ribbon to dust

[-MC]

I have alot of magnesium ribbon and I want it to be magnesium dust.
I was just grinding it with a file and collecting the dust but this is time-consuming and innefficient. Any better way to go about it?

[asilentbob]

You could attempt to ball mill it with very hard and heavy milling media... However... If you don't open the ball mill every once and a while to let the magnesium surface get oxidized... at some point all of it will just burst into flames...
http://en.wikipedia.org/wiki/Pyrophoricity

The better way is just to buy it.