Grey Alumina Powder

Grey Alumina Powder

Grey Alumina Powder: Introduction and Applications

Introduction:

Grey alumina powder also known as grey aluminum oxide (Al₂O₃), is a form of aluminum oxide that is produced through the bayer process from bauxite ore. It typically has a greyish or off-white color, which distinguishes it from the more common white alumina powder. The grey color of the alumina powder is often due to the presence of trace elements, impurities, or residual compounds that were not fully removed during the refining process.

Properties

Physical Properties:

Appearance: Grey or light off-white powder with fine granules.

Hardness: Alumina has a hardness of 9 on the Mohs scale, making it highly abrasive and suitable for grinding applications.

Density: The density of grey alumina typically ranges from 3.9 to 4.1 g/cm³.

Melting Point: Alumina has a high melting point of approximately 2,050°C, giving it excellent thermal stability.

Solubility: Alumina is insoluble in water but soluble in acids like sulfuric acid and in strong bases.

Chemical Properties:

Chemical Stability: Alumina is chemically stable and is resistant to most acids and alkalis.

Oxidation Resistance: It has high resistance to oxidation and is used in applications requiring high temperature or harsh chemical environments.

Reactivity: Grey alumina, due to its specific chemical composition, may contain some trace metals or impurities, which can slightly alter its chemical reactivity compared to pure white alumina.