Corundum is an aluminum oxide that occurs in nature as a mineral; industry uses synthetic corundum, which is cheaper than natural corundum and is obtained by smelting bauxite.
It is a non-toxic abrasive that actually contains no free silica and other ingredients harmful to health, unlike other cheap products used for sandblasting.
The main characteristic of corundum is its high hardness (9 Mohs: just a little lower than diamond), which guarantees excellent grinding capabilities and the speed to obtain the desired results on any type of material. It has high impact resistance and is particularly suitable for situations where the abrasive can be recovered during the sandblasting process. Various types and a wide range of particle sizes meet various needs in terms of roughness and surface finish.
High purity and the absence of contaminants make it possible to obtain completely clean surfaces and prepare them for subsequent processes.
The types of aluminum oxide used in sandblasting are:
1. Red/brown corundum is mainly composed of aluminum oxide and therefore contains almost no iron. The special composition makes this angular mineral extremely stable, combining properties of hardness and density. Used for aluminum sandblasting, steel carpentry, grinding wheel production, stone and glass screen printing. Reddish brown corundum is less pure than white corundum.
2. White corundum is composed of crystallized alumina smelted from alumina. It is characterized by high purity and highly regular shape. It is used as non-ferrous and corrosive blasting material in situations where ferrous metal contamination must be strictly avoided: it is mainly used in special applications (aerospace sector or reactor structures), such as cleaning of stainless steel, aircraft and turbine components, non-ferrous metals and its alloys, plastics or glasses.
One possible alternative to corundum is the use of stainless steel shot and grit, especially when the blasting system provides abrasive recycling.
The advantage of stainless steel shot and steel grit is that it can be used for blasting operations on aluminum and non-ferrous metals as well as stainless steel parts (such as corundum), but for the same quantity, it allows a higher number of cycles, resulting in less waste, And significantly reduce dust emissions during the process.
