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| Names | |
|---|---|
| Preferred IUPAC name Zirconium(IV) silicate | |
| Systematic IUPAC name Zirconium(4+) silicate | |
| Other names Zircon Zirconium(4+) orthosilicate | |
| Identifiers | |
3D model (JSmol) | |
| ChemSpider |
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| ECHA InfoCard | 100.030.216 |
| EC Number |
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| MeSH | Zircon |
| UNII | |
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| Properties | |
| O4SiZr | |
| Molar mass | 183.305 g·mol−1 |
| Appearance | Colourless crystals |
| Density | 4.56 g cm−3 |
| Melting point | 1,540 °C (2,800 °F; 1,810 K) (decomposes) |
| Structure | |
| tetragonal | |
| Thermochemistry | |
| 98.3 J/mol K | |
Std enthalpy of formation(ΔfH⦵298) | −2044 kJ/mol |
| Hazards | |
| NFPA 704 (fire diamond) | |
| Flash point | Non-flammable |
| Safety data sheet (SDS) | MSDS |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Zirconium silicate, alsozirconium orthosilicate, ZrSiO4, is achemical compound, asilicate ofzirconium. It occurs in nature aszircon, asilicate mineral. Powdered zirconium silicate is also known as zircon flour.
Zirconium silicate is usually colorless, but impurities induce various colorations. It is insoluble in water, acids, alkali andaqua regia. Hardness is 7.5 on theMohs scale.[1]
Zircon consists of 8-coordinated Zr4+ centers linked to tetrahedral orthosilicate SiO44- sites. The oxygen atoms are all triply bridging, each with the environment OZr2Si. Given its highly crosslinked structure, the material is hard, and hence prized as gemstone and abrasive.
Zr(IV) is a d0 ion. Consequently the material is colorless and diamagnetic.
Zirconium silicate occurs in nature as mineralzircon. Concentrated sources of zircon are rare. It is mined from sand deposits and separated by gravity. Some sands contain a few percent of zircon.[2]
It can also be synthesized by fusion ofSiO2 andZrO2 in an arc furnace, or by reacting a zirconium salt withsodium silicate in an aqueous solution.
As of 1995, the annual consumption of zirconium silicate was nearly 1M tons. The major applications exploit its refractory nature and resistance tocorrosion byalkali materials.[2] Two end-uses are forenamels, andceramic glazes. In enamels and glazes it serves as anopacifier. It can be also present in somecements.
Another use of zirconium silicate is as beads formilling andgrinding.
Thin films of zirconium silicate andhafnium silicate produced bychemical vapor deposition, most oftenMOCVD, can be used as ahigh-k dielectric as a replacement forsilicon dioxide in semiconductors.[3]
Zirconium silicates have also been studied for potential use in medical applications. For example,ZS-9 is a zirconium silicate that was designed specifically to trap potassiumions over other ions throughout the gastrointestinal tract.[4]
Zirconium silicate is also used asfoundry sands due to its high thermal stability.[5] It is also the primary source ofzirconium, which is used in various applications, including innuclear reactors, due to its high resistance to corrosion and lowneutron absorption.[6]
Zirconium silicate is an abrasive irritant for skin and eyes. Chronic exposure to dust can cause pulmonarygranulomas, skin inflammation, and skin granuloma.[7] However, there are no known adverse effects for normal, incidental ingestion.[8]
