... .alumina content as high as 99.4% White aluminium oxideis a high-quality alumina powder as raw material, made of fused ... high as 98.5%, and its slightly higher than the brown corundum hardness, toughness is slightly lower, high purity, self-sharpening is ... good, grinding ability, heat a small, high efficiency, acid and alkali corrosion, high temperature 1750 ...