Merryp
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Convenient route of reducing nitrate to nitrite?
There are various reducing agents listed for molten nitrate; ideally, I'd like to avoid lead or other heavy metals.
Carbon or iron sounds reasonable, but what kind of yield can you expect with those?
Would it be advantageous to use a soluble reducing agent (sugar, ascorbic acid), to get it very evenly mixed with the nitrate, prior to drying and
heating?
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Alkoholvergiftung
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Sulfur,Pyrit,Sulfuriron,iron,FeO Charcol, Coke,
56% 66,7% 63%, 86,4% 83,25% 77%.in present of NaOH or other molten alkali. Without under 45%.
2NaNO3 + 2NaOH + C = 2NaNO2 + Na2CO3 + H2O
With Carbid in molten KNO3
CaC2 +5 KNO3 = CaCO3 +5 KNO3 + CO2
With Copper powder in present of molten KOH.
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Alkoholvergiftung
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oh i ve forgotten my favorite is an wet Methode. Reduction with hydrogen.
50g of NaNO3 in 150ccm Water , 350ccm ammonia solution 9% after mixing add 60g zink powder. put Reaktion fessl in an bucket of Cold water and hold
Temperatur between 20 to 25 C. After all zink is added and the liquid gets an clear Color it s finished. Yield around 96%.
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Merryp
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Quote: Originally posted by Alkoholvergiftung  | oh i ve forgotten my favorite is an wet Methode. Reduction with hydrogen.
50g of NaNO3 in 150ccm Water , 350ccm ammonia solution 9% after mixing add 60g zink powder. put Reaktion fessl in an bucket of Cold water and hold
Temperatur between 20 to 25 C. After all zink is added and the liquid gets an clear Color it s finished. Yield around 96%. |
So that'd yield insoluble Zn(OH)2, gaseous NH3, and a nitrite solution, right?
Sounds convenient.
Would that also work with NaOH + Al, or is the NH4+ ion a required step?
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Alkoholvergiftung
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I have this from an patent but if you dont follow the instructions especialy Temperatur and concentration you reduce the nitrite to Nitrogen. ive read
vinegar works too. To strong acids and bases dont work i think because they reduce it to Nitrogen. oh some one made something
similar on YouTube. https://www.youtube.com/watch?v=5Sgd1wjpywc
vinegar and ironpowder should work too.
[Edited on 4-10-2019 by Alkoholvergiftung]
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Merryp
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| Quote: Originally posted by Alkoholvergiftung | I have this from an patent but if you dont follow the instructions especialy Temperatur and concentration you reduce the nitrite to Nitrogen. ive read
vinegar works too. To strong acids and bases dont work i think because they reduce it to Nitrogen. oh some one made something
similar on YouTube. https://www.youtube.com/watch?v=5Sgd1wjpywc
vinegar and ironpowder should work too.
[Edited on 4-10-2019 by Alkoholvergiftung] |
Thanks.
Do you have a link or copy of that patent?
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Alkoholvergiftung
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It s in german.I have it on my harddrive and here is the link i hope it works.
https://depatisnet.dpma.de/DepatisNet/depatisnet?action=pdf&...
https://depatisnet.dpma.de/DepatisNet/depatisnet?action=pdf&...
The secound is compled
[Edited on 4-10-2019 by Alkoholvergiftung]
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Lithium
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I’ve done this before by roasting sodium nitrate with calcium sulfite in a steel tin. The sodium nitrate was made by combining aqueous solutions of
Mg(NO3)2 (store bought as a plant nutrient) and Na2CO3 (made by heating bicarb soda to decomposition over a stove) and filtering off the MgCO3 (or was
Mn(NO3)2 used? This was a long time ago). The CaSO3 was made by combining aqueous solutions of sodium metabisulfite (beer brewing sanitiser) and
calcium chloride dihydrate (from a beer brewing company, but can be bought as ‘DampRid’) and filtering off the CaSO3 precipitate. For roasting, I
assumed the formula CaSO3.3H2O for calculating the mass needed to reduce NaNO3, and used a 1.2 molar excess of sulfite I believe. The NaNO2 was
purified by leaching from the roasted mass, followed by a series of evaporations and filtration to remove calcium salts. The sodium nitrite that this
method afforded is still sitting on my shelf, and makes brown fumes when conc HCl is added; I haven’t assessed the purity of the material
quantitatively.
