Calcined alumina, also known as aluminum oxide (Al2O3), is produced by heating aluminum hydroxide at high temperatures, typically above 1100°C. This process removes water molecules and results in a highly pure, crystalline form of alumina. Calcined alumina is known for its exceptional hardness, high melting point, and excellent thermal stability. It is widely used in a variety of applications, including refractories, ceramics, abrasives, and as a raw material for the production of aluminum metal. Additionally, calcined alumina is used in the manufacture of high-performance materials, such as spark plug insulators and cutting tools, due to its mechanical strength and resistance to wear and corrosion.”