7 replies to this topic

[jcow]

i have a large amount of ammonium nitrate and i was wondering if it is possible to make poassium nitrate from it. it is mentioned on the 'ammonpulver' thread that potassium nitrate can be made from ammonium nitrate and potassium carbonate. is this possible? how would it be done?

i currently only have access to sodium chlorate and potassium permanganate so advice would be appreciated.

Edited by jcow, 20 February 2006 - 07:01 PM.

[JamesH]

i have a large amount of ammonium nitrate and i was wondering if it is possible to make poassium nitrate from it. it is mentioned on the 'ammonpulver' thread that potassium nitrate can be made from ammonium nitrate and potassium carbonate. is this possible? how would it be done?

i currently only have access to sodium chlorate and potassium permanganate so advice would be appreciated.

Under no circumstances should you attempt to mix sodium chlorate with ammonium nitrate as ammonium chlorate will be formed, which is a highly unstable explosive compound which is liable to explode without provocation, even in solution according to shimizu.
Neither should you ever mix potassium permanganate with ammonium nitrate as ammonium permanganate will be a reaction product which is also a highly unstable explosive compound. Such an admixture is liable to spontaneous combustion.

Lucky you asked for advice! I'd hate to imagine what could have happened if you had mixed any of those two chemicals with ammonium nitrate!

To answer your question, potassium nitrate can be produced by the reaction of ammonium nitrate with potassium carbonate or chloride.
You need to make super-saturated solutions of the two salts in a stoicheometric ratio then combine them.
Then you will have to crystalize and recrystalize the resulting solution to remove the byproduct, ammonium chloride, if potassium chloride was used as the potassium reagent. If you used potassium carbonate as the potassium reagent the resulting byproduct, ammonium carbonate, can be removed from the solution by boiling. The action of boiling will decompose the ammonium carbonate into ammonia gas and carbon dioxide. A final recrystalization will ensure a fairly high purity potassium nitrate.

However, potassium nitrate can be purchased relatively easily and cheaply so the above process is hardly worth the effort in my opinion.

Glad to have been any assistance.

Edited by JamesH, 20 February 2006 - 08:52 PM.

[jcow]

Sorry, i didnt mean mix the chlorate with the ammonium nitrate!
I was just saying that i only have chlorate and permanganate for making pyrotechnic devices.

Thanks for the advice, google searches returned no useful results.I can get potassium nitrate,but i just always wondered if there was a use for ammonium nitrate apart from high e*plosives. i have tried making black powder with it, but it just froths up into a mess with loads of smoke.

lo-salt is 66% potassium chloride 33% sodium chlorite, i assume if i use this i would get a mixture of sodium nitrate and potassium nitrate. this could then be fractionally crystalised.
i think wood ash is a potassium compound but i'm not sure if its carbonate.

Edited by jcow, 21 February 2006 - 04:17 PM.

[Mumbles]

Wood ash is primarily K2CO3. There is however some insoluble calcium. You you added the ashes to water, filtered, and boiled off the water you would get mostly pure Potassium Carbonate. Another possibility is looking for "Potash" fertilizer. It should be fairly pure K2CO3. Check the label, I got screwed and got KCl by mistake. It was labled "Potash", but on the side it said it was derived from Muriate of Potash, which is KCl.

For pyrotechnic use, I suggest not using Lo-salt. You will never be able to get the sodium contamination out. Another possibility is getting KCl for water softeners. You may need to ask for it special. I don't remember what it is used for, but it is about US$6 for 55 pounds.

[jcow]

thanks,

I should be able to get large amounts of wood ash. I looked on google and I found this: http://cavemanchemis.../chpotash2.html If this is correct, then 1000lb beech wood only contains 0.9lb potassium carbonate, so i would need a lot of ash. I searched for the the term 'stoicheometric ratio' and it only returns info on car tuning! How could i work out the stoicheometric ratio for this rection? i have around 3kg ammonium nitrate to hand.

Edited by jcow, 22 February 2006 - 04:57 PM.

[Mumbles]

Yes, that is probably true. Wood is indeed mostly cellulose and other flammable things. 1-2% ash doesn't seem unreasonable. That is however .6% ash. I don't know much about beech wood, perhaps it burns unusually clean. Just have a bon fire and pick up the ashes. You actually amass quite a pile. If you have a charcoal grill, also a good source for ashes.

As far as the stoichiometric ratio thing, it helps to spell stoichiometric right first. Perhaps this will help your searching.

[EnigmaticBiker]

thanks,

I should be able to get large amounts of wood ash. I looked on google and I found this: http://cavemanchemis.../chpotash2.html If this is correct, then 1000lb beech wood only contains 0.9lb potassium carbonate, so i would need a lot of ash. I searched for the the term 'stoicheometric ratio' and it only returns info on car tuning! How could i work out the stoicheometric ratio for this rection? i have around 3kg ammonium nitrate to hand.

Try Searching for Potassium carbonate on this forum, someone may be selling

Potassium Carbonate would probably be the best salt for KNO3.

You could check out "Potash" fertiliser (not a blend) which is often crude Potassium Sulphate, obtained from rock.
I have cleaned K2SO4 for recrystallising salts, dissolve in hot water, filter (through fine cloth), filter again (through lab or paper coffee filter), boil until crystals appear in quantity, cool for a few hours, use a fine sieve to get clean crystals.
A lab reagent or technical grade would be far better.
You'll need to do some research. Double decomposition and fractional crystallisation of salts may not be obvious and I've not done that one with NH4NO3.

You might be able to get Sodium Nitrate (hygroscopic) by using Sodium Hydroxide (caustic soda) with NH4NO3, it should release ammonia vapour on boiling.

Read enough chemistry to understand what you are attempting.

[adamw]

Would you be confident that the end product was pure enough (free of any NH compounds)??

If you can get KNO3, which isn't exactly expensive... why bother to synthesise it? Use you ammonium nitrate for your garden!