Calcined Bauxite

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Product Description
Benefits & Application Details


The main constituent of Portalum A25 is Corundum. The material is micronized using Refractory Agglomerated Super Calcined bauxite.

Corundum is a crystaline off-colour Aluminium Oxide, characterized by:

  • High inertness in various media
  • High density and, as a result, low oil absorption
  • High Mohs hardness of 8.5
  • High Refractive Index of 1.64


Basic properties

Property Value Unit
Moisture 0.1 [%]
Hardness (Mohs) 8.5 [-]
Oil Absorption 13 g/100g
Al2O3 88 [%]
SiO2 6.5 [%]
Fe2O3 1.8 [%]
Density 3.8 [kg/ dm3]


The high hardness and high density of the Portalum A25 makes the material very useful for making abrasive and friction materials. It can be part of the formulations used in the manufacturing of brake-pads.

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