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metallic sodium

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roddenberry

Sun Sept 20 2009, 03:38PM

Registered Member #2272 Joined: Wed Aug 05 2009, 01:34AM
Location:
Posts: 7

I've seen this Youtube video on how to create metallic sodium out of sodium salts and magnesium powder.

I was wondering about a few things... I imagine that the resulting metallic sodium is heavily contaminated with remains of salts and magnesium? Can the resulting sodium be purified a bit?

I was hoping to attempt this with sodium bicarbonate (Cow Brand) because it's plentiful and inexpensive. Would this work as well as sodium nitrate or sodium hydroxide?

And what about potassium? Would this process work with potassium salts?

If anyone has ever attempted this experience, i'd like to know if the results are worth the effort. I live in a densely populated urban area (Montreal) and this experience can only be attempted somewhere far from here. So I want to make sure I won't waste my time and energy if it's not worth the effort.

Robert

Brett Miller

Sun Sept 20 2009, 05:44PM

Registered Member #593 Joined: Tue Mar 20 2007, 12:32AM
Location:
Posts: 50

Funny coincidence...I too was watching that video with envy, as well as the reply video he posted to his own video, showing a higher yield water-cooled variation on the first method, using a smaller crucible. It should be quite simple (due to the relatively low melting point of metallic sodium) to melt down the various contaminated ingots in an inert liquid and consolidate the pieces into a large fragment for storage...I'd store under oil. I think he mentions this idea in the video, or someone else does in a text reply.

I am planning on making some myself as soon as I gather all the proper ingredients. Once many years ago I was able to come up with a decent quantity of finely powdered magnesium using a bench grinder, and one of those magnesium bar camping fire starters with a flint rod on the reverse side. I just ground it over a piece of paper, and every now and then would empty the contents of the paper into an off site container...just in case a spark flew and ruined the pile of magnesium. Of course I always had a fire extinguisher standing by.

What started this for me was the fact that my wife is currently in school for nursing, and was discussing the chemistry of the body, including the role of Potassium and Sodium. It got me thinking about elemental Potassium/Sodium and I told her about the hydrogen production and heat those metals release upon reaction with water. This lead me to YouTube.

If I produce any Sodium I'll notify you via this thread.

-Brett

Bored Chemist

Sun Sept 20 2009, 06:32PM

Registered Member #193 Joined: Fri Feb 17 2006, 07:04AM
Location: sheffield
Posts: 1022

Brett,
what sort of fire extinguisher did you have?
Most of them won't put out a metal fire.
Roddenbury.
Bicarbonate of soda probably won't work.
Anyone thinking aboutr that reaction needs to know thet you can't use an aluminium pan- the molten NaOH will eat it.
On the whole this experiment isn't a good idea.

Chris

Sun Sept 20 2009, 10:30PM

Registered Member #8 Joined: Thu Feb 02 2006, 04:34AM
Location: Harlowton, MT, United States
Posts: 214

The temperatures involved in this reaction are well above the boiling point of metallic sodium. The setup he used in that video is very crude; it is impossible to get a good yield with it or any subtle variations of it, not to mention it is a horrible idea for a host of reasons as stated already by Bored Chemist. Instead, this reaction should be carried out in a sealed steel retort, backfilled with noble gas such as argon or helium (CO2 reacts vigorously with both sodium and magnesium, and nitrogen reacts with magnesium). A vacuum can also be used, and will even lower the temperature required for the reaction, as it works by boiling off the most volatile metal. External heat can be applied to drive the reaction, requiring temperatures in excess of 900Â°C which can be reached by a propane torch only if the vessel is well insulated such as with some firebrick or ceramic wool. A wood or coal fire fed by a blower is also a good option. The sodium is distilled out and collected in an adjacent vessel, highly purified. An apparatus like this can be made from threaded black pipe fittings pretty easily. If you can't figure out how to design such an apparatus, it is likely you shouldn't be playing with this reaction anyway.

This reaction will work for any alkali metal, and is used industrially to extract potassium and cesium (but with calcium or sodium as the reductant instead of magnesium since they are cheaper industrially). It works with chlorides as well as hydroxides, and there is little reason not to use the chloride salts as they are much cheaper and easier to obtain, as well as much nicer to work with.

A few notes on safety:

While the reaction won't be nearly as violent in the absence of air, it should still be considered an explosion hazard. The outlet/condenser of the retort should not be too restricted, and I would recommend a relief valve maybe using a ball bearing that sits over a hole.

The temperatures involved exceed the melting point of aluminum and brass, not to mention aluminum and zinc are reactive, so don't use those metals anywhere on it.

