site logo

The difference between white corundum powder and alumina powder

The difference between white corundum powder and alumina powder

White corundum powder and alumina powder have the same appearance and similar names. Many people want to clarify the difference between them. The following Qianjiaxin Refractories will distinguish it from its own composition.


1. White corundum powder

(1) Crystal form: trigonal crystal system;

(2) Density: 3.90 g/cm3;

(3) Hardness: Knoop hardness 2000-2200Kg/mm2, Mohs hardness 9.0;

(4) Melting point: 2250C;

(5) Maximum operating temperature: 1900C;

(6) Specific heat (Cal/g.C): 0.26 (20-90C);

(7) Thermal conductivity: 900C at room temperature (Cal/cm3.sec.C);

(8) Refractive index: e=1.760 w=1.768 (Na line);

(9) Coefficient of linear expansion: (7-9)*10^-6/K(0-1600C).


2. Alumina powder

(1) Appearance: white powder, crystalline phase γ phase;

(2) Average particle size (nm): 20±5;

(3) Content %: greater than 99.9%;

(4) Melting point: 2010℃-2050℃;

(5) Boiling point: 2980 ℃;

(6) Relative density (water = 1): 3.97-4.0;

(7) Color: white, dark blue after calcination.


White corundum powder can be used as contact media, insulators and precision casting sand, etc. Alumina powder ze can be used in heat conduction, polishing, electroplating, catalyst, etc.