Sciencemadness Discussion Board - Get Zirconium from Zirconium Tetrachloride

Get Zirconium from Zirconium Tetrachloride

TheAMchemistry87 - 1-9-2012 at 11:30

So whats a good metal to use to react with Zirconium Tetrachloride to recieve the Zirconium Metal ?
Aluminum? Magnesium?

AMchemistry

kristofvagyok - 1-9-2012 at 11:35

Magnesium, sodium, potassium, calcium ect.

Aluminum sometimes (mainly home chemist's supply) contains iron and a lot other things what is aint so good for pure reactions.

But also: use the search engine and read the Inorgo chem book by Brauer, as I remember there is a method for this...

Hexavalent - 1-9-2012 at 11:39

This should definitely be in the beginnings section.

I don't know enough about zirconium chemistry to be certain, but as far as reduction potentials go I think magnesium should work. Consult 'plante1999' - he may be able to say for certain.

Doing the reduction electrolytically may also be an option.

Quote: Originally posted by kristofvagyok

Magnesium, sodium, potassium, calcium ect.

Are you implying that this be done in aqueous solution? Hydrolysis would happen for sure...even if this was possible, then the reaction of Na, K or Ca with water would be a problem, no? If done in an alcoholic solvent, then the formation of alkoxides could also be problematic.

[Edited on 1-9-2012 by Hexavalent]

kristofvagyok - 1-9-2012 at 11:48

Quote: Originally posted by Hexavalent

If this is done in aqueous solution, then the reaction of Na, K or Ca with water would be a problem, no? If done in an alcoholic solvent, then the formation of alkoxides could also be problematic.

ZrCl4 is really unstable in presence of water, it hydrolises rapidly as I remember, so just solid state reduction could be done where the sodium with it's low melting point is one of the best.

[Edited on 1-9-2012 by kristofvagyok]

barley81 - 1-9-2012 at 11:51

Brauer says that zirconium can be prepared by heating ZrCl4 together with Na metal, or by reduction of ZrCl4 vapor with Mg in helium atmosphere.

Other methods: reduction of ZrO2 with Ca metal, or reduction of K2ZrF6 with Na metal.

Hexavalent - 1-9-2012 at 11:53

kristofvagyok

Ah yes, I see. Would a solid-state reduction be efficient, though? How practical is it? Would it have to be done under an inert gas? No offence, TheAM, but if you're asking a question like the one here then I don't think you should be handling liquid sodium by yourself.

[Edited on 1-9-2012 by Hexavalent]

blogfast25 - 1-9-2012 at 11:56

ZrF4 + Mg is basically the Kroll process (Ti and Zr) applied to zirconium. Don't try that at home! Both obtaining signifcant quantities of ZrCl4 and the actual reduction reaction aren't exactly child's play! The reduction reaction (with Mg or Na) is seriously exothermic and ZrCl4 is quite volatile. Volatile + heat = pressure!

Aluminium is generally (bar exceptions) not a great reductant for chlorides: it's HoF isn't very high and it is also very volatile (in some set ups the latter can be an advantage, of course).

Quote: Originally posted by Hexavalent

Ah yes, I see. Would a solid-state reduction be efficient, though? How practical is it?
[Edited on 1-9-2012 by Hexavalent]

About as practical as not possible at all. TiCl4 and ZrCl4 aren't your usual ionic chlorides: they're about as covalent as CCl4.

[Edited on 1-9-2012 by blogfast25]

kristofvagyok - 1-9-2012 at 12:04

The method with liquid sodium is a pity, the only thing what is important that a really strong walled glass is needed for this method (not a test tube!!!!).

It should be performed as the following: in a large round bottomed flask filled half with paraffin oil, some sodium is melted on a sand bath (10% more that what will be needed to the reduction) with a PTFE stirring bar (IKA stirrer preferred) and the powdered ZrCl4 is added slowly. A highly exotermic reaction will take a place at the bottom of the flask and the NaCl what will form will float up the the top of the molten sodium. The produced Zr metal will remain at the bottom.

At the end of the reaction, the excess sodium is decomposed by methanol, the solids are filtered out and washed with water, dried, pure Zr could be obtained, easy, the only problem is when shit glassware is used and it breaks... That could hurt.

