Sciencemadness Discussion Board - brick sodium

brick sodium

Maya - 4-7-2012 at 15:16

what is the best way to cut a 5 inch by 5 inch by 10 inch SODIUM metal ingot?

DJF90 - 4-7-2012 at 15:19

How about a large kitchen (chef's) knife...

Lithium - 4-7-2012 at 16:51

yeah, heat up a large knife so it cuts easier and off you go!

Endimion17 - 5-7-2012 at 00:59

Kitchen knife? No.

Heated knife? No.

When you've got such large brick, you finally start thinking that sodium really is a piece of metal. Hard and thermally conductive.

Use large garden scissors. Or a large chisel and a large hammer.

Arthur Dent - 5-7-2012 at 03:26

@ Maya: I'm curious, do you own such a beast? If so, How?

Robert

unionised - 5-7-2012 at 03:52

"what is the best way to cut a 5 inch by 5 inch by 10 inch SODIUM metal ingot? "
Carefully, and with gloves on.
Not with a saw (even if that's how you would usually cut through a big lump of metal) because you don't want the sawdust.

Maya - 5-7-2012 at 15:50

Quote:

Maya: I'm curious, do you own such a beast? If so, How?

Yes, courtesy of a Large Motor Vehicle Co.

But still in the original plastic packaging because unsure
exactly how best to cut it. Presently it is Too big to put in any jar

Zan Divine - 5-7-2012 at 16:32

You can forget about sawing it if lithium is any kind of model. I had a Lithium ingot about 3 inches in diameter and maybe 3 inches long. I tried a metal cutting bandsaw on low speed, but it kept grabing the blade. No go with a hacksaw either. The teeth fill up and stay filled with the soft sticky metal.

Really, what you need to do is use is a big freakin' knife. 5 inches sounds big but it really isn't so bad (hmmm..in comedy parlance that would be the set-up...). Sodium metal is so soft that it flows under very modest pressure. If someone handed you a 1" rod of sodium, you'd be able to rip it in half with your gloved hands. A person of normal strength, sitting astride this ingot would be able to grip the ends of a machete and slowly just push the knife down through it while rocking the blade from side to side.

Fully realizing that not everybody has a machete (although my friggin' neighbors cut their bushes with one) you could easily improvise by taking a strip of 1/8" steel a couple inches wide a and using a grinder to sharpen an edge. If you don't have some basic tools you face a rough task.

With my second Li ingot, I flattened it down to 1" in the sealed Mylar bag using a hydraulic press. I could then use large tin snips to cut it. A general note on snips...they don't work so well on things larger than their bite....they will work, but it won't be easy.

A big, wide and sharp chistle and a big hammer is a less elegant second choice.

[Edited on 6-7-2012 by Zan Divine]

vmelkon - 5-7-2012 at 20:08

Besides the chisle and kitchen knife advice above, you can heat sodium under oil until it melts and then you suck up the sodium with a glass syringe and dump it into a mold of your choice.
There was a video of that on youtube. The guy had a 4.5 Kg brick. He had bought a glass syringe (large) for 5 $ from ebay.

Zan Divine - 6-7-2012 at 13:19

Vmelkon, that is a great alternative.

If you try this Maya, the key is remembering that if you let the syringe cool below ~98 C the Na freezes. That is skin burning temperature so use gloves and work quickly.

* A note of caution about syringes full of molten reactive metal...NEVER push hard if the needle is starting to freeze. If the syringe ruptures for any reason you can be seriously hurt. A good hot air gun (not a hair dryer) will help.

Endimion17 - 6-7-2012 at 14:31

Melting is also ok if you work very carefully. Although not probable, sodium fire is not cool and if someone tries to put it out with water (you never know who can see the fire and foolishly try to help), a detonation occurs.

Try melting your sodium in a beaker filled with kerosene or paraffin oil, and then pour it in an ice cube tray. There's always some protective liquid above. When it solidifies, simply remove it like ice. Voila, sodium cubes.

