Sciencemadness Discussion Board

NaK alloy

Scratch- - 23-2-2005 at 13:49

I am wanting to produce and ampoule some liquid NaK alloy. Heres what I'm planning on doing:

Need:
Argon (Welding shops)
Crucible stand
Oxygen/acetylene torch
Sodium hydroxide
Potassium hydroxide

Have:
Goggles
Gloves
Apron
Test tube
Metal spoon
Carbon electrodes (You can get them from carbon-zinc batteries)
AC adapter
Wire
Crucible (Or crack proof ceramic container)
Dish
Large airtight container with the top open (For doing things under argon)


Procedure:
1. Put on goggles, gloves and apron
2. Heat the top neck of a test tube and almost seal it
3. If step 2 doesn't work then get ampoules
4. Drill a small hole (1-2mm) in a metal spoon
5. Prepare the AC adapter and electrodes
6. Place crucible on its stand
7. Heat crucible gently to drive off moisture
8. Put sodium hydroxide in the crucible and heat gently to drive off moisture
9. Before hydroxide cools pour argon into crucible
10. Heat crucible until hydroxide melts
11. Heat electrodes to drive off moisture
12. Insert electrodes and apply electricity
13. Continue heating hydroxide until a generous amount of sodium forms
14. Immediately take out sodium and cool under argon, store in mineral oil
15. Repeat steps 7 to 15 for the potassium hydroxide
16. Heat the test tube to drive of moisture, put under argon
17. Heat crucible to drive off moisture
18. Put 60 percent potassium and 40 percent sodium in the crucible under argon
19. Heat until both are melted together well
20. Heat spoon to drive off moisture
21. Pour mixture through the spoon into the test tube until about half full
22. Put the rest of the mixture in a container under argon
23. Heat the neck of the test tube and close the end
24. Smooth out the neck of the test tube
25. Clean up apparatus

neutrino - 23-2-2005 at 14:06

If you’re using argon, make sure to have a steady stream to remove the oxygen formed. What are you using for a crucible? Sodium hydroxide is very reactive and will promptly destroy glass, ceramic, and most metals (some are resistant, though).

Scratch- - 23-2-2005 at 14:14

One of those cheap $3 crucibles you always see in chem labs. Its ceramic, although I think its treated to be chemicaly resistant? I have some copper roof flashing and I believe that Reverend Necroticus Rex used copper electrodes in a similar procedure to produce Na or K? Although, I want to avoid impurities as much as possible (While being as cheap as I can :) ).

unionised - 24-2-2005 at 01:24

"Large airtight container with the top open (For doing things under argon) "
Nice trick if you can do it.

Organikum - 24-2-2005 at 04:38

Useful materials for the reaction vessel:
- nickel or nickel plated iron (best)
- iron (steel)
- copper

/ORG

Scratch- - 24-2-2005 at 05:43

I probably shouldn't try to use the torch under argon though, so I'll have to take the crucible out while doing that. I have small steel cups and I can make copper crucibles probably, but I also have a Canadian coin thats from a year that it was suppost to be nickel. I might be able to plate a good layer onto the steel.

Marvin - 2-3-2005 at 04:02

Making potassium metal is not required. Make twice the sodium you need, dry the potassium hydroxide (fuse and then crush) and then heat the sodium with the pot hydroxide. The ratio and the degree of heating determine which alloy you get, then just decant the liquid alloy from the sodium when cold, I can look this information up if you get this far.

Heat from under the metal container, and steel will survive ok for this, and provide a steady stream of argon directed at the cathode, this will work fine.

The liquid alloy should only be made in very small amounts oweing to its tendecy to burst into flames as soon as it hits air. Its nowhere neer as nice to handle as solid sodium or potassium.

Scratch- - 31-3-2005 at 20:04

Thanks for your help. I'm currently redoing the garage (where I do chemistry) so it may be awhile before I can post results. I just got a nickel crucible too.

Madandcrazy - 16-5-2005 at 06:15

Whats the NaK alloy liquid for ?
Is it a easy alloy or a chemical substance ?

Needed materials for the vessel are all
materials they don`t react ;) with the
K/Na chemicals and they are heat resistant.

The gas needed that the metals not react with the air ?