There was a paper I read or research that lead me to believe that this would work, and I have detailed notes on performing this experiment if anyone
is interested. I also have pure NaNO2 from a chemical supply company which I could use to test how pure this material is if anyone is interested.
All materials were easily accessible and purchased locally in Australia.
Converting NaHCO3 to Na2CO3 was done because bicarbonates of alkaline earth metals (or Mg in this case, I think) aren’t particularly stable and will
decompose at room temp in aqueous conditions to form the carbonate, causing effervescence upon addition of NaHCO3 to Mg(NO3)2.
I assumed 3 waters of hydration for the CaSO3 because I think that was most stable and most likely to form in aqueous conditions at room temperature
(I think).
The CaSO3 precipitate was made in a plastic bin, diluted heavily to aid filtration, then filtered through a sock, washed with several litres of water,
then filtered through kitchen paper and dried over anhydrous CaCl2 in a sealed container to avoid exposure to air.
The NaNO3 was heated until dry.
Roasting of the nitrate and sulfite was performed in a steel milo tin in a fireplace, heating the mass to a dull red glow for 20 hours or so.
Na2S2O5 + H2O <—> 2NaHSO3(aq)
2NaHSO3(aq) + CaCl2.2H2O(aq) —> 2NaCl(aq) + CaSO3.3H2O(s)
2NaHCO3(s) —heat—> Na2CO3(s) + H2O(g) + CO2(g)
Na2CO3(aq) + Mg(NO3)2(aq) —> MgCO3(s) + 2NaNO3(aq)
NaNO3(s) + CaSO3.3H2O(s) —heat—> NaNO2(s) + CaSO4.xH2O + (3-x)H2O(g)
Li
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Merryp
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yup, thank you.
quite elaborate, but very informative!
Do you happen to have an idea regarding the reduction in solution via hydrogen?
Assuming NH4OH + Zinc works, I'd guess that NaOH + Al should do the job as well, right?
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rockyit98
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you don't need reducing agents at all just need to heat it long enough.
The thermal decomposition of sodium nitrate
2NaNO3 → 2NaNO2 + O2
The thermal decomposition of sodium nitrate to produce sodium nitrite and oxygen. This reaction takes place at a temperature of 380-500°C.
Impurities: sodium oxide Na2O, nitrogen dioxide NO2.
no cleanup afterwards.
but when i need NaNO2
concentrated nitric
Cu + 4HNO3 → Cu(NO3)2 + 2NO2 + 2H2O
dilute acid
3 Cu + 8 HNO3 --> 3 Cu(NO3)2 + 2 NO + 4 H2O
bubbling con.acid exhaust to cold water and adding Na2CO3 or NaOH (cooling the reaction will produce NO and at the end of the reaction it will because
dilution)
NO2 + NO + 2NaOH → 2NaNO2 + H2O
try this
[Edited on 5-10-2019 by rockyit98] something is wrong can't upload the file.
[Edited on 5-10-2019 by rockyit98]
"A mind is a terrible thing to lose"-Meisner
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Boffis
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In the days before you could buy it OTC in the UK I used to prepare sodium nitrite by reducing molten sodium nitrate with molten lead. Sounds complex
but its easy to do if you can heat a reasonably large crucible and the lead oxide is easily separated.
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Merryp
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| Quote: Originally posted by rockyit98 | you don't need reducing agents at all just need to heat it long enough.
The thermal decomposition of sodium nitrate
2NaNO3 → 2NaNO2 + O2 |
The equilibrium isn't favourable to nitrite, though. NO2 ions are less stable than NO3. You'd end up with sodium oxide at high temperature, or a
reaction back to nitrate at low temperature.
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