Technical calcined alumina is made from smelter grade alumina. The manufacturing process involves the removal of impurities and re-calcination with appropriate mineralisers to achieve a very high content of alpha alumina.
Bisley services the refractory industry with both ground and unground grades. Options include super-ground aluminas (2.0-3.5 microns), low soda reactive types (obtained by washing the precursor or by soda extraction during calcinations).
The main applications for calcined aluminas are: refractories, glass and enamel, tiles and porcelain, mechanical, electric and electronic ceramics.