Colloidal dispersion of a compound of another element selected from cerium and zirconium, rare earth metals, titanium and tin, dispersible solids based on this compound and methods for their production

摘要

Colloidal dispersions, in a continuous phase, contain a compound of cerium and another element M selected from among zirconium, rare earths (Ln) other than cerium, titanium and tin, wherein such compound is in the form of a mixed oxide in which the cerium and the element M are in solid solution; the cerium is in the form of cerium III in an amount expressed in cerium III/total cerium atomic ratio ranging between 0.005 and 0.06 and the dispersion is produced by forming a liquid medium comprising cerium salts, in particular of cerium III, and the element M, contacting the medium with a base to provide a pH of not less than 9, separating and washing the resulting precipitate and peptizing same by treating with an acid whereby the dispersion is obtained.