metalresearcher - 6-9-2016 at 11:12
When I melt a tiny chunk (1g) of Mg metal and add a knifetip of KNO3 to it, it starts burning.
I did the same with aluminum and heated the droplet of Al to above 800 C (bright red). Then I put a knifetip of KNO3 onto it but nothing happened.
Al powder with KNO3 biurns immediately without preheating, like Mg powder.
So why not heated Al ?
moominjuice - 6-9-2016 at 11:31
It has been a while since i tried to melt Aluminium but (if i recall corretly) when it solidifies it has a thicker layer of oxide than normal, i
suspect that this forms while the metal is molten (for obvious reasons) and i suspect that your nitrate is just sitting on top of the oxide layer and
remaining separate. i suspect that if molten Al were poured onto your oxidizer then you might have a better reaction but i would think this likely to
be dangerous.
(edit; typo)
[Edited on 6-9-2016 by moominjuice]
Morgan - 6-9-2016 at 15:46
I remember putting a few tablespoons of KNO3 in some aluminum foil and wadding it up into a baseball size crumple of foil and then placing it in the
coals in my fireplace. After the foil became quite soft I poked it a few times with a poker which created glints of white light before suddenly
igniting into a intense white light making the room several times brighter.
moominjuice - 6-9-2016 at 16:57
not the most scientific method but relevant so thanks.