Well, no, you WON'T have thermite, that's aluminum and iron oxide. but
finely divided metals are a hazard by themselves, fire and explosion.
We had a local knive maker's operation burn completely to the ground
when light alloy grinding dust caught fire in the dust collection
ductwork. Had been in business making cast magnesium alloy-handled
steak knives since before my folks were married. Now it's just a vacant
lot. Nuf said.

Stan