HNO3 your way

[crazyboy25]

Impressive, I always heard under atmospheric pressure HNO3 decomposes and brainfevert took several hours to get a few ml's care to explain your method?

[tentacles]

I vacuum distill, and even under vacuum it comes out a bit yellow at first. I start with room temp acid and salt, though, could probably get white fuming if I froze the stuff first.. But for my uses, I don't bother. I don't see how you're getting white fuming with the brainfever method, on a coffee maker hotplate. Tell us your secrets! Edited September 30, 2008 by tentacles

[al93535]

I start with 202 grams of very pure KNO3. This gets milled to a fine powder. I place 175 mls of H2SO4 (room temp) into a beaker and add the KNO3 over about 90 seconds with stirring. This does generate heat, but thats what I want. I Let it fume for about 2 minutes while getting the rest of the set up together.

 

I use the hot plate from a coffee maker as the heat source. I use a 2 gallon pickle jar and I pour the mixed acids in. Next I place a tiny mason jar in the bottom upside down, I am unsure of the size, but its really small. I then put a pint mason jar right side up on top of that. Of course you can use beakers, but this is what I started out with years ago so I still use it. I place the entire set-up on the hotplate and get a gallon zip lock bag. I slice the bag from corner to corner. I place the corner as far in as I can without touching the mason. I run a rubber band around the mouth and bag to hold it in place. I fill it with ice water and adjust the bag so it JUST clears the lip of the jar inside, with the tip of the corner going farther into the inside jar. I think I get good results because of the high surface area for the acid to condense, AND because I always keep the bag full of ice water, (at least as often as i can).

 

This takes about 24 hours to get 120 mls. But what the hell, its easy, I replace the ice when I can, and I get a very good product. Its crystal clear and is very pure, especially if you dry the kno3, and boil your H2SO4. I just keep it going for a week and get quite a bit of acid. This goes SLOW... but whenyou add the distilled acid to some more sulfuric to redistill, it goes alot faster.

 

I ordered some high accuracy graduated transfer pipettes and a cylinders so I can test the density of the acid. I will report back when I get some numbers.

 

I can assure you, its PETN and RDX grade....

[jadesource]

I start with 202 grams of very pure KNO3. This gets milled to a fine powder. I place 175 mls of H2SO4 (room temp) into a beaker and add the KNO3 over about 90 seconds with stirring. This does generate heat, but thats what I want. I Let it fume for about 2 minutes while getting the rest of the set up together.

 

I use the hot plate from a coffee maker as the heat source. I use a 2 gallon pickle jar and I pour the mixed acids in. Next I place a tiny mason jar in the bottom upside down, I am unsure of the size, but its really small. I then put a pint mason jar right side up on top of that. Of course you can use beakers, but this is what I started out with years ago so I still use it. I place the entire set-up on the hotplate and get a gallon zip lock bag. I slice the bag from corner to corner. I place the corner as far in as I can without touching the mason. I run a rubber band around the mouth and bag to hold it in place. I fill it with ice water and adjust the bag so it JUST clears the lip of the jar inside, with the tip of the corner going farther into the inside jar. I think I get good results because of the high surface area for the acid to condense, AND because I always keep the bag full of ice water, (at least as often as i can).

 

This takes about 24 hours to get 120 mls. But what the hell, its easy, I replace the ice when I can, and I get a very good product. Its crystal clear and is very pure, especially if you dry the kno3, and boil your H2SO4. I just keep it going for a week and get quite a bit of acid. This goes SLOW... but whenyou add the distilled acid to some more sulfuric to redistill, it goes alot faster.

 

I ordered some high accuracy graduated transfer pipettes and a cylinders so I can test the density of the acid. I will report back when I get some numbers.

 

I can assure you, its PETN and RDX grade....

 

When your redistilling let me see if Im understanding your process you take the nitric out of your middle jar reset it up with new kn03 and new sulferic then you pour you first distilation into that mix and start the process again and by doing it twice your getting this kind of yield or are you saving up all your first yields then putting them back in by themselves Im confused but very interested. . Bill

[al93535]

To re-distill HNO3 you take your previously distilled acid and add it to 98% sulfuric acid. 1:2 ratio HNO3:H2SO4. Then distill that just like with the kno3 and sulfuric.

