Sciencemadness Discussion Board

Diving Into the World of Fulminates

Lewis - 30-8-2008 at 01:23

Hello everyone. This being my first thread here, I'm a little anxious, but I hope this doesn't rub anyone the wrong way as I'm pretty sure this hasn't been covered so far.

Let me first say that I'm not new to the world of energetics, but thusfar have used only organic peroxides as primaries. I've decided to experiment with Hg fulminate, and have everything prepped for a first run. I am, however, a little apprehensive...

My main concern stems from the source of my mercury, which was from the bowels of my ancient house. I was carting away the scrap cast iron from our ~110 year old heating system, when I inverted a section of piping and inadvertently sent a small deluge of elemental mercury onto the ground! Our furnace was a hulking beast-- a mass of clay, asbestos, and iron. God knows what sort of combustion products have been left in those pipes throughout the years (it once used coal, but had been retrofitted to burn natural gas somewhere down the line).

Back to mercury fulminate, I'm a little unsure as to what small contaminants of other heavy metals in the mercury could do to the reaction. Obviously silver, although it seems hugely unlikely, would cause a major problem. Past that I have no idea what else could screw up or make unsafe this reaction.

Visually, the mercury looks mostly pure, with a small amount of dark scum spread around in its mass. I have the equipment to distill it I suppose, but it seems wasteful, hazardous and frankly a waste of time. Another concern is what to do with the leftover reaction products after the Hg fulminate is made, most of which are very toxic.

I think I've gone on long enough here. I appreciate any thoughts.

Leander - 30-8-2008 at 09:43

According to PATR and Urkanski small ammounts of other metals such as copper and zinc produce MF as a white participate of roughly 95% purity, while pure reagens grade Hg/HNO3/EtOH gives a sand couloured, brown or gray product wich has a higher purity of roughly 98%. Nowhere in both sources the possibility of other fulminates participating out of a one pot synthesis is mentioned.

I personally don't think its possible either, since other fulminate salts such as cadmium- copper- and sodium fulminate are always made by the action of amalgams, witch take hours if not days to produce a traceable ammount of corrosion on the other metals, leading to the possible formation of other fulminates. The synthesis of MF schould'nt take more than 20 min, so any intervention between free mercury, MF and other metals should have all taken place in a really short ammount of time, unsufficient to get that reaction going.

Though, starting with an amalgam in a MF synthesis could be dangerous, since the formation of other more sensitive fulminates is more likely to happen, because of the larger reaction surface beween mercury, mercury fulminate, and other metals. I think it can be done, but you should always consider en treat the reaction product as being contaminated and potentially dangerous.

[Edited on 30-8-2008 by Leander]

crazyboy - 30-8-2008 at 09:59

Mercury fulminate is generally considered less powerful and less sensitive than other primaries such as AP. However there are some things you should take into consideration, do your research thoroughly. The reaction is quite violent and produces a lot of toxic gas. Mercury is also considered dangerous if you inhale fumes. I would suggest you get another source of mercury, that mercury could have been contaminated with any number of metals.

Lewis - 30-8-2008 at 12:51

Quote:
Originally posted by crazyboy
Mercury fulminate is generally considered less powerful and less sensitive than other primaries such as AP.


This is interesting... Acetone Peroxide never struck me as a powerful primary, but it's fine if MF is a little weak. It needs only to detonate ETN. I was thinking of an 80/20 chlorate mix as cited in various places.

I really doubt I'd go out of my way to find clean mercury, as my whole reason for choosing this primary was based on the fact that I had some mercury lying around.

By the way... I have the means to ventilate all fumes outside my workspace-- no worries there.

a_bab - 6-9-2008 at 09:30

I don't think MF is less "powerful" than AP, nor it is less sensitive. It can dtn when scratched with a dried grass straw.

Lewis - 7-9-2008 at 22:21

/\ Indeed.

And by the way, if anyone is interested, I didn't try the synthesis because I decided it wasn't worth the risk of forming some unstable compound I didn't predict.

[Edited on 8-9-2008 by Lewis]

grndpndr - 14-9-2008 at 01:30

You may regret that particulaly if youve discarded the Mercury.My first fulminate synthesis and Its so much superior to PA in all ways as a detonator
including simplicity of synthesis and half the battle a source of Mercury. Free but questionable purity mercury I would have tried 1/2 a std batch or 2.5grs its being synthesised you have plenty of opportunity to remove yourself from the vicinity.Or place a barrier between you and the simple synthesis.If you notice unusual sensitivity det of its own accord or even as sensitive as AP you have the option of purifying the MF with instruction on both megolomanias website and powerlabs synthesis.MF is still a great Home primary despite its age,AP IMO poses a greater danger than possibly contaminated mercury.APs a finger eater IMO and unnescessary risk.

chemoleo - 14-9-2008 at 17:27

I would seriously advise against AP - there are countless of threads as to why - for starters it is unpredictable, different batches have different sensitivities unless conditions are fiercely controlled. There are many better primaries, I've even heard of silver acetylide nitrate being used for ETN. HMTD springs to mind too, much safer than AP. MF should be perfectly adequate. After all it was (is) also used commercially. ETN does not need much initiating power to detonate.

As to your Hg- as you have to work it up as the nitrate salt anyway, perhaps you can think of a purification scheme that weeds out most other metals... i.e. AgCl is insoluble, while Hg2Cl2 is not, based on this you can remove the silver. You can use various other anions to remove other metals this way.

magneet - 15-9-2008 at 10:40

Quote:

I've even heard of silver acetylide nitrate being used for ETN
Silveracetylide-nitrate is alot more underestimated about its ability to initiate insensitive secundairy’s in its practical primairy function.
The reason is simple, when research into its practical function exceeds someone’s ability to make more advanced primairy’s like lead azide for example, nothing feeds the need to make it work anymore.

Lewis - 17-9-2008 at 16:16

Quote:
Originally posted by grndpndr
You may regret that particulaly if youve discarded the Mercury.


Not a chance! That stuff is way to cool to throw out (not to mention I don't know how I'd get rid of it).

Perhaps I'll synthesize about a gram in the standard fashion. After washing and decanting, I'll gingerly transfer some wet crystals to some sort of drop-rig, and leave them there until dry.

COPAE sites Hg(CNO)2 as having a drop test sensitivity of 2-4 cm for a 2kg weight.

If it was going off from a significantly weaker impact, I'd know something was up.

[Edited on 17-9-2008 by Lewis]

grndpndr - 20-9-2008 at 17:29

If your mercury is satisfactory i would be willing to bet you'll be pleasantly suprised with the results from what ive always felt to be a more sympathetic primary (than AP)particulrly if for some reason yor compelled to use a composite cap even TNP/FM if sufficient precautions agaisnst cross contamination.The destructive effect of even a small comp. cap; FM- w/1gr.of TNP/PETN/RDX etc quite likely to = #8 cap.:o

[Edited on 20-9-2008 by grndpndr]

[Edited on 20-9-2008 by grndpndr]

12AX7 - 24-9-2008 at 21:43

Re: subject,

I imagine an immense sea of mercury fulminate, beaches and dunes and ripples; and myself, as if jumping off a dreamland diving board, careening gracefully into the center. And then with a flash, this imaginary world... ceases to exist.

Tim

grndpndr - 16-10-2008 at 06:43

Poetry,how about bathed in the warm glow of nuclear fire?LOL:(Either way almost a religious experience assuming I did not end up a crispy critter.



[Edited on 16-10-2008 by grndpndr]

OWCHITBUURNS!!! - 18-10-2008 at 13:45

cant seem to find it on the net now, but i used directions for synthisising picric acid , from from cheaply procured acetysallic and sulphuric acid,and potassium nitrate from a german site which i think was called LAMBDA synth ,it had about 4 synthesis methods,ill see if i cant find the pdf i made from that page

grndpndr - 23-10-2008 at 03:56

Do a site search on Picric acid should reveal so many synthesis youll be wondering which to use ?

