Sciencemadness Discussion Board

Ammonium Nitrate

MagicJigPipe - 7-4-2008 at 10:00

I called some local fertilizer suppliers in hopes of finding some ammonium nitrate in a decent quantity (i.e. A 50lb bag that would basically last me forever). Ammonium nitrate is no longer sold in my area in anything but "ton amounts to authorized purchasers". Most of them said, "you're not going to be able to find any of that around". Only one mentioned the large quantity purchases being allowed. Obviously, no more 50lb bags here.

A few of them had "calcium ammonium nitrate" and they said that was the closest I was going to get to NH4NO3. What's funny is, most didn't even know what potassium nitrate was.

Surely this calcium ammonium nitrate can be used to make HNO3. But it really doesn't sound to practical to convert other nitrates to NH4NO3 through nitric acid.

Damnit this sucks. I should have ordered that 50lb bag off that trinitylabs site when it was still up. SHIT!

ScienceGeek - 7-4-2008 at 10:40

Don't you guys have instant cold packs in the US? If yes, they can't be that expensive...?

MagicJigPipe - 7-4-2008 at 10:52

They are VERY expensive for how much NH4NO3 you get out of them. Something like $3 for 25-100 grams. That's $300 for 2.5-10kg. THAT SUCKS. I suppose you have to do what you have to do, though.

Potassium nitrate is cheaper than that here. Even at pharmacies it is $2.75 per 170g.

Apparently trinitylabs still carries it but check this shit out:

AMMONIUM NITRATE PRILLED 5 LBS.....$29.17
AMMONIUM NITRATE PRILLED 25 LBS.....$99.12
AMMONIUM NITRATE 50 LBS PRILLED......$198.24

Still pretty damn expensive. Not to mention the probably outrageous shipping fees.

[Edited on 7-4-2008 by MagicJigPipe]

ScienceGeek - 7-4-2008 at 10:55

That is quite expensive.

But the KNO3...to give it some perspective: here in Norway, 90g of KNO3 at the pharmacy is approx. the equivalent of $20.

microcosmicus - 7-4-2008 at 11:38

Quote:

Don't you guys have instant cold packs in the US? If yes, they can't be that expensive...?


Yes, but, as I understand it, nowadays many of them are filled with urea.
Since cold packs typically don't state their ingredients, one could be on
a wild goose chase buying different types and testing their contents.

With those prices and availability, it looks like a scaled down Ostwald process
may be worth considering . . .

http://www.physicsdaily.com/physics/Ostwald_process

evil_lurker - 7-4-2008 at 11:47

How much ya want?

Pleny of fertilizer dealers around here sell it.

Apparenlty the folks round here got more common sense than they do fear of terrorism.

[Edited on 7-4-2008 by evil_lurker]

Pulverulescent - 7-4-2008 at 11:47

Quote:
Originally posted by MagicJigPipe
What's funny is, most didn't even know what potassium nitrate was.
Surely this calcium ammonium nitrate can be used to make HNO3!


If you'd said Nitre or Saltpeter they might have twigged!
I have calcium ammonium nitrate, or C.A.N. as it's called here.
It's cheap, too!

I dissolve it in water, a few pounds at a time.
When the clay(?) settles it can be decanted, or filtered if you're in a hurry.
The NH4N03 isn't very pure (various phenolics?) but crystallised from a cooled saturated solution it's not bad!

If its solution is evaporated a cream-coloured cake is left, which if heated to its decomp temp will slowly whiten to something like packed snow; reasonably pure.

Just don't inhale the fumes!!!

Oh, and careful heating is advised!

Alkali-nitrates are best for HN03; hot concentrated H2S04 is a good enough oxidiser to oxidise NH4N03 to N2 + H2O.
The distillation will start OK but when the temp approaches 120*C your HN03 will be seriously diluted.

Eventually only water and N2 will come over!

To get other nitrates you could try metathesis with a K or Na salt, but check solubilities so you'll know which precipitates first.

