Sciencemadness Discussion Board - Ammonium nitrate to ammonium sulfate

Ammonium nitrate to ammonium sulfate

johncena - 5-2-2016 at 02:52

Hi everyone! Is it possible to make ammonium sulfate from ammonium nitrate? If so, how? I need it as a further precursor to sodium bisulfate. I KNOW that the bisulfate is readily available and can be easily bought online, but in my country it's A REAL PAIN to find chemicals like it! I really have a bunch of ammonium nitrate, so that's why I'm asking for.

P.S. Please do not involve sulfuric acid! I'm actually making the bisulfate as a substitute for the acid.

[Edited on 5-2-2016 by johncena]

Detonationology - 5-2-2016 at 07:00

Almost all preparations that I am familiar with include the use of sulfuric acid. Sulfates and bisulfates are difficult to make and are difficult to ensure the purity because of the equilibrium. Yes, bisulfate salts are the probably the more favorable product, but sulfate salts will also be produced.

hissingnoise - 5-2-2016 at 09:05

Quote:

I KNOW that the bisulfate is readily available and can be easily bought online, but in my country it's A REAL PAIN to find chemicals like it!

The only contact some of us have with that particular salt is when we're 'fucking and blinding' about how hard it is to wash out of our RBFs after distilling HNO₃!

ave369 - 5-2-2016 at 22:58

Don't they use lead and acid car batteries in your country? If so, you can always buy the Bat - battery acid, which is 36% sulfuric acid.

johncena - 6-2-2016 at 01:41

Quote: Originally posted by ave369

Don't they use lead and acid car batteries in your country? If so, you can always buy the Bat - battery acid, which is 36% sulfuric acid.

Yeah, I already concentrated sulfuric acid from a car battery, however, the yield is quite low. I'm planning to make various experiments and acids with it, so this is very little compared to my needs. The bisulfate has similar properties with the acid and I think it can be made in bigger quantities. Sadly, there aren't any shops and markets where I can buy the chemicals I need, so I have to start from scratch.

deltaH - 6-2-2016 at 02:23

I like these kinds of problems, but this one is tough!

I assume you can source a gypsum-based white wall plaster or 'Plaster of Paris' in your country? That's calcium sulfate hemihydrate and a cheap OTC source of sulfate. Now according to wikipedia data numbers, calcium oxalate is 300 times less soluble than calcium sulfate, so you MIGHT be able to affect a metathesis.

The equilibrium is not that great, so you would need to pass a solution of oxalic acid through a column packed with gypsum power and a dilute solution of sulfuric acid should elute from the bottom, which you can concentrate further by boiling.

Oxalic acid is available in some countries as a wood preservative or something like that, my hardware store used to sell 500g packets of it, then again, most chemicals are readily available here, so that doesn't mean much

I suggest you hydrate the plaster first (i.e. mix with water and let it 'set' hard), then grind that solid to a powder and fill up a column with that, else when you pour the oxalic acid solution at the top, it might well cake up and stop eluting. That might happen anyway :mad:

Anyway, this is all speculation and potentially very dangerous, just some hypothetical thoughts for potentially new routes to sulfuric acid.

ASIDE: For those in the know, what I am thinking of here is analogous to eluting sodium hydroxide from a column packed with lime using a solution of washing soda, exploiting the insolubility of calcium carbonate, despite the lime being moderately insoluble (but much less so than the carbonate).

Once you have a fairly conc. sulfuric acid, you can then mix it with ammonium nitrate and distil off nitric acid and leave behind a residue of ammonium bisulfate.

A word of caution, conc. sulfuric acid and oxalic acid react to form carbon monoxide (extremely toxic), but I don't think this happens in dilute solutions, but be prepared that it might and work in a FUME CUPBOARD!

This certainly might happen if there is any residual oxalic acid and you boil down the solution to concentrate the sulfuric acid.

[Edited on 6-2-2016 by deltaH]

j_sum1 - 6-2-2016 at 03:32

Good thinking delta.