OWCHITBUURNS!!! - 23-10-2008 at 12:43

my bad , meant to post this on another board
and i have NO FREAKING CLUE how to DELETE posts on this fourm????, so moderators feel free to delete both .

seeing as i found it i thought id slap it up there anyway cause i
like the way it lists ALL the procedures ,with pictures between each intermediate step.all procedures ...except the one involving hot nitric acid ,and wood EEEK!! ;) ,also seems less wastefull than most synthesis's.oh ja i meant Salicylic Acid in my last post

heres the link, its german so slap it into bablefish or gogle translations http://www.lambdasyn.org/synfiles/pikrinsaeure.htm

grndpndr - 29-10-2008 at 17:33

Though blessed with gift of a 1/4lb dist. merc from a friend,gold mining country still after all these years so its not uusual to find mercury for the purification process from the black sand bearing gold.And even caps now and then as privately owned mines still exist in the hills.MF would have still been a 1s choice primary due to simplicity of glasware and as well as all around suitability, sensitivity far from excessive still quite powerful but somewhat difficult to press to optimum
density.relatively easily procured precursors f whic only 2 are even of moderte difficulty obtaining and perhaps 10 min of Time from start to finish of good quality MF.Must be quite cautious of all fumes however the merury, heavy metal very painful poison.

quicksilver - 31-12-2008 at 09:19

CLEAN UP YOUR Hg:

Obtain a large hypodermic of veterinary size (horse/cattle hypodermic: new) Place cotton in the bottom of the barrel of the syringe. Place the Hg that you want filtered on top of the cotton and place the plunger in the body and "squirt" the Hg into a container. Repeat w/ fresh cotton...
[Use cotton, it will work well. Courser filter material is unnecessary.]

This is obviously not the most complete method HOWEVER, it will pull all the external oxides and "crud" from the floor and - in fact - will function well for the purpose of obtaining clean elemental Hg for your purposes.
THIS DOES WORK! It also is a metal you are working with. That metal will not be contaminated without some effort. If it merely spills or is exposed to some superfluous junk; this is a well used method to clean it up quite well.

I obtained about a pound of Hg from switches at a junk-yard, using the same mechanism for cleaning up the material and the resultant Hg was fine for the purposes outlined & w/ no problems! In order to contaminate Hg on an elemental level you would need to do more than spill it.
If it's got "crud" in it: you have now a method to clean it up. I've used this technique & it works VERY well!





[Edited on 31-12-2008 by quicksilver]

Hennig Brand - 12-8-2009 at 18:37

I like your mercury cleaning technique, it seems like it would be very effective. I am going to give it a try soon.
I have made a couple of small batches of MF in the last couple days. The first batch I used 90% nitric and didn' t wait for the nitrogen oxides to clear before adding ethanol, and it reacted very fast 1-2 seconds and when it did it nearly covered everything with mercury nitrate, HNO3 and ethanol. The last time (today) I used 5g mercury, about 40mL of ~70% HNO3 and 55mL 90% ethanol. This time I let the NO2 clear mostly after all mercury reacted and used a bigger beaker just in case. I added the ethanol and it took a good 5 minutes for the reaction to really start, and when it did it took about 15-20 minutes to complete. This was a hell of a lot more relaxing than starting in 1 second and over in 1 minute or so. What I want to know is, how much should I expect for a yeild from 5g mercury? Also most sources I have seen say that it doesn' t store very well. I think I have seen some say a few months to six months. How did industry make dynamite caps last for years, and the military make caps and rifle primers last for years. I have heard that people have shot old rifle shells with mercury fulminate in them that were maybe 50 years old. Is it just really good purification, or is it some kind of stabilizing chemical and/or technique?

Rich_Insane - 13-8-2009 at 16:19

I don't think you guys see the advantages of AP and HMTD. They are just really easy to synthesize. I can't afford silver nitrate or an acetylene maker, so I'm restricted to explosives that are based simply off of nitration and organic peroxides (mercury is too expensive for me). Silver acetylide is way to expensive for me to produce. MF is promising, but mercury isn't very easy to obtain cheaply. I am talking under $15 for 10 g.

Back to the topic: To purify mercury, just do what quicksilver did. No distillation needed. The main concern would be sensitive fulminates -- metal impurities shouldn't be too large, in fact there probably isn't enough to cause you any problem. What I'd worry about is not inhaling any of the byproduct gasses from MF detonation, because you produce mercury vapor, which is definitely something you do not want to breath.

ammonium isocyanate - 13-8-2009 at 17:15

The Science Company has 3x distilled mercury, 30 something bucks for 100g and fifty something for 250g IIRC.

Rich_Insane - 13-8-2009 at 21:21

Actually.... Daigger has 100 g 3x Distilled Mercury for $7.99 :o

Hennig Brand - 25-8-2009 at 16:21

Just got back from a week and a half work trip. While I was in an industrial park buying paint, I stopped in at a chemical supply place. I asked for their catalogue, and among the other things in there was mercury, for around $11.50 an ounce IIRC.

Hennig Brand - 27-8-2009 at 06:41

Does anyone know if mercury fulminate can be purified, recrystalized from boiling water? I know I have seen this described at least a couple times in old books, but was a little hesitant to try it. It seems like it could be done safely, but maybe I am missing something. Any input appreciated.

I was just reading from the thread "Picric Acid different instructions", and in the last post there on pg 14 is a description by Rosco Bodine on recrystalizing MF from water. I am glad to see it, because the couple times that I have seen it mentioned in books, it was described as common practice at the time (late 1800' s to early 1900' s), but didn' t describe how it was done at all. Thank you Mr. Bodine.

Does anyone know from either experience, or reading what the solubility of MF is in water? I guess I can experiment and see, but if someone knows I would appreciate it.

[Edited on 27-8-2009 by Hennig Brand]

grndpndr - 28-8-2009 at 04:01

This is directly related to hennig's questions as to stability and storage time of HG fulminate.I have read that bakelite was a material used in the manufacture of hg fulminate detonators as it was inert to the HG fulminate.bakelite is obviously obsolete Is anyone aware of other materials that were used in the manufacture of hg fulminate caps, etc.HG fulminate was introduced in the early 18th cent long before the civil war for use in copper percussion caps for rifles .All iknow about the old percussion caps is they were filled with the appropriate amount of HG fulminate and a paper likely laquered disc pressed on top preventing the loss/contamination,water absorbtion of the HG fulminate.
Perhaps a laquer coating,parraffin,polyurethane coating of the interior of the detonator?Being wartime before modern transportation its easily concievable these rifle percussion caps werent issueed for often at least a year or more surely contained before issue in a vapor/water tight container.

[Edited on 28-8-2009 by grndpndr]

hissingnoise - 28-8-2009 at 05:37

Quote: Originally posted by Hennig Brand  
Does anyone know if mercury fulminate can be purified, recrystalized from boiling water?
Does anyone know from either experience, or reading what the solubility of MF is in water?

According to Davis in COPAE, one litre of water dissolves 0.71 gm @ 12*C and 7.7 gm @ 100*C.
And MF, crystallised from water contains 1/2 H2O. . .
He mentions purifying MF by dissolving in NH4OH and precipitating by addition of 30% acetic acid.
I'd be inclined to go the NH4OH route for safety's sake!


Hennig Brand - 28-8-2009 at 08:08

Just found this link this morning, and from a little experimenting I believe it to be fairly accurate solubility information. Seems to be in the ballpark anyway, (my experiment was pretty crude).
MF solubility
http://wiki.answers.com/Q/Is_Mercury-II_Fulminate_Soluble_in...

Thank you Hissingnoise, I didn' t actually see your post till after I had posted (I refreshed the last page, but never checked for another page). I guess the solubility info for boiling water checks out nicely, between the two sources (if they are infact different sources, hard to know sometimes). I'll leave this post as it provides a little confirmation, even though your source hardly needs it. Thanks.

[Edited on 28-8-2009 by Hennig Brand]

hissingnoise - 28-8-2009 at 10:46

You're welcome! Davis's book is well worth downloading from the forum library, btw.
Urbanski it ain't, but it's quite good for its day. . .

Hennig Brand - 30-8-2009 at 06:23

I have already downloaded it, along with everything else I could find to download on the subject in the last few years. This is just a case of me trying to rely on google to do the work for me, and not doing a thorough job of my own homework using the published sources. Thanks for indulging me anyway.

By the way, in COPAE it states that MF crystallised from water contains 1/2 H2O. What is the consequences of this? Is it going to be hard to get the water out of the MF?

garage chemist - 30-8-2009 at 06:54

Mercury fulminate can be purified by dissolving in ammonia and precipitating with acetic acid, as shown at Powerlabs:
http://www.powerlabs.org/chemlabs/fulminate.htm

hissingnoise - 30-8-2009 at 13:53

Quote: Originally posted by Hennig Brand  

By the way, in COPAE it states that MF crystallised from water contains 1/2 H2O. What is the consequences of this? Is it going to be hard to get the water out of the MF?

