Sciencemadness Discussion Board

Recycling H2SO4

underground - 4-8-2018 at 21:20

I was wondering if it is possible to recycle and use again any leftover h2so4 after a nitration. If AN would be used as a nitrated salt, while you concentrating it, ammonium nitrate/sulphate will decompose together with any leftover nitric acid remaining only h2so4 right?

[Edited on 5-8-2018 by underground]

OneEyedPyro - 4-8-2018 at 23:36

I thinkthe sulfate could really only be removed by distillation.

happyfooddance - 4-8-2018 at 23:57

Quote: Originally posted by OneEyedPyro  
I thinkthe sulfate could really only be removed by distillation.


Mmmm, I am not 100% certain but I think if ammonium is the cation the sulfate should decompose at boiling temps.

OneEyedPyro - 5-8-2018 at 22:46

You're probably right. Ammonium sulfate should basically decompose into ammonia and sulfur dioxide at those temps, but I'm not sure though either.

Microtek - 15-8-2018 at 22:13

I would distil at reduced pressure, and then possibly fortify by running it through an SO3 absorber (mostly because I've recently made one; simply distilling it would be fine for most purposes).

underground - 16-8-2018 at 00:02

I dont have the equipment to vacume distil it, i just want to keep everything simple. Ammonium sulphate decomp temp is close to the boiling point of h2so4. I believe even if you are going to use concentrated h2so4 with added AS for any nitration, the additional AS wont contribute to any reduction of the final yields.

[Edited on 16-8-2018 by underground]

Microtek - 16-8-2018 at 22:01

So what is it that you propose to do? Simply boil down the mixture of SA, NA, NH4HSO4, (NH4)2SO4 and AN (and remains of whatever has been nitrated) that is left over from some nitration reaction? Do you have a glass distillation apparatus (even if it is not practical to pull a vacuum on it)? The fumes that come off that operation will be extremely corrosive and toxic.

Sulaiman - 17-8-2018 at 05:58

Quote: Originally posted by Microtek  
... an SO3 absorber (mostly because I've recently made one ...


Details, notes or video available ?

underground - 17-8-2018 at 06:20

Quote: Originally posted by Microtek  
So what is it that you propose to do? Simply boil down the mixture of SA, NA, NH4HSO4, (NH4)2SO4 and AN (and remains of whatever has been nitrated) that is left over from some nitration reaction? Do you have a glass distillation apparatus (even if it is not practical to pull a vacuum on it)? The fumes that come off that operation will be extremely corrosive and toxic.


I dont have the apparatus but i am doing it outdoors and i am really away

Microtek - 20-8-2018 at 22:46

@ Sulaiman:

I posted a thread in Technochemistry about it:

Contact process

@ Underground:

I really think you should invest in some glassware (it costs next to nothing on ebay), at least a distillation setup. This would allow you to produce pure fuming nitric acid, which works much better than nitrate + sulfuric acid.
But if that is out of the question, then go ahead and boil down your sulfuric acid waste. Just be aware of the drawbacks:

- The acid won't be pure, as some amount of salts will remain.
- You will lose some of the sulfuric acid to evaporation, even though you may operate below the boiling point.
- The fumes will be toxic corrosive, lacrymatory and very noticeable (by both sight and smell/choking sensation)
- If there are remains of the nitrated substance in the waste acids (and there usually will be), you may get flashing or even proper explosions as you heat it.