1)ChemicalComposition:Reduction:≤13%Fe:≤0.4%Al2O3:≥45%Na:≤0.3%SO4=:≤1.5%2)PhisicalCharacter:PoreVolume:≥0.35ml/gSpecificSurface:≥250m2/gAbrasionindex:≤2.5%Fineness:0--40μm:≤20v%0---149μm:≥92v%3)Micro-activity:800℃/4hr,100%Vapor:≥70