P

kilowatt - 7-4-2008 at 11:51

It's the same deal here; you can't buy it in bags, period. I had the good fortune of having a friend in Florida who made the 2000 mile road trip up here once, and he brought me 3 50lb bags, but I still feel like I don't have enough to last a lifetime. It seems ironic, but there in Florida where they have some of the strictest laws and crackdowns in the country, you can still buy it at feed stores. Some day I may have to make my own from scratch via calcium nitride or urea and Ostwald processes. Maybe someone here who can still buy it would be willing to ship you some, but like anything I wouldn't expect it to be available to the public anywhere for long (of course you know this as well as I, where most people don't seem to realize the severity of the problem). You've simply either got to buy it from a willing farmer or other individual who can still get it, or make your own.

Converting calcium ammonium nitrate to ammonium nitrate via nitric acid and ammonia wouldn't be too bad really. You wouldn't need anything fancy, since just the wet ammonia and raw wet nitric you'd get out would work fine for making ammonium nitrate. The biggest expense would be the alkali and the sulfuric acid needed to do that, but it beats the hell out of $200 plus shipping don't you think? Maybe you could even use an electrolytic process with addition of ammonia and precipitation of calcium hydroxide off the cathode to convert it more directly and cheaply (at the expense of time no doubt). Beyond that the Ostwald process would be my only other suggestion, and it should not be too hard (just really slow) if you get yourself an old catalytic converter.

[Edited on 7-4-2008 by kilowatt]

Xenoid - 7-4-2008 at 12:13

Around here, Calcium Ammonium Nitrate (CAN) is about a 20% blend of Calcium Carbonate (limestone) with ammonium nitrate. I bought a 25Kg bag as a source of ammonium nitrate. The carbonate is easily separated by dissolution and filtering. The big drawback is getting the ammonium nitrate out of solution and in a dry form. If you just want it for nitrate metathesis reactions (like I did) it's fine!

It's mentioned in several threads on this site, or Google "CAN".

smuv - 7-4-2008 at 12:16

Sodium and i believe calcium nitrate can be bought unsuspiciously from pottery suppliers. Even if you can't find a well stocked store in your area, combined with a few other useful reagents, the cost of shipping should be worth it.

kilowatt - 7-4-2008 at 12:17

Oh, well that makes it easy then. Ammonium nitrate is not that hard to dry either, again just time consuming. I have recrystallized some of my AN fertilizer before just to make it more pure. It does not form any hydrates as far as I know. Are you just referring to the tedium of boiling off the water?

NH4NO3

MadHatter - 7-4-2008 at 12:27

Ca(NO3)2 + (NH4)2SO4 --> 2NH4NO3 + CaSO4

Both readily available and cheap at the local agricultural supply where I live.

The CaSO4 precipitates out instantly. Filtering can be a pain but it can be done.

Pulverulescent - 7-4-2008 at 13:55

Once, when I needed some NH4Cl, I mixed AN and ordinary granular table-salt (stoichiometrically) in a metal dish and heated the mixture.

NH4Cl sublimed from the mix, condensing on a large cold glass parabola over the dish in high purity.

Had the stuff been finely ground and well mixed, it would probably have gone all the way to NaN03, with all the NH4Cl on the glass.

Temperature control might be needed to prevent reduction of the nitrate to nitrite!
Careful slow heating is called for, in any case.

P

MagicJigPipe - 7-4-2008 at 14:06

Quote:
Originally posted by MadHatter
Ca(NO3)2 + (NH4)2SO4 --> 2NH4NO3 + CaSO4

Both readily available and cheap at the local agricultural supply where I live.

The CaSO4 precipitates out instantly. Filtering can be a pain but it can be done.


I'm sure I can find some calcium nitrate, too. It's twice the nitrate per mole (compared to NH4NO3), as well!

Have you tried this MadHatter? If so, is there any more you can tell me before I try?

I found this info on "CAN" while searching google.
Quote:

CAN contains 27% nitrogen and 8% Calcium as Calcium Carbonate (lime). It consists of dust-free, white free-flowing granules.


Quote:

Calcium ammonium nitrate (CAN) contains 27 % N and 20 % of ground limestone. Nitrogen is half in the nitrate form and half in the ammoniacal form. This results in rapid as well as permanent effect. The granulation of this fertilizer ensures a quick and exact dosing.
Quote:

Calcium Ammonium Nitrate (CAN 17) is a versatile fertilizer that contains 8.8% calcium and 17% nitrogen. The nitrogen is one-third ammonic form and two-thirds nitrate form. CAN 17's largest market currently is among California and Arizona vegetable growers, although that is changing as growers in the Pacific Northwest discover the advantages of offering both an available and a reserve form of nitrogen in addition to soluble calcium


Is this really just a calcium salt and Ammon. Nitrate mixed together? Does the compound 5Ca(NO3)2.NH4NO3.10H2O actually exist? If so, is that what CAN is? I suppose what I am asking is-- what is it exactly?

