Mercury fulminate question

[vlodjak]

I have a small question about mercury fulminate,
some days ago i tried to make it by using 15 ml HNO3, 10 ml ethanol and 1 g mercury. I think i didn`t use enough mercury because the mercury nitrate solution was a bit more yellow than greenish, but after the reaction with ethanol i got about 1/4 cc of almost pure white christals. When i ignited it, it made more like a phomp than a cracking sound.

Is this kind of deflagration normal, or i should of purified the cristals? By the way how is the best way do dosage mercury without scales, maybe with a syringe?

[Cordtex]

vlodjak:
Since mercury salts are sensitive to light(or UV?), maybe your reaction was exposed to light, so you got a yellowish color(possible?). My fulminating mercury white crystals used to become greyish-brown after the washing and drying process. And for the "phomp", guess it's usual when small ammounts are ignited, it leaves no residue but a metalic grey splashing pattern over the surface where it was ignited.

[hinz]

If you only ignite the MF without a container around it, it's normal because the explosive can't greate a shockwave and there is only a heatwave which sets the HE up. Heatwaves are normally not very fast. (something about 400-1200m/s ,the deflagration velocity of BP)
But if you put the HE in a sealed container ( a paper tissue or some PE foil may be enough for some primaries ) the explosive can create a shockwave aggainst the container and the shockwave sets up the whole HE in a few microseconds. On this way your MF detonates with a velocity of something about 2500-4500m/s
If you press it the VoD should be higher,if not, your VoD is low.
So if you warp your MF in some paper it won't cracking, I suppose, but stay away from it when it detonates when you use something else than paper.

Using a syringe could work,but mercury has a high surface tension, so your syringe shouldn't have a to small inlet if you want to pull it through. Pipets should also work. (1ml is equal to 14.09g)

[tom haggen]

If you did some stoichiometric calculations then you would have known if you had the correct amount of mercury. Maybe you should do some more reading. Nice sound effects.

[vlodjak]

thanks for the info, and sorry for those "newbie" questions

[Cordtex]

Here is a low quality movie, I shot it few nights ago, very small ammount of fulminate of mercury. The background noise: PC PSU.
http://geocities.com/mypyrolab/movies/onc-hg-onc.avi

[lucas]

10g of mercury metal was dissolved in 70% nitric acid, 70ml and left for a hour. The mixture was swirled to make it uniform as a denser layer was present. The Acid was rich with dissolved NO2. Methylated spirits was poured into the beaker and immediately a violent reaction occured and spat out the contents before addition of all the metho, 100ml was complete.

This has not been observed before, during several batches.

This may be due to the large amount of NO2 present and due to the addition of ethanol to acid instead of acid to ethanol. No dilution of the metho was done.

The acid and metho were not hot.

[c.Tech]

That violent reaction could have been because of additives in the methylated spirits.

Addition of bittering agents so children don’t drink it and methanol and to make it toxic so it can be sold to all ages + without alcohol tax.

[lucas]

Again 10g of mercury was dissolved and added to 70% nitric acid, 70ml. After dissolving the mercury, a small amount, less than 5ml, of metho was added to the acid. A violent emission of fumes and bubbling occurred for a moment. The acid was then slowly added to the rest of the 100ml of metho and the last trace of acid rinsed in with water. No obvious reaction ocurred for some time. The reaction proceeded as per normal, with a vigorous bubbling and fuming statring after a few minutes and subsiding a few minutes later. A large amount of sandy coloured precipitate formed.

Conclusion:
Mercury in nitric acid solution must be added slowly to the alcohol. Never add alcohol to nitric.