Electrically fused from Bayer alumina ,white colour, its hardness is a little higher ,but toughness slightly lower than that of Aluminum .It is used for fabrication of bonded and coated abrasive products for the grinding of the steels with great hardness, such as high carbon steel ,allor steel, and high speed steel.Its non-abrasive uses are precision casting moulding sand ,spray coating material ,catalyat carrier ,high temperature ceramic ,and super refractory material,etc. Size Al2O3 Fe2O3 Na2O+K2O SiO2 Density Fire-Resistance Bulk Density Volume Density % % % % g/cm3 ¡ãC g/cm3 g/cm3 Grain 99 0.05 0.4 0.06 3.96 1850 1.5-1.95 3.6 Fine 98.5 0.07 0.4 0.08 3.94 1850 1.4-1.8 3.5 Micropowder 98 0.07 0.4 0.08 3.94 1850 1.4-1.8 3.5. 25 kg / bag/50kg/bag/ton bag.