I'd say, guessing, it will slowly evaporate @ r.t. or in a dessicator. . .
MF is practically non-hygroscopic!
I wouldn't use H2SO4 to dry it, though.

Rosco Bodine - 30-8-2009 at 18:32

Quote: Originally posted by Hennig Brand  

I was just reading from the thread "Picric Acid different instructions", and in the last post there on pg 14 is a description by Rosco Bodine on recrystalizing MF from water. I am glad to see it, because the couple times that I have seen it mentioned in books, it was described as common practice at the time (late 1800' s to early 1900' s), but didn' t describe how it was done at all. Thank you Mr. Bodine.
[Edited on 27-8-2009 by Hennig Brand]


You are welcome. Now there is another thing that I have been thinking about as a kind of "virtual experiment" in the mind of Rosco, that is in that category of "thinking outside the box" which might be right down the alley for fearless and inquisitive type A personality crazyass ;) fulminate experimenters who just have to know for sure :D ......
and of course I am musing about the possible formation
of a silver fulminate / mercury fulminate double salt which
seems like a possibility that has not been mentioned or
at least I haven't seen it mentioned anywhere in the literature. It would seem like that given the recrystallization
method from NH4OH being applicable to both, that a coprecipitation scheme could be worked out which very possibly could give a double salt providing synergistic enhancement of the initiating properties and more acceptable
sensitivity than silver fulminate alone. The physical manipulation techniques for silver fulminate are exacting, risk ridden as in fraught with danger, so this is no experiment which I would recommend for inexperienced or unsophisticated pursuit. I cringe at some of the stuff I read about as "variations" of procedures where it is clear folks really don't "get it" why small changes can turn a relatively lower calculated risk of a safer procedure into a recipe for disaster. The way you do physical manipulations and reactions in chemistry and the amounts of things you are working with and the process conditions you are employing
can have definitive bearing on whether or not your next experiment is your last. Even things that would seem to be mundane can bring surprises. So have the depth to think an experiment through very well in your mind and work it out on paper before actually implementing the real thing. That way
the odds are better you will "live long and prosper" :D

A double fulminate of zinc and silver has been reported and details are needed. Evidently boiling silver fulminate with powdered zinc replaces exactly half the silver and no more
to produce the double fulminate. This may be an interesting material for experimental investigation of its properties.

Reportedly contacting zinc fulminate with mercuric chloride will displace the zinc and give mercury fulminate, and possibly
likewise contacting the double fulminate of zinc and silver
with mercuric chloride or perhaps better with mercuric nitrate
will displace the zinc portion of the double salt of the fulminate of zinc and silver, to produce the double fulminate
of mercury and silver. I do not know what may be the reaction dynamic there and if it would be favorable or not, these are preliminary speculations.

http://www.youtube.com/watch?v=zLZysDhVmD4&fmt=18 Alkaemy - The Merlin Mystery - Legend of the Stone

http://www.youtube.com/watch?v=lYNTDx6fJoU&fmt=18 Alkaemy - Nimue's Lament (with lyrics)

http://www.youtube.com/watch?v=Yw0RcKaL6Hs&fmt=18 Himalayan Sky

http://www.youtube.com/watch?v=m40wcqlt1Uo&fmt=18 Orchid Potion

http://www.youtube.com/watch?v=RGWH9md3Grc&fmt=18 Gregorian Chill Out Music

Attached is an excerpt from an old chemistry textbook circa 1903 which shows some reported experiments parallel to what I have been speculating, and indeed the double fulminate of silver and mercury has been prepared, though no properties for it are reported. Thorpe 1922 has some more general information that is fulminate related, see second file attached. My own idea is that Bridges 1869 text
identifying that fulminic acid is a dimer and bibasic acid and polymeric rather than mono isomeric with regards to cyanic acid is probably correct in spite of other more modern references to the contrary.

Attachment: Pages from Chemistry__inorganic_and_organic 706-708.pdf (314kB)
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Attachment: Pages from A_dictionary_of_applied_chemistry Thorpe 1922.pdf (313kB)
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[Edited on 31-8-2009 by Rosco Bodine]

Attachment: Pages from A_manual_of_elementary_chemistry 1869.pdf (204kB)
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hodges - 1-9-2009 at 14:27

Finally made some mercury fulminate this past weekend.

Previously I had tried to make silver fulminate without success - could never get the reaction to start. I believe this is because I used AgNO3 and HNO3 instead of dissolving silver in the HNO3. Apparently there must be dissolved nitrogen oxides present for the reaction to start reliably.

I took a small drop (about 0.2g) of Hg metal and dissolved it in about 1.5ml of 70% HNO3. This was pretty slow for some reason (took about 30 minutes). I then added about 1.5ml of EtOH. This resulted in an immediate runaway reaction, with dense, heavy clouds of vapor being produced. Based on smell (I was carefull not to smell too much), I'm pretty sure the heavy vapor is acetaldehyde. Acetaldehyde boils around room temperature and is very soluble in water so I'm guessing that is what the white vapor is. Bubbling continued for about a half hour, at a slower rate. It looked like the solution was boiling slowly the whole time.

The mercury fulminate precipitate was light gray in color. I washed it several times in water and allowed it to dry in a small plastic cup. When dry, small amounts deflagrate with a "whump" sound, similar to TATP. However, I was not able to set this off with a blow from a hammer. Probably was not completely dry.

It seems the final product contains some free Hg. I put a small amount on a piece of aluminum foil to dry and it ate a hole through the foil, leaving a large volume of Al(OH)3.

Sometime I will try the silver fulminate, now that I think I know what was wrong before.

Hodges

grndpndr - 2-9-2009 at 20:22

Would you consider the tin foil experiment with other sample metals?Say tin copper,bronze brass, steel ,anything on hand?if really in an experimental mood coated with something like polyurethane,parafinn.shellac.For the life of me I havent been able to find what was used for detonator shells using Hg fulminate prior to bakelite in the early 20th centrury.

as for the reaction of hg and nitric acid of 68-70% I rarely saw any reaction even on heating but stirring made the hg react and dissolve in the Nitric, the remainder of the lab as described.The whys and wherefores are far beyond me
But even a a small whiff isnt advisable if you value your CNS.HG vapor!I think it best to wash with ethanol,drys quicker etc.[Edited on 3-9-2009 by grndpndr]


[Edited on 3-9-2009 by grndpndr]

[Edited on 3-9-2009 by grndpndr]

hodges - 3-9-2009 at 17:35

I could try some other metals next time - I don't have any mercury fulminate left this time though. I'm guessing that steel would be okay since mercury does not react with steel.

Hodges

Rosco Bodine - 4-9-2009 at 23:31

Here's another old reference circa 1870 which lists many different fulminates and provides a bit more information about preparation and properties

Attachment: Pages from A_dictionary_of_chemistry 1870.pdf (692kB)
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Rosco Bodine - 6-9-2009 at 07:52

Here is still more detail on fulminates, preparations and properties from Gmelin circa 1855, more is here concerning
the lead zinc double fulminate and other substituted fulminates. These reactions and compounds are interesting
in particular to me because of the possibility of forming double salts or clathrates between the fulminates and
basic or normal picrates or styphnates, which could represent novel energetic materials having desirable properties as initiators.

Attachment: Pages from Hand_book_of_chemistry Gmelin 1855.pdf (835kB)
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hodges - 6-9-2009 at 15:46

Quote: Originally posted by Rosco Bodine  
Here's another old reference circa 1870 which lists many different fulminates and provides a bit more information about preparation and properties


Thanks Rosco.



The main smell I detected when making mercury fulminate was acetaldehyde. I doubt there is much mercury vapor present given the temperatures involved, although of course there might be small mercury particles carried into the air by the bubbles. Either way, sounds like this is something to avoid breathing.

I did have some very limited success creating silver fulminate, after two more tries. On the first try, I let about 0.1g of silver dissolve in about 2ml of HNO3, waited for it to cool, and then added 2ml EtOH. Although I did see some small bubbles, kind of like the solution was slowly boiling, I did not see any vapor cloud. The bubbling continued for about 30 minutes, and no product precipitated. I suspect the vapor was just plain aldehyde from the reaction of the alcohol with the nitric acid. I tried a second time, this time adding the alcohol while the silver was still reacting. This resulted in much faster bubbling, along with NO2 vapors. After a couple of minutes, the reaction became so vigorous that it boiled out of the small plastic cup I was doing the preparation in (which was about 10 times taller than the depth of the liquid in it). This time I got a tiny amount of precipitate, as fine as dust. So fine that I could still see the bottom of the cup through them. From the residue from the boilover I found a speck about the size of a crystal of salt. I dried this and it detonated with a definite snap from the flame of a lighter. Tried washing the fine powder at the bottom of the cup but yield was so low there was practically nothing left after the washing.

