AfricanPyro - 17-3-2011 at 11:24
Hi everyone. Long time reader, first time post.
Ammonium Nitrate is hard to come across here in Africa, so I went the instant cool-pack route. The cool-packs state, "Ammonium Nitrate &
additives", so I bough a few packs to try out. In around 90% of the cool-packs I opened the AN was a brownish-grey color and some had a hint of white.
I tested it with a 90/10, AN/AL and had a full detonation.
The additives obviously have very little to no effect, but I was wondering for common-knowledge what this additive could possibly be? I have heard
that they sometimes add Urea to the cool-packs, but Urea is colorless. Any ideas?
Bot0nist - 17-3-2011 at 11:47
Can you post the brand name or find an MSDS? The manufacturer may list the ingredients if asked correctly. You could try separation via decanting and
recrystallizing if the contaminants are less souluble than NH<sub>4</sub>NO<sub>3</sub>
quicksilver - 17-3-2011 at 12:24
Rust from the prill tower (if it's prilled)....most likely cause of discoloration. Not a big deal in so far as utility is concerned: as if pure
nitrate were needed you'd re-crystallize anyway. Contaminant level could be less than 1% Fe for coloration issues to be observed.
SB15 - 17-3-2011 at 13:04
Cold pack ammonium nitrate is pretty low quality. I buy only one brand and most of the material is contaminated with either yellowish material or
chunks of brown crap. Neither affect performance in explosives, but you certainly wouldn't want to use the non-purified material for lab syntheses.
I typically recrystallize col pack AN before use. It has an extremely high solubility in water, but the differential solubility in hot and cold
solutions is high enough to allow for effective recrystallization. Dissolve 1kg in 1L of room temperature water, filter multiple times to remove
insoluble impurities. Boil the solution down until it becomes saturated at ~100*C, then allow it to cool slowly to below 0*C. Filter the crystals and
dry them in an oven, then repeat the process with the liquid filtrate to get as much AN out of solution as possible.
This should produce a relatively pure grade of material.
hissingnoise - 17-3-2011 at 13:20
NH<sub>3</sub> for use in agriculture is often gas-liquor derived and contains phenolics and other aromatics!
The amount of purification it's subjected to depends on the intended use.
The compounds present in this stuff often produces a reddish-brown colour . . .