[Edited on 7-4-2008 by MagicJigPipe]

Zinc - 7-4-2008 at 14:19

How do you dry ammonium nitrate? I put it in the oven (slightly open to allow water to escape) and heat it to around 120-150 C (it starts to smoke heavily if overheated) for some hours. Then I pour it from the dish on some Al foil. When it cools I break it up and dry it for an hour or two with a hot air blower. I noticed that my ammonium nitrate melts at a lower temperature than it should. And when heated with the hot air blower it doesn't melt but still some smoke is produced (smells the same as when AN decomposes). Well it contains some magnesium nitrate (around 5%). Perhaps that is the reason?

MagicJigPipe - 7-4-2008 at 14:25

If it melts before it's supposed yo that usually means it's hydrated but since NH4NO3 doesn't complex with water I'm not sure what your prob is.

Zinc - 7-4-2008 at 14:33

Well it is possible that it is hydrated but I don't think so as it worked great in APAN, MEKPAP/AN and various pyrotechnic mixtures.

microcosmicus - 7-4-2008 at 14:42

It seems that there is indeed such a double salt, which has its own CAS number (15245-12-2) :

http://ctd.mdibl.org/detail.go;jsessionid=2BCA76D75A8DF0BD7D...

http://www.bibra-information.co.uk/chemlist-C.html

However, it seems that the fertilizer may not be the double salt, but a
mixture of two salts according to our friends at Homeland Security:

http://64.233.169.104/search?q=cache:68Po-TIRUCoJ:www.fwaa.org/Hot_Topics/TFI-Memo1.pdf+%22calcium+ammonium+nitrate%22+%22double+salt%22&hl=en& ;ct=clnk&cd=5&gl=us&client=firefox-a

Basically, they can't figure out whether CAN fertilizer is a watched
chemical because their list only includes ammonium nitrate; presumably,
terrorists have no use for the double salt ;)

Aqua_Fortis_100% - 7-4-2008 at 14:46

Hello MagicJigPipe ,

I remember one time not_important saying that using this procedure (calcium nitrate + ammonium sulphate) will not give a very pure product since the Ca++ ions will tend to be more soluble in presence of ammonium ions..

Another idea from N.I. is that you can also mix (NH4)2SO4 and KNO3 solutions and cool well (K2SO4 is the least soluble), remaining NH4NO3 that is easily further purified..

not_important - 7-4-2008 at 14:53

CAN-17 is a solution of calcium and ammonium nitrates
http://www.simplot.com/agricultural/plant/cal_ammon_nitrate....

CAN in solid form usually is CaCO3 + NH4NO3, from the EU:
Quote:
However, in practice, products containing limestone and/or dolomite and with nitrogen content <28% are designated as Calcium Ammonium Nitrate (CAN).

but check the spec sheet and MSDS on the specific product.

In the case of limestone + AN, solution in warm water quickly followed by filtration should give decent recovery. Too long of contact with hot water will drive off NH3 and CO2, leaving you with mixed nitrates.

Hot methanol should dissolved nitrates away from carbonates and sulfates.

If your raw materials lead you to precipitating CaSO4 from mixed nitrates, note that CaSO4 is slightly soluble in water and more so in solutions of ammonium salts or mineral acids. The later causes a little trouble when making HNO3 from H2SO4 and Ca(NO3)2. For making AN, the filtered solution can be treated with ammonium carbonate to precipitate much of the calcium as CaCO3. Alternatively the solution can be evaporated on a water or steam bath, then the AN can be extracted with methanol; if you do this use a slight excess of ammonium sulfate as calcium nitrate is also soluble in methanol.

