METHOD OF PREPARING MIXTURE FOR SYNTHESIS OF WOLLASTONITE AND COMPOSITION THEREOF Russian patent published in 2010 - IPC C04B33/24 

FIELD: chemistry.

SUBSTANCE: invention relates to production of synthetic wollastonite from natural material and industrial wastes and can be used in production of building ceramics, porcelain and semiporcelain products, ceramic tiles, dry construction mixtures, high strength cement mortar etc. The method of preparing a mixture for synthesis of wollastonite involves fine grinding the calcium-containing component of the mixture in a bead mill using a dry method until complete passage through a 0063 sieve. The crude mixture is prepared by mixing the finely ground calcium-containing component with amorphous silica in a bead mill for 0.5 hours, with initial particle fineness which provides molar ratio CaO:SiO₂ equal to 0.9-1. The crude mixture is subsequently plasticised by adding organic binder. The crude mixture is packed by briquetting via semidry pressing at pressure 20-25 MPa. Further, drying and calcination are carried out at temperature 1000-1050°C, while maintaining maximum temperature for 1 hour. The mixture for synthesis of wollastonite contains the following components in wt %: calcium-containing component from the chalk group, limestone - 60-62.5; microsilica - 37.5-40.0; organic binder - 6-8 (over 100).

EFFECT: reduced defects in products, utilisation of industrial wastes.

5 cl, 1 ex, 3 tbl