Sciencemadness Discussion Board

melting NH4NO3

mykhal - 4-4-2003 at 06:34

Some years ago I was trying to convert granullar (pearls ?) ammonium nitrate into powder form, but it was too difficult to pulverize in mortar, the granules were too hard. So I simply melted it in the aluminium pot on the electric kitchen cooker, hoping the cooled material will be more pulverable. Later I realized I was very dangerous, it could explode.
Did anyone try this?

a_bab - 4-4-2003 at 06:48

Well, melting AN could be a way of obtaining N2O (laughing gas). So it's not THAT dangerous to melt it. It can explode if there are some organic matter traces in it, and in big quantities. There are lots of theories rearding this issue; the general idea is to raise the temperature of a AN mass suddenly to a certain degree.
Otherwise it'll decompose violently (it's like a violent boil).

Use your mum's electric grinder instead. It's very productive !

pearls

mykhal - 4-4-2003 at 07:03

we had no grinder at home. What do you mean exactly by the electric grinder?
It is interesting that the NH4NO3 'pearls' contain hole in it. Dos it has something to do with the way how it is manufactured?

Cappy - 6-4-2003 at 22:25

a_bab, when you say electric grinder, do you mean something like a coffee bean grinder or a blender? Would a flour sifter work? Is ammonium nitrate impossible to set off with physical shock?

Mykhal, are the crystals harder than granulated sugar crystals?

mykhal - 7-4-2003 at 01:23

Quote:
Originally posted by Cappy
Mykhal, are the crystals harder than granulated sugar crystals?


I'm not sure I've ever seen granulated sugar. But if I imagine it, I'd say <b>yes</b>, granulated ammonium nitrate is harder.

a_bab - 7-4-2003 at 01:24

Yes, I was refering to the cofee grinder. It's made with a steel blade which is rotating real fast and breaks up (almost) anything. There is NO WAY to set off the AN by the means of friction. I know guys which are crazy enough to grind TOGETHER KNO3, S and C :o :o :o !!!There are even hilarious facts like "Thedanger of being blown up because of sleeping with a bag of AN under the bed it's the same as being hit by a metheorite in the hed".

Haggis - 7-4-2003 at 07:55

I grind my ammonium nitrate with a mortar and pestle. The prills are soft. When it is powdered, I pour the powder in a beaker and heat all the water off. Sometimes the bottom layer melts some when you don't stir it enough. I don't think that there's any risk at all for ammonium nitate to decompose without a huge shockwave. Even when it is contaminated with many organic substances, it won't 'explode' because you ground it up.

Cappy - 7-4-2003 at 09:13

Quote:
Originally posted by mykhal

I'm not sure I've ever seen granulated sugar. But if I imagine it, I'd say <b>yes</b>, granulated ammonium nitrate is harder.


By granulated sugar, I mean sucrose in regular, table sugar form. Not powdered as in confectioner's sugar. I've tried grinding sugar with a wooden spoon and plate, and it very difficult if not impossible. I'll try with metal spoon and plate soon.

[Edited on 4/7/2003 by Cappy]

mykhal - 8-4-2003 at 01:36

Quote:
Originally posted by Cappy

By granulated sugar, I mean sucrose in regular, table sugar form.

So you mean crystalline sugar? By <i>granular</i> ammonium nitrate I did not mean crystalline :)

Nevermore - 22-7-2003 at 07:16

Well, following the procedure for activating it and then crushing in a mortare would yeld easily a good powder.
Just mix 10 ml water to 100g AN, mix well, put in oven and cook it for a couple of hours till it is completely dry, usually below 100°C, and it will yeld a very fragile prills easy to break and to reduce in powder, take care to save the powder in airtight container, or with the moist from the air will became a solid block.
:P