I think the "government" thing is a possible hoax.......or typical "theorizing" by people who really have no experience and no real knowlege. The latter is more likely, the writer was not there, and did not see whatever happened, if anything.
That said, I have "ground" aluminum and followed up with steel, on the belt sander, and seen a few bright white flashes. So I suppose its possible.
But the details in that "government" report are highly suspect....there may have been a flash, etc, but I strongly doubt it was just like that.
Giving the diameter of teh "fireball", etc, etc. Oh, pu-leEEEse. That guy wasn't there, and I'll bet the "victim" has no clue.... in that kind of situation you generally don't, it comes down to "what the %%%%?".
I know folks who have TRIED to get a thermite reaction to "go". It isn't easy, and I doubt 12 rivet heads will do the job. Maybe if they were magnesium....
That goes double because the "mixing" won't be very good between the aluminum and steel dust. The real thermite is well mixed, in the right proportions. Random mixing from grinding will be uneven, with layers formed, etc.
Finally, the steel isn't ALL or even MOSTLY turned to ferrous oxide. There are sparks, yeah, but most of the grinding dust I get is still "steely-looking". So you are down to "lighting" the aluminum. If actual thermite reactions had occurred, it would have left globules of steel.
Possibly it lit some aluminum, just by hot sparks, but even that isn't easy. I gotta wonder if that report is even partly accurate.
Then also, the "fireball" seems odd also. Thermite is spectacular, but it does not explode. If it threw that much stuff around it wouldn't be useful, it would blow itself out of the pot.
Aluminum dust also doesn't just jump up and explode, even if provoked. One is left to wonder if the ingredients in teh occurrence were all known and listed.... like what other dusts were around?
Was the steel that was being ground oily? An oil mist explosion would be possible if so.
Grinding aluminum on a wheel is just not done....loads up as umpty-bump people have said above. I doubt there would be much dust, looks like it mostly sticks to the wheel, depending on alloy. Yet another strike against the "report".
[ 07-22-2005, 04:58 PM: Message edited by: J Tiers ]