| Pages:
1
2 |
ShadowWarrior4444
Hazard to Others
Posts: 226
Registered: 25-4-2008
Member Is Offline
Mood: Sunlight on a pure white wall.
|
|
You must not seal the chamber completely when heating; the increased pressure may cause a breach in addition to reducing the amount of sodium that
will boil off. Also, in this particular case the sodium would likely condense and stay as a liquid due to its close proximity to the heat source--this
may cause it to drip back down. (Upon contacting the PbCl, it will revert.)
You will most likely need a separate chamber for sodium condensation, and a useful way to usher the sodium into this chamber could be putting the
inert gas outlet in it. I also seem to recall designs that include a trough of sorts for allowing the sodium to drip into a collection chamber.
[Edited on 7-26-2008 by ShadowWarrior4444]
|
|
|
Picric-A
National Hazard
Posts: 796
Registered: 1-5-2008
Location: England
Member Is Offline
Mood: Fuming
|
|
well i didnt show it well in te diagrm but the cruicible would be about 30cm high but yes the pressure would be a sight problem...
maybe if you first flushed the vessel out with an inert gas, then you pulled a slight vaccum on it?
or if that fails, non-return valves?
You would have to keep it airtight or else oxygen would diffuse in and it would result most likely with an explsoion 
|
|
|
ShadowWarrior4444
Hazard to Others
Posts: 226
Registered: 25-4-2008
Member Is Offline
Mood: Sunlight on a pure white wall.
|
|
| Quote: | Originally posted by Picric-A
well i didnt show it well in te diagrm but the cruicible would be about 30cm high but yes the pressure would be a sight problem...
maybe if you first flushed the vessel out with an inert gas, then you pulled a slight vaccum on it?
or if that fails, non-return valves?
You would have to keep it airtight or else oxygen would diffuse in and it would result most likely with an explsoion |
Sodium will not explode in an oxygen environment, only burn.
The somewhat 'golden' rule of heating things up is making sure they are *not* pressure sealed. You would much rather have some of the sodium burn than
the entire vessel breaching to spray sodium and lead everywhere.
Oxygen will not diffuse in if you have a slow current if argon, it is much 'heavier' than air. A one way valve on the exit may be useful to conserve
argon, but a vacuum will be created when the chamber cools and so must be repressurized with argon before opening.
Ancillary: A vacuum distillation of sodium may be useful, but thus far I have not heard of it being used as an industrial practice; there is perhaps
good reason for this. As in other vacuum distillations, you’ll need to rigorously check for leaks and have argon standing by for repressurization.
[Edited on 7-27-2008 by ShadowWarrior4444]
|
|
|
Tin man
Harmless
Posts: 34
Registered: 12-9-2016
Member Is Offline
Mood: Gruntled
|
|
I would try heating NaCl with molten aluminium intead of lead, because aluminium has a higher boiling point and is way less toxic. I would also think
Al would be a better reducing agent.
|
|
|
Texium
|
Thread Moved
12-9-2016 at 14:34 |
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by Tin man  | | I would try heating NaCl with molten aluminium intead of lead, because aluminium has a higher boiling point and is way less toxic. I would also think
Al would be a better reducing agent. |
That couldn't work because AlCl3 is highly volatile.
In the past sodium metal has been used to reduce AlCl3 though:
http://www.azom.com/article.aspx?ArticleID=1530
[Edited on 13-9-2016 by blogfast25]
|
|
|
Cryolite.
Hazard to Others
Posts: 269
Registered: 28-6-2016
Location: CA
Member Is Offline
Mood: No Mood
|
|
That is true, but I wonder if sodium hydroxide and aluminum would work. Sort of like a magnesium thermite reaction, but more controlled and with
aluminum instead. The aluminum oxide formed is pretty much nonvolatile, so that's a plus.
The issue is that a lot of anhydrous metal chlorides are pretty volatile, due to them being covalent compounds.
|
|
|
Tin man
Harmless
Posts: 34
Registered: 12-9-2016
Member Is Offline
Mood: Gruntled
|
|
Oh, I should have thought about that. What about zinc powder and NaOH. Just cause zinc powder can easily be made by electrolysis of sodium zincate
solutium, adding to the OTCness.
[Edited on 13-9-2016 by Tin man]
|
|
|
elementcollector1
International Hazard
Posts: 2684
Registered: 28-12-2011
Location: The Known Universe
Member Is Offline
Mood: Molten
|
|
| Quote: Originally posted by Cryolite. | That is true, but I wonder if sodium hydroxide and aluminum would work. Sort of like a magnesium thermite reaction, but more controlled and with
aluminum instead. The aluminum oxide formed is pretty much nonvolatile, so that's a plus.
The issue is that a lot of anhydrous metal chlorides are pretty volatile, due to them being covalent compounds. |
Technically it does, but separation's a chore.
https://www.youtube.com/watch?v=seSg_GWj1b0
Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
|
|
|
Tin man
Harmless
Posts: 34
Registered: 12-9-2016
Member Is Offline
Mood: Gruntled
|
|
Would getting to 883°C( sodium's BP) be possible with a propane torch?
[Edited on 13-9-2016 by Tin man]
|
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
Not really, no. Vacuum will depress the BP though.
Both K and Na have been obtained by reactive distillation of suitable Na/K compounds with reducing agents like C or Fe (and others), at high
temperatures. None of these methods are particularly suited to hobbyists, though...
