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Melgar
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[*] posted on 25-5-2010 at 16:30
Easy nitric acid


I used to use this method before I got an actual distillation setup. It's pretty easy and gives white fuming nitric acid. It should definitely be done outside with proper protective gear though, since if you're not careful, the plastic bag can slip and spill water into the sulfuric acid which as we all know generates a lot of heat. For the rubber band, you need to use a really heavy one, and ideally more than one. The bag HAS to be polyethylene. I always used translucent shopping bags from a local grocery store that was trying to encourage recycling the bags so they put this huge recycle logo with "LDPE" (low density polyethylene) underneath it. I suppose if you wanted to make sure, you could mix a little H2SO4 and nitrate salt (with an excess of the H2SO4) and drip it on the bag. If it doesn't discolor or damage the bag, you're probably fine. Some orange discoloration is probably ok, since nitric acid can stain polyethylene.

Basically, the way it works, is the ice water in the plastic bag bulges down in the middle, so when nitric acid condenses on it, it tends to drip down to the lowest point, then into the small jar. The heat needs to be carefully controlled, since if it's too hot, the nitric acid in the small jar will boil, and if it's too cool, the nitric acid won't drip into the small jar at a fast enough rate to keep it cooler than its surroundings. Ice should be periodically replaced as it melts, and ideally salted with NaCl (good) or CaCl2 (best) to lower the temperature of the mixture. This results in colder nitric acid dripping into the small jar, keeping the small jar cooler, and reducing evaporation from it, thus improving yields.

In any case, I haven't seen this method described very well here, so I figured I'd lay it out. Yields won't be quite as good as with a distillation setup, since you can't turn up the heat too high, but they're still very respectable.

nitric.png - 102kB

[Edited on 5/26/10 by Melgar]
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pjig
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[*] posted on 25-5-2010 at 19:45


nice setup.....:D
I'd say its as simple as it gets! I can see in a pinch how this could prove to be very useful to get small amounts of white nitric acid.
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Melgar
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[*] posted on 25-5-2010 at 22:50


Quote: Originally posted by pjig  
nice setup.....:D
I'd say its as simple as it gets! I can see in a pinch how this could prove to be very useful to get small amounts of white nitric acid.

Yeah, it definitely is. And no one that doesn't have a glassware distillation setup has any business messing around with large quantities of fuming nitric acid anyway! :P
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[*] posted on 26-5-2010 at 13:40


This kind of method was discussed extensively at roguesci a few years ago. I used it myself at the time, but found that if you buy a large wine glass or other appropriately shaped glass bowl, you avoid many of the problems with marginal compatibility of LDPE and HNO3. You just break off the stem of the wine glass and you're ready to go.

Edit: Also, a small glass with stem serves very well as the receptacle as it raises the collected nitric acid out of the hot mixed acid. This reduces refluxing of the collected nitric and thus also decomposition.

[Edited on 26-5-2010 by Microtek]
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pjig
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[*] posted on 26-5-2010 at 15:35


That seems to make more sense. I guess you could take a mason jar(with nitrate and acid) and place the wine glass W/ broken stem directly on it. Fill it with ice water and start distilling :D..
This would save time in the tear down, and set up.
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[*] posted on 26-5-2010 at 16:35
Nitric Acid


Looks like BarinFever's method. IIRC, temperature control was essential to obtain
white HNO3. If temperature in the reaction became too high, the result was
fuming red HNO3.




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[*] posted on 26-5-2010 at 20:34


I had someone recommend an old coffee maker hot plate as a heat source for this method. I saw pictures of it. Nearly clear nitric acid, but the yield wasn't great and took most of the day to collect.
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Melgar
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[*] posted on 26-5-2010 at 20:56


Yeah, I wouldn't think a coffee maker would be quite hot enough. I found that using calcium chloride ice melter let you turn up the heat and collect quite a bit faster. The jar I used kind of had a bulge in the middle that held up the small jar so it didn't get too hot.
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[*] posted on 26-5-2010 at 21:09


Been there done that. Its an improvised cold finger. They work great or small scale workings and its a shame people do not give them the attention they should get.

As an added note to high a heat will get red Nitric acid so slow and steady wins the race





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Jimbo Jones
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[*] posted on 27-5-2010 at 00:34


Funny that everyone links this method to BrainFever, when the original idea came from ex member of RS (also a member here) named simply RED. Inspired by his work, I made my own version, but after some tests I just switch to the classic distillation setup. The method actually works, but only for small scale distillations and with huge time & energy looses. The pic’s below are from my first setup, which was made before five or six year.

http://img541.imageshack.us/i/pic5005.jpg/

http://img718.imageshack.us/i/pic5008.jpg/

http://img190.imageshack.us/i/pic5009.jpg/

After some tests I discover that if you using some sort of isolation (aluminum foil, asbestos) on the outer side of the main container, this prevents the condensation of the formed nitric acid on the cooler, inside surface and form condense only on the ice cold, suitable conical material. Using sodium or potassium nitrate is also superior, because ammonium nitrate decomposes in much lower temperatures.