ABC fire extinguishers, CO2 fire extinguishers, and obviously water, will all have quite the opposite effect if you use them to put out a class D (metal) fire. These materials are all quite happy to act as an oxidizer for magnesium and sodium. You need to either have a class D fire extinguisher (very expensive) or halon fire extinguisher (will release hydrogen halides on application to heat and strong reducing agents) on hand, or be prepared to smother it with an alkali metal or alkaline earth metal chloride or oxide/hydroxide.

Brett Miller

Thu Sept 24 2009, 04:32AM

Registered Member #593 Joined: Tue Mar 20 2007, 12:32AM
Location:
Posts: 50

Chris, Bored Chemist,

I wish there was a "grownups only" forum where we could talk about whatever procedure without fear of some incompetent tweenybopper cloning our experiments and blowing various digits off. I forgot how many kids are actually on here. It's been a while since I logged on. I guess I left my fooling around with pyro days decades ago in my childhood, and forgot that for some...that may be now. I should know that from looking at youtube.

That's about it. Try not to noob slap 35 year old university educated adults. Thank you.

-Brett

Chris

Thu Sept 24 2009, 10:39PM

Registered Member #8 Joined: Thu Feb 02 2006, 04:34AM
Location: Harlowton, MT, United States
Posts: 214

Brett: where do you get off trying to flame me for mentioning safety regarding a potentially dangerous reaction? This isn't even your thread, and I wasn't even replying to you. I was addressing the original poster. Did you read my post as a condescending safety lecture directed toward you? Someone asked how to get pure sodium from a metal replacement reaction and I told them, in a lot more detail than you did. I don't care how old you are or what you graduated from; your initial post didn't mention any background and reads as if you had little experience. If you're such a brilliant and experienced chemist, why are you even fooling around with such an inefficient method? You should know better. I read your original reply. I see you've deleted most of it now, but you blatantly disregarded everything I said and made your post into a personal attack. You spoke as if I was some child who had no idea what I'm talking about, when in fact I have a great deal of knowledge and experience with such things. You are unbelievably hypocritical to confront me for making assumptions about peoples' background. I think others here should see this behavior so they know what you're on about.

That's about it. Try not to noob slap 23 year old university educated custom knifesmiths/foundry operators, ESPECIALLY when they aren't even talking to you.

roddenberry

Thu Sept 24 2009, 10:46PM

Registered Member #2272 Joined: Wed Aug 05 2009, 01:34AM
Location:
Posts: 7

Thanks guys, for the advice... anyway, this experiment looks a bit hazardous and I don't even have the physical space to attempt it, so i'll look at other alternatives. BTW, I am a 46 yr. old graphics designer and electronics hobbyist, with a slight mad scientist streak... LOL

- Robert in Montreal

Bored Chemist

Fri Sept 25 2009, 08:04AM

Registered Member #193 Joined: Fri Feb 17 2006, 07:04AM
Location: sheffield
Posts: 1022

Bret
Re. "That's about it. Try not to noob slap 35 year old university educated adults. Thank you."

Try not to act like a noob.

BC (a 43 year old unniversity educated professional chemist; as if that makes any difference).

Steve Conner

Fri Sept 25 2009, 08:46AM

Registered Member #30 Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706

Gentlemen, try not to noob-slap each other or the thread will be locked.

For metal fires, you need a dry powder extinguisher, or the ghetto version, a big bucket of sand.

Brett Miller

Fri Oct 23 2009, 04:43PM

Registered Member #593 Joined: Tue Mar 20 2007, 12:32AM
Location:
Posts: 50

Chris,

I edited my original post because someone pointed out in a PM that it was an emotional overreaction. I looked at my post, thought about it, and agreed that I was wrong and most of what I posted was incorrect and reactionary. The tone of my reply stemmed from the notion that what experiments I do and the risks I take are my prerogative, and I will discuss them with other people like yourself on forums with no fear of the foolish copying me and getting hurt.

You're still sore over reading my original post. I'm sorry about that. I rescinded that letter, and now that you know that, it shouldn't be doing damage. I think on the occasion of that post, I even confused one of "bored chemist"'s posts with your words, and heaped some of that grief onto you. Also wrong, but it is worth noting that you are just as willing to get pissed over nothing as I was.

Let's just get over it and return to the good stuff.

Lately I've been spending time coding demos in Assembly Language on the C64. I like to check in to this forum every now and then to see what's going on and if there are any new TC topologies being developed. Honestly I'd forgotten how tight everything is here...speech is regulated, and threads are kept tight as a drum. It's good for project productivity and keeping subjects from wandering in a thread, but not good when someone (like me) lets his guard down and expresses emotion. Forgive.

-Brett

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