Sciencemadness Discussion Board

HNO3 and HDPE issue

chemliner - 31-8-2013 at 11:41

I have aquired 10l of 60% HNO3. Acid came packed in HDPE bottle(original package) , which have changed color from white to slightly yellow. After checking few compatibility charts i realised that its only matter of time before my container ruptures and spills the acid. Only viable option now is to transfer acid to more compatible container. Would soda-lime glass be appropriate material for long term storage of 60% nitric acid?

bfesser - 31-8-2013 at 11:47

<strong><a href="viewthread.php?tid=25209&page=2#pid293777">Storing concentrated Nitric Acid</a></strong>

<a href="https://en.wikipedia.org/wiki/Soda-lime_glass" target="_blank">Soda-lime glass</a> <img src="../scipics/_wiki.png" /> should be fine, but you should be concerned with the cap/liner.

In the future, please try the <img src="./images/xpblue/top_search.gif" /><a href="search.php">Search</a> function and Google before starting new topics.

Welcome to Science Madness. :)

cyanureeves - 31-8-2013 at 11:51

my nitric has never eaten through soda lime glass but lids are a whole different thing.i think teflon lined bottle caps are more important and thatis what i am looking into.one 8 oz. bottle with teflon lined lid will cost just as much as 20 teflon lined bottle caps on e-bay.it doesnt matter much to me what size bottle cap because i will just try different bottles until i find the right one.

blogfast25 - 31-8-2013 at 12:38

Quote: Originally posted by chemliner  
After checking few compatibility charts i realised that its only matter of time before my container ruptures and spills the acid. Only viable option now is to transfer acid to more compatible container. Would soda-lime glass be appropriate material for long term storage of 60% nitric acid?


The yellow is normal: at 60 % HNO3 the acid is always slightly yellow. It does not stem from dissolution of the container material, if that is what you're thinking.

You're probably reading too much into compatibility charts. If the acid was sold to you in that container you can reasonably expect it to be very resistant to its content. And HDPE is very chemically resistant.

My 70 % HNO3 came in a 5 L HDPE jerry, I've kept it there for years and see no significant degradation of the container at all.

I store smaller quantities (< 1 L) in another HDPE container, one that previously stored 95 % H2SO4 (as drain unblocker) and also find it more than adequate.

Glass is of course even more chemically resistant but does have the drawback of being fragile. If a full HDPE container is dropped on the floor, it might crack (but it's by no means certain), but when a soda glass bottle cracks it shatters the stuff all over the place.

My advice would be to keep the 60 % HNO3 in its original packaging and keep an eye on it.

[Edited on 31-8-2013 by blogfast25]

papaya - 31-8-2013 at 13:32

Just a question: is aluminum suitable or it'll degrade and contaminate acid?

PeeWee2000 - 31-8-2013 at 13:49

I agree with blogfast HDPE should be able to stand up to nitric acid no problem as long as its kept at or below room temperature, I kept some in a HDPE bottle in my barn attic for a while and the bottle became very soft but even then it didnt leak or fail now days I keep it in a nice freezer.
The nitric acid would react with the aluminum quite quickly, nitric acid reacts with most metals. So no aluminum is a terrible choice to store nitric acid.

MichiganMadScientist - 31-8-2013 at 16:25

Quote: Originally posted by chemliner  
I have aquired 10l of 60% HNO3. Acid came packed in HDPE bottle(original package) , which have changed color from white to slightly yellow. After checking few compatibility charts i realised that its only matter of time before my container ruptures and spills the acid. Only viable option now is to transfer acid to more compatible container. Would soda-lime glass be appropriate material for long term storage of 60% nitric acid?


This is interesting. Many people here report that long term storage of Nitric Acid in HDPE has worked out fine for them. For me, I notice that over time, the HDPE bottles start cracking.

HDPE has for me, not held well for long term storage of conc. Nitric Acid. And, if those fumes escape, they will rust the crap out of any rustable metal you have nearby.:o

I store all of my conc. Nitric Acid in glass. If you are really feeling froggy, get an old school glass container will a glass stopper.

Of course, if I had my way, I would store almost everything in glass. But that's just me....:)

[Edited on 1-9-2013 by MichiganMadScientist]

chemliner - 1-9-2013 at 02:12

HDPE container seems quite strong and tough but over time that should change, and transfering conc. nitric acid from soft cracked container is something i dont want to do. Do you have any recomendations on how to transfer liquids from barrels to small bottles safely because tilting a barrel full of conc. acids is not an option.

Fantasma4500 - 1-9-2013 at 05:05

aluminium container would be a good idea
otherwise get some aluminium tape and totally seal in the whole bottle, then you should be pretty well off.. 2 layers to be sure
for transferring it i'd say you just tilt it over, i dont see the big problem.. if youre afraid of it breaking while youre at it, put it in a plastic bucket that you ofcourse cleaned
puncture the container
and then from the bucket pour it into other plastic containers

blogfast25 - 1-9-2013 at 05:16

Quote: Originally posted by papaya  
Just a question: is aluminum suitable or it'll degrade and contaminate acid?