Hodges


Rosco Bodine - 6-9-2009 at 17:22

These "ancient arts" always intrigue me because of the obscurity of what could be very good pertinent information on which possible followup experiments of interest were never done. I especially like the analysis
of old time chemists who did the "mental virtual and logical analysis" of structures by experimental observations and deduction, scientifically sleuthing to get the lowdown on how unknown compounds are probably structured, as compared with already well known compounds. Everyone should admire the abstract thinking of these perceptive scientists of old who had none of the modern instruments as helpers, and no great body of prior art on which to rely, but were doing good basic scientific investigation, using what little information and theory they had to advance the art.
I especially like the nitro-acetonitrile and the bibasic acid
and dimer analytical hypotheses concerning fulminic acid.
Modern references, at least those I have seen are not comprehensive in describing or resolving the obvious issues raised by the perspicacious observations of the ancient experimental chemists who do have an obvious point in what they are saying about the legitimacy of conclusions which their experimental results would seem to indicate.

Excerpts are attached for an 1844 Lancet article by Justus Liebig and a later 1876 article by Edmund Davy, cousin of Humphry Davy, doing followup experiments concerning some of his father's earlier work with fulminates.

Attachment: Justus Liebig circa 1844 The_Lancet.pdf (468kB)
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Attachment: Davy_The_American_Chemist circa 1876.pdf (893kB)
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[Edited on 7-9-2009 by Rosco Bodine]

fulminate complexes

Formatik - 7-9-2009 at 13:54

I know of the patent by Hurst to stabilize silver fulminate to make it only temporarily relatively insensitive, but would it be possible to prepare a fulminate complex like silver-zinc fulminate or potassium-silver fulminate without having to isolate and form silver fulminate first?

Rosco Bodine - 8-9-2009 at 06:31

I'm not sure what sort of manipulations may be workable
for an indirect route to the silver double salts. The zinc lead double fulminate was one that caught my notice as interesting.

Hennig Brand - 8-9-2009 at 16:18

I have made silver fulminate probably more than 20 times, and am no where near to having it all figured out. Sometimes it works out pretty well, and sometimes it does not. I first started experimenting with it about 3 years ago, at that time I couldn' t even get the reaction to start with the ethanol, silver nitrate(made from silver + HNO3) and HNO3. I was using crappy 95% ethanol from the drugstore which had all sorts of other crap in it, which I don' t believe really added anything to my experiment if you know what I mean. I found if I heated it on a sand or water bath to somewhere between 40-60C the reaction would start, but petered out quickly leaving little SF (using the rubbing ethanol). I was reading a silver fulminate thread at the time from this site, and there I learned that acetone could also be used to provide the methyl group (I think thats correct), and fascilitate the reaction. I found the acetone to be much more reactive and could easily lead to a runaway, so I mixed it with the rubbing ethanol and used careful heating. I got a very explosive product that was fun to play with, but my yeild where nothing to brag about. I also soon noticed some batches were much more powerful and destructive in small amounts than others. That was when I learned how easy it was to make very contaminated SF. I believe the heating is necessary to start the reaction, or at least that is how it has been for me, and how I have seen it written in many sources. However when the reaction starts(sometimes pretty close to 60C) the reaction quickly generates much more heat(exothermic), and much higher than 60 or 70C silver oxide is produced quite readily. I have had batches that proceeded too vigorously, with too much heat, and all I got was silver oxide, no SF at all. At the time I was brewing, but hadn' t yet the skills to make high concentration and purity ethanol. I should try a batch of SF with my home made ethanol of 90% or higher, I bet it works much better than the rubbing ethanol. Maybe I wouldn' t need the acetone at all. What I did the last couple of times I made SF, was use heat (carefully) to get the reaction going, watching a thermometer all the time. Once the reaction got started I would put the flask in cool water as much as was needed to keep the temperature well down below where the oxide is formed. As the reaction proceeds at some point heat will probably be needed to keep it going (hot water/sand bath). I don' t think even then that much over 60C is desirable though. SF is much trickier than MF in my humble opinion.
This was posted by Axt in the thread called Silver fulminate synthesis- Attachment: A Reappraisal of Silver Fulminate as a Detonant .pdf
I found it very useful and informative, at the time and still now.

[Edited on 9-9-2009 by Hennig Brand]

grndpndr - 10-9-2009 at 06:19

SF certainly sounds as though its the more difficult, if its available to you I have heard everclear is a good source of 180 proof
ethanol just dont drink it!:oLikely more toxic than the mercury,or rather youll think so next AM!Thanks for the links everyone!

[Edited on 10-9-2009 by grndpndr]

quicksilver - 16-9-2009 at 07:50

The double fulminate will work as energetic materials to a degree. I have a Pb/Hg & Zn/+ paper somewhere. However if one does not have the proper glassware and some way of keeping clear of the fumes (personal opinion here) Hg Fulminate might be the most insidious toxin in this hobby. I think hydrazine gives more warning. What Hg does to the CNS is no joke. Lungs can recover from scaring, livers can recover from fatty deposit, but what mercury does to one's CNS - you will not know until either you get seizures or some other ugly outward issues.....please be serious with Hg.

Bikemaster - 16-9-2009 at 11:42

What are the best way to "save" our nervous systheme with the mercury, the mercury fulminate synthesis and the burning of mercury fulminate???
Will it be safe enough to use glasses, smock, gaz mask and nitril gloves for the use of mercury metal and the synthesis of the MF???
And for the burning test of MF, will it be safer to make test outside??? I have a fume hood, but i am not sure that all of the fume will be going oustide...

Taoiseach - 16-9-2009 at 22:34

@Hennig Brand

in one of those excerpts Rosco posted above, it says that moist SF when dried in direct sunlight will become so sensitive that it goes off from merely touching it. Can you confirm this? Whats your take on its stability?




HG fulminate toxicity

grndpndr - 18-9-2009 at 00:27

I knew a person very well who used a full lb of dist merc in HG fulminate labs over a period of perhaps a year over 10years ago
using normal precautions during the labs as well as whenever working with the substance.He was still tremor free as well as free of any cns effects i noticed or his Drs noted over 10 years later.Certainly not the mad hatter effect in his case although thats no reasons not to be very cautious with this or any lab involving any # of precursors.Those who work with nitric acid
in labs also risk instant death or a slower death from pulmonary edema a week later.Is that sufficient reason to stop all labs where the possibility of noxious fumes are likely?I dont think so,I do think its an obvious decision to use the proper protective equipment just as one would in sports or any risky endeavor.Unfortuneately my friend the lab rat died from a head on collision not CNS deterioration at the age of 40.



No one I know is out to win the darwin award despite what some unfamiliar with the hobby may think .

[Edited on 18-9-2009 by grndpndr]

Rosco Bodine - 18-9-2009 at 06:19

In an old Gmelin handbook from 1857 is reported a double styphnate of nickel and potassium, a brown crystalline and probably anhydrous salt which detonates with "tremendous violence" on heating. This may be worth an experiment as a candidate material for admixture with a fulminate, which could have a synergistic effect even beyond the already known synergistic mixture of mercury fulminate and lead styphnate. Such compositions could occupy a niche between the performance of mercury fulminate and lead azide and could have value as initiators. A zinc fulminate - lead fulminate double salt in admixture with the nickel styphnate - potassium styphnate double salt could be a synergistic mixture .....but whether or not the mixture is compatable or would be reactive is unknown. Some of these hypothetical mixtures may work or may not, and I find no references to such experiments having already been done, although it could be that such mixtures have already been investigated, and the references are obscure.

