Verfahren zum Herstellen körniger, amorpher Kieselerde

摘要

A method of precipitating spherical amorphous silica in high yield uses a carboxymethyl cellulose (CMC) as a coagulation growing agent during neutralization of alkali silicate with an acid. Preferably CMC having a etherification degree from 0.8 to 2.0 and a polymerization degree from 10 to 3,000 is added in an amount from 1 to 100% by weight reckoned as SiO2 with respect to silica in the alkali silicate to provide amorphous silica particles having high sphericalness. Spherical amorphous silica particles can be obtained in high yield having a BET specific surface area from 25 to 800 m<2>/g, an apparent specific gravity from 0.1 to 0.8 and a particle diameter from 0.2 to 50 mu m.