Calcium and magnesium nitrates are fairly hygroscopic, in attempting to take them to dryness you can end up with a mush formed from melted hydrates of the nitrates. Mixed ammonium+(calcium,magnesium) nitrates do not dry well, as the Ca/Mg nitrates tend to 'melt' in their own water of crystallisation, so the product always is moise appearing. Even if you get a mixed ammonium+(calcium,magnesium) nitrate dry, it readily picks up moisture again.

table of solubility of CaSO4 in various water+acid mixtures here:
http://www.sciencemadness.org/talk/viewthread.php?tid=9848&a...

Calcium Nitrate

MadHatter - 8-4-2008 at 11:21

The calcium nitrate I use is the mixed NH4NO3/Ca(NO3)2. The trick is to precipitate and
filter the CaSO4 as much as possible. NH4NO3 is highly soluble even in cold water.
I can't find the solubility curves for CaSO4 in ammonium salt solutions.

One other thing: That mixed Ca(NO3)2 is usually coated with wax for time release.
So I put it in a filter and pour ice water through to leave the wax behind before proceeding.
Don't use hot water for that step. The wax gets soft and clogs the damn filter.

Zinc - 8-4-2008 at 13:15

I have a problem. My AN starts to smoke heavily when I dry it before it melts. The smoke is white, thick and has the smell of decomposing AN but AN doesn't decompose on such a low temperature. I heat it at around 80 C. It does contain around 5% of (MgNO3)2. Does anyone know why it smokes like that?

MagicJigPipe - 8-4-2008 at 13:56

Does NH4NO3 sublime readily at elevated temperatures? I always thought it started to decompose a little below it's melting point.

not_important - 8-4-2008 at 16:40

Any organics or transition metal nitrates could be accelerating the decomposition. It likely is best to attempt to crystallise the AN, remembering that in crystallisation you are not going to get 100% of the substance - you must leave liquid. Filter off and drain the crystals, dry them at low heat - 40 C or so. If they don't go dry then it is magnesium salts causing the problem, you'll have to remove the Mg by precipitation with ammonium carbonate or strong aqueous ammonia.

Attached is a PDF that contains just an image file, showing solubility of CaSO4 in the presence of several ammonium salts. Ammonium nitrate can increase the solubility as much as 5 times, with means a gram of CaSO4 in 100 cc of liquid.

Attachment: CaSO4_sol_ammonium.pdf (93kB)
This file has been downloaded 861 times

len1 - 15-4-2008 at 06:32

Yes we discussed this before, the thing is that the sulphate has the equilibrium

SO4- + H+ -> HSO4-

and this means CaSO4 is going to be more soluble in acidic solutions.

Ammonium salts tend to be acidic, hence calcium sulphate dissolve more readily in them. If you make the solution basic by adding ammonia - that aspect of the problem will solve, and the NH3 will not contaminate the product

Sauron - 15-4-2008 at 07:45

You know, I have highly eclectic chemical interests and have been at this for a long time - like 45 years. And very rarely have I ever felt deprived because I didn't have ammonium nitrate.

Now don't get me wrong. I fully agree that any of us who wants AN ought to be able to have it, and I am the last person to say nay to that. But apart from my abortive foray into blueing salts 20 years ago I have never felt the need to have a 25 Kg sack of AN sitting around.

The only chemical application that ever came up for me was the old route to guanidine nitrate, and that route is really passe, so no one needs AN for that. Axt has fully demonstrated the alternative OTC route that is safer and there is also commercially available guanidine carbonate.

So I would like to know just what other applications you guys have for AN that are so compelling? List them here please.

Furthermore it seems to me that evil_lurker is right and AN's unavailability is a regional issue, not a national one (for now anyway) so you can buy it and transport it if you want it bad enough.

If you just need a few Kg then those $4 a lb prices look very friendly to me. Everything and I mean everything I buy is imported, and costs me an arm and a leg.

So what I am hearing is a lot of whingeing about how you can't get it LOCALLY and in 50 lb SACKS but you can still get it for $4/lb to $6 a lb and you can still get 50 lb sacks in other parts of the country and so one etc.

Lots of things I can't get alt all at any price and I must MAKE often at considerable trouble and expense.

