Process of manufacturing a silica powder

摘要

A new sol-gel process is claimed for the manufacture of silica powder starting with a suspension of silica and soot particles in water. The suspension is gelified and the gel obtained dried by microwave heating. The dry gel is fractionated to give silica grains of diameter 10-1000 mu m with an apparent density of 0.5-0.6 g/cm<3> and porosity less than 20 %. The particles are sifted to a range of 100-500 mu m. The original soot particles are less than 0.1 mu m and the silica particles greater than 1 mu m.