| abstract |
A process for obtaining alpha-alumina in powder form having a particle median size distribution D₅₀ from 0.1 to 1 micron and having coarse particles larger than 3 microns being less than 2% comprises subjecting solid powder of hydrated Al₂O₃, or hydrated aluminium chloride or sulphate, to a calcination treatment to transform it to alpha-phase alumina and to obtain a powder having a surface area from 2 to 12 m²/g; and grinding the powder. |