Quote: Originally posted by Antiswat  
aluminium container would be a good idea


Aluminium is a very reactive element and the WORST possible choice. The acid would chew through the metal in minutes, depending only on wall thickness. DO NOT TRY THIS!!!:mad: Even use of Al as some kind of outer container would be folly as any leaking acid would quickly burrow itself through the reactive metal. Please, don't let anyone start rambling on about 'passivation': the oxide layer is far too thin to resist strong acids for very long.
Quote: Originally posted by chemliner  
HDPE container seems quite strong and tough but over time that should change, [...]


And yet you provide no mechanism by which this 'change' 'should' occur...

HDPE is mechanically relatively strong because it is a 'high polymer' (very high MW, typically 20,000 to 1.5 million depending on grade) and because it contains microcrystalline areas ('crystallites') which act as cross-links and which further increase mechanical toughness. Over long periods of time UV radiation (direct sunlight, mainly) can cause degradation, especially when combined with heat, due to radical mechanism chain-splitting. The resulting reduced MW leads to reduced mechanical strength. Needless to say, most commercial grades are somewhat protected by anti-UV agents.

Chemically HDPE has the structure of a very, very long, mostly linear alkane. It's fully saturated. You wouldn't try and use a strong acid (an oxidising one or other) to attack such a structure: reactivity would be absolutely dismal, especially at room temperature. By and large, heavy gauge HDPE containers are suitable for storage of HNO3 up to 70 %. Unscrupulous operators may use substandard materials but bar that, it's a good choice of material. As indicated before, buy any drain unblocker (95 % H2SO4) and chances are very high is will be packaged in a HDPE bottle.



[Edited on 1-9-2013 by blogfast25]

Twospoons - 1-9-2013 at 14:19

In my case the original HDPE nitric acid container developed a tiny leak on a seam. This may be a common weak point in HDPE containers. I lost a few liters of acid before I realized what was happening, and ended up with a large hole in the floor. All my acid is now in glass, and has been in the same glass for 18 years - no leaks.

Bot0nist - 1-9-2013 at 17:19

I get my conc. sulfuric acid by the liter from a biodiesel supplier, and I store my and 70% HNO<sub>3</sub> (made using Magpies writeup in publication) in one of the empty HDPE bottles. It has been stored without trouble or loss for over a year and a half at room temp. It still titrates the same, and the bottle seems completely unharmed. No swelling, brittleness, or leaks. Just a slight yellow discoloration. I have a glass stoppered vial that I keep 100ml or so in near the bench for convenient use though.

AndersHoveland - 1-9-2013 at 21:32

Quote: Originally posted by blogfast25  
Chemically HDPE has the structure of a very, very long, mostly linear alkane. It's fully saturated. You wouldn't try and use a strong acid (an oxidising one or other) to attack such a structure: reactivity would be absolutely dismal, HDPE containers are suitable for storage of HNO3 up to 70 %.

This is what I once would have thought, but even 25% nitric acid very slowly attacks polyethylene bottles. In chemistry classes the plastic bottles holding nitric acid are replaced every year. Moist nitrogen dioxide seems even more corrosive.

The chemistry behind this is probably a complicated discussion.

I had a glass bottle of 70% nitric acid, and after several years of storage (in the upright position), the acid fumes caused the plastic lid to become brittle and crack, the lid then fell off by itself. This is the bottle that the nitric acid was sold in, and I assume the lid was made of HDPE.

vmelkon - 6-9-2013 at 18:34

What about storing it in a wax (paraffin) bottle? You would of course have to make it yourself.

cyanureeves - 6-9-2013 at 18:55

surely not wax.isnt there an explosive compound made by nitrating paraffin? i just won 11 amber bottles with teflon lined caps for a dollar on ebay,got a lecture on why he advertised teflon like and not teflon lined. teflon is a registered trademark from dupont and his "teflon" was PTFE and not dupont's. excuse ME senor chikin!!i will be going"warriors come out to playay".i deserve these bottles.

ElectroWin - 7-9-2013 at 06:05

Quote: Originally posted by cyanureeves  
surely not wax.isnt there an explosive compound made by nitrating paraffin? i just won 11 amber bottles with teflon lined caps for a dollar on ebay,got a lecture on why he advertised teflon like and not teflon lined. teflon is a registered trademark from dupont and his "teflon" was PTFE and not dupont's. excuse ME senor chikin!!i will be going"warriors come out to playay".i deserve these bottles.


wouldn't nitration happen on -OH groups? (which paraffin does not have, i think)

cyanureeves - 7-9-2013 at 07:19

got no idea ElectroWin but what i am probably thinking about is wax and chlorate that was used in wwll, hell it might have just been a hollywood movie i saw.the sticky bomb used in private ryan.

