| 摘要 |
PROBLEM TO BE SOLVED: To obtain silica gel particles having superior flowability and suitability to filtration as powder and ensuring low viscosity as a slurry, enhanced particle strength, suppressed powdering and a reduced wear tendency by specifying the median diameter of silica gel, particles by a crushing method on the basis of volume and the content and roundness of specified particles. SOLUTION: The objective silica gel, particles have 2.5-20 μm, in particular 4-15 μm median diameter on the basis of volume and <=35 wt.%, in particular <=30 wt.% content of particles whose particle diameter is <=3/4 of the median diameter. The roundness of particles whose particle diameter is 0.5-2 times the median diameter under observation with an electron microscope is 70-95 and the amt. of particles having <=90 deg. angles is <=10%, in particular <=8% by number. The silica get particles have 200500 m<2> /g, in particular 250-400 m<2> /g BET specific surface area, 0.4-1.5 ml/g, in particular 0.6-1.2 ml/g pore volume by a nitrogen adsorption method and 0.3-0.6 g/ml, in particular 0.32-0.45 g/ml bulk density measured by an iron cylinder method after drying at 110 deg.C. |
