Potassium Nitrate

Potassium Nitrate (KNO3) is much used in low explosives and
incindiaries,
(black powder for example) and will find much uses as oxidizer
in ignitors and such.

This is in the synthesis section, but it was
more of a purification then anything else.

You still need a source of
nitrate, it was the discovery of just that, that led to the creation of this
page.

Et voila, here it is. A stable in an old farm. The stuff is just growing
on the walls here :)

A close-up. How
come there's KNO3 growing on the walls here? Well ...
The room
this picture was taken in used to be a stable for animals over the last century.

The manure of these animals got a hold in the porous ground, and got all
worked up by various bacterias
(do a google search on this subject if you
want more details)
The nitrate was the end form, and it was just there,
enriching the soil.
Now, in this warm weather, the moisture in the ground is
going up in the walls, where it
evaporates, leaving the KNO3 behind in a
very fine crystaline form.

This is all that I could gather from the
walls, not much, but hey, it's free :)

As you no doubt
noticed, it's all dirty, and far from pure.
Alot of paint and dust came
along with the nitrate.

For it to be usefull, it must be purified.
The picture below shows what is needed.

I placed the raw
potassium nitrate in the white filter, while I was heating up 200 ml water.

Next, I poured the hot water gently over the raw nitrate, giving it the
chance to dissolve.
Better do it in multiple steps, letting the water run
trough and then add some more.

Do this untill the 200 ml water is used
up (run the very last bit down the sides of the filter paper)

Next is an
unsharp picture, but it shows what it's supposed to show. Volume of the water
increased !!
Also remember the dirt in the filter is not completely dry yet,
so I guess there would be about 275 ml in total.

In the next step
we add the same amount of alcohol to the nitrate solution, to make the nitrate
precipate.
This is a slightly exothermic process, but nothing to be worried
about.
Put the mix in the fridge anyway, and let it cool down to less then
10ï¿½C.

Next step is to filtrate the potassium nitrate (I used the brown filter
to make it show better on pics)

In the next
picture, you see everything on a row.
From left to right we have the dirt,
the KNO3 and some of the alcohol/water mix.

I boiled down
the alcohol and water mix to about 50 ml again, in order to get more KNO3 out of
it.

When volume was decreased enough I added the same amount of alcohol
again and refiltered.

The combined yield was about 75 grams. I weighed
the impurities too, that was 37 grams.

The product in
this form is a super fine crystaline, nice and pure white.

And "Why
do this when you can buy it pure and cheap in 25 kg bags?" Simple, for the fun
of it :)
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