Attachment: pages from Hand_book_of_chemistry 1857.pdf (392kB)
This file has been downloaded 834 times

[Edited on 18-9-2009 by Rosco Bodine]

Hennig Brand - 20-9-2009 at 17:32

@Taoiseach
I have never dried it in direct sunlight, so I don' t know. I do find however that its sensitivity for most samples is much less than what we hear about (at least for me). I can say that the sensitivity varies with the batch, and that for my samples very little friction or percussion was needed to initiate detonation, but it still always took much more than simply touching it. Touching is kind of a relative term though I guess. The sharp sand in those little bang snaps is definately needed to make them reliable. I have even found that if I didn' t use sharp sand and used round sand, from say a beach, that they had to be thrown quite hard. I do find that it seems to darken up and lose a certain amount of power over time, which I have been attributing to sunlight(I had a few small samples that sat out in dishes indoors, not in direct sunlight but even reflected light seemed to cause breakdown). I haven' t done a lot of testing and I think my Silver Fulminate samples have all been quite impure. I have only had a couple batches where I actually saw good crystal formation to. The other thing to remember is I have only been playing with tiny amounts, the more of an explosive you have especially a sensitive one, the greater the danger. There is more potential energy of course, but also the potential for an accident is greater for various reasons. I think reproducability is probably one of the biggest problems with SF, and who knows maybe I have just been lucky and never hit one of those super sensitive batches. I may test the sunlight thing with a small batch, and see if I can get an observable result. I am curious now.

Melgar - 23-4-2010 at 12:46

I think that assuming silver fulminate can be used reliably is a big mistake. There are much safer ways to detonate ETN. Flash powder can do it, or mixing the ETN with aluminum powder can make it so you can detonate it with a nichrome wire.

method for taming silver fulminate?

Rosco Bodine - 23-4-2010 at 15:54

I have an idea for a possible way of making silver fulminate in a less sensitive form, and a proposed experiment.

A smaller particle size will generally result in less sensitivity, and greater safety in handling .....and it would seem likely that this generality would apply to silver fulminate. Also
it can accomplish a further desensitizing for particles to be coated with a less sensitive or inert material, and this may also be applicable to silver fulminate.

Recrystallization of mercury fulminate can be done from boiling water and this may also be possible for silver fulminate, either from boiling or near boiling hot water.
There is an enormous reduction in solubility with decreasing temperature, so it would seem likely that a very fine particle size of silver fulminate could be obtained by rapidly streaming
a very hot solution containing about two and one half grams per liter of silver fulminate into a rapidly stirred larger quantity of ice water, perhaps with crushed ice then added
to rapidly precipitate the silver fulminate as very small particles. Then a solution of sodium or ammonium dichromate
is added to the stirred suspension of microcrystalline silver fulminate, which should result in each silver fulminate particle
becoming coated, sealed and encased in a microscopically thin layer of adherent and low solubility, and relatively inert silver dichromate. The chromated silver fulminate anticipated to result should be a brilliant red colored material.

The supernatant solution could be decanted and the material rinsed with distilled water onto the filter.





[Edited on 23-4-2010 by Rosco Bodine]

hissingnoise - 24-4-2010 at 02:37

Silver fulminate is much less soluble than MF.
What's wrong with MF?



[Edited on 24-4-2010 by hissingnoise]

Rosco Bodine - 24-4-2010 at 04:38

I'll try to again find the reference, but I think a solubility of about 2.7% is what is found for silver fulminate in boiling water, decreasing to something like twenty milligrams per liter or similar tiny amount in the cold and for the chromate of silver even lower solubility still.

edit: I just checked one reference. Federoff is showing solubility 2.5 grams per liter H2O at 100C and .075 grams per liter at 13C.

There is a disadvantage about mercury fulminate because it requires a substantial amount of it on the order of a quarter gram, where is its critical mass to detonate high order, therefore it is not as useful as an accellerant in synergistic mixture with another material like lead styphnate in the same way
as would be for example lead azide. Silver fulminate is easily made and would have greater usefulness if not for its extreme senstivity. And that sensitivity
may not be an insurmountable problem, if it is indeed a problem of crystal size as has been the factor noted to be probable in the literature. A similar sensitivity
issue can arise for other primary explosives and process modifications can be made to produce a material having improved handling safety.

[Edited on 24-4-2010 by Rosco Bodine]

watson.fawkes - 24-4-2010 at 06:42

Quote: Originally posted by Rosco Bodine  
I have an idea for a possible way of making silver fulminate in a less sensitive form, and a proposed experiment.
I can't say I'm very familiar with sol-gel reactions, but they seem to be the ordinary way that folks make micron-scale particles these days. I mention this because these techniques give rather good consistency in particle sizes. The problem I foresee with a mechanical precipitation is too much variation in particle size. In the case of silver fulminate, one large particle is enough to ruin your day.

Having said that, I'd suggest using a micro-orifice and a high enough output velocity to generate plenty of shear force in the liquid, but not enough to cause cavitation. Lots of shear force should drop your particle size down appreciably. Injecting into a stream of cooling water moving transverse to the direction of injection would further prevent fluid hot spots from forming.

Rosco Bodine - 24-4-2010 at 07:38

Actually this is not a colloid about which I am thinking, even though there are references to small particulate silver fulminate and lead azide and other materials as "colloidal" or amorphous in form ....in reality the particles are definitely microcrystalline and are grown crystals in a specifically small size range rather than being a dispersion from some sort of wet milling operation. The technique which I am contemplating is a crash precipitation / crystallization of a near saturated hot solution, by rapid cooling.......a sort of wet method for doing the same thing as a flash evaporation of a hot liquid being sprayed as an atomized mist into a vacuum.....which can produce even smaller crystals. Adding a soluble starch like dextrin can inhibit crystal growth and keep the crystals small. The chromating step which I was contemplating should stop the redissolving and crystal growth of the silver fulminate crystals and thereby stabilize the material.

watson.fawkes - 24-4-2010 at 08:03

Quote: Originally posted by Rosco Bodine  
in reality the particles are definitely microcrystalline and are grown crystals in a specifically small size range rather than being a dispersion from some sort of wet milling operation.
The end-product you're suggesting seems like quite a good idea. Your post on this had three interrelated items: 1) small crystal sizes, 2) chemically inert coating for them, and 3) a means of making them. I wasn't adequately clear, but I'm suggesting sol-gel as an alternate only for number 3. You'd use a hot sol, as before, and then some kind of flash gellation, not that I know how to do that, but there seem to be some awfully rapid phase transitions available. The key would seem to be to have the gellation not involve the fulminate directly, but rather to trap the fulminate in the gel matrix while it's still in solution. Then when the gel cools off, you get your fine particles. So there are three phase regimes (temperature-determined, presumably): a) sol with fulminate in solution, b) gel with fulminate in solution, c) gel with fulminate microcrystals. Since you've already suggested dextrin, it's certainly possible that there's some appropriate polysaccharide to use for the gel matrix; the food industry has certainly done a lot of engineering work on this class of chemicals.

The advantage, particularly for the amateur, if this can be made to work, is that there's no mechanical devices to get just right or that need tuning. It's just heating, mixing, and cooling.

Rosco Bodine - 24-4-2010 at 08:39

What may work is simply to pour the boiling near saturated solution of silver fulminate over crushed ice, in a quantity that all of the ice will be melted and the resulting mixture will be at perhaps 5 or 10C, and then the mixture is stirred up and an ice cold solution of a dichromate is added in a lump, with everything kept in suspension for a few minutes to complete the reaction.

watson.fawkes - 24-4-2010 at 09:48

Quote: Originally posted by Rosco Bodine  
What may work is simply to pour the boiling near saturated solution of silver fulminate over crushed ice [...]
That sounds more reliable as far as mechanical means go, as 1) you've got the latent heat of melting ice providing a larger heat reservoir and 2) less concern about adequate liquid/liquid mixing. It seems that you could modify an ice cream churn with a dropping funnel for the process.

Rosco Bodine - 24-4-2010 at 10:09

Even if it worked it would still be something of an academic curiosity, or an
improvisational alternative. Still it is intriguing if there could be such a way of desensitizing silver fulminate, since it has been for so long a material known for sensitivity and unpredictability....it is something of an intellectual challenge to
formulate any solution for those issues.

quicksilver - 24-4-2010 at 15:04

There was a patent mixing of Ag & Hg in a fulminate synthesis. If I remember correctly the purpose was to "concentrate" the weight of mercury fulminate needed for a given cap size. TTBoMK it was not used commercially.

Rosco Bodine - 24-4-2010 at 15:41

Yeah, earlier in the thread I speculated about the possible existence of a double fulminate of mercury and silver before finding references that it is indeed known.
And it would make sense that the silver fulminate content would act as an accellerator for the mercury fulminate. I am not inclined to favor a mercury containing compound where alternatives may serve as well or better. It is a matter of curiosity to me if organic fulminates may be possible or complexed metal fulminates, and what efforts may have been made to produce obscure fulminates
via the sodium nitromethane intermediate.

