| Description |
TiO2 occurs in many silicates in nature, accounting for over 1% of the earth's crust. Thus it is manufactured using a variety of materials and processes.
Although titanium is the strongest white pigment known for many uses, in ceramics the whiteness (and opacity) it imparts to glazes is due to its tendency to crystallize during cooling. While titanium dioxide is used in glazes as an opacifier, it is not as effective and easy-to-use as tin oxide or zircon. It can be used as an additive to enliven (variegate, crystallize) the color and texture of glazes (rutile works in a similar manner). In moderate amounts it encourages strong melts, durable surfaces and rich visual textures.
Titanium is available both as raw and surface treated products. Non-pigmentary grades flow more freely in the dry state. Self opacified enamels are made by adding titanium during smelting to super saturation. Upon firing the enamel, the titanium crystallizes or precipitates to produce the opacity. Titania is also used in dry process enameling on cast iron appliances for its effect on acid resistance, color and texture. In glass, non-pigmentary titanium dioxide increases refractive index, intensifies color. |