Process for obtaining zirconium silicate ceramic pigments

摘要

Process for obtaining zirconium silicate ceramic pigments. The starting point is a mixture of zirconium and silicon alkoxides in appropriate proportions together with a compound which contains a chromophor element if it is intended that the pigment should be coloured. The mixture is sprayed using a dry inert carrier gas and the liquid particles of the aerosol formed in this way are subjected to hydrolysis when the aerosol is mixed with a current of a moist gas; the solid particles formed separate out from the carrier gas by filtration. In order to achieve a Zr/Si ratio of 1 in the final product, the mixture of alkoxides is prepared so that the atomic ratio of Zr to Si contained within it is also unity and before spraying it is subjected to a prehydrolysis treatment consisting of agitation in an atmosphere having a moisture content of at least 40% until the increase in viscosity indicates that the necessary Zr-O-Si bonds have been formed. <IMAGE>