The corundum is an aluminium oxide(Al2O3) crystallized in the trigonal system. It is present in nature as a mineral and some varieties, of various colours, are precious gems: sapphire (light blue), ruby (red), emerald (green) and amethyst (violet).
Thanks to its low cost compared to the natural one, synthetic corundum obtained through bauxite (aluminium hydroxide) casting is used in the industrial sector.
The application fields are various. Among them we can find: sandblasting and abrasive wheels.
It is a non-toxic abrasive, without free silica and components which are harmful to health, compared to other cheaper products used for sandblasting.
The high purity degree and the total absence of impurities allow obtaining perfectly clean surfaces, ready for subsequent working processes. Moreover, it allows treatment of noble metals, plastic materials, glass, stainless steel, and the use in the dental, gold-smith sectors, etc.
Uses and Advantages
The sharp-shape grain, the high hardness (9 Mohs: only one point lower than diamond), the exceptional abrasive power and the good resistance to impact make it particularly suitable to the sandblasting operation above all in blow-by plants.
The wide range of granulometries and the various available types allow getting roughness and surface finishing degrees suitable to multiple needs.
It can be used in free casting sandblasting machines and in pressure or suction pressure compressed-air sandblasting cabins.
Types employed in the sandblasting field are:
- RB: Deferrizated brown red corundum;
- BB: White corundum characterised by high purity and absence of contaminating stuffs. It is particularly used to sandblast stainless steel, glass, plastic and in the dental a goldsmith sector.
- ISO 11124