Leander - 25-4-2010 at 02:50

Are you accually going to try this desensitizing method? Solving 'intellectual challenges' for the sake of 'academic curiosity' has little meaning without experimentation.

Rosco Bodine - 25-4-2010 at 06:18

Honestly I do not know for certain if I will ever actually perform this experiment or not. My attention and time seems to be constantly diverted and required by other matters than enjoying experimentation which I would like to be doing.

Certainly it was not my intention to cause annoyance by sharing thoughts on this or any other proposed experiment. I read about and post concerning many more experiments than I actually have the time to do or may not even be inclined to do. I often share my thoughts with others who may have a particular interest and who are actively or periodically experimenting with a particular type of compound. An untested idea may have no substance in the present sense but may have value as a kind of proposal for where things may logically be going next in further experiments which may be worthwhile doing later.

I have a huge backlog of experiments to do, but that should not be a reason to keep secret or keep silent about something like this which may be pertinent to a particular line of research where others are already looking.


hissingnoise - 25-4-2010 at 11:59

Quote:
My attention and time seems to be constantly diverted and required by other matters than enjoying experimentation which I would like to be doing.

What we have here is a clear case of Da Vinci Syndrome. . .




Mr. Wizard - 25-4-2010 at 12:16

Quote: Originally posted by hissingnoise  
Quote:
My attention and time seems to be constantly diverted and required by other matters than enjoying experimentation which I would like to be doing.

What we have here is a clear case of Da Vinci Syndrome. . .




So it has a name? :-) I thought I was the only one.

Work, the curse of the leisure class.

Rosco Bodine - 25-4-2010 at 17:23

I believed it better that rather than to keep silent,
that I should share whatever I can while I still can,
but if you wish it to be otherwise......
then I apologize for the imposition

http://www.youtube.com/watch?v=k0J7Zx-F1uA&fmt=18 Deep Peace

quicksilver - 26-4-2010 at 05:29

For the man who shared clathrates with the majority of energetic materials hobbyists and related issues, silence would be a terrible waste of a vast pool of knowledge.

hissingnoise - 26-4-2010 at 05:40

Seconded. . .
We're all ears - I mean eyes!





stygian - 29-4-2010 at 12:41

I've always heard that the less common fulminates were prepared via metathesis with the mercury salt, but I just stumbled across this http://books.google.com/books?id=J55D3HcgPuoC&pg=PA119&a...

Doesn't sound like something I'd want to try though.

copper fulminates

Formatik - 29-4-2010 at 15:19

Be wary of anything written in that book, it also claims NH4ClO3 is stable.

Early chemists have tried to make copper fulminate from the same way as with Hg, Ag, and failed. I had, but lost a reference where this was mentioned and other metals were tried as well but also didn't work.

Note how there are zero references above. Note also how there are no descriptive details at all about the compound.

Cupric fulminate doesn't even exist as far as the literature is concerned. It's not listed in Federoff, Gmelin, etc. Cuprous fulminate is known but it is easily oxidized, and has to be made e.g. from Hg(II) fulminate and copper. Then there are also complexes of copper fulminate.

That procedure is a phony.

Hennig Brand - 25-5-2010 at 13:38

I have been playing with Silver Fulminate a bit lately and thought I'd post my process and results.
-1.1g silver
-9mL 85% HNO3
-9mL H2O
Unless I messed up somewhere this should give me nitric acid of a little over 50% concentration (wt%).
In place of pure ethanol I used 9mL of my 90% pure homemade ethanol, and 3mL of hardware acetone.
Process:
I first dissolved the silver in the HNO3 using a hot water bath to help. I used a 600mL beaker and a small pot that the beaker sat in sidways with the top sticking out/laying against the top of the pot. I filled the pot with boiling water from a kettle. After silver was dissolved I let it cool to room temperature. Some silver nitrate precipitated so I added water dropwise with swirling till all was dissolved. I prepared a cold water bath right beside my hot water bath. I next heated the silver nitrate-nitric acid solution back up to around 50C, then added the ethanol-acetone (12mL). The reaction didn' t start, so after adding fresh boiling water to my hot water bath, heated the reaction beaker up to 60C or so and kept it there until after a few minutes the reaction started. This is where it gets tricky, once the reaction starts the temperature can jump very quickly, and there is not far to go before the reaction is ruined. I have found that much over 80C and the product is seriuosly degraded, and up to 90C or more it is ruined. If you keep a close eye on the thermometer and when the temperature starts to rise on its own get ready with the cold water bath and swirling to prevent hot spots, overheating, and over 80C decomp. Through the course of the first few minutes the water bath will be needed less and less till the temperature starts to drop slowly on its own as the reaction slows. It took about 15 minutes for the reaction to come to completion, just letting it cool naturally on its own to room temperature. Rinse with water the same as with mercury fulminate to get ride of acid and contaminants. I did four or five small rinses, but some books say to do 10-12. It is very insoluble in cold water, so it wouldn't hurt to do more probably. The first few if done properly, are the most important obviously.
I blotted out most of the moisture with paper towel, then put the filter paper and SF on a small plate, and put the plate over a bowl filled with hot water from the tap(72C). I had 0.53g of dry SF in 30min. I felt perfectly safe doing this as it was a very gentle heat, and much below the lowest explosion temp I have seen(in book) of 130C for dry SF.
I keep getting about 0.5g from a gram of silver, which seems to be about half what I should be getting from what I can read. It is nice stuff though:).
I find the stuff to be powerful and sensitive, but I feel much of its bad reputation comes from people confusing fulminating silver for fulminate of silver(Silver fulminate).

[Edited on 25-5-2010 by Hennig Brand]

a_bab - 25-5-2010 at 14:04

Oh, I woudn't feel too safe with 5 grams of SF around, which is plenty enough to vaporize some fingers. More crystals=more friction=more chances for an accident to take place.

Hennig Brand - 25-5-2010 at 14:58

Oh shit I meant 0.53 grams, sorry about that. Yes the half gram kind of makes me pay attention actually:)

beware of fulminate itch

The WiZard is In - 25-5-2010 at 15:48

Contact dermatitis from silver fulminate - fulminate itch
IAN R. WHITE AND R. J. G. RYCROFT
Department of Occupational Dermatology, St. John's Hospital for Diseases of the Skin.
Contact Dermatitis 1982; 8: 159-163

Although fulminates were widely used in the past as explosives, they are now little
encountered. Fulminate itch is of historical interest. We have investigated a factory
utilizing silver fulminate in the manufacture of explosive snaps. Workers in this factory
still experience the 'itch', which we consider to have both an irritant and an allergic
basis.

Few industries have a unique location, but we have investigated a skin problem in a
factory manufacturing silver fulminate and there is no similar installation in the Western
World. The related compound mercury fulminate has, however, been manufactured in
many places and in large quantities at various times because of its use as a detonator
in percussion caps. The only commercial use of silver fulminate is producing the
explosive 'snaps', to be found, for example, in Christmas crackers.

Mercury fulminate is well known to cause a dermatitis which has been termed 'fulminate
itch'. Little investigation has been made concerning the mechanism of this problem. A
similar itch has been found to occur amongst workers engaged in producing 'snaps'
from silver fulminate.

The Factory

Silver fulminate is produced by the reaction of ethanol with silver nitrate in the presence
of nitric acid. comes down as a flocculent precipitate which is filtered off and washed to
remove the excess acid.

The fulminate is mixed with a water soluble adhesive to form a creamy paste which is
then hand painted onto one end of strips of manilla cardboard, (Fig. la). This process is
called 'lining'. The painted strips are air dried in trays and then taken into a room where
they are individually fed by hand into machines which semi automatically tape them to
similar strips which have one end coated with sand (Fig. I b). This procedure is termed
'bonding' and it produces the final snap. Pulling the two ends of the snap causes friction
between the fulminate and sand with a consequent explosion (Fig. I c).

The Problem

The majority of employees in the factory Silver fulminate is produced by the reaction are
female and most (about 50) work at the 'bonding' process which takes place in a well
ventilated room, but as some five million snaps are produced each week, one would
expect that some fulminate dust would be found on machinery and in the air. Over many
years the factory management have noticed that most of the employees who have been
troubled by skin irritation have worked in the bonding room. New employees are warned
that they may develop a dermatitis; a proportion do and a number of them subsequently
leave. A core of relatively 'resistant' workers remains. The only two males employed in
the manufacturing process actually make the silver fulminate, and in the past one of
these had had a number of small painful ulcers on his hands which had been difficult to
heal, but since has had no eruption of any kind.

