About Zircon and Zirconium Silicate

As of 1995, the annual consumption of zirconium silicate was nearly 1M tons. The major applications exploit its refractory nature and resistance to corrosion by alkali materials. Two end-uses are for enamels, and ceramic glazes. In enamels and glazes it serves as an opacifier. It can be also present in some cements. Zirconium silicate occurs in nature as mineral zircon. Concentrated sources of zircon are rare. It is mined from sand deposits and separated by gravity. Some sands contain a few percent of zircon.

The ceramics sector is the largest market for zircon in terms of volume. Zircon is mostly used in this industry to opacify (or whiten) the ceramic body and surface. Zircon can be used as a fine powder in ceramic combinations to boost the body's overall whiteness or in engobes to create a white, opaque layer that conceals the colour of the body. Additionally, it serves as a raw ingredient in frit compositions that create glossy, opaque, white glazes for ceramic glazes in order to boost their opacity. Zircon greatly increases resistance to chemical and abrasion assault when utilized in surface glazes. Zircon has a high refractive index, which makes it a good opacifier. Ceramics seem white, glossy, and opaque because to the visible light scattering properties of finely milled zircon grains.

Description

• Off white mineral powder that is chemically inert and stable to very high temperatures. Insoluble in water, dilute acids and hot concentrate sulfuric acid.
• Chemical Name: Zirconium silicate
• Chemical Formula: ZrSiO4

Synonyms

• Zircon, zircon our, zircon sand, zirconium silicate, zirconium orthosilicate, ZrSiO4, hyacinth, silicic acid zirconium(4+) salt), zirconium silicon oxide, CAS# 10101-52-7

Chemical Properties

• ZrO2= 65.9%, SiO2= 32.0%

Typical Applications

• Primary source for investment casting shell molds, foundry cores, metal chills, ladle brick, welding rod coatings, abrasive cleaning, Opacifirs in ceramic and mold washes.

Molecular Weight (g/mol.)	183.1
Bulk Density (lbs./ft.3)	172-182
Specific Gravity	4.5-4.6
Solid Specific Heat	0.132
Melting Point (°C)	2200-2550
Boiling Point (°C)	2200-2550
Surface Area (m2/g)	2200-2550
Mohs Hardness @20°C	7.5-8.0
Color	off-white