Hexavalent - 1-9-2012 at 12:12

Quote: Originally posted by kristofvagyok

IKA stirrer preferred

Any particular reason why?

Also, could you not substitute a well-made crucible for the flask?

Myst32YT has a video on making sodium peroxide where he melts sodium metal into a crucible; http://www.youtube.com/watch?v=ZqEWUw6sgpA

barley81 - 1-9-2012 at 12:17

I have heard that stirring molten alkali metals with teflon stir bars can lead to violent explosions. The overhead stirrer's agitator is probably glass, so it won't pose that risk.

blogfast25 - 1-9-2012 at 12:18

kristof, 'easy' really is the understatement of the year, as far as I'm concerned. This is something a hobbyist cannot pull off.

It's even far from certain that the initially solid ZrCl4 will react with liquid but relatively cold sodium. Assuming the reaction needs heat to get started, the ZrCl4 starts subliming at 331 C! And once reaction does start, huge amounts of enthalpy are generated. This requires a pressure vessel and some serious temperature controllers to keep in control of things.

[Edited on 1-9-2012 by blogfast25]

blogfast25 - 1-9-2012 at 12:21

Quote: Originally posted by barley81

I have heard that stirring molten alkali metals with teflon stir bars can lead to violent explosions. The overhead stirrer's agitator is probably glass, so it won't pose that risk.

'explosions' may be an overstatement but molten alkali metals can react violenty with halocarbons, including PTFE (Teflon, essentially).

kristofvagyok - 1-9-2012 at 12:34

Quote: Originally posted by blogfast25

kristof, 'easy' really is the understatement of the year

It's even far from certain that the initially solid ZrCl4 will react with liquid but relatively cold sodium. Assuming the reaction needs heat to get started, the ZrCl4 starts subliming at 331 C! And once reaction does start, huge amounts of enthalpy are generated. This requires a pressure vessel and some serious temperature controllers to keep in control of things.[Edited on 1-9-2012 by blogfast25]

This is an easy reaction, no special things are required, no special conditions and no special reagents... I think that it is not a big deal, just don't break the glass

The liquid sodium (slightly above 100Celsius) is enough for the reaction and the high excess of paraffin oil, the stirring prevents the higher temperature and the "problems". Also, it is recommended to add the ZrCl4 in small portions...

I had no problems with PTFE bars and sodium, I have only once burned PTFE shavings with magnesium... But it was at several huderead celsius and it was boosted with some KClO3.... But safety first, I agree, PTFE is not the best, but I had no problem with it in the past. So, use any else polymer coated bars.

The IKA is preferred, because it has a stronger magnet compared to most other manufacturers, and to my experiences with most third party stirrers it often happens that they throw off the magnet at fast stirring and heating what is aint a good thing at this reduction.

[Edited on 1-9-2012 by kristofvagyok]

blogfast25 - 1-9-2012 at 12:56

Kristof:

Are you speaking from personal experience here? Or do you have an authorative text you’re quoting from? (In the latter case, please share)

The Standard Enthalpy of Reaction for ZrCl4(s) + 4 Na(s) →Zr(s) + 4 NaCl(s) is a whopping – 663.5 kJ/mol (NIST Webbook data), barely 200 kJ less negative than Classic Thermite ( -851 kJ/mol)!

Unless the ZrCl4 is added in really small amounts at one time, allowing sufficient cooling between the enthalpy bursts, this is really dangerous stuff to be carried out in glass, w/o cooling etc etc.

If it were that easy, you’d find Youtubers showing it off.

kristofvagyok - 1-9-2012 at 13:10

This was written in an old inorgo. chem. lecture note according to my memories, but next week I will perform this experiment in the lab if I will find the ZrCl4 or ZrOCl2...

Hexavalent - 1-9-2012 at 13:17

'Bump' my question... what about the use of ceramic or porcelain crucibles as reaction vessels?

TheAMchemistry87....it looks like you probably won't be performing this synthesis in your lab, after all.