Anyway back to basics. What do you need the AN for? Because as I said: I have rarely ever felt the slightest need for it. So I am very curious.

kilowatt - 15-4-2008 at 08:18

Are you kidding? AN is the one of the best sources of bulk ammonium and nitrate ions, two of the most versatile ions there are. I have used it as a ready source for making strong ammonia, metal nitrates (and thus nitric acid) and nitrous oxide, as a convenient cooling solution, and as a powerful oxidizer for solid rocket propellants. Those are just a few uses I have found in my relatively short time in chemistry, and was able think of right off the top of my head. Just because you don't use a particular chemical much doesn't mean it is useless for other chemists.

[Edited on 15-4-2008 by kilowatt]

Sauron - 15-4-2008 at 08:32

No I am not kidding. Because those metal nitrates you are talking about (Na, K, Ca) are generally a lot easier to acquire than AN. As Polverone pointed out you don't make HNO3 directly from AN anyway. And not everyoen has to make their own nitric acid, after all.

MJP the thread author is not to my knowledge into rocketry. Cooling baths? Yes but there are alternatives for those, plenty of them.

So how much N2O are we talking about?

In all my decades of chemistry there are only half a dozen or less chemicals I have bought in bulk.

Citric acid
Diammonium phosphate
Magnesium sulfate
TCCA
Dextrose
Bentonite
Diatomaceous earth

Most of those pertinent to fermentation of ethanol which I no longer do.

Kilowatt, I did not say I think you shouldn't have it or be able to get it. I am just wondering why you want to. Is this hoarding against a perceived absence of it from the market?

[Edited on 15-4-2008 by Sauron]

kilowatt - 15-4-2008 at 09:23

For many of us who have trouble buying the chemicals that are easily derived from AN, AN is the best way to get them. Buying nitric acid or metal nitrates is not as easy for some of us as it is for you, myself included, not to mention they are much more expensive in my experience. That's really what it comes down to for me. Cost really is the biggest factor for some of us. And yes, it is a good idea to stock up on chemicals that may soon be more unavailable to the public. That way, when you can't get them anymore, you are still able to use them for some time.

Utilizing AN as a nitrous oxide source (for running a nitriding burner, chemical syntheses, etc) is, for me, a heck of a lot cheaper than leasing a cylinder of the gas and getting it refilled, too. This is only the case for small amounts as the decomposition becomes too dangerously exothermic in bulk quantity, but I can't see myself ever needing a large flow of nitrous oxide. We all have our different chemicals that are easier or harder to get depending on region and circumstances. We have covered AN and many alternatives, which is good.

[Edited on 15-4-2008 by kilowatt]

Sauron - 15-4-2008 at 10:21

The third source for N2O is the small capsules/cartridges sold in restaurant supply shops for whipped cream dispensers. These look just like CO2 cartridges for BB and pellet pistols. No drayage on these, they are disposable, and no hazard from heating the AN to dryness.

MagicJigPipe - 15-4-2008 at 19:41

Oh yeah, I remember buying a bunch of those at a head shop when I was younger. They sell these things to open them then you put it in a balloon and breathe it in. It was fun but not enough for me to do it more than once. The "hangover" was almost as bad as from alchohol. Extreme fatique. Profuse sweating. Dysphoria.

Not something I would reccomend doing on more than an occasional basis.

I've often pondered if N2O could be useful in the lab since it's OTC and readily available but I haven't found anything extremely interesting to do with it.

Anyway, I don't really need a 50lb bag of ammonium nitrate, I really don't NEED any. I just thought that maybe one day I will find it interesting and will not be able to obtain it. So, I thought I might as well get as much as I can right now if it's cheap enough. Yes, I can make it but it would just be easier to buy it now rather than make it later.

Only thing I find very interesting about it is it's explosive properties. I'm not entirely disinterested in energetics.

Really, I have to admit it has a certain allure because of it's status as a big "no, no". Maybe subconsciously I want it just because of it's bad press. You know, when you tell a kid that something is bad and they do it just because they know it's bad.

That's why I want to find it cheap (or an easy way to make it). Because I don't really need it.

Was that confusing and complex enough for you? Haha!

Pulverulescent - 16-4-2008 at 02:01

It's a kind of status-symbol for mad scientists!

P

Ammoniun Nitrate

dshively2 - 26-1-2013 at 15:41

If you go to www.lastmanstandingtargets.com and use the coupon code NHbulkDiscount you can get 50lbs of ammonium nitrate for 109.99!