Sciencemadness Discussion Board

All sorts of fires

mick - 23-9-2004 at 10:40

Fires seem to come up regularly in all sorts of threads. Just a coments about personal fires.
When I started work as a technician, I found an old 50g bottle of lithium aluminium hydride which had cracked all round the bottom of the jar. Any water could mean a fire, the roof leaked in places. If anyone picked it up to use, they could be covered in the stuff. I decide to neutralise the stuff. I check the official procedure out, which was
Dry butanol + sand on a metal tray and add the LiAlH4 slowly.
I cleared the fume cupboard and put an up turned metal trash can lid with sand in. added some dry butanol and started to add the LiAlH4 with stirring. nothing happened, added a bit more and a bit more and then the solvent was on fire. Some one went to press the fire alarm. I grabbed a CO2 extinguisher and LiAlh4 does explode with CO2, I did not know then, but it just looked like fireworks going away from you. After all the the stuff had gone out, to sort the rest of it out I dumped a load of Dri-ice on it, it was there, by the time the fire brigade turned up it was all sorted.
If I want to sort out LiAlH4 or sodium or other similar stuff now I always use salt + ice + water. Dig a valley, put a screen in front of your self and add it slowly with the wind blowing away from you. Nothing else can catch fire.
Some things catch fire on contact with water, some things break down water to flammable stuff but in general if you have got enough water you should be able to quench most reactions on a certain scale.
Be careful of phosphorous
If you read other peoples near misses it makes you think.
mick