[jadesource]

My question would be, Im trying to do this all with the Rooto brand sulfuric. Other than the coloring which obviously has some bleed over as stated by others . Does it have to be the 98% to get a good re distillation and if the by product of using that lower grade material is a few % less of pure product can we live with that for most things. I have the 98% but only about 1/2 liter leftover from the good old days and my local Chem supplier basicly now doesnt stock shit, every thing i used to get just going there they now have to order and I can get it faster and sometimes cheaper shipped from the internet . Sad state of my local suppliers I would say. Bill

[tentacles]

jade: Why not just buy 98% drain cleaner sulfuric? Liquid lightning at walmart, or many others. It is *always* packaged in a bottle, with a plastic bag around the bottle, that's a pretty sure sign you've found the right stuff. I've never had bleed over from using the "blue shit" or the "Brown shit", but I use a proper distillation rig and vacuum distill.

[jadesource]

My friend I did not know that the drain cleaner could be had in 98% thank you for the heads up.

[jadesource]

Part of my problem with the bleed over comment was having read just a vast number of the posts in several sections, i thought that i had remembered someone posting about it. sorry If I misquoted. i usually end up here when its late and the old brain is not as fast as it used to be. thanks for the help

[tentacles]

No problem.. I think you'll find the results using the purer drain cleaner to be more than satisfactory for whatever your needs may be. My distillation rig supplies me with HNO3 that is honestly more pure than I'd like - 98-99% HNO3 is a PITA to store. My wife doesn't like having it in the freezer, and there's essentially no other option short of diluting it.. All I keep around is a little 100ml volumetric cylinder of the stuff, though. I use it for nitrate synthesis, making Pb(NO3)2 mostly. I've made a bit of silver nitrate too.

[jadesource]

Most of the Hno3 I deal with has been store bought and used mostly for mining assays but i went out the other day and checked my bottle it had been at least a year since I used it. i wanted to clean some mercury off some gold nuggets for a friend. I opened the bottle and had about a teaspoon left. It just evaporated right out of the bottle it was a little purer than it really needed to be but it was an outrages deal. My old time mining buddy laughed at me and said well you never sealed the top with wax did you. I guess when your 75 you can give us young guys half your age a load of crap. so i thought I would give this a try .He's still waiting for his gold to get cleaned. But I really just wanted to try the chemistry with the getto method of distillation with the way things are you never know when the powers that be might start to think we dont deserve to have access to those chems. Ok my old time mining buddy said I couldnt distill nitric without a bunch of expensive equipment. So in reality im just doing to prove him wrong but i need to get a bunch more work under my belt in chemistry there is no better teacher than hands on practice.

[a_bab]

My 5 cents (hope it wasn't mentioned before):

 

In order to concentrate the HNO3 there is the method of methylene chloride (dichloromethane), that is supposed to disolve the ure HNO3 (discussed on the E&W forum).

 

BUT I learned that magnesium nitrate, which is a very good dessicant, can be used for the same purpose. It doesn't dissolve in HNO3, and it works in the same way as calcium chloride for acetone. Moreover, the same system can work for other acids (magnesium perchlorate for perchloric acid (extremely DANGEROUS!); copper sulphate for sulphuric acid etc).

 

These coresponding hygroscopical salts are able to suck up the water all the way to 100% acid.

[Swede]

How about some of the commercially available molecular sieves to grab that nasty water and yank it from our mineral acids?

[tentacles]

I'd think the nitric acid would dissolve the sieves, they're just a specialized form of zeolite, aren't they?

 

a_bab: Very interesting idea with the dessicants! The copper sulfate doesn't dissolve in sulfuric acid?

 

Jade: That's why I keep my fuming stuff in the freezer. Also, I seal the ground glass stoppers with teflon tape. This is a *must*.

[crazyboy25]

Interesting but I have no way of getting anhydrous magnesium nitrate does anything else like anhydrous magnesium sulfate work? tentacles you mention you get 98%+ nitric acid what are you using as a vacuum source?

[tentacles]

crazy: A vacuum aspirator, I bought a cheap LDPE (might actualy be PP) one from ebay a while back.. There's info on it in this thread somewhere, I had to fabricate a nozzle for it, though. You can find them on ebay for cheap. I made a faucet adaptor for mine as well, but that's because I wasn't willing to spend Home Depot kind of money on one. I've only measured up to about 28" of vacuum through it, but that's certainly good enough. I haven't even bothered drying my H2SO4 or nitrate first, and the last batch came out about 99%. Granted, I did do it in the winter, and it's so dry up here that everything is dessicated just by the air. Anhydrous copper sulfate? Just put it on the counter for a week and you'll have those nice white crystals.

