Steviep,
Sparklers are made of a mixture of aluminum and iron powder. Magnesiun is even more volitile than aluminum and can ignite on its own.
I had left very fine aluminum dust (powder) on the bench and it was mixed with some other iron dust that was already there. When I next started grinding iron, lawn mower blade I think, it was throwing some serious sparks onto the aluminum/iron dust that was there. The mixture ignited with a huge flash. It singed the hair on my arm. Stuff reacted almost like gunpower, or flash powder.
I think what is happening is the large surface area of the aluminum oxidizes and causes the iron to burn, like what happens in an oxygen cutting torch.
-- Michael :-{| Diapers and politicians both need to be changed often; and for the same reason.
