Zirconium Dioxide
Zirconia, ZrO2
Chemistry
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Miscellaneous
- Family: Opacifier
- Region: None
- Mined At: Unspecified
- Raw Mineral: No
- Generic: No
Notes
Zirconium Dioxide or zirconia (ZrO2) is a metallic oxide either processed from the mineral Baddeleyite (zirconium oxide) or extracted from zirconium silicate sand. While there is an abundance of raw material (mostly from Australia and South Africa), processes to extract the ZrO2 are varied and expensive (e.g. fusing, leaching, plasma arc, dissolution and precipitation). Purities range from 75 to >99%. Each process produces zirconias that have their own unique properties. Considerable tonnages of zirconia are used each year (10s of 1000s of tons), far more than hitech materials used for similar purposes.
The form in which zirconia crystals exist changes with temperature (monoclinic to 1170C, tetragonal to 2370C, cubic to melting at 2880C).
In ceramics zirconia is used for a number of things:
-It is employed in stain formulations to stabilize and assist certain colors.
-It is added to non-oxide ceramics as a sintering aid (to help glue the particles together).
-Added to body and glaze formulations to promote hardness.
-Used in crucilbles, nozzles and valves to resist the attack of molten metals.
-Used as an opacifier in glazes and frits (makes transparents white). Opacifying power is similar to zirconium silicate (6-9% for semi-opacity, 10-15% for full opacity).
-Used as a whitener in porcelains.
Zirconia has other interesting uses also:
-Its hardness and resistance to heat make it suitable for use in abrasives, cutting tools and engine parts.
-It is useful as a medical implant material because bone will form a bond with alumina matrixes that have porosity.
-Its ionic conductivity makes it valuable in sensors and fuel cells.
Partially Stabilized Zirconias (PSZ)
are made by adding small amounts of lime, yttrium or magnesia to create a multi-phase matrix (all three crystal types) that has a higher strength.
Suppliers
- Generic
Authors
- Tony Hansen (Owner)
XML
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<material name="Zirconium Dioxide" descrip="Zirconia, ZrO2" generic="0" rawmineral="0" searchkey="" loi="0.00">
<families>
<family name="Opacifier"/>
</families>
<oxides>
<oxide symbol="ZrO2" name="Zirconium Dioxide" status="" percent="100.000" tolerance=""/>
</oxides>
<references>
<reference name="seealso" reason=""/>
</references>
<suppliers>
<supplier name="Generic" country="" url="" label=""/>
</suppliers>
<notes>
<note>Zirconium Dioxide or zirconia (ZrO2) is a metallic oxide either processed from the mineral Baddeleyite (zirconium oxide) or extracted from zirconium silicate sand. While there is an abundance of raw material (mostly from Australia and South Africa), processes to extract the ZrO2 are varied and expensive (e.g. fusing, leaching, plasma arc, dissolution and precipitation). Purities range from 75 to >99%. Each process produces zirconias that have their own unique properties. Considerable tonnages of zirconia are used each year (10s of 1000s of tons), far more than hitech materials used for similar purposes.
The form in which zirconia crystals exist changes with temperature (monoclinic to 1170C, tetragonal to 2370C, cubic to melting at 2880C).
In ceramics zirconia is used for a number of things:
-It is employed in stain formulations to stabilize and assist certain colors.
-It is added to non-oxide ceramics as a sintering aid (to help glue the particles together).
-Added to body and glaze formulations to promote hardness.
-Used in crucilbles, nozzles and valves to resist the attack of molten metals.
-Used as an opacifier in glazes and frits (makes transparents white). Opacifying power is similar to zirconium silicate (6-9% for semi-opacity, 10-15% for full opacity).
-Used as a whitener in porcelains.
Zirconia has other interesting uses also:
-Its hardness and resistance to heat make it suitable for use in abrasives, cutting tools and engine parts.
-It is useful as a medical implant material because bone will form a bond with alumina matrixes that have porosity.
-Its ionic conductivity makes it valuable in sensors and fuel cells.
Partially Stabilized Zirconias (PSZ)
are made by adding small amounts of lime, yttrium or magnesia to create a multi-phase matrix (all three crystal types) that has a higher strength.
</note>
</notes>
</material>
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