[crazyboy25]

Great! I have a vacuum aspirator from eBay. I tried to make a recirculating station with a 1/2 HP sump pump but it failed miserably I don't have a sink in my garage but I'm working on it so I'll do it then. I have distilled maybe 100ml yellowish nitric acid without vacuum (I plan to re distill with vacuum) I keep it in an amber bottle in the freezer it fumes quite a bit.

 

 

I was asking about anhydrous magnesium sulfate not copper sulfate and not about how to make it (I already have it) I was asking if it could be used to concentrate nitric acid to 98%.

[tentacles]

I'd check the solubilities of the sulfate vs the nitrate salt of magnesium, but I don't see why not. You can always "cook" the salt to dry it, and then dessicate with another (more durable if necessary) salt like calcium chloride.

 

I've considered making a recirc system for the aspirator, I have a pump at my parents' that would possibly work.. For every inch of vacuum you want the aspirator to pull (ideally at any rate) you need 1 psi of water pressure to develop that suction. So, realistically you need a 30 to 60 PSI capable pump at the flow rate you'll be gushing through.. Me, I use tap water since it's paid for with our rent. Yes, I'm a bastard, but I don't want to have a damned pool pump running while I distill nitric, which isn't very often anyways.

[a_bab]

I'm afraid that only magnesium nitrate will work for concentrating ntric acid, and copper sulphate dissolves in sulphuric acid; so may be the epsom salt in nitric acid.

 

Why not making the magnesium nitrate straight from nitric acid/magnesium for the ones with access to magnesium metal.

 

More of an OTC method would be:

 

1. Epsom salt + carbonate of soda will get you with the insoluble magnesium carbonate and sodium sulphate that can be washed out

2Na(CO3)2 + MgSO4--->Na(SO4)2 + MgCO3

(Unless magnesium carbonate can be obtainable OTC)

 

2. Ammonium nitrate can be boiled with Mg carbonate to get the Mg(NO3)2 along with lots of foaming and stench (ammonia + CO2) -presumably a slow reaction due to the insolubility of the MgCO3 - similar to the method of getting barium nitrate from barium carbonate and ammonium nitrate (described in one of the AFN papers)

[Yankie]

Why not making the magnesium nitrate straight from nitric acid/magnesium for the ones with access to magnesium metal.

 

Why not buy the Magnesium Nitrate from the nursery, If you can get it in Australia than it should be easy to get elsewhere.

 

Is it possible to extract the Magnesium metal from magnesium nitrate?

[tentacles]

I'm pretty sure that the result of adding magnesium to nitric acid (of any concentration) would result in the rapid oxidation of the magnesium... whether or not that would proceed to form Mg(NO3)2 is anyone's guess. I'd suggest using a displacement reaction to form it.. Perhaps calcium nitrate + Mg sulfate. calcium sulfate precipitates, filter it off, and then crystallize the Mg(NO3)2 and attempt to dry. Simple, cheap, easy to do.

[Miech]

Is it possible to extract the Magnesium metal from magnesium nitrate?

You could do that using some exotic and very reactive metals, but it wouldn't be worth the effort and costs. I've heard about reacting it with some kind of halogen, and then heating it so much it falls apart, but I really would prefer just to buy it.

[Swede]

Tentacles, I was under the impression that concentrated nitric does NOT react with alumina to create Aluminum nitrate. I have very little knowledge or experience with molecular sieves, but if it worked, it'd be a very handy thing. But I think what will happen is that the water-absorbing pores would quickly become deactivated.

[tentacles]

It might work, but the sieves aren't pure alumina, so it's hard to say what would happen. It could be worth a try, but you'd have to quantify the results somehow, or it's just pure conjecture.. Also, there's no way you should ever try to reuse the sieves after this - even after a good wash there would likely be traces of HNO3 on/in them that would release lovely NO2 gas upon heating.. that stuff is horrendously corrosive.

[Bug_X]

How can you tell if the glass will handle vacuum or not?

 

I got this parts from a friend and I want to distill some HNO3 under vacuum.

 

http://img179.imageshack.us/img179/6088/bild007rd6.jpg

 

Do you think it will handle it or brake?

 

Very grateful for any help!

Dear Christian