Where did you get your ZrCl₄ from anyway?

plante1999 - 1-9-2012 at 13:19

Good luck finding ZrCl4, its not OTC, at best you will be able to make it from the easier procedure I developed, old procedure use zirconium dioxide, carbon, Chlorine and 1000 degree Celsius. Seriously I recommend to use the fluoride instaid of the chloride, and use calcium instead of sodium, don't try to do it in glass, use at least ceramic. The reaction is manageable for someone with at least some knowledge in IVB column elements.

blogfast25 - 1-9-2012 at 13:32

Quote: Originally posted by kristofvagyok

This was written in an old inorgo. chem. lecture note according to my memories, but next week I will perform this experiment in the lab if I will find the ZrCl4 or ZrOCl2...

ZrOCl2 is a completely different animal. I'm not even sure it's possible to obtain it in anhydrous form. I have about 100 g of homemade ZrOCl2.8H2O. It's likely to convert entirely to ZrO2 on dehydrating. And even if you could make anhydrous ZrOCl2, converting it to ZrCl4 would be difficult.

As plante wrote: ZrCl4 is very difficult to buy and very hard to synthesise at the home lab level.

Still, I look forward to your experimenatl results. I have my own planned route to Zr, hence my interest.

[Edited on 1-9-2012 by blogfast25]

kristofvagyok - 1-9-2012 at 13:43

Quote: Originally posted by blogfast25

ZrOCl2 is a completely different animal.

As plante wrote: ZrCl4 is very difficult to buy and very hard to synthesise at the home lab level.

Still, I look forward to your experimenatl results. I have my own planned route to Zr, hence my interest.[Edited on 1-9-2012 by blogfast25]

Yes, I know that ZrOCl2 is completely different, but as the topic title says metallic Zr should be obtained from ZrCl4... So ZrOCl2 is also an alternative....

And the ZrCl4 is also not an impossible task, I won't prepare it from ZrO2, I don't have that much time, but maybe there will be a small ampoulle somewhere in the lab, who knows...

blogfast25 - 2-9-2012 at 05:21

An alternative in what specific way?

elementcollector1 - 2-9-2012 at 19:45

Do tell how a home chemist could prepare ZrCl4 from materials around him (cubic zirconium, possibly zircon, etc)...
It would probably involve some very strong acids.

I can attempt the ZrCl4-Na reduction, as fairly soon I will have everything but the ZrCl4.

blogfast25 - 3-9-2012 at 06:05

Quote: Originally posted by elementcollector1

Do tell how a home chemist could prepare ZrCl4 from materials around him (cubic zirconium, possibly zircon, etc)...
It would probably involve some very strong acids.

I can attempt the ZrCl4-Na reduction, as fairly soon I will have everything but the ZrCl4.

For ZrCl4 look up 'Kroll process zirconium'. Making this chemical at home in any significant quantities is most probably outside the capacity envelope of most backyarders. It's certainly outside of mine!

ZrOCl2.8H2O home synth has be described on this forum at least twice. Search 'zirconium' by 'blogfast25' and ye shall find. But zircomium tetrachloride and ziconyl chloride are very different things...

[Edited on 3-9-2012 by blogfast25]

elementcollector1 - 3-9-2012 at 15:36

"For a simpler procedure see: Inorg. Syn., 4, 121-126(1953)."
Where do I find this?
Also, I don't think I can do the dioxide + carbon + chlorine thing easily, not without some serious heat and apparatus.

blogfast25 - 4-9-2012 at 05:39

Quote: Originally posted by elementcollector1

Also, I don't think I can do the dioxide + carbon + chlorine thing easily, not without some serious heat and apparatus.

In a nutshell...

Try Georg Brauer's 'Preparative Inorganic Chemistry' (SM Library) for possible alternative prep.

In any case, here’s Brauer on the reduction of ZrCl4 with sodium (so much for using glass apparatus

):

Page 1173:

III. ZrCl4 + 4Na = Zr + 4 NaCl
233.0 92.0 91.2 233.8
Up to 1 kg. of sublimed ZrCl4, crushed to lumps, and 450 g.
of distilled Na may be reacted in one run in a sealed steel tube
at 850°C. The bottom of the tube is charged with a layer of Na;
this is followed by the reaction mixture (ZrCl4 + Na), topped with
a layer of Na. Since the vapor pressure of ZrCl4 is considerably
lower than that of TiCl4, the processing of larger quantities is
simpler. The heat evolved in the reaction is so large that partial
sintering of the metal occurs.

