Storing AN

Cold packs as a source for pure AN

Purification method 2 – Crystallization using methanol

Purification method 1 – Crystallization using water

It is possible to purify using simply water. You basically crystallize it from water as it has a solubility differential over temp in that. It is possible to remove many impurities by just dissolving it in boiling water..you will dissolve anything ionic. Filter it while really hot to remove insoluble’s then let it cool and collect the AN. If you want really pure stuff, do a couple more recrystallizations to get out any remaining impurities. And NO! You do not need pure AN to make ANFO or ANNM. Believe me I have detonated enough ANFO full of sticks, sawdust, plastic chunks, and miscellaneous crap to know.

However, if there are sodium compounds in there then he can't just dissolve in water and filter.

If you encounter problems try reducing the amount of water used or else reduce the temperature. Don't use boiling hot water. Try to get the temperature of the water to 50 deg. or so. This will reduce the yield but it will avoid some substances with a low solubilty to dissolve. Ammonium nitrate dissolves 118g/100g water @ 0C therefore reducing the temperature will still dissolve much of the nitrate.

The following method will show you at least the best known purification method. This is done by boiling Methanol Alchohol and adding the fertillizer Ammonium nitrate until no more of it will dissolve. 20.2 g AN (NH4NO3) per 100 g methanol at 30 degrees C. There are values for other temperatures too, but solubility doesn't seem to vary rapidly.This is then cooled in an ice bath and the white crystalls deposited at the bottom are pure Ammonium Nitrate. Thus the pure Ammonium nitrate can be heated on a lowest temperature on a pan in the oven until very dry. Store it in a tightly closed container.

Another similar method is the following: to purify "dissolve the fertilizer in hot methanol and filter the solution. By mixing the solution with an equal volume of unleaded gasoline, the ammonium nitrate will instantly crystallize."

If you are having problems converting fertilizer to a more pure form just try using some other source of ammonium nitrate, like cold packs, or another brand of fertilizer containing ammonium nitrate. The AN from Cold packs is however 10 times as expensive as the fertilizer AN resulting in a limitation regarding the procurement of large quantities.

The shelf life of cold packs (100% AN) is approximately 1-2 years from production date which is usually specified on each package. So, if you need a large quantity, start you’re an acquisition phase aprox 6 months prior to the execution of the mission. Note that the special plastic and vacuum packing is done to ensure this long shelf life so if you take out the AN from the cold packs it might influence the shelf life, regardless of how effectively you manage to contain it. If you are packing it yourself with traditional plastic the shelf life may be dramatically reduced, perhaps down to 4 weeks with poor packing. This will depend on how well you pack it, how much oxygen is available, humidity, temperature during storage etc. Container: heat- OR acid-resistant OR plastic). Instead of storing a 500 kg (which might be poorly packed for long term storage) you should consider breaking the large bag into smaller 50 kg bags. Try to order specialized plastic bags for this purpose.

Дата добавления: 2015-05-31