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Author: Subject: LAH storage
Stibnut
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[*] posted on 26-2-2017 at 13:24
LAH storage


I've just ordered 10 g of LAH. What would be the best way to store and handle it, to avoid mishaps? I have ~400 mL of dried THF (stored over sieves for months). Would it be a good idea to store it as a THF solution, rather than as a solid? Also, are there any safety concerns I should know about other than that it obviously burns/explodes on contact with water?
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[*] posted on 27-2-2017 at 06:31


I store my LiAlH4 as a dry powder in a special bottle with a very well sealing GL45 screwcap. Sealing is of utmost importance if you want to keep the material good for a long time. A simple little jar with a standard plastic cap is not sufficient. Such a jar slowly exchanges fresh air, each time when it thermally cycles (e.g. between 30C on hot days and 20C during the night). Over the months, this leads to slow deterioration of the material and after a year or so most of your LiAlH4 will be oxidized and will have lost its reducing power.



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zed
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[*] posted on 27-2-2017 at 17:49


Me, I always liked it pacified by mineral oil. Used to come that way from Ventron.
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[*] posted on 2-3-2017 at 11:34


I bought the same material hoping to use it for super flash powder... at $1 a gram it is expensive. After experimenting with it I have been to scared to mix it with powerful oxidizers. When mixed with AN prill and aluminum powder a small drop of water turns the mixture into a very fast burning flare.

I don't know of any practical uses... maybe an oxidizer that is not the least bit hydroscopic would be good with it. lucky we have low humidity here in the SW.
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Stibnut
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[*] posted on 3-3-2017 at 02:16


How dangerous is it if it were to be accidentally exposed to humid air, and if I stored it as an anhydrous THF solution, would it be stable indefinitely? I have heard of the stuff causing fires before, but I'm not sure what I would have to do to set it off accidentally other than mixing with water or oxidizing agents.

I mostly want to use it as a reducing agent for organic chemistry - no particular reaction in mind, but it is so versatile that there is a lot I can do with it. Its solubility in THF is pretty high: 13 g/100 g at RT, and THF is one of my favorite solvents for its versatility, intermediate polarity, and fairly low bp. I could store it under mineral oil or hexane, too, but this would seem to pose problems for weighing it out, whereas a solution with a known concentration would be easy to deal with.
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Geocachmaster
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[*] posted on 3-3-2017 at 03:57


If you are concerned about fire, sorting the container in a paint can full of sand or kitty litter is a option. It would be difficult for a fire to get out of control when you are there, given you are not dealing with large amounts of solvents and have fire extinguishers. Storing it this way ensures that it would be safe when you are not around.
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[*] posted on 3-3-2017 at 16:42


I'm not terribly concerned; I've just never worked with it before and am not totally clear on how easily it can start fires in humid air.

It just arrived today. I'm putting it in my makeshift desiccator - just a lock-lid jar with moisture-indicating Drierite. With an airtight container and a dry environment, it will be fine. It can chill out there with my PBr3 and AlCl3. :)
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