IV. ZrCl4 + 2Mg = Zr + 2 MgCl2
233.0 48.6 91.2 190.4
As in the magnesium process for Ti, Zr may be prepared by
reduction of ZrCl4 vapor with Mg in a helium atmosphere (see
references below for further details).

V. Zrl4 = Zr + 2I2
598.9 91.2 507.7
The glowing wire temperatures during refining should be
~1400°C in the case of Zr and ~ 1600°C in the case of Hf. The
Pyrex vessel must be kept at 600°C. The crude metal obtained
from the chloride is the most suitable raw material. Recently
Zr has been prepared in large glass vessels in the form of rods
weighing up to 200 g.

[Edited on 4-9-2012 by blogfast25]

Wizzard - 4-9-2012 at 06:12

Crystal Bar technique has my vote!! If one makes it hot enough (real white heat), you can make crystals of Zr!

blogfast25 - 6-9-2012 at 05:56

Brauer’s synthesis of ZrCl4 can be found on page 1203. It’s the usual carbochlorination of ZrO2 with C and Cl2. The way it’s described is a little simpler than I imagined it would be bit it’s still no mean feat to pull off at the level of a backyard scientist. I quote:

ZrCl4
ZrO2 + 2C + 2C12 = ZrCl4 + 2 CO
123.2 24.0 141.8 233.0 56.0
An intimate mixture of one part of pure ZrO2 and two parts of
calcined carbon black or sugar charcoal is placed in a porcelain
boat and heated at 500°C in a stream of Cl2; or, preferably,
ZrO2 with no admixtures is chlorinated in a Cl2-CCl4 gas mixture
produced by passing Cl2 through a wash bottle (70°C) filled with
CCl4. The initial chlorination temperature is 350°C, but is
gradually raised to 700°C.
The equipment is similar to that described on p. 889 for the
preparation of BeCl2, except that, when working with Cl3-CCl4,
a trap for the unreacted CC14 must be inserted in line after tube
A. Since ZrCl4, which sublimes at 331°C, is difficult to r e -
condense, it is advisable to use a long tube (600 mm.), preferably
of Vycor. The additional resublimation at 300-350°C is carried
out in a stream of H2, a treatment which more effectively removes
the oxide and FeCl3 present.
Alternate method: The industrial chlorination of ZrC prepared
from ZrSiO4 is described by W. J. Kroll et al. [Trans. Electrochem.
Soc. 89, 263 (1946); 92, 187 (1947); J. Electrochem. Soc. 94,
1 (1948)].
PROPERTIES:
White crystalline powder. Sublimation point 331°C, m.p. (under
pressure) 438°C; d 2.80. Yields a mist of hydrochloric acid in
moist air; violently decomposed by H3O, forming the oxychloride.
Soluble in alcohol and ether. Crystal structure: type D l x .

kristofvagyok - 15-9-2012 at 12:22

I have made the reaction and You were right, in these conditions the reduction didn't work. My memory should get a refresh from inorgo chem.

The Zr didn't all reduced, I used ZrOCl2 and found a strange thing: it was refluxed for circa 10 minute in paraffin oil, the resulting sodium lumps were thrown in propanol, diluted with methanol and finally the not reacting lumps were thrown in water. While it reacted normally a white fluffy participate formed what didn't dissolved in the water. Any idea anyone? Because if it didn't had reacted at all, it should have left back ZrOCl2 what is soluble in water.

blogfast25 - 16-9-2012 at 07:25

kristof:

Zirconyl chloride, now known to be [Zr4(OH)12(H2O)16]Cl8(H2O)12 , rather than previously thought to be ZrOCl2.8H2O, would be a very unlikely candidate for reduction with sodium. All that water, to begin with…

In all likelihood your fluffy precipitate is hydrated zirconia, Zr(OH)4.nH2O, presumably you did get a bit of sodium zirconate(s) (there are several of them)? These hydrolyse quickly to hydrated zirconia with water. Or some sodium hydroxide: that would hydrolyse the ‘zirconyl chloride’ in a jiffy: this polymeric structure can only exist in neutral/acidic conditions.

Zirconium’s tendency to form these polymeric cations is also the reason why polymeric structures that include Al and Cl can be formed, used extensively as the active ingredient in roll on anti-perspirants (from which ‘zirconyl chloride’ can be extracted relatively easily…

[Edited on 16-9-2012 by blogfast25]