[Edited on 9-7-2013 by cyanureeves]

Fantasma4500 - 20-9-2013 at 09:35

well, blogfast25, you see.. aluminium doesnt react with nitric acid
it does however react with NO2, but thats quite slowly, i dont know about the oxide layer, but i know that aluminium is suitable for HNO3
there would nearly always be abit of NOx in it, so it wont last forever, but what does last forever anyways

just for the sake of proving myself and my experience wrong ill go ahead and dump some aluminium foil in 62% HNO3, but i have covered many many reaction vessels with steaming hot HNO3 with aluminium foil

papaya - 20-9-2013 at 10:39

Please report back Antiswat, I also thought Al is quite resistant to nitric (may depend on concentration).
Btw., how nitric acid is transferred and stored in industry (big quantities) ?

blargish - 25-9-2013 at 15:55

This thread reminds me of the first time I tried to store fuming nitric acid. Had it in a glass bottle with a phenolic cap, and found it a month later with part of the cap looking like it had been liquefied, and on the brink of rupturing :o Teflon just may have been a better option... :D. Pretty stupid of me now that I think of it hehe

Fantasma4500 - 26-9-2013 at 02:05

actually i didnt dump aluminium foil in nitric acid as i had a little aluminium cup standing around for drying, i put in abit of HNO3 62% and heard abit of bubbling (yeah it wasnt 100% clean, some weird dark stuff in the bottom)
it seazed after short time, and it was let stand +4 hours, there was no real heating, as expected nothing happened to it..

on my 5L HNO3 containers its explained how to use it to clean aluminium with HNO3, just aswell as NaOH is used for steel cleaning, due to the fact that NaOH doesnt react with proper steel (SS, 316) and also HNO3 and Al

there is ONE thing although...
i would suggest anh. HNO3 would be preferred for aluminium, as if its not anhydrous it does ofcourse contain water.. and water with aluminium is where the problem is

potentially a soda can could even be used to store HNO3, although there is a plastic film inside of it, and that might react with the HNO3 (might need testing, perhaps??)
it can simply be removed by heating the can until the plastic pyrolises / decomposes

just for the scientific matter ill link to a trusted chemist
http://youtu.be/u4Ha1SJrazY?t=19s

papaya - 26-9-2013 at 04:13

I remember years ago I made an effective battery (you could replicate from curiosity) - take HNO3(don't remember conc, must be 50% or less), dissolve some NaCl into it, submerge Al foil (larger area better) and graphite as another pole. It gave VERY high current despite it's small size (was done in the plastic cap of cola bottle) and I could lit a small wolfram light bulb with it. Quite interesting thing - when the circuit is open - there's no reaction on Al, when shorted - it starts to bubble, when opened again - reaction stops- it resembles Li - thionyl chloride battery in that fashion (actually I was seeking that kind of behavior). What I want to say - it didn't work well (or at all) if no NaCL was added(highly promotes corrosion), and even after that it reacted noticeably only when circuit was shorted - so pure Al must withstand I think.

woelen - 27-9-2013 at 06:49

I purchased 69% HNO3 in a HDPE jerrycan (2.5 liters). The jerrycan was good, also after a long time of storage, but I had issues with the jerrycan getting wet on the outside, especially in wintertime during grey and humid days. The wet stuff is dilute acid and it corrodes everything nearby.

I then put the jerrycan in a plastic bag, but this was not of real help. When i removed the bag after some time, I even noticed fumes! From that time I changed things drastically. I have taken glass reagent bottles with GL45 screw caps, which have a teflon liner inside. Since then I have not a single issue anymore. I have 2 one liter bottles of the acid now and half a liter I have in a smaller 'working bottle'. The acid is pale yellow, nearly colorless.

I would not feel comfortable having the acid stored in aluminium, or having aluminium caps in contact with the acid. It certainly would contaminate the acid and although the acid may passivate the aluminium I do not feel confident that this effect is strong enough for long term storage. So, my first choice is glass with a carefully selected cap, second choice is the original HDPE bottle, but with measures taken such that the corrosive fumes around the bottle are neutralized (e.g. store in a loosely sealed bucket in which some Na2CO3 or NaOH is stored as well in an open dish and which is inspected every few months or so).

AndersHoveland - 27-9-2013 at 08:17

Aluminum is resistant to nitric acid if the acid concentration is over 95%, but if the concentration is below 80%, or if the nitric acid is heated above 40 °C, the corrosion rate is much faster.
Handbook of corrosion data. Bruce D. Craig, David S. Anderson, ASM International

Still, resistant does not mean it will not slowly corrode. I would not advise using aluminum containers for long-term storage.

Aluminum containers can be used to perform nitrations, however. Just make sure there are no chloride ions around.