Hollow balls of aluminium oxide. Used for thermal insulation between 1200oC and 1900oC.
Particle size: 1mm to 2mm is kept in stock, other sizes can be ordered.
Bulk density: 0,6kg / litre.
Composition: Pure alpha alumina, 99 to 99,5% Al203
0,1 to 0,7% SiO2
0,02% CaO +MgO
Particle shape: Near spherical, allows good packing and easy flow; it can be poured into place and it can be drained out of a lining through a hole.
Melting point: Approx 1990°C.
Hardness: 9 on the Moh scale
Handling: Bubble alumina is totally inert and harmless.