[Edited on 13-9-2016 by blogfast25]
|
|
|
Tin man
Harmless
Posts: 34
Registered: 12-9-2016
Member Is Offline
Mood: Gruntled
|
|
Could one use a charcoal furnace designed to melt aluminium? Aluminium's melting point is 660°C.
|
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
Yes.
|
|
|
Dan Vizine
National Hazard
Posts: 628
Registered: 4-4-2014
Location: Tonawanda, New York
Member Is Offline
Mood: High Resistance
|
|
On eBay you can purchase SS 304 cylinders similar to the familiar "lecture bottle" and smaller. Prices can be as low as $40.
Reactor (w/o leaks) issue solved.
You can purchase nickel flakes in graphite as sealant. Leak issue solved.
Any form of compressed air feeding a charcoal fire will give you copious amounts of heat. Hard coal is even better. 40-odd years ago unintentionally
melted a 1/2" thick solid Nichrome crucible that way. A vacuum cleaner supplied air. It was the foundry in a 5 gallon pail once described in Popular
Science ( back when it was actually a useful magazine).
Using He destined for party balloons is not too good an option. Some has oxygen in it and none of it is pure. Bloxygen (argon) may be worth looking
into, I have only used commercial tanks. I have no idea exactly how pure it is.
A vacuum is very desirable. Vacuum pumps are $$$, but eBay provided me with a Hitachi "Cute Vac" pump for $75 (two stage, oil-filled, vane-type). The
main shaft seal leaks and someday I'll replace it, but it takes days of continuous running to lose a liter of oil ($15). A vacuum pump is one of the
most vital pieces of equipment in the lab. Unless a pump has been run with low oil and been burned and scored inside (only a fool would try to sell
that mess), most pumps can be rebuilt with new vanes, springs, seals and filters with re-build kits to give near-new performance.
When condensing, beware of a plug forming in the condenser. SS is a good choice. Transition to glass with a rubber stopper. You'll want a hot air gun
handy when and if you distill Na out of the reactor, you never know where or if a plug will occur until you have run several reactions.
As blogfast25 noted, these reductions with less-active reductants require more demanding conditions. Unless this is meant as absolutely pure science,
just to see it work, this is a tough road to travel.
Incidentally, K is much safer to work with from certain standpoints. K can be heated to 300 C in air without burning, Na burns spontaneously at half
that temperature. Keeping an open condenser (free of plugs) is easier, too.
"All Your Children Are Poor Unfortunate Victims of Lies You Believe, a Plague Upon Your Ignorance that Keeps the Youth from the Truth They
Deserve"...F. Zappa
|
|
|
aga
Forum Drunkard
Posts: 7030
Registered: 25-3-2014
Member Is Offline
|
|
Here, on one occasion, charcoal & a hairdyer on the end of a 1m steel pole created enough heat to melt copper.
~1085 C
|
|
|
Tin man
Harmless
Posts: 34
Registered: 12-9-2016
Member Is Offline
Mood: Gruntled
|
|
Sorry if this is a stupid question, but would potassium require a higher or lower temperature to form? assuming the same reducing agent was being
used.
|
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by Tin man | | Sorry if this is a stupid question, but would potassium require a higher or lower temperature to form? assuming the same reducing agent was being
used. |
Analogous Na and K compounds tend to have very similar Enthalpies of Formation. For that reason it's to be expected that using the same reducing agent
will require similar temperatures.
But since as these metals are then obtained by distillation and K has a higher BP, K may require higher temperatures.
[Edited on 23-9-2016 by blogfast25]
|
|
|
Meltonium
Hazard to Self
Posts: 97
Registered: 23-9-2016
Location: Home in pajamas
Member Is Offline
Mood: Fluorinated
|
|
Instead of using argon as an inert atmosphere, could you use a CO2 generator, or would that react?
Also, you could use a vacuum aspirator to create the low pressure; however, I'm not sure if the presence of the water may be risky business.
|
|
|
Metacelsus
International Hazard
Posts: 2539
Registered: 26-12-2012
Location: Boston, MA
Member Is Offline
Mood: Double, double, toil and trouble
|
|
Carbon dioxide will react with alkali metals at these temperatures. (Have you ever seen the demonstration where burning magnesium is put into a block
of dry ice? It would be like that.)
|
|
|
m1tanker78
National Hazard
Posts: 685
Registered: 5-1-2011
Member Is Offline
Mood: No Mood
|
|
Liquid sodium reacts with dry CO2 to form varying degrees of Na2CO3, C, and CO. The reaction initiates between 250C
and 300C[1]. Depending on the temperature, a glassy intercalation of the solid products + sodium can be obtained. The reaction produces
enough CO that it can be 'flared' off in air and produces a beautiful tenuous light blue flame.
Short answer: Stick to argon.
[1] Miyahara, S. (2011). "Experimental Investigation of Reaction Behavior Between Carbon Dioxide and Liquid Sodium." Nuclear Engineering and
Design #241.
Chemical CURIOSITY KILLED THE CATalyst.
|
|
|
Tin man
Harmless
Posts: 34
Registered: 12-9-2016
Member Is Offline
Mood: Gruntled
|
|
Nitrogen doesn't react with sodium to my knowledge. It would be a lot cheaper than argon.
|
|
|
| Pages:
1
2 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
