How is calcined alumina used in ceramics and industrial products?

Calcined alumina is produced by heating aluminum hydroxide at temperatures exceeding 1,050 °C (1,900 °F) to remove chemically combined water. This process results in a material characterized by extreme hardness, high density, chemical purity, and high electrical resistivity.12

These properties make calcined alumina highly versatile for various industrial ceramics and products:

• Electrical and Electronic Components: Its low electrical conductivity and high resistivity make it ideal for spark-plug insulators and integrated-circuit packages.21
• Abrasives: Due to its extreme hardness (9 on the Mohs hardness scale), it is used in sandpaper grits and grinding wheels.21
• Medical and Laboratory Applications: It is utilized in bone and dental implants, as well as specialized laboratory ware.2
• Industrial Refractories: It serves as a vital material for refractory linings in industrial furnaces, providing resistance to heat and chemical attack.21
• Specialized Uses: It is also used in the production of glass and porcelain. When modified with additives like magnesia, it can be made translucent for use in high-pressure sodium-vapour streetlamps.12