CO2AtmosphereGuy
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[Advice Sought] I'm trying to generate a dry CO2 atmosphere to extract Li in.
My goal is to remove untarnished lithium from AA batteries. The problem is that lithium will tarnish in the presence of oxygen or water vapor. How-to
guides also warn that inevitable short circuiting of the battery while cutting through the casing often leads to fires. Extracting lithium in a carbon
dioxide atmosphere seems to resolve these issues.
My planned workspace will be a 40L tub covered in plastic wrap sans two holes for my arms. Reacting vinegar with baking soda in a plastic bottle
attached to a hose seems like an easy way to generate a carbon dioxide atmosphere in my tub. I'm worried water will escape into the carbon dioxide as
vapor, but by running the gas/vapor mixture through an intermediate container filled with dried Epsom salts I should be able to dry my carbon dioxide.
I'm hopeful this setup will give me a largely oxygen and water vapour free environment in which to work.
edits in bold
I have four questions:
Do you see any obvious problems I should expect to encounter with my setup? It's overly complicated.
How do I calculate the amount of baking soda and vinegar required to generate 40L of carbon dioxide?
Should I use a large shallow intermediate container to maximize the desiccant's surface area?
Is there an easier way to obtain a dry carbon dioxide atmosphere? Yes! Buy a CO2 canister and a regulator. It's so incredibly simple. CO2
tanks are only filled 30-40% with liquid CO2 so there may be other gasses in the tank, but they'd be lighter than CO2 anyway. There probably isn't a
risk of water vapor in the CO2, but I'd run it over some Epsom salt anyway just be safe.
[Edited on 10-11-2013 by CO2AtmosphereGuy]
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Metacelsus
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Lithium, a powerful reducing agent, will probably react with your carbon dioxide. Even magnesium is active enough to "burn" in a carbon dioxide
atmosphere.
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Mailinmypocket
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Perhaps canned duster will provide the blanket of gas needed?
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Wizzard
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Canned duster is butane, among other things.
Edited slightly - If you want a helium atmosphere for your project, look into balloon helium which doesn't have "safety" oxygen in it. Methods to
remove the oxygen using a cold trap and liquid nitrogen could be dangerous to the amateur chemist.
Trap this helium in a semi-sealed vessel, and work from the bottom - Helium rises, and with only holes in the bottom for access, you'll be in good
shape for long enough to get some work done.
[Edited on 11-10-2013 by Wizzard]
[Edited on 11-10-2013 by Wizzard]
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chemrox
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Buy a bottle.
"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
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Oscilllator
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If you get the right canned dusted it should provide an inert atmosphere. My duster contains 1,1,1,2-Tetrafluoroethane (R134A). Would this provide an
inert atmosphere?
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Agricola
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Lithium hydroxide is used in spacecrafts to remove CO2 from the air. Lithium metal of course is more reactive than lithium hydroxide. Bad idea.
I think the use of an inert gas is unnecessary. If you really want one you can use dry hydrogen. Be sure there are no flames or sparks anywhere of
course.
Read this before trying to diassemble the battery.
[Edited on 10-11-2013 by Agricola]
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bfesser
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<img src="../scipics/_warn.png" /> Keep in mind that disassembling Li batteries is quite hazardous! <img src="../scipics/_warn.png" />
Beside the obvious risk of fire, the electrolytes tend to be <a
href="http://www.sigmaaldrich.com/materials-science/material-science-products.html?TablePage=106039043" target="_blank">quite toxic</a>
<img src="../scipics/_ext.png" />. Wear goggles or even a full face shield, double up on gloves, wear an apron if available, and avoid
inhalation (do this outside or in a fume hood)! That is incorrect. <em>Get your facts right before
making such claims; particularly without reference.</em><a href="http://en.wikipedia.org/wiki/Gas_duster" target="_blank"> | Quote: | | Hydrocarbons, like butane, were often used in the past, but their flammable nature forced manufacturers to use fluorocarbons. <img
src="../scipics/_wiki.png" /> |
</a>Personally, I've never seen a can of compressed hydrocarbons for
this purpose, only the fluorocarbons. That would be
sufficiently inert for room temperature lithium, yes.
I've used a small pipe cutter with some success to remove the casing from lithium batteries without shorting. It's important that the wheel is sharp,
and the position of the cut must be chosen carefully. I wouldn't recommend it to you.
[Edited on 10.11.13 by bfesser]
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WGTR
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Materials Handbook: A Concise Desktop Reference François Cardarelli
Springer, Mar 19, 2008 - Technology & Engineering
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elementcollector1
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Quote: Originally posted by WGTR  |
Materials Handbook: A Concise Desktop Reference François Cardarelli
Springer, Mar 19, 2008 - Technology & Engineering
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Could you fill a container with oil that had previously been dried extensively, hold the lithium under the oil while you cleaned it mechanically, and
then store the lithium?
