Boron containing precipitated silica

Abstract

There is prepared precipitated silica containing boron and having the following physical-chemical data ______________________________________ Loss on heating Weight % 14-40 pH 4-6 Conductivity in 4% aqueous /.mu.S <800 dispersion Bulk density g/l 130 .+-. 100 Sieve residue according to Alpine >63/.mu. Weight % <0.1 SiO.sub.2 content based on original Weight % 9-76 material B.sub.2 O.sub.3 content based on original Weight % 10-51 material Na.sub.2 O content based on original Weight % <0.5 material So.sub.3 content based on original Weight % <0.8 material ______________________________________ The product is obtained by supplying precipitated silica and ortho boric acid in the ratio of 0.1-3.5:1 continuously to a jet mill and micronizing them together by means of the air of the mill at room temperature.

Dependencies are inferred from the claim text.