Making sodium nitrate

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jason_recliner

Well-known member
Joined
Apr 6, 2014
Messages
847
Location
Melbourne, Australia
Most nitrates can be used to make Poor Man's Aqua Regia (PMAR), however ammonium nitrate (NH4NO3) is one of the more hazardous options as one can unwittingly create explosive compounds. However it's quite easy to convert to sodium nitrate (NaNO3) or potassium nitrate (KNO3).

This is the method I have used in the past to convert ammonium nitrate to sodium nitrate. Credit for the method comes from Nurdrage of YouTube, though I modified the process very slightly.

Unfortunately I am unable to include photos as I sourced my ammonium nitrate from instant cold packs. I have since converted the last of my supply and in this country ammonium nitrate cold packs have since been replaced with urea.

This has to be done outside away from neighbours, or in a fume hood. The process produces large amounts of ammonia gas and therefore may be unsuitable for converting large amounts due to the volume of gas released. For this reason, I also like to make small amounts at a time.

When working with sodium hydroxide, always be sure to wear skin and eye protection.

  • Obtain ammonium nitrate from an instant cold pack. Make sure it's dry so you can weigh it accurately. My last cold pack was moist inside and I had to dry it out.
  • Put 80g of NH4NO3 into a 250ml beaker or preferably a plastic container.
  • On top, layer 40g of sodium hydroxide (NaOH). Do not stir. Since both of these are hygroscopic it will start reacting immediately and ammonia gas will be released.
  • They will also react aggressively when wet, so go slowly.
  • Apply a light spray of water on top and let it react initially before adding more water. It will also start to get warm. Then add another light spray.
  • Once it settles down again, add about 30ml of cool water and let it react completely. Finally, stir in about another 40ml of water until it's all completely dissolved, and let it stand until the area doesn't smell like ammonia. This might be half an hour.
  • Light brown sediment may occur. This is anti-caking agent in either input material.
  • Filter the solution into an evaporating dish and dry it out to a salt. You should be left with around 85g of very clean sodium nitrate.

These input values are very conveniently spot on 2:1 by weight. The figures here are for one mole.
The 40g of sodium hydroxide can be substituted for 56g of Potassium hydroxide to make 101g of potassium nitrate.
 
Personally, I'd completely forget about using (or even mentioning) ammonium nitrate as it is a very effective explosive when mixed with one other easily obtainable ingredient (don't ask). It used to be made by terrorists by the carload! (sic) and is the main reason that it is virtually impossible to get here in Indonesia. Probably the same in Aussie. These two countries work closely together and are very serious about their anti-terrorist activities, so I'd imagine you'd attract unwelcome attention if it were known you were making/using the stuff.

I have no problem, though, getting nitric acid and making AR directly would, ironically, be cheaper than the "Poor Man's" version.
 
Gratilla said:
Personally, I'd completely forget about using (or even mentioning) ammonium nitrate as it is a very effective explosive when mixed with one other easily obtainable ingredient (don't ask). It used to be made by terrorists by the carload! (sic) and is the main reason that it is virtually impossible to get here in Indonesia. Probably the same in Aussie. These two countries work closely together and are very serious about their anti-terrorist activities, so I'd imagine you'd attract unwelcome attention if it were known you were making/using the stuff.

I have no problem, though, getting nitric acid and making AR directly would, ironically, be cheaper than the "Poor Man's" version.

Actually if you sharpen your buying habit you can mke poor mans cheaper than AR.
 
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