The setup below is also homemade, but works as good as my professional apparatus. No fancy parts or expensive and hard to improvise joints. The only part, which I bought, was the 2 l. Florence flask, but in the past I use champagne bottles with great success too.

http://img35.imageshack.us/i/42030.jpg/

http://img517.imageshack.us/i/42073.jpg/

http://img96.imageshack.us/i/42091.jpg/

Sometimes I use it again, just because the nostalgia is too strong.
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[*] posted on 27-5-2010 at 01:48


It's just a vqariation of the old russian way to make vodka with simple equipment ...
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[*] posted on 27-5-2010 at 10:55


Quote: Originally posted by chief  
It's just a vqariation of the old russian way to make vodka with simple equipment ...


Info and pics :D:D:D
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[*] posted on 27-5-2010 at 12:37


Whenever I've heated household glass jars over the hotplate, I've noticed they tend to explode (the bottom blows out) sooner or later. Instead of a jar, I would use a heat resistant glass cooking pot. Axt demonstrated a very similar distillation, and he used two beakers IIRC. Aluminium is probably more resistant than polyethylene to warm nitric acid. But then the acid would have some Al contamination. Some heat resistant glass tea pots might work well in distillation setups alone (just connect the snout to a tube, and secure the top).

TM 31-210 describes a setup (below) with a glass bottle, using a pasty mixture of KNO3 and H2SO4 (less than 1/4 volume) to distill nitric acid. The setup brings together two glass bottles supports the bottles with rocks with the empty bottle being slightly lower than the distillation bottle and the receiving bottle being cooled by periodically having water poured on it. And the bottle to be heated inside a tin can filled with sand or gravel.

The setup uses paper with a tape seal (regular, electrical) to bring together the two bottles. Using paper which is sealed with tape is not a good idea for a corrosive and oxidizing acid like HNO3, the superior thing to use is Teflon. Wrapping with aluminium foil (and then taping with electrical tape) is another less noble option. This is not a good setup especially since overheating the heating bottle can easily burst it, wetting also does the same. I wonder if it was even tested.

It was also pointed out in another thread by franklyn, but some older literature distills nitrate and H2SO4 in cast iron retorts. The acid strength would need to be kept high since unalloyed and low-alloyed cast iron are said to corrode very fast in dilute or intermediate acid at all temperatures. That's another distillation possibility.

For saftey reasons, to newbies reading this. Do not inhale nitrogen oxides! They are deadly gases that cause pulmonary edema. I have inhaled a significant amount of them once as a careless teen and coughed up blood chunks the next day, I was lucky to not have died (coughing up blood is one sign of pulmonary edema).

nitric_dist.png - 14kB

[Edited on 28-5-2010 by Formatik]
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Jimbo Jones
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[*] posted on 28-5-2010 at 03:45


Just to clear things up, both of the apparatus above use sand baths. The sand itself was carefully sifted and dried before the distillations.
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[*] posted on 28-5-2010 at 03:48


I assume that the cap for that bottle is made of aluminum? It did not experience degradation due to hno3 exposure?

Another method that does not involve saran wrap or wine bottles is to use a broken wine/martini glass (the stem is snapped off). I believe Axtran originally posted this method.




[Edited on 28-5-2010 by Chainhit222]




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Jimbo Jones
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[*] posted on 28-5-2010 at 03:59


It’s plastic cap from empty sulfuric acid bottle. Any improvisations (plugs from Teflon or aluminum foil) are also possible.

[Edited on 28-5-2010 by Jimbo Jones]

[Edited on 28-5-2010 by Jimbo Jones]
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Melgar
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[*] posted on 2-6-2010 at 00:53


I've only ever had glass jars or bottles (of the type food or alcohol comes in) break when they were either cold and placed on a hot surface, or hot and cooled very quickly. And then, only when they've been empty of liquids or nearly so. It's been my experience that if you have a cast iron round heating surface on your hotplate, you can heat jars and bottles on this just fine, but if you have a coil that you can see glow, you need a sand bath or something to even out the heat.

Whenever I've done this, I've put a cold jar on a cold hotplate, then turned the hotplate on and not removed the jar until I'm done and the hotplate's turned off and cold. Doing it this way, I haven't had a problem yet.
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