Black fused alumina, also known as black aluminum oxide, is a type of abrasive material that is commonly used in various industrial applications. It is made from the high-quality bauxite ore by fusing it in an electric arc furnace at high temperatures. During this process, the aluminum oxide content in the bauxite is reduced, resulting in a material that is predominantly composed of aluminum oxide and iron oxide.

1. Color and Appearance: As the name suggests, black fused alumina is black in color. It has a matte appearance and a high hardness.

2. Hardness: Black fused alumina is known for its high hardness, making it suitable for abrasive applications. It is often used for cutting, grinding, and polishing metals, ceramics, and other materials.

3. Abrasive Properties: It is an abrasive material with excellent cutting and grinding properties. It is used in applications such as sandblasting, grinding wheels, abrasive belts, and abrasive powders.

4. Strength and Durability: It has good strength and durability, making it a reliable choice for applications where wear resistance is essential.

5. Chemical Composition: Black fused alumina typically contains aluminum oxide (Al2O3) as the primary component, along with iron oxide (Fe2O3) and small amounts of other impurities.