NAstra® is an iron silicate (copper slag) abrasive. NAstra® is produced in accordance with DIN EN ISO 11126-3. It is a perfect blasting grit for blast cleaning steel, stone and concrete, and for the removal of mill scale, rust, old paint and dirt.
During melting of copper ore concentrates an iron silicate is formed. This is passing a groove and is granulated at a temperature of approximately 1250 °C, using a temperature-controlled pressurized water jet. After cooling down in a tank with fresh water, the fine particles are separated from the granulate manufactured in this way. It is a vitreous amorphous slag, it does not absorb water. During the manufacturing of the abrasive no crushing or grinding procedures are included. Therefore, the single abrasive particle is not broken up and retains its extreme hardness and tenacity which is the case for all particle sizes.
NAstra® used as blast cleaning abrasive for all application fields in conventional corrosion protection on almost all surfaces. It is suitable for surface preparation standards SA-3, SA-2½, SA-2 and SA-1. It is a non-hazardous material, containing less than 0,1% free crystalline silica.