Sodium Nitrate Smoke Bomb

[Nude Anaglyphs]

I tried making a smoke bomb using the classic sugar and potassium
nitrate recipe (melting the two together to make a hard carmel
like substance). But, instead of using potassium nitrate, I used
sodium nitrate.

The reaction is quite different. Instead of burning like rocket
propelant, it burned very slowly and cleanly (not producing that
much smoke). Also, the flame was intensely bright and intensely
yellow (I had a big blue dot in front of my eyes that lasted
several minutes).

After the flame went out, I walk over to where it was burning and
there was a thick molten blob glowing where the smoke bomb had
been. After this blob cooled and hardened, it was a white brittle
mass with a texture sort of like chalk. I call it "smokebombite".
I poored some vinegar over some of the smokebombite and it fizzed
up.

So, my questions are:

o Why did my bomb burn so slowly? I understand that NaNO3 is
very hygroscopic, but I had it stored in a sealed jar.

o What is smokebombite? Is it sodium bicarbonate?

NA

[Lloyd E. Sponenburgh]

"Nude Anaglyphs" <nudean...@yaEXPUNGEhoo.com> wrote in message
news:125f2el...@corp.supernews.com...

> o Why did my bomb burn so slowly? I understand that NaNO3 is
> very hygroscopic, but I had it stored in a sealed jar.

Although sodium nitrate (Chile Saltpetre) is an effective oxidizer, it's not
as energetic as is potassium nitrate.
Further, sealing it in a jar would not preclude that the material was wet.
However, caramelizing the mix should have driven off most of the water.

> o What is smokebombite? Is it sodium bicarbonate?

It's probably mostly a mixture of sodium carbonate and sodium oxide. It's
quite corrosive.

I've made successful "caramel candy" rockets with sodium nitrate instead of
the potassium salt. At elevated pressures, the burn rate increases enough
to be useful. "Berg's Blasting Powder" and other commercial rock-heaving
powders were made from the sodium salt, as well. Sodium nitrate is/has been
the oxidizer of choice in certain military illumination flares.

LLoyd

[dave e]

Nude Anaglyphs wrote:
> I tried making a smoke bomb using the classic sugar and potassium
> nitrate recipe (melting the two together to make a hard carmel
> like substance). But, instead of using potassium nitrate, I used
> sodium nitrate.
>
> The reaction is quite different. Instead of burning like rocket
> propelant, it burned very slowly and cleanly (not producing that
> much smoke). Also, the flame was intensely bright and intensely
> yellow (I had a big blue dot in front of my eyes that lasted
> several minutes).

Flame color depends on the type of metal. Sodium is intensely yellow.
Potassium is more bluish/purple, but often the potassium color is
masked by any contaminating sodium (unless the potassium is relatively
pure).

Dave

[mss...@newsguy.com]

I'll agree with Lloyd that your fizzing reaction was produced by sodium
carbonate.

Potassium carbonate is always present in ordinary black powder fouling,
which exhibits an alkaline pH and is not (contrary to widely held
belief) innately corrosive (it's hygroscopic, and the water it takes up
from the atmosphere is the agent of corrosion).

A trick I learnt about shooting black powder in cartridge firearms is
to deposit, as soon as practicable after shooting, the empty cartridge
cases in a large jar of white vinegar. Modern black powders tend to
produce hard, caked fouling when shot at high pressures (unlike the
moist, "greasy" deposit one typically finds in firework mortars). The
vinegar reacts effervescently with the carbonate in the fouling, which
helps to dislodge it, and makes subsequent cleaning of the cases with
soap and hot water much easier. NB - the ladies of the household will
appreciate if you do the vinegar treatment out-of-doors rather than in
the kitchen. It also liberates some hydrogen sulphide.