gnitseretni
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Stainless steel pot ok?
Could one use stainless steel pots to distill nitric acid? So far I've been doing it the brainfever way but i'd like to try vacuum distillation to get
a purer product because my NA is always yellow.
I found stainless steel pots at the walmart that have a glass lid with a SS rim around it. I already got me two of those pots. I broke the glass and
laid the rim on a flat piece of metal and poured aluminum in it and now i have an aluminum lid :-) I drilled a hole in it for my condenser. I wrapped
the gasket, that fits around the rim, with teflon tape.
I wanted to just do it without asking here if using SS pots was a good idea, but... i'd feel better if someone who distilled NA before using SS pots
told me that its ok to do so and that the NA vapors won't react with my SS pot or whatever and form sensitive peroxides around the lid or something
like that 
So all i need to know is if SS pots will withstand two or three distillations without giving unwanted side reactions or something like that.
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Xenoid
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Iron and chromium tend to be passivated by nitric acid, so I guess SS will be OK, although I haven't tried them for this purpose yet, let us know how
you get on!
What I don't understand is why you smashed the glass lids, They normally have a knob with a hole drilled through, if it wasn't big enough, enlarge it
with a glass drill.
Check where the pots originate. I have found that modern SS originating in China and especially India is total crap! I had some thin SS pots that I
had some NaCl and KCl solutions in, they started to leak after about 48 hours. Numerous pinholes formed, I think they were formed from tiny specks of
steel wire embedded in the SS during the brushing/polishing process. Check your pots are thick and free of imperfections!
Regards, Xenoid
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not_important
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Halides are real tough on ferrous alloys, stainless steel or not. Oxidising mixtures are often OK, although elevated temperatures can be an issue.
Be aware that there are many types of "stainless steel", you're talking about a large family of alloys. So if someone reports success or problems when
using stainless steel, unless they specify the allow class you may have entirely different results than they did.
But you are right, much of the consumer goods coming from Asia are lowest cost, which generally means as cheap of materials as can be had. For SS this
means alloys that barely fall under the definition of stainless steel, with segregation of alloy constituents being common.
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MadHatter
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Stainless Steel
I wouldn't use stainless steel with any acid. As for BrainFever's method, you may
have to lower the temperature on the hotplate for a clearer product.
From opening of NCIS New Orleans - It goes a BOOM ! BOOM ! BOOM ! MUHAHAHAHAHAHAHA !
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gnitseretni
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| Quote: | Originally posted by Xenoid
What I don't understand is why you smashed the glass lids, They normally have a knob with a hole drilled through, if it wasn't big enough, enlarge it
with a glass drill. |
Yeah it had a knob. The hole was 1/4" in diameter. Not big enough. Now don't laugh but i didn't know they had drills specifically for glass. **
embarrassed **. Where do you get those anyway cuz i've never seen them in stores i think, else i would've known they existed. But hey, let me know
where i can get em so i know for next time. Woulda been nice if i could've kept the glass in there so i can see what's going on.
The pots were "made in Pakistan". Guess i got the cheap stuff? They're pretty thin, but at least no imperfections.
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Xenoid
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| Quote: | Originally posted by gnitseretni
Yeah it had a knob. The hole was 1/4" in diameter. Not big enough. Now don't laugh but i didn't know they had drills specifically for glass. **
embarrassed **. Where do you get those anyway cuz i've never seen them in stores i think, else i would've known they existed. But hey, let me know
where i can get em so i know for next time. Woulda been nice if i could've kept the glass in there so i can see what's going on.
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They are available in hardware stores (in the ceramic tile sections) or a specialist floor tile shop or maybe from a glazing shop. Admittedly they are
pretty expensive, being diamond coated and all. They need to be cooled with water, this can be done by making a little "pond" using plasticene or
putty around the area you are drilling. Google glass drilling, you'll get the idea.
Edit:
Thinking about it, you could probably enlarge the 1/4" hole by using some coarse "wet & dry" emery paper, wrapped around a partly slotted wooden
dowel, fitted in a drill. I use this "technique" with ordinary "sand paper" for metal, plastic and wood, quite often. Depends a bit how big a hole you
want.
Regards, Xenoid
[Edited on 27-8-2007 by Xenoid]
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Twospoons
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Search on ebay for " diamond core drill". These can be used on glass - with plenty of water for cooling / lubrication. You can get almost any size
from 3mm to over 150mm.
