Process of making a silica powder and use of such a powder in the manufacture of optical fibre preforms.

摘要

Process for the manufacture of a silica powder by a sol-gel method, characterised in that - a suspension in water of synthetic silica soot, with a specific surface lower than 80 m<2>/g is produced, in a proportion of 50 % to 75 % by weight of silica, - the said suspension is gelled, - the gel obtained is dried under microwaves and the dry gel is broken up into silica granules exhibiting an apparent density of the order of 0.5 g/cm<3> to 0.6 g/cm<3> and a porosity of less than 20 %, - a screening between 100 mu m and 500 mu m is performed. m