Shaped bodies of calcium silicate and process for producing same

A process for producing a shaped body of calcium silicate comprising the steps of mixing together a milk of lime having a sedimentation volume of at least 45 ml and a crystalline siliceous material in a water to solids ratio of at least 9:1 by weight to prepare a starting slurry, subjecting the starting slurry to hydrothermal reaction while agitating the slurry with heating at increased pressure to obtain a slurry of xonotlite or foshagite crystals, shaping the slurry and drying the shaped product.

An aqueous slurry of calcium silicate characterized in that the slurry contains globular secondary particles dispersed in water and comprising lath-like xonotlite or foshagite crystals, the crystals having an index of crystallite antigrowth of at least 15 and three-dimensionally interlocked with one another into the particles, the globular secondary particles having an outside diameter of about 10 to 80 .mu.m and an apparent density of up to 0.13 g/cm.sup.3 and being in the form of a shell with a hollow interior space and a thickness of about 0.3 to about 10 .mu.m.

Globular secondary particles of calcium silicate comprising lath-like xonotlite or foshagite crystals having an index of crystallite antigrowth of at least 15 and three-dimensionally interlocked with one another to the form of a hollow shell having a thickness of about 0.3 to about 10 .mu.m, the particles being about 10 to about 80 .mu.m in outside diameter and up to 0.13 g/cm.sup.3 in apparent density.