Magnesium Sulfate Black Powder?

[6squirrels]

I'm super into chemistry, and am very much a nerd in that sense. My friend found some Epsom salt which I read on the package to be MgSO4 x 7H2O. I later looked up Magnesium Sulfate on wikipedia (because like I said, I'm a nerd), and there was a very very brief section on pyro use.

 

"Magnesium sulfate is used as a reactive compound in the manufacture of black powder where it contributes to a violent burn rate thus reducing material costs." - wikipedia

Confused, I tried to look for more info on the compound, like decomposition temp and incompatible chems, but nowhere that I could find had anything. I did find that someone said making bp with Epsom salt is a felony, but just in general I'm curious to know how MgSO4 would be used in a bp, or in any other pyro compositions. I don't plan to make it, saying as I've heard words like "volatile" and "felony" associated with it, but knowledge is power and I'm full of curiosity. If anyone's got any info, I'd be very grateful.

[asilentbob]

Sulfates can act as oxidizers at high temperatures. Calcium sulfate and aluminum powder for example, whose claim to fame is that when hydrated it can form a sort of plaster of paris "incendiary". Or part of the oxidizer bill in compositions can be sulfates like with strobe compositions. Hydrated magnesium sulfate would be less effective than anhydrous. I have never heard of it being used as a replacement for potassium nitrate in black powder, I'd guess that someone just put it in to wikipedia who doesn't know what they are talking about. That said, I suppose that if you worked out the stoichiometry and then fiddled with it a bit to take atmospheric oxygen into account you might get a useable composition, though I imagine it would be very hard to light and not particularly useful.

 

EDIT: If just added as a few percent to BP, I'm not sure what kind of effect it would have.

Edited March 15, 2012 by asilentbob

[brimstoned]

I'm curious if fine Al could be made to react with all that bound H2O?

[AirCowPeacock]

Perhaps it is used as an additional oxidizer, IncreasIng the burnIng temprature. Say like 40% to 60% potassIum nItrate, 10% to 30% Magnessium sulfate, 15% to 20% Charcoal, 10% to 15% Sulfur. Edited September 23, 2012 by AirCowPeacock