Silicon Dioxide. Specification Adsorptive value: RH=20%11.55min RH=35%27.22min RH=50%39.23minLoss of drying: 1.59%maxQualified ratio of spherical granules: 98.0% min.Bulk density, g/l : 752 minQualified size ratio: 97.5% minStill adsorption capacity, ml/g: N2 1.31, CO2 29.6PH: 4.05Packing: 25kg/bag,.