Fleaker - 6-7-2012 at 14:41

We used to cut it warm with a butcher's knife. This was 4.5" round logs that were about 2 kg a piece. This can be done under kerosene or in a dry box if one is careful.

m1tanker78 - 6-7-2012 at 20:08

I use a large kitchen knife or sometimes a clean machete to cut through large logs/bricks of sodium. The thinner the blade, the better. One hand on the handle, the other hand near the tip and use a rocking motion while pressing down firmly. Don't use a slicing motion. It won't be a clean cut but I doubt that'll bother you much.

Molten sodium is difficult to pour into ice cube trays. If you pour too much (it happens, trust me), you risk having a nasty sodium fire. I like the syringe idea but have never tried it.

The best tool in my arsenal is a large Japanese filleting knife.

Tank

Maya - 7-7-2012 at 03:44

<<<We used to cut it warm with a butcher's knife. This was 4.5" round logs that were about 2 kg a piece. This can be done under kerosene or in a dry box if one is careful. >>>

That's what I'm leaning towards Fleaker.
Dry box/ butcher knife.
Did you really need to warm the logs or knife up, what temp?

vmelkon - 7-7-2012 at 05:54

I found the video of the guy with the oil + glass syringe technique
http://www.youtube.com/watch?v=-6jVyDFqy0Q

Endimion17 - 7-7-2012 at 06:59

Quote: Originally posted by vmelkon

I found the video of the guy with the oil + glass syringe technique
http://www.youtube.com/watch?v=-6jVyDFqy0Q

Hmmmmm, I thought there should be my reply in the comment section... I guess he removed it. :S
That really isn't a way to refine sodium. It's very dangerous and irresponsible. Sodium must be under the protective liquid at all times. He's frying a sodium brick with a gas stove, FFS. The oil could've caught fire.
Also, it's not ok if you need the pure reagent. He didn't even remove the crust, and it's visible as inclusions while he's sucking the melt into the syringe. Sodium has a nasty habit of creating blobs that won't join together, and while larger batches spontaneously join due to the weight, smaller ones need rotating magnets, like YouTuber Nurdrage has shown with potassium in one of his videos (check it out). Sometimes you can merge them with a glass rod.

Sodium is melted under the paraffine oil, using a hotplate (NO FLAMES!) and a thermometer to ensure the temperature doesn't get much higher than 100 °C. From my experience, 110-115 °C is enough.
It's best to remove the crust before you begin, and to salvage the crust-sodium waste separately, otherwise the crust traps lots of sodium blobs.
When the metal melts, the beaker is tilted to decrease its surface and then is left to cool down.
I've done this a couple of times and I know how frustrating it can be.

[Edited on 7-7-2012 by Endimion17]

Maya - 7-7-2012 at 07:36

I AM DEFINITELY not melting any Kg sized logs of Na under Any conditions.........
I am positive my insurance will not cover that

Zan Divine - 7-7-2012 at 08:10

Endimion, that wasn't what I pictured either...open flames, somewhat flammable liquid & sodium. Definitely rolling the dice. I'm sure it works 99+% of the time but it is so messy and hazardous if it fails.

Sodium fires ought not to be confused with sodium/water events (which are waay worse), but it's still bad enough.

Glovebox and a big knife? That's another way to roll the dice. 15 mil gloves go $200/pair currently. Let me know if you want to order replacements....But, why risk it?

Sodium metal deserves respect but not awe. It can be handled in air without a second thought. Six months ago I was way more wary of Na. Since then I've had ocassions to pound, press, melt, pour, and generally experience Na and it's really not a beast. I think I first lost a little respect for Na when I found you can dry solvents/oil off it with paper towels and nothing happens. Just don't lose all respect for it.

[Edited on 7-7-2012 by Zan Divine]

Endimion17 - 7-7-2012 at 09:13

Quote: Originally posted by Zan Divine

Endimion, that wasn't what I pictured either...open flames, somewhat flammable liquid & sodium. Definitely rolling the dice. I'm sure it works 99+% of the time but it is so messy and hazardous if it fails.

That's my opinion, too.

Quote:

Sodium fires ought not to be confused with sodium/water events (which are waay worse), but it's still bad enough.

The thought of losing such precious reagent is... ugh. Sodium fires can be contained with dry sand, however the stuff can reignite if it's not properly dealt with. I'd put sand over it and after it cools, dump it into the kerosene.
Also, if the fire happens in a closed environment, the smoke can be fatal. Sodium hydroxide aerosol, and some peroxide/oxide smoke after the water vapor has been depleted. It happened at least once on a larger scale.
I suppose pulmonary edema can result from even short exposure. Fortunatelly, the larynx contracts... or perhaps unfortunatelly, because you can't breath.

