?, etc.)

My concern with this mixture, as with all mixtures that contain ammonium and chlorate compounds, would be the possibility of ammonium chlorate being formed, which is well known to be a very unstable compound capable of exploding spontaneously. If I ever prepared such a mixture, I would try to use it as soon as possible and not store it for long periods of time, which would increase the chances of that dangerous compound being formed.

[Edited on 26-10-2010 by Blasty]

Blasty - 13-4-2011 at 22:20

I found this passage in Tenney L. Davis' Sugars in Fireworks and Explosives (The Sugar Research Foundation, 1948, page 152) appertaining to the general topic of this thread:
Quote:

Nitrolactose has been recommended for use in detonators and blasting explosives. Large describes primary charges for compound detonators consisting of mixtures produced by the concurrent precipitation of nitromannite or nitrodulcite with PETN or nitrocellulose and/or with tetryl or other nitro-compound. In particular he recommends a concurrently precipitated mixture of nitromannite 50 parts, nitrolactose 35, and tetryl 15. These mixtures when lighted by a flame burn in the open with a flash, but when confined in a blasting cap shell, they detonate and are capable of initiating the high explosive secondary or main charge of the detonator. Lange finds that nitrocellulose alone is satisfactory for this purpose, and reports that 0.2 g. detonates nitromannite and that 0.5 g. causes the satisfactory detonation of tetryl.



I am not sure if there was a typo here and the "Lange" reported as finding that nitrocellulose by itself can detonate nitromannite and tetryl is actually the same person as the "Large" referred to earlier in the passage. The Large patents Davis refers to are U. S. Patents 1,928,204 to 1,928,207:

http://www.google.com/patents/about?id=aB5FAAAAEBAJ&dq=1...

http://www.google.com/patents/about?id=aR5FAAAAEBAJ&dq=1...

http://www.google.com/patents/about?id=ah5FAAAAEBAJ&dq=1...

http://www.google.com/patents/about?id=ax5FAAAAEBAJ&dq=1...


[Edited on 14-4-2011 by Blasty]

quicksilver - 14-4-2011 at 07:55

I am familiar with the [written] material, & it is a typo TTBoMK. Apparently Davis had either worked for or consulted with the Sugar Research Foundation in expounding the boundaries of their sales (explosives). There is more to this via additional papers published by Davis. There was some interest in using MHN as it filled a gap between primary and secondary and it's use in detonators. A nitrated sugar could present a substantial sales agenda, etc.
Pyrotechnia has a free download entitled "Essential Tenny Davis" which has SOME of the material. Davis published long before the classic 1940's work and some of this material is still available now that he has become so popular. Unlike many other polyols mannitol & lactose were fairly common and less expensive. However they needed a higher level of nitration to become appropriate for explosive use. Even Schonbein had worked with nitrated polyols back in the mid-19th century.

Blasty - 18-5-2011 at 15:41

Quote: Originally posted by Blasty  
Something that Castellanos says in his patent also struck me as curious: even black powder charges were apparently being used to attempt to detonate dynamites. It doesn't seem that the fulminate blasting cap was as universally accepted as one would think from reading most history books on the subject.


I found this passage regarding this subject in the Proceedings of the National Safety Council, 1918, page 1122:

"It is a common practice in some sections to place a dynamite cartridge in the bottom of a bore hole and the main charge of black powder on top of that, firing the black powder with fuse or squib. The dynamite explodes from the shock of the black powder but it does not explode as completely as when detonated by blasting cap, so that it is doubtful if any real benefit is obtained by this method. Different explosives have such different rates of detonation that it is not only wasteful but frequently dangerous to use this method of blasting."

It seems that as late as the 1910s there still were miners using black powder to set off dynamite.