Zirconium occurrence extraction

1. Zirconium

2. Occurrence
It is a rare metal because its found in few
sources .
The sources are
Zircon – ZrSiO4
Zirkelite – (Ca,Fe)O.2(Zr,Ti,Th)O3
Baddeleyite – ZrO2
Kosnarite – KZr(PO4)3

3. extraction
Mostly extracted from Zircon and Baddeleyite .
From Baddeleyite (ZrO2)
 It is decomposed by fusion method , fused either
caustic soda or soda ash to convert it into sodium
zirconate . Fusion with soda ash require higher
temperature than it with caustic soda .
ZrO2 +Na2CO3 Na2ZrO3+ CO2
ZrO2 +2NaOH Na2ZrO3+ H2O
 The product is extracted with water , then it is
hyrolysed to give insoluble hydrate oxide
Na2ZrO3+ 2H2O ZrO2 . H2O +2NaOH

4.  The mass is extracted with HCl and the solution on
evaporation yields the crystals of zirconyl chloride
ZrO2 . H2O + 2HCl ZrOCl2+ 2H2O
 The crystals are redissolved in water and the
solution of , hydrated ZrO2 is precipitated by
ammonia and on ignition gives zirconium dioxide .
 Zirconium metal is obtained by alumino ferric
method
3ZrO2 + 4Al 3Zr + 2Al2O3

5. From zircon (ZrSiO4)
 Finely pulverized zircon is mixed with lime and
carbon . The mixture is then heated to a high
temperature zirconium carbide is formed . The
product is extracted with water , then converted
into ZrCl4 by treatment with Cl2 at 300⁰C
ZrC + 2Cl2 ZrCl4 + C
 Then it is treated with ammonium hydroxide to
yield zirconium hydroxide which on ignition is
converted into zirconium oxide .
ZrCl4 + 4NH4OH Zr(OH)4 + 4NH4Cl
Zr(OH)4 ZrO2 + 2H2O
 On reduction ZrO2 is converted into zirconium
metal .

6. purification
The metal in above is not pure . The pure metal is
obtained by van arkel process .
ZrI4 (g) Zr + 2I2
Zr + 2I2 ZrI4 (g)

7.  In this method impure metal is heated with a
limited amount of I2 in an evacuated glass
apparatus .
Zr + 2I2 ZrI4 (g)
(impure)
 ZrI4 vapours formed are allowed to diffuse on
to a tungsten filament at a very high temperature .
The vapours of ZrI4 decomposes and the pure
zirconium metal is gets deposited on the W-
filament .
ZrI4 (g) tungsten filament Zr + 2I2
(pure)

8. Properties
physical properties
Exist in two form
1) metallic form – silvery white metal , melting
point 1857⁰C
2) Amorphous form – bluish black powder
Chemical properties
1) Reaction with water
Zr+ 2H2O ZrO2 + 2H2
2) Reaction with air
Zr + O2 ZrO2

9. 3) Reaction with alkali
when fused with alkali in presence of air forms
alkali zirconate .
Zr + 2NaOH + ½ O2 Na2ZrO3 + H2
4) Reaction with acids
React with dil. HCl form zirconium chloride .
Zr + 4 HCl ZrCl4 + 2H2

10. Uses
• Zirconium is used for the cans that hold reactor fuel
rods in the nuclear industry.
• It is used as pressure tubes in Canadian nuclear
reactors and in the reactors of the US navy’s nuclear
submarines
• It is used as an ingredient to increase the strength
of Mg alloys for e.g when such alloys are used in
aircraft this results in lighter weight component for
the same strength .
• it is extensively used by the chemical industry due
to resistant to corrosion .

11. ZrO2 – Zirconium oxide
Preparation
 On Hydrolysis Zirconium yields zirconium oxide .
 Zirconium in presence of air gives zirconium oxide .
Zr + O2 ZrO2
Properties
White powder
Melting point - 2715⁰C
Boiling point - 4300⁰C
Zr+ 2H2O ZrO2 + 2H2

12. Reduction
on reduction metal is obtained .
ZrO2 Zr + O2
Hydrolysis
On hydrolysis zirconium hydrolysis is obtained .
ZrO2 + 2H2O Zr(OH)4

13. The applications of zirconium oxide
are given below:
• in ceramics for making ceramic pigments, porcelain
glaze, etc.
• In making abrasive, insulating and fire-retarding
materials.
• exhibits pyrooptical properties, hence used for
optical storage, light shutters and stereo television
glasses.
• Zircon mixed with vanadium or praseodymium
makes blue and yellow pigments for glazing pottery.