hi guys,
I would have posted this in the L.E. section, but then I thought surely someone is going to rape me on the triviality of the subject.
So here it ends up in the water cooler section :( .
Anyway... it actually *is* trivial...
but I managed to get hold of some of the above, (NH4)2Cr2O7, a beautiful crystalline orange-red substance (from a photography supplier). It burns very nicely, liberating a comparably huge amount of green Cr2O3. (Its well known in school experiments, kinda the first you get to see... called the chromate volcano).
Anyway, I discovered that the container of this had the very distinct 'explosive' sign on it... and they wouldnt put it there without a reason. After all, NH4NO3 never has it, although it is probably more powerful in terms of explosive force than the dichromate.
So.... that brings me to the question....
Did anyone actually try to set this off? Ammoniumdichromate? The label blatantly indicates that this is possible. But despite a search within this forum I couldnt find advice/help.
Anyone got more experience on it, than just making chromate volcanoes?

chemoleo

Be careful with that shit... Like all Cr (VI), it's a potent Carcinogen

If you milled it down, you might be able to use it as an oxidant in general pyro compositions, it's also used in Chlorate electrolysis cells and as a stabiliser for Tovex, among other things. Isn't it also added to comps containing fine flake Mg to prevent corrosion?

sure.... it's toxic like all the Cr (VI) ions... btw ever saw that movie with julia roberts, Erin Brockvich??
I have no intention of using it in pyro mixtures, as it has a perfect OB anyhow, i.e.
(NH4)2Cr2O7 --> Cr2O3 (green) + N2 + 4H2O.
Hence you couldnt contribute much by using it in pyro mixes.. they are likely going to be more powerful anyhow....
All I wondered whether that explosive sign was merited... and whether/how I could elicit that particular property :D

Just because it has an explosive sign on it doesn't mean it can detonate. NM only has a flammable liquid on it and it can explode like AN as you mentioned. They tend to over rate things, AN generally has an oxidizer symbol on it but is a poor oxidizer when it comes to pyro comps. I think this may be the same with your dichromate...

I agree with blindreeper, I have seen some aerosol cans of hairspray with the "Danger, Explosive" logo on them (no, not the flammable logo, the explosive one). This was just because the can will burst if heated :rolleyes: .

And to think, pyrodex is only classed as a "Flammable Solid", damn these classification systems are screwed up...

Yea they are screwed up! Where I work we have lab grade jars of ammonium nitrate which only have an oxidizer symbol on it and no explosive sign, Lead nitrate as only irritant. :rolleyes:

Ammoniumdichromate is listed as an explosive compound because it is more shock sensitive than dinitrobenzene. (that's the official definition)

Anyways, shock sensitivity relates to the decomposition reaction here, not a detonation.

To be short: If you hit it hard enough with a hammer it'll decompose in the usual fashion.