Quote:

Glovebox and a big knife? That's another way to roll the dice. 15 mil gloves go $200/pair currently. Let me know if you want to order replacements....But, why risk it?

If he fills it with nitrogen/argon, it's ok, but can he cut through 5 inches of metal? No.
I have experience with an almost 2 inch thick brick. It's simply too hard and it took me like 15 minutes of messing with a small knife.
Heating the knife doesn't help because the heat is being quickly drawn away.
It would be the best if he can find large garden scissors or a chisel and a large hammer. Otherwise, proper melting is the way to go.

Quote:

Sodium metal deserves respect but not awe. It can be handled in air without a second thought. Six months ago I was way more wary of Na. Since then I've had ocassions to pound, press, melt, pour, and generally experience Na and it's really not a beast. I think I first lost a little respect for Na when I found you can dry solvents/oil off it with paper towels and nothing happens. Just don't lose all respect for it.

I've been handling sodium for the past 15 years and I agree with you. It won't catch fire spontaneously even if dry. It won't do anything even if you briefly touch it with dry hands. Once I even took a M&M's sized piece still wet from the kerosene and squished it between my fingers. No damage at all.
The only spontaneous, small fiery burps of fire I've seen was with very tiny pieces on a hot summer day, when the relative humidity is low. If it's high, it soon cakes itself in a hydrogencarbonate-hydrogen foamy goo.
I imagine that a brick-sized piece can catch fire under specific conditions.

It can be a scary beast, but if you keep a healthy approach, it can't harm you... unlike white phosphorus which is the fucking Dracula of the periodic table, making bloody mess if lifted for too long from its watery grave.
The only reason why I'm working quickly with sodium is to reduce its wasting and contaminating organic solvents which I'm trying to dry. If I had a lot of money and used sodium for fooling around, I wouldn't care to slice it like kids slice clay in kindergardens.

Zan Divine - 11-7-2012 at 19:30

Endimion: "If he fills it with nitrogen/argon, it's ok, but can he cut through 5 inches of metal? No."

Hard to say. Fleaker (see above) cut 4.5 inch ingots.

It wasn't the atmosphere of the gb that concerned me...it was the fairly heavy use of a large knife with 15 mil butyl gloves. One slip and $200 flies out of your pocket.

[Edited on 12-7-2012 by Zan Divine]

DJF90 - 11-7-2012 at 22:51

I've cut through an inch of sodium with a knife before with no issues. I can't see why the dimensions provided by the OP would be any more problematic. A large kitchen knife (one of those "13 inch chef's knives") will make good work of it, especially if you ensure its sharp before use. Don't use a slicing action, but pure downwards force. you'll want to provide force at the tip of the blade as well as at the handle. Any difficulty can be overcome using a rubber mallet

I'd suggest cutting it into 1x1x5" "ingots" if these are not too big for whatever container you intend them for. You'll get 50 such ingots out of the dimensions you describe!

Endimion17 - 12-7-2012 at 00:38

Quote: Originally posted by Zan Divine

Endimion: "If he fills it with nitrogen/argon, it's ok, but can he cut through 5 inches of metal? No."

Hard to say. Fleaker (see above) cut 4.5 inch ingots.

It wasn't the atmosphere of the gb that concerned me...it was the fairly heavy use of a large knife with 15 mil butyl gloves. One slip and $200 flies out of your pocket.

[Edited on 12-7-2012 by Zan Divine]

Crap, I see now.

Quote: Originally posted by DJF90

I've cut through an inch of sodium with a knife before with no issues. I can't see why the dimensions provided by the OP would be any more problematic. A large kitchen knife (one of those "13 inch chef's knives") will make good work of it, especially if you ensure its sharp before use. Don't use a slicing action, but pure downwards force. you'll want to provide force at the tip of the blade as well as at the handle. Any difficulty can be overcome using a rubber mallet

I'd suggest cutting it into 1x1x5" "ingots" if these are not too big for whatever container you intend them for. You'll get 50 such ingots out of the dimensions you describe!

