Abstract: The present invention herein provides silica powder which can be incorporated into a sealing material at a high content to thus give a sealing material having excellent moldability. The silica powder at least has, in the volume-based frequency distribution of particle size as determined by the laser diffraction-scattering technique, a maximum frequency value for a mode peak 1present in a particle size range extending from 1 to 4 ?m and a maximum frequency value for a mode peak 2 present in a particle size range extending from 15 to 55 ?m, wherein the maximum frequency value for the mode peak 2 is greater than that for the mode peak 1, the mode peak 2 has a shoulder, and the content of particles whose particle size ranges from 15 to 55 ?m is larger than that of particles whose particle size ranges from 1 to 4 ?m.

Abstract: The present invention herein provides silica powder which can be incorporated into a sealing material at a high content to thus give a sealing material having excellent moldability. The silica powder at least has, in the volume-based frequency distribution of particle size as determined by the laser diffraction-scattering technique, a maximum frequency value for a mode peak 1 present in a particle size range extending from 1 to 4 ?m and a maximum frequency value for a mode peak 2 present in a particle size range extending from 15 to 55 ?m, wherein the maximum frequency value for the mode peak 2 is greater than that for the mode peak 1, the mode peak 2 has a shoulder, and the content of particles whose particle size ranges from 15 to 55 ?m is larger than that of particles whose particle size ranges from 1 to 4 ?m.

Abstract: An apparatus for producing inorganic spherical particles by supplying raw material through a burner so as to pass through a flame and injecting it into a cooling tower, characterized in that the inner surface of the cooling tower is made of a metal.