Sciencemadness Discussion Board

Alternative way to make sodium first try

metalresearcher - 10-9-2010 at 12:02

Based on the first message of this topic I found out on this site that more reactants can issue sodium metal when heted together to about 1000oC. So I tried Na2CO3 and Mg metal.

Na2CO3 + Mg --> MgO + CO2 + 2Na

I put fine powered anhydrous soda with chunks of Mg metal in a Schott Duran test tube as a retort. I put a stopper with a narrpw tube in it to allow the air to come out.
Then I heated it till 1000oC with a propane burner (gets hotter than my natural gas fired Bunsen). The mixture melted and I really saw some yellow sparks escaping from the mixture. But .... the test tube softened as it were a plastic one :mad:
To prevent the tube from melting (and expose the mixture to the open ait I stopped the burner and let it cool down.
I'll retry it with a steel tube as a retort.

Here the deformed test tube with the mixture in the bottom:

schott-duran-exit.jpg - 39kB

NightHawkInLight - 24-9-2010 at 19:39

This may help you, it is a post I made on another forum:

A recent experiment of mine involved the production of the highly reactive element sodium from sodium hydroxide and another less reactive metal, in this case magnesium. The reaction is as follows:

2Mg + 2NaOH = 2MgO + 2Na + H2

The magnesium (finely powdered) first ignites burning in atmospheric oxygen contained in the reaction vessel. This initial reaction produces enough energy to initiate the primary reaction. The Mg has enough desire for the oxygen contained in the NaOH to actually rip it from the hydroxide group, freeing hydrogen gas and sodium. The reaction is violently exothermic. More than enough energy is released to ignite the hydrogen gas which burns as the reaction progresses. The sodium is produced in a liquid state due to the temperature of reaction, and some of it vaporizes giving the flame a strong orange/yellow color.

To keep the sodium from burning immediately upon production, a loose fitting lid is placed over the reaction vessel, allowing the burning hydrogen to escape, but sealing the vessel off from atmosphere once completed. The lid is then not removed until the reaction cools to air temperature, at which point mineral oil should be added to the resulting slag to prevent further oxidation of the product.

Presumably this experiment could be preformed with other metals acting upon the hydroxide group, such as aluminum. It is also quite likely that this process could free most if not all metals from their hydroxides because the reaction does not involve the metal contained in the hydroxide, but the hydroxide group alone. All hydroxides should therefore be susceptible to separation via magnesium and possibly aluminum.

Here is a video of the experiment being conducted:

http://www.youtube.com/watch?v=faorfmRkCv0&feature=playe...

Ideally purification and removal of the sodium from the MgO slag would be as simple as heating the mixture under mineral oil to the melting point of sodium at which point it would gather together. So far I have been unable to do that successfully. It is possible the products needed to be heated longer or they needed to be more finely ground to free the sodium.

-Ben

Rogeryermaw - 24-9-2010 at 20:20

@ NightHawkInLight i watched that video like 10 times. i am a fan of your channel and was planing to use this method to produce sodium for drying of certain solvents. how would you rate the purity of your product after the drop through oil to water then floating back to the oil layer?

12AX7 - 24-9-2010 at 23:32

Sodium hydride is a large product of the hydroxide reduction, unfortunately.

Supposedly, doing it in a bomb has better results.

Tim

NightHawkInLight - 25-9-2010 at 13:51

Quote: Originally posted by Rogeryermaw  
@ NightHawkInLight i watched that video like 10 times. i am a fan of your channel and was planing to use this method to produce sodium for drying of certain solvents. how would you rate the purity of your product after the drop through oil to water then floating back to the oil layer?

I couldn't tell you the purity. I did not preform any tests. I doubt the purity is very high, simply because of the method used. It is likely not pure sodium, but an alloy of sodium and an unknown percentage of magnesium. In any case, it should work fine for drying solvents.

blogfast25 - 26-9-2010 at 11:44

I see the dream of producing significant amounts of sodium metal other than by electrolysing either molten NaOH or NaCl remains alive. I say 'dream' because while NightHawkInLight's experiments are meritable and his vids fun to watch, what he does is still a relatively far cry from producing anything near technical grade sodium. The product is still far too contaminated. This was also the case with the product obtained by some experimenters on our forum: these products are fun to watch skid on water of set fire too but aren't much use for any other purpose.

For small amounts of purer Na, I'd still prefer to electrolyse small amounts of molten NaOH with carbon electrodes, with argon blanket...