Lew Hartswick wrote:

Don Foreman wrote:

On Thu, 13 Mar 2008 13:06:12 -0700, Gunner
wrote:

http://www.thesun.co.uk/sol/homepage...icle900459.ece


Meanwhile, last I looked anyway, regulations required a fire
extinguisher every 25 feet in a slate mine in Wales.
I've never seen slate ignited, but it must be nasty!


Slate : Metamorphosed shale. ie. clay just how hot would it
have to be to be ignited? Wonder what is flamable in a
slate mine?
...lew...


Also Dust...

Almost any dust is explosive when the mixture is right.