Purifying sodium nitrate

[BurritoBandito]

I have a ton of NH4NO3 at my house right now and no KNO3. I thought it may be worthwhile to make some NaNO3 by reacting a solution of 1 mole NH4NO3 (80 grams) & 150 mL H2O with 1 mole NaHCO3 (84 grams). The resultant solution is then boiled down to decompose any residual NH4HCO3. Though this does work it is not as pure as I would like it to be (prolly due to weighing inaccuracies and such). Both the NaNO3 and the NaHCO3 Pretty much share solubility in all of the readily available solvents that I know of. This is a problem in terms of attempting to separate them via recrystallization. Evaporating the H2O in a centrifuge and ideally the NaNO3 would recrystallize on the bottom since it is more dense. There are a few issues with this idea too though. Namely, lack of apparatus and the fact that their densities are so close NaNO3 is 2.26 g/cm^3 and NaHCO3 is 2.20 g/cm^3. Any help or ideas would be greatly appreciated.

[Mumbles]

It wont be particularly efficient, but I'd suggest fractional crystallization. Sodium nitrate is about 10x more soluble than sodium bicarbonate. My experience with nitrate is that they tend to grow large well form crystals, but bicarbonates do not and tend to powder out or form microcrystals. This should also help in separating them, as any small fragments or powders can be suspended and decanted.

[BurritoBandito]

Hey thanks again for the quick response. I think it may just be better for me to save my ammonium nitrate for other uses and go buy some potassium nitrate. And Mumbles, I really do appreciate you taking the time to reply to my posts and patronizing a newbe such as myself. This site is awesome and I'm grateful to have happened upon it. You guys rock.

[BurritoBandito]

Just in case this benefits anyone else...

I realized that my issue was that due to the hygroscopic nature of ammonium nitrate my solution was too sodium bicarbonate heavy. The answer to this problem is to desiccate both chemicals prior to weighing. Rookie mistake.