I think if you were to exploit the properties of oxalic acid, magnesium sulfate would be a better sulfate source.
Add solutions of oxalic acid and epsom salt and magnesium sulfate will precipitate. Leaving dilute sulfuric acid behind. ( Make OA the excess reagent.)
Concentrate your acid and then react with ammonium sulfate as deltah described.

deltaH - 6-2-2016 at 05:03

Quote: Originally posted by j_sum1

Good thinking delta.

I think if you were to exploit the properties of oxalic acid, magnesium sulfate would be a better sulfate source.
Add solutions of oxalic acid and epsom salt and magnesium sulfate will precipitate. Leaving dilute sulfuric acid behind. ( Make OA the excess reagent.)
Concentrate your acid and then react with ammonium sulfate as deltah described.

YES, nice one j_sum! Epsom salts (magnesium sulfate) is sometimes sold as bath salts.

[Edited on 6-2-2016 by deltaH]

j_sum1 - 6-2-2016 at 05:23

Hey. It's not my idea. I read it here somewhere.
I had a play with it myself but decided that the H2SO4 produced was both more dilute and more expensive than the methods I currently use. I think it might be worth a revisit at some stage though.

It is better to have oxalic acid as the excess reagent because any that remains decomposes when boiling down the sulfuric acid. The same cannot be said for MgSO4 remaining in your solution. Be aware that the dilute acid will contain 0.38 g/100mL of dissolved magnesium oxalate also which is not trivial. But I think this will also decompose -- probably to MgO which will precipitate as the acid is concentrated.

For the record, my method for H2SO4 is also OTC -- I electrolyse copper sulfate in a plastic jam jar. I am yet to experiment with MnSO4 electrolysis. I think this results in MnO2 being produced -- which I could then recycle. Passing SO2 through it (burning garden sulfur) converts it to MnSO4 again. (Nurdrage shows a method.)

Anyway, there are a few methods for sulfuric acid which you can react with ammonium nitrate to give your ammonium sulfate. Pick one that matches what you have available.

I must confess that I find this a strange problem. Where I live, ammonium sulfate is way ease to obtain than ammonium nitrate.

johncena - 6-2-2016 at 07:44

Thanks for the ideas, guys! I opted to use the electrolysis of copper sulfate method, but it yieled very little ammounts of conc. acid (I used quite a bit of the sulfate fyi).
As for the oxalic acid method, I like this one. However, the oxalic acid is extremely rare in my country and this is again impossible.

deltaH - 6-2-2016 at 08:06

Emmigrate... just kidding!

The funny thing is that oxalic acid can be made from the oxidation of sugar with nitric acid according to wikipidia, but requires a vanadium pentoxide catalyst... but overall that would constitute the most complex (and impractical) process for making ammonium bisulfate I have EVER heard off, but it's cute:

(i)calcium sulfate + oxalic acid[from step (iii)] => calcium oxalate + sulfuric acid
(ii) sulfuric acid + ammonium nitrate => ammonium bisulfate + nitric acid
(iii) nitric acid + sugar => oxalic acid [to step (i)]

Chemistry equivalent of a Rube Goldberg machine, sorry I couldn't come up with anything practical and simple :mad:

j_sum1 - 6-2-2016 at 16:32

Quote: Originally posted by johncena

Thanks for the ideas, guys! I opted to use the electrolysis of copper sulfate method, but it yieled very little ammounts of conc. acid (I used quite a bit of the sulfate fyi).
As for the oxalic acid method, I like this one. However, the oxalic acid is extremely rare in my country and this is again impossible.

My method for copper sulfate electrolysis.
50-100g of CuSO4.5H2O dissolved in about 200mL of water. Cathode is a piece of copper wire. Anode is a strip of lead flashing. I run approximately 0.5 amps through it for roughly 24 hours. (I always do a calculation to set the time and current appropriately.) It pays to overcook the electrolysis by 10-15% to get rid of the last Cu2+ ions. Otherwise the H2SO4 is green when boiled down.
It doesn't produce a lot. 50g of copper sulfate yields only a couple of mL of concentrated acid. But even at the low amperages and low concentrations of CuSO4 that I use, I can put through a run every 24 hours and it doesn't take too long before I have quite a bit to boil down.