@bfesser; I'm not saying the risk should be understated, but I have curiously never once caught a battery on fire while disassembling it. I always
hacksaw off one or both of the end caps, and then saw down the length of the battery to pry it open and reveal the contents. Has never once failed,
although if I recall, a lithium battery did get unusually warm once (I put it down outside for a short while - didn't explode, and cooled down
quickly, so I resumed work).
Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
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CO2AtmosphereGuy
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Thank you all for the helpful replies. :-)
Cheddite Cheese, Agricola: I am not a chemist and I could easily be wrong, as I was about lithium reacting with pure oxygen, but the Wikipedia entry
for lithium says lithium carbonate forms as a secondary reaction after lithium hydroxide has been formed. I have taken that to mean carbon dioxide by
itself will not react with lithium.
Wizzard: That seems like the ideal way to generate an inert atmosphere, but it also sounds expensive. I'm scared of working with liquid nitrogen and I
have no idea how to get my hands on some. If I ever need a high quality inert atmosphere, that's definitely the procedure I'll use.
bfesser: Thank you for your sobering reply. I intend to use Li-FeS2 batteries (Energizer brand) which sounds relatively safe. The biggest risk appears
to be that FeS2's oxidation is extremely exothermic, but I hope a CO2 atmosphere will avoid that risk. I also intend to wear goggles, a particle
filter, a long-sleeved wool shirt, and wool gloves with latex gloves over them. When it comes to my safety, I err on the side of paranoia.
WGTR: Though I was wrong that oxygen by itself is enough to corrode lithium, it still presents a fire risk. I'm also concerned that atmospheric
nitrogen will react with lithium to form lithium nitride, but that may only happen with burning lithium.
elementcollector1: Maybe. That would probably be safe too. But I'm scared of dipping my hands in a flammable substance while short circuiting a
battery that may be filled with a small amount of O2 and the highly reactive lithium I seek.
chemrox: Apparently they sell bottles of liquid CO2 at Walmart. I've read contradictory statements as to how to turn the CO2 into a gas. Either way,
it's incredibly endothermic and may even freeze any water vapor (which would be awesome for me). I'm definitely going to read more about this before
trying anything.
Oscilllator, Mailinmypocket : Thank you for your suggestions. I'll definitely read more about R134A, but I'm hesitent to use something so exotic
sounding due to my ignorance.
[Edited on 10-11-2013 by CO2AtmosphereGuy]
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Marvin
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Lithium will burn in CO2 as well as most halogen containing organic gases. Liquid halogen containing organic compounds pose an explosion
risk in contact with alkali metals generally.
I would suggest welding grade argon, but dry air is probably fine. I can't comment on other battery components.
If you want to get paranoid about water vapour. Carbon monoxide will not burn in P2O5 dried oxygen, and you can distill
Phosphorous in the latter. Turns out water vapour is quite important to flames and we rarely experience this because most things we want to burn
contain hydrogen anyway.
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adamsium
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Just a note about condensing oxygen from a gas stream with liquid nitrogen - this is really not something you want to be doing if you're inexperienced
with chemistry, as you could be in for a very nasty surprise. We are very careful to avoid liquid oxygen forming in the cold traps on high vacuum
lines in the lab, and with good reason around organic compounds.
I know you're unlikely to use that method and there shouldn't be much in the way of organics around, but I felt that it needed saying. It's also not
that one absolutely cannot work with liquid oxygen, but it's really not something you want forming without knowing how to handle it (and not handle
it).
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Wizzard
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@bfesser - I'm in the US, and butane was/is a common ingredient in canned air.
http://en.wikipedia.org/wiki/Gas_duster
http://chemistry.about.com/b/2013/09/05/canned-air-isnt-air....
http://mindmachine.co.uk/products/118_Chem_Air_duster.html
At least do a cursory Google search before making such claims; particularly without reference.
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bfesser
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Wizzard, as my profile states, I'm in the US, as well. <!-- I've never seen a butane gas duster—and I've used
many cans of the stuff, from numerous manufacturers. Granted, the composition could vary from state to state. Oh, and chemistry.about.com is an
unreliable reference at best (despite the author's credentials), which is more than can be said for your third link.
