Abstract: Glass fibre reinforced plasterboard comprising a gypsum matrix of high density with embedded staple glass fibres therewith forming a pressure resistant solid body frame in which are embedded a plurality of very small hollow spaces of 5-350 .mu.m diameter, produced by a fine-pore foam or at least partially by small particles of non-porous and non-water absorbing fillers. During the manufacturing process of such glass fibre reinforced gypsum board, the gypsum and the fibre pieces are given only so much water that the water/gypsum ratio does not exceed 0.6, whereafter a foam and/or pourable or free-flowing fillers are added in such quantities that the apparent density of the entire board is at least 20% smaller than the density of the bonding means component of the matrix and the paste are subjected while being formed, to a vibration.

Abstract: Disclosed are micronized synthetic calcium silicates in the form of fluffy particles of needle-like calcium silicate crystals having a particle size of about 0.5 to 50 microns and an average particle size d.sub.50 of from 5 to 25 microns, and preferably of from 7 to 15 microns, obtainable from micronized, approximately spherical synthetic calcium silicate hydrate aggregates having a diameter of from 10 to 150 microns. They are preferably used in filled and unfilled liquid resin systems.

Abstract: Asbestos-free brake lining comprising phenolic resin and usual fillers and in addition an amount of a synthetic hydrated calcium silicate particle of xonotlite with a substantially spherical morphology and a mean diameter of 50 to 70 .mu.m with an open inner structure and an outer shell with a close limited crystal structure with pore openings of up to 10.sup.-7 m in the outer shell.

Abstract: 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.

Abstract: Lightweight insulating boards in accordance with the present invention comprise Portland cement, fibers and fillers including:(a) 50-75% by weight of cement,(b) 0-5% by weight of cellulose fibers,(c) 0.5-4% by weight of alkali-resistant fiber material,(d) 5-20% by weight of mica,(e) 5-20% by weight of light filler and(f) 8-25% by weight of hydrated lime.They are shaped into boards from a suspension and are set at least 15 days, and preferably 28 days. The insulating boards of the present invention meet all of the requirements set for such materials regarding flexural strength, incombustibility, and the like.

Abstract: 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 as catalysts for the oligomerization of olefins and, having been loaded with platinum, as hydrocracking catalysts.

Abstract: Amorphous, approximately spherical silica particles prepared by the acidic hydrolysis of an approximately spherical synthetic calcium silicate having a uniform microgranular structure on their external surfaces and a structure in the interior thereof which structure only weakly recall the original crystal needle structure of the starting material. The average external particle size is from 15 to 80 .mu.m, the apparent particle volume is from 1.3 to 3 cm.sup.3 /g, and the specific surface area is from 250 to 800 m.sup.2 /g. The silica particles are particularly suitable for use as catalyst supports.

Abstract: Immobilized enzymes covalently bound to an inorganic carrier by an amino group through a bifunctional spacer have improved properties when the carrier is formed of amorphous, approximately spherical silica particles obtained from synthetic calcium silicate. The silica particles have an average particle size of from 15 to 80 .mu.m, an apparent particle volume of from 1.3 to 3 cm.sup.3 /g, and a specific surface area of from 250 to 800 m.sup.2 /g.