The Patients

10 females who had been working with silver fulminate for varying periods of time were
examined, and of these 7 said that they had had rashes whilst employed. The 10
subjects were patch tested with 1% silver fulminate in pet. and also with 1% aqueous
silver nitrate and 1% ammoniated mercury in pet. In addition control patients in our clinic
were tested with the same preparation of fulminate. The histories of the 7 people who
had problems are as follows. No patient gave a history of atopy or previous allergy
except where indicated.

Patient no.1 had been in the bonding room for two weeks when she developed a rash
in the nasolabial folds, an itchy nose, running eyes and a burning sensation of the
eyelids. Her hands and wrists were also affected and she had blisters in the mouth.

The eruption settled whilst away from work but within two days of return she had
developed erythema and esiculation around the mouth, under the chin, on the back of
the neck and on the hands. She also had a nose bleed.

Patient no. 2. had worked in the factory for 40 years and on examination was foundto
have the greyish pigmentation of argyria in the conjunctivae, pertoral area and on her
fingers. She remembered developing an itchy red rash on her face shortly after
starting employment but she continued at her work and the rash settled. She had had
flexural eczema as a child.

Patient no. 3 developed a papulovesicular eruption on her face and arms three
weeks after working in the bonding room. The rash settled after three weeks away from
work, but despite returning to the same job she has had no further problems in the last
two years.

Patient no. 4 noticed red, itchy spots on her forearms six months after starting work as
a bonder, they cleared several weeks later despite continuation of her work. She has
had no problems during the subsequent two years.

Patient no. 5 had a transient rash on her face when she first started lining and
frequently had an itchy red rash on her forearms in the ensuing three years. She did not
develop any problem whilst in the bonding room for six months.

Patient no. 6; during nine months employment as a bonder, she had frequently
experienced irritation and redness on her face, neck, arms and hands. At no time had
there been any vesiculation and examination showed only lichenification in the dorsum
of her hands. She suffers from hay fever.

Patient no. 7, who had been employed for nine months developed pert
orbital oedema after three weeks of bonding but no rash elsewhere. A similar but more
severe episode occurred six months later. She noted that her eyes were frequently red
and itchy, with the problem starting early during the working week and settling over the
weekend.

Results

The results of patch testing at 2 days with 1% silver fulminate in pet. are shown in Table
1. No reactions were seen to silver nitrate or ammoniated mercury. 'Altest' strips (Imeco,
Sweden) were used on the factory patients and 'Finn chambers' (Epitest, Finland) on
the controls. The results show that patient no. 1 had a marked reaction to silver
fulminate which was of a quite different order to the irritant reactions produced in her
colleagues who had had a history of a rash and another colleague who did not have this
history.

At 2 days an irritant response of varying degrees was found in 12 of the 34 control
patients; this had completely faded in all but 5 patients after 4 days.

Discussion

Mercury fulminate was discovered by Ed ward Howard (1774 1816) and since 1814 has
been used by the military as a detonator in percussion caps. In 1842 Henry Hennell
destroyed both himself and part of the Apothecary's Hall in London whilst working with 6
lb of mercury fulminate intended for use in the 1st Afghan war.

Leibig analysed the elemental composition of silver cyanate and silver fulminate in
1823. He found that although the two compounds had the identical formula AgCNO they
had quite different chemical and physical properties. Three isomers with the general
formula HCNO are known.

isocyanic acid HN = C = 0
cyanic acid HO—C = N
fulminic acid HO—N = C

Of these cyanic acid and isocyanic acid are tautomers but fulminic acid is a simple
isomer with no tendency to equilibrate with the other two substances.

Although mercury fulminate explodes violently on percussion, silver fulminate is more
inert to such treatment but it is very sensitive to friction, when it will explode with greater
force than its mercury counterpart. Both compounds can be handled safely when they
are damp. It is be cause of the characteristics of silver fulminate that the only
commercial application of the compound is in the manufacture of 'snaps'. Most of the
dermatological literature concerning fulminate relates to the cutaneous reactions
amongst those handling mercury fulminate in munitions factories during the two World
Wars when 'fulminate itch' was a well recognised problem. It is considered that the two
fulminates induce similar skin eruptions.

Although the 'itch' was frequently encountered in the munitions factories, there was
great individual susceptibility to the problem such that the majority of individuals were
slightly affected and only a few badly so (1). The condition tended to be worse in warm
weather and the exposed parts of the body were the areas normally involved. The
published accounts all describe similar clinical appearances of the 'itch' (2
4). In the mildest cases there might be erythema on the anterior surface of the forearms
and dorsa of the hands. More severely affected individuals might have facial erythema
especially around the nose, mouth and chin but also on the neck and behind the ears,
and pert orbital oedema was frequent amongst these individuals. In extreme cases,
vesicles, bullae and pustules could be found at all the above sites. The dermatitis was
considered to be particularly bad after 5 to 6 days of continuous exposure to fulminate.
Dermatitis could be produced on covered areas of the body as dry fulminate permeated
workers clothing. Folliculitis was occasionally reported as occurring on hairy limbs.

A conjunctivitis was often found to be an early complaint amongst susceptible individ
uals and nasal irritation was also common (5). Perforation of the nasal septum similar to
that caused by chrome has also been described.

Great care was needed when fulminate was being used by individuals who already had
a cut or abrasion on their hands as small necrotic ulcers were prone to develop (6).
These 'powder holes' could take several weeks to heal and might even progress to
penetrate joints and bone.

Silver fulminate was known in the trade as “white salt.” It was reported to induce a
stomatitis easily in females soon after they started work using the compound (2). Al
though relapses were said to be rare, a few individuals showed great sensitivity to this
salt.

In none of the quoted accounts was patch testing performed, although the words 'ir
ritant' and 'sensitization' can frequently be found. Although we were able to examine
only one patient with an active dermatitis, it can be seen from the characteristics of this
eruption and from the accounts of her colleagues who had been affected in the past,
that the present problem is similar to the historical descriptions. In view of this and the
results of our patch tests, we consider that it is the fulminate moiety of the compounds
which is responsible for the cutaneous complaints.

Our prime patient under investigation developed an exudative dermatitis of her arms
and face two weeks after starting her job, and on recovery developed a vesicular
eczema in the same area after only two days of re-exposure. The story suggests that
she became rapidly sensitised to fulminate which was confirmed by the positive patch
test reaction to silver fulminate.

We believe that fulminate is able to induce both an irritant and an allergic contact
dermatitis. That some workers develop a rash which becomes less of a problem as they
continue to work, suggests a process of 'hardening' against allergic or irritant factors.

References

1. Hunter D. The Diseases of Occupations, 5th Ed. London: English University Press,
1975:312 315.
2. Prosser White R. The Dermatergoses or Occupational Affections of the Skin, 3rd Ed.
London: H. K. Lewis, 1928: 125:186-190.
3. Schwartz L. Dermatitis from explosives. Journal of the American Medical Association
1944: 125:186 190.
4. Schwartz L, Tulipan L, Birmingham D J.Occupational Diseases of the Skin, 5th Ed.
London: Henrv Kimpton, 1957: 446.
5. Swanson C. Effects on the skin of irritant explosives. Proceedings of the Royal
Society of Medicine 1943: 36: 633 638.
MacLeod J M H. Necrosis of the skin from handling 'composition' (an explosive). British
Journal of Dermatology 1916: 28: 135.

Fig. 1. A manila strip with one end coated with fulminate: (a) is taped to a similar strip
tipped with sand (b). Pulling the two ends apart causes friction on the fulminate and an
explosion ensues (c).

Hennig Brand - 25-5-2010 at 16:05

Interesting, I particulary like the description of how the Christmas crackers are made.

Hennig Brand - 25-5-2010 at 18:15

http://pubs.acs.org/doi/abs/10.1021/ja02259a034
This is where I found an article, which shows the incredible stability of silver fulminate if article can be trusted. The sample of SF was over 40 years old, not stored completely out of light, and when tested tested practically identical to a fresh sample both in performance and chemically.(note: sample was stored under water however, this is good practice anyway for safeties sake)

This patent talks a lot about desensitizing SF, mostly the ammonia method used with the throw down/bang snaps during manufacture, and sometimes shipping. It does give some other examples as well. I apologize if this has all ready been posted, it seems like the kind of thing that would be.
http://www.freepatentsonline.com/4270435.html

Maybe someone can help me out, what I stated as the explosion temperature a couple posts up, for some reason I was thinking that was the decomp temp. Does anyone know what the decomp temp for Silver fulminate is? I know I have put small amounts on a fairly hot wood stove and been frustrated by no bang.