I let the rest of your post go unacknowledged before, because I didn't want to sound like I was attacking you, but since you've chosen to be
argumentative, I'll reply to it now. The rest of your post was largely unhelpful and downright dangerous advice. I had even considered pruning it
when I first read it, due to the inherent danger in what you proposed, but decided that anyone with half a mind would realize it's nonsense and
dismiss it. [edit] I'm not surprised to see that others have commented on the danger and uselessness of your suggestion.
First of all, how do you expect someone who can't even obtain metallic lithium (from a source other than batteries) and doesn't know how to work in an
inert atmosphere to get his/her hands on liquid nitrogen? Second, you failed to mention the dangers associated with liquid oxygen, particularly in
the vicinity of a reactive alkali metal! Third, you claim that "all oxygen and air will condense out." That's simply wrong. Finally, your last bit
of advice about working in an inverted box with arm holes in the bottom is downright useless. Have you tried this? Do you understand the first thing
about how gases behave? I suggest that you start by reading a discourse on diffusion.
Next time you choose to argue with someone, get your facts straight <em>beforehand</em>. If you really want to prove me wrong, do a
comprehensive survey of the canned duster products available in the United States, and list them alongside their major constituents. I'm not going to
put the effort into this, as you've essentially discredited yourself by your other claims.
I look forward to being proven wrong.
[edit] -->
<em><strong>CO2AtmosphereGuy</strong>, welcome to ScienceMadness!</em> 
[Edited on 10.11.13 by bfesser]
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CO2AtmosphereGuy
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| Quote: Originally posted by bfesser | Finally, your last bit of advice about working in an inverted box with arm holes in the bottom is downright useless. Have you tried this? Do you
understand the first thing about how gases behave? I suggest that you start by reading a discourse on diffusion.
<em><strong>CO2AtmosphereGuy</strong>, welcome to ScienceMadness!</em>
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It sounds like Wizzard and I have the same understanding of how gases work. I wanted to use a heavier gas with holes at the top; he wanted to use a
lighter gas with holes at the bottom. I assumed water vapor from the air would diffuse into my CO2 tub, but I also expected gravity would
keep oxygen and nitrogen out. I've seen a video of a paper boat floating on an argon sea that seemed to confirm my belief. Am I dead wrong? Will
oxygen and nitrogen diffuse into my CO2 atmosphere? I'm going to go read the Wikipedia entry for diffusion now.
Also, thank you for the welcome. :-)
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elementcollector1
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Unfortunately, diffusion seems to happen regardless of density - this is why hydrogen is not so easily separated from air, for instance.
Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
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Wizzard
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@CO2AG - Helium will collect in the top of an inverted container - Diffusion is a hours-scale problem for a container large enough to work in.
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bfesser
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<strong>Wizzard</strong>, waving your arms about at the interface of the (primarily) helium and the (primarily) air is going to mix it and
<em>quickly</em> compromise the effectiveness of your 'inert' atmosphere.
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CO2AtmosphereGuy
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My CO2 atmosphere worked. :-) I was able to take my sweet time getting the lithium out and into naphtha and it's only slightly tarnished
compared to the pictures I've seen online. :-) I have no idea what to do with it now that the cool factor of holding an ultra-light metal with the
consistency of soggy pasta has warn off. Trying to make an inert atmosphere was more fun than playing with lithium. I guess I'll setup an experiment
to try to measure oxygen and nitrogen diffusion into my gloveless glovebox. Thankfully since dissolved CO2 is acidic, that shouldn't be
hard.
Thank you all for your help. CO2AG out.
Edit:
Oh, and I don't think diffusion was much of an issue. I covered ~80% of my tub with plastic wrap. I just left room for my arms to fit in and I kept
the CO2 gently blowing so it was slightly pressurized. During the entire procedure, I never took my arms out so there wasn't a lot of arm
waving along the medium between my CO2 atmosphere and my yard's atmosphere. The tarnish probably came from me short circuiting the battery.
Due to my two sets of gloves I couldn't feel it getting hot, but I can't imagine it didn't short circuit at some point.
[Edited on 10-11-2013 by CO2AtmosphereGuy]
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bfesser
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I'm glad to hear of your successful extraction. No photos to share?
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CO2AtmosphereGuy
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Taking photos never even occured to me. I will when I do something geniuenly interesting, though.
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zenosx
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I have stored my Li under mineral oil for quite a while, and while it has a good oxidized layer after 6 months it hasn't deteriorated significantly,
and most of the oxidation was from extraction in open air . At the time I just
wanted to fool around with it.
Funny how fooling around with something ends up making you look like a fool... suppose that's why that's the expression,,
anyway,, mineral oil = good. Although it will tend to want to float on the surface.
A question that sometimes drives me hazy: am I or are the others crazy?
Albert Einstein
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