Well, you're wrong. Cutting a 5 times thicker piece is more than five times worse. It truly shows you: "Hey, I'm a piece of metal, FU".

DJF90 - 12-7-2012 at 01:41

I'll agree that it is not going to be easy but I had no problems cutting through an inch with a knife and I'm sure a large kitchen knife and a rubber mallet would make short work of it. I have a couple kilo so maybe when I need to use some of it I'll post a video (the large ingots are still in sealed tins and I have 400g or so under oil in a jar so it won't be anytime soon). Obviously it wont be as monstrous as cutting through a 5x5" cross section, but it'll illustrate the point.

Maya - 14-7-2012 at 14:35

Ok , so maybe a 13 inch butcher knife, rubber mallet if needed, big plastic box, big gloves and putting the dogs in their crates will do.
Oh, I can also flood the box with argon first but I don't know how critical that is. Atmosphere would quickly be displaced and it is 90%
humidity here in summer. Waited 3 years , I can prolly wait till lower humidity in winter.

No melting of multi Kg pieces of Na in my place please!

[Edited on 14-7-2012 by Maya]

Endimion17 - 14-7-2012 at 15:52

Quote: Originally posted by Maya

Ok , so maybe a 13 inch butcher knife, rubber mallet if needed, big plastic box, big gloves and putting the dogs in their crates will do.
Oh, I can also flood the box with argon first but I don't know how critical that is. Atmosphere would quickly be displaced and it is 90%
humidity here in summer. Waited 3 years , I can prolly wait till lower humidity in winter.

No melting of multi Kg pieces of Na in my place please!

[Edited on 14-7-2012 by Maya]

You don't need argon. Just make sure to moisten the brick with some of its protective liquid if you're so scared of it. It can't burst to flames and it won't. I did almost the same thing with one sodium brick. Actually, I've never even moistened it, just kept working with my knife.

In order to burst to flames, it needs a large surface area relative to its volume, just to name one factor. A huge lump draws away any surface heat made by oxidation. That's why only small pieces can burst to flames, but only if other criteria are met, too.

m1tanker78 - 14-7-2012 at 16:02

Quote: Originally posted by Maya

[...]and putting the dogs in their crates will do.

I had to think about that one for a second. Yeah, a chunk of sodium would be a dog treat from hell.

Tank

RadioTrefoil - 17-7-2012 at 23:42

Quote: Originally posted by vmelkon

Besides the chisle and kitchen knife advice above, you can heat sodium under oil until it melts and then you suck up the sodium with a glass syringe and dump it into a mold of your choice.
There was a video of that on youtube. The guy had a 4.5 Kg brick. He had bought a glass syringe (large) for 5 $ from ebay.

Haha, I saw that video (from SodiumInfo). It didn't look particularly safe, he just had a pan full of molten sodium on an open gas stove. Don't you think it would be a bit of a fire hazard?

vmelkon - 18-7-2012 at 03:56

To me, it looks like the part where he has the block in the pan is safe. The sodium is covered by oxide so it should be fine.

The part where he takes liquid sodium out looks dangerous. I have to admit I don't have experience with sodium. I don't know why it didn't immediately oxidize (the part where the sodium was on top of the silicone molds). Weird.

Endimion17 - 18-7-2012 at 06:13

Quote: Originally posted by vmelkon

To me, it looks like the part where he has the block in the pan is safe. The sodium is covered by oxide so it should be fine.

The part where he takes liquid sodium out looks dangerous. I have to admit I don't have experience with sodium. I don't know why it didn't immediately oxidize (the part where the sodium was on top of the silicone molds). Weird.

It's never covered with oxide(s). The "rust" is a mix of hydroxide, carbonate and hydrogencarbonate. The older it is, the more hydrogencarbonate there is.
What's protecting sodium is a thin layer of its protective liquid. It simply won't do any harm as long as it's wet with kerosene.

Sucking the melt with a syringe is not dangerous if the syringe can handle the temperature level. Even if the melt falls out, as long as it doesn't contact incompatible compounds, it won't ignite. Sodium can ignite only when sodium vapors are present in quantities above mere traces, and that's around its boiling point and above.

It might even be a good idea to leave it to solidify in a syringe. A nice ingot can be made that way.