Helicopter: "helico" -> spiral, "pter" -> with wings
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DerAlte
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Try an ordinary masonry drill from a hardware store, they cut concrete. Using Tungsten carbide. Der Alte
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evil_lurker
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Or buy break down and buy a nice borosilicate flask with a ground joint... a 3L flask is only around $60 new and by the time you try and afro-engineer
something you'll be out just the same amount of money once you figure in your materials and time wasted.
Let me tell you that hot nitric acid is NOT something to be played around with, and I think boiling nitric would eat thru 316SS like a knife thru hot
butter.
[Edited on 28-8-2007 by evil_lurker]
Not all chemicals are bad. Without chemicals such as hydrogen and oxygen, for example, there would be no way to make water, a vital ingredient in
beer.
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undead_alchemist
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Consumer SS from Asia is crap.
Its true, you really don't know what else is in it.
I was doing some tests with some SS scrub pads as packing, and they rusted in no time.
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scientistfromdarkness
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Aluminum pot is the best for nitric acid distillation. Nitric acid does not attack aluminum at all.
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Xenoid
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| Quote: | Originally posted by scientistfromdarkness
Aluminum pot is the best for nitric acid distillation. Nitric acid does not attack aluminum at all. |
Nitric acid, dilute or concentrated acts so slowly that nitric acid is said to have "no action on aluminium". Indeed aluminium containers are, or at
least were, used for transporting nitric acid.
By "distill nitric acid" I assumed he meant distill from nitrate and sulphuric acid.
I haven't done a nitric acid distillation yet, but I would think the concentrated sulphuric acid added to the nitrate would react "rather badly" with
aluminium.
Regards, Xenoid
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12AX7
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I've had nitric and sulfuric acids in contact with aluminum before. Any water present will cause hydrogen, NO2 and bad pitting, but roughly anhydrous
seems to be okay.
Tim
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gnitseretni
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i've actually been trying to cast aluminum pots before resorting to SS pots. But i failed every time so i had to find something else. Doesn't mean i'm
giving up on trying to cast aluminum pots though.
I also got me a 1 gallon glas pot and a glass drill and i managed to drill a hole in the lid. All i need now is a gasket for the glass pot and time
and i could start distilling using the glass pot and a SS pot with an aluminum lid.
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gnitseretni
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when i first started this thread i had two SS pots but used one for yet another unsuccessful attempt to cast an aluminum pot, so i got a glass pot and
managed to drill a hole in the lid and used teflon tape as my gasket. I took my glass and SS pot, hooked up all the pumps for the water aspirator and
condenser and started distilling. I used the SS pot to collect the HNO3 and was heating the glass pot containing the KNO3/H2SO4 mixture. I didn't
drill a hole for the thermometer so i just put it in the waterbath. I heated the mix all the way to 90C (yeah, heated a glass pot to 90C  ) but never really saw alot of vapor. I know that HNO3 boils at 83C but how can you
tell? I was expecting it to bubble alot and that it would get real foggy inside the glass pot because of all the vapor, but it didn't.
Anyways, i thought everything was going well but then i noticed that the potassium sulfate was slowly disappearing. This is when i stopped distilling.
I took the aluminum lid of the SS pot and found out where the sulfate had gone 
I also noticed that my acid wasn't fuming. I weighed 10 mls of it and it only weighed 11.38 grams.
Wouldn't know how but maybe some water got into my acid through the vacuum hose. That would explain why it is so dilute. But how the hell the sulfate
got in there i have no idea!!
I know the pics are crappy but it was the best i could do.
EDIT: how do you attach more than one pic?
[Edited on 2-9-2007 by gnitseretni]
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froot
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I heard that cast iron is safe to use with nitric acid?
If you can use glass appauratus, do so, it eliminates all variables associated with poor quality steel. Drilling glass is a very delicate process. You
can use a tungsten tipped masonary drill but you must use a rigid pedestal drill with a very slow speed setting, and constant light pressure. The
glass you are drilling must be emersed in water.
We salute the improvement of the human genome by honoring those who remove themselves from it.
Of necessity, this honor is generally bestowed posthumously. - www.darwinawards.com |
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chucknorris
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Ok I have some processes where glass cannot be used, for ex KOH NaOH fluorine compounds etc. harsh stuff that will eat through glass like nothing.
I thought of making stainless distilling pot and column. Could a normal stainless pots available at dairy stores be used or are they unusable for
these processes?
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