James Silverton wrote:
> Cindy wrote on Mon, 21 Jun 2010 13:13:44 -0700 (PDT):
>
>>> While we are on the topic of the magic of metallurgy, it may
>>> interest people to know that powdered aluminum is considered
>>> to be hazardous materials that is subject to spontaneous
>>> combustion.
>
>> Yeah, but it's more fun if you mix it with an oxidizer and put
>> it into a
>> cardboard tube.
>
> It can be ignited but I really doubt about *spontaneous" combustion even
> if you could get it to burn. I know if you mix aluminum powder with iron
> oxide (rust) and ignite it, you get one of the hottest fires that exists
> and it will even burn below water. They call the mix Thermite.
>


Under the regulations for shipping hazardous materials, non-coated
aluminum powder is a Class 4.3 Packing Group II because it reacts
vigorously with water and Packing Group II because it reacts vigorously
with water. Care must be taken to make sure that it is kept dry, even
protecting it from humidity. I have heard of cases of it catching fire
while sitting on trailers in truck stops. You cannot use water to
extinguish the fire.