Mercury fulminate is a primary explosive that is synthesized through the reaction of mercury metal with nitric acid, followed by the addition of ethanol. This produces fulminic acid, which reacts further to form mercury fulminate crystals. Though it is sensitive and toxic, mercury fulminate was widely used as a primary explosive in the past. The synthesis involves dissolving mercury in nitric acid, then adding ethanol to produce white mercury fulminate crystals, which can be purified by dissolving in ammonia and acidifying with acetic acid. Mercury fulminate must be handled carefully due to its sensitivity.

1. 12/27/22, 09:43
Mercury Fulminate
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https://williestop.tripod.com/Highexplosivespictorials/mercuryfulminate.html
Mercury Fulminate
Mercury fulminate is a sensitive primary explosive. In its pure form, it is a white powder. It was a widely
used primary a while ago but has now been replaced with less toxic explosives though it is still used at times.
The synthesis is rather simple and the reactants needed are fairly common in a standard lab. It is synthesized
by the action of excess nitric acid on mercury metal producing Mercury (I) Nitrate. The mercury (I) nitrate
and excess nitric acid react with ethanol forming a vast chemical change which ultimately results in fulminic
acid.
2HNO3 + Hg ----> HgNO3 + NO2
HNO3 + C2H5OH ----> CH3CHO + HNO2 + H2O
CH3CHO + HNO2 ----> CH2NOCHO + H2O
CH2CHONO <===> CHCHONOH
CHCHONOH + HNO3 ----> CHCOOHNOH + NO2 + H-
CHCOOHNOH + NO2 + H- ----> CNO2COOHNOH + H2
CNO2COOHNOH ----> CNO2CHNOH + CO2
CNO2CHNOH ----> HNO2 + HONC
HNO2 ----> NO + OH- (The nitrogen monoxide will react with the air forming nitrogen dioxide which is
why the reaction gives off nitrogen dioxide after a while)
2HONC + OH- + HgNO3 ----> Hg(ONC)2 + HNO3 + H2O
Reaction from COPAE, thank you lacrima for pointing this out to me
Materials Equipment
Mercury Metal 20x150mm test tube
70% Nitric acid
100ml beaker or
equivalent
96% Ethanol (I consider
absolute ethanol a waste
for this)
Funnel and filter paper
Ammonia solution

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Mercury Fulminate
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(Prep/OTC) litmus paper
Acetic Acid (Prep/OTC)
Into a 20x150mm testtube (or equivalent), pour 10mls of 70% Nitric acid. Add to this 1 gram of mercury
metal. Now, you can leave this and walk away for about 30 minutes or so as the mercury dissolves. Do not try
quickening the reaction by heating it up. I have tried this before and managed to get the contents of the
testtube on my hands and face (it shot up in the air and rained down on me). Of course, I was using an
alcohol burner for this. A water bath might work. Either way, its not neccesary to heat it up, just walk away.
The reaction will evolve a bit of nitrogen dioxide gas which is another good reason to go away. After it is
done the contents of the testtube will be a greenish-yellow color (it varies). In a 100ml beaker or equivalent
device pour 20mls of 96% Ethanol which should be around 25C. If it is not then warm it up, if it is above
25C it will be fine, just use it. Quickly pour the contents of the testube into the beaker container the ethanol
and step back. Caution: Never use a testtube for this part of the reaction, it will shoot out and cover your lab
table or whatever table you use with small ammounts of the reaction mixture. A lot of a poisonous, flammable
gas will be evolved at this time. Also some nitrogen dioxide may be evolved. When the reaction subsides you
will see some white crystals in the reaction vessel.
Pour the contents of the reaction vessel through some filter paper to collect the crystals of mercury fulminate.
First wash once with some water, and then finally with some ethanol. This is your crude mercury fulminate
which can be used as is, or purified. If it is not purified it becomes less storage stable and also less stable all
around.
To purify, dissolve your crude mercury fulminate in some concentrated ammonia water. 25mls of 10% should
do it. A dark grey solution will form. Run this through a filter to remove any unreacted mercury and other
impurities. Add your acetic acid dropwise until the mercury fulminate begins to crystalize. Continue the
addition until the solution is neutral (shows no acid nor base on red & blue litmus papers). Add about 50ml of
distilled water to this and filter the mercury fulminate out. It should be a white, crystaline powder.
This explosive can also be mixed in a ratio of 9 parts (by weight) mercury fulminate with 1 part (by weight)
potassium chlorate (Thank you powerlabs for this information). Load moist into detonators and always
ground yourself whenever you're about to handle mercury fulminate.