1
Octavian Anton, Dirk Van Wouwe: Synthetic crystal aggregates of xonotlite and process for preparing same. Redco, Wegner & Bretschneider, July 18, 1989: US04849195 (2 worldwide citation)

In synthetic, substantially spherical crystal aggregates of xonotlite having a particle size of more than 20 microns, and preferably up to 150 microns, up to 30% of the silicon atoms can be replaced by titanium or zirconium atoms, and inert particles can be incorporated in the crystal aggregates.


2
Octavian Anton, Dirk Van Wouwe, Georges Poncelet, Pierre Jacobs, Johan Martens: Silica-particles containing alumina, process for preparing same and the use thereof. Redco, Wegner & Bretschneider, January 19, 1988: US04720475 (1 worldwide citation)

Amorphous, substantially spherical silica particles obtained by acidic hydrolysis of substantially spherical synthetic crystalline calcium silicates having a size of from 20 to 120 microns are coated with a layer comprising silica and alumina. The silica particles obtained may be directly employed a ...