Didn't notice this before, Wikipedia says autoignition happens at 170C, for silver fulminate.


[Edited on 26-5-2010 by Hennig Brand]

Hennig Brand - 30-5-2010 at 05:14

Sorry for double posting, but I have something to report, I'll make it quick.
I tried a few more batches since the last one I posted and have gotten my yield up to around 0.75g Silver Fulminate per gram of silver used.
At least for me, with the materials I am using the decomp temperature is actually much below 80C. On one of my partly unsuccessful runs I noticed a very large precipitate but within 2 seconds the temperature rose 5 or 10C and the precipitate vanished. Silver fulminate seems to form almost instantly and can vanish just as quickly if temperature is not very closely controlled.
The next batch I was very determined to capture this large yeild, and by being super vigilant with temperature I did get most of it I think(0.83g from 1.1g silver). I kept the reaction down below 70C almost the whole time, it jumped over for a second at the start of the reaction. It was hard keeping it cool. I think large batches would be next to impossible to control.
Liebig claimed to get about a gram from a gram of silver, and I am now starting to see that I probably can to. Liebig was apparently a real expert when it came to silver fulminate.

Silver Fulminate seems so much more difficult than mercury fulminate to synthesis properly, am I just going about it wrong?

Zinc - 27-1-2011 at 11:17

Sorry to bring up an old thread, but this one seemed the most suitable for the question that I have.

Could perhaps the HNO3 made from Ca(NO3)2 and H2SO4 be used to make mercury fulminate?

I was thinking to first mix Ca(NO3)2 with H2SO4 to make the HNO3. If the H2SO4 is detrimental to the fulminate-forming reaction, an excess of Ca(NO3)2 would be added to the H2SO4 to use it all up. The result would be a thick suspension of CaSO4 and HNO3 (with the excess Ca(NO3)2), to wich a correct amount of water would be added to dilute the HNO3 to 50-60%. Then the mix would be filtered, or left to stand for some time so that the CaSO4 settles and the HNO3 can be decanted.
The HNO3 made this way would contain some dissolved CaSO4 (dont know how much of it dissolves in 50-60% HNO3) and Ca(NO3)2 or H2SO4 (depending on which of the two was in excess).
I dont think that some Ca(NO3)2 and CaSO4 would interfere with the formation of Hg(ONC)2, but I could be wrong, and I belive that there is much more chance that the H2SO4 would interfere instead of the salts.

Zinc - 2-2-2011 at 06:10

Yesterday I made some Hg(ONC)2.

To cca. 6g of Hg i added 45ml of 60-70% nitric acid (which was made from NH4NO3 and boiled down battery acid in an extremly improvised and crude distillation setup, and then diluting it with water). After the Hg dissolved (it took around 15-20 min) I added 55 ml of denaturated 96% ehanol to the nitric acid/mercury solution. As the reaction didn't start I heated it a bit, then it vigorously started and was complete in a few minutes. The mercury fulminate was washed several times with water (untill the wash-water was neutral) and left to dry in the baker. Today while the powder is still damp I transported it to a sheet of newspaper.

It is not dry yet so I can't weigh it but I think that there are at least 5-7g of it.

otonel - 6-2-2011 at 13:05

Is good cooper fulminates for uses like priming in gun caps?
I find that recipe to making cooper fulminates in book "Preparatory manual of explosives" and is easy to make but I don`t know how safety and useful is that



Copper fulminate
Use: Substitute for mercury fulminate.
Molecular weight: 147.584
Flammability: Explodes when ignited
Detonating velocity: Similar to mercury fulminate
Toxicity: Moderate
Sensitivity: Easily detonated
Classification: Primary explosive
Stability: Low
Overall value (as primary explosive): Low
Procedure 4-08A: Preparation of Copper fulminate
Materials:
1. 100 milliliters of 70% nitric acid
2. 30 grams anhydrous copper-II-nitrate
3. 120 grams 95% ethanol
Summary: Copper fulminate is prepared in a similar fashion as the mercury salt; by the addition of a hot nitrate acid solution upon ethyl alcohol. In this case, anhydrous copper nitrate is dissolved in nitric acid, the mixture is then heated, and the ethanol dropped in. As the reaction proceeds, the copper fulminate will precipitate. It is then easily filtered-off, washed, and dried. Note: Various modifications to this procedure exist.
Hazards: Use proper ventilation when handling 95% ethyl alcohol, and avoid inhalation of vapors.
Procedure: Place 100 milliliters of 70% nitric acid into a beaker, and then add 30 grams of anhydrous copper-II-nitrate. Note: if the copper nitrate fails to dissolve, add water drop wise, until the copper nitrate dissolves. Then rapidly stir this mixture at
room temperature for 24 hours. Thereafter, slowly heat the mixture to about 80 Celsius with rapid stirring, and then carefully add 120 grams of 95% ethanol while stirring the reaction mixture. After the addition of the alcohol, remove the heat source, and allow the reaction mixture to cool to room temperature. Afterwards, rapidly filter-off the precipitated copper fulminate, wash with several hundred milliliters of cold water, and then dry in a desiccator filled with anhydrous magnesium sulfate. Should be stored in a desiccator over sodium sulfate in a refrigerator.


gregxy - 6-2-2011 at 15:59

That method will not work. You can only make fulminates that way with mercury
and silver.


Check out "The chemistry of powder and explosives" by Davis.

hissingnoise - 7-2-2011 at 05:21

Quote: Originally posted by otonel  
"Preparatory manual of explosives"

The procedures in that book are not to be trusted!
Check out COPAE as gregxy suggested!
It can be downloaded from the site library . . .


quicksilver - 7-2-2011 at 12:56

I actually went after that 2nd edition of that book because many of the patent # were incorrect. Later I thought it was a real waste of my time because if the guy didn't edit it carefully; why should I? The book is a mess partially due to some of the background (patent material) being quite true & some being much too obscure to verify.
I checked out his 3rd edition: same deal. - Not as bad but then there were some issues that were simply sloppy.
The copper fulminate issue was a sloppy mess. The addendum was "essentially "it's just like Hg fulmniate in process"....WHAT? :(

There are some others like ammonium chlorate and copper azide that are just dangerous "death mixes" & have no real value.
The author went from attempting to develop a company "Paranoia Publications" to a "print-as-you-sell" self publishing firm that essentially is designed for authors who want their "market feelers" in print so they can send them to large firms as an attempt as getting a contract.

The author also did some other works that I have a problem with. He wrote a book on chemical weapons that is a serious prescription for killing yourself with toxins. The CS & CN tear-gas synthesis were somewhat unclear. But basically the "heavy" stuff was not OK. The gentleman apparently has use of a VERY well equipped lab so that many of his synthesis in his explosives texts make use of the more (or most) expensive means to an end.

"Just pour the acetic anhydride from your gallon jug into your $60,000 rotary evaporator....." :D



[Edited on 7-2-2011 by quicksilver]

Blasty - 8-2-2011 at 03:30

Quote: Originally posted by gregxy  
That method will not work. You can only make fulminates that way with mercury
and silver.


Check out "The chemistry of powder and explosives" by Davis.


Or he could just have used the search feature and easily find this thread dealing with the very topic:

http://www.sciencemadness.org/talk/viewthread.php?tid=599&am...

quicksilver - 8-2-2011 at 06:51

The "fumes" of a proper fulmiate reaction produce acetaldehyde, ethanol in abundance which are set in a distillation-type condenser that is "recycled" back to more of the mercuric nitrate making for a very efficient production mechanism. The introduction of copper into Hg Fulminate yield a large level of HgNO3 in the finished product (a yellow fine powder) which basically ruins the energetic properties of that material.
There HAS been a great deal of differing fulminates & in an odd similarity to some other materials, some of the elements just don't have energetic properties while others are much too sensitive. The actual chemistry of fulminates was not clearly understood till quite a long time after it had been in commercial production. The isolation of fulminic acid had made some chemists believe that simple addition could produce the finished energetic; which didn't appear to be the case. (Davis)
There HAD been attempts to subdue the sensitivity of Ag fulminate by the addition of other metals but the results were not as predicted. The fulminates are unique.