Spherical particles of titanium dioxide coated with a uniform layer of iron oxides, having a narrow size distribution, and process for preparing the same

Abstract From the Canadian patent

Spherical particles having sizes below 1 µm or at, maximum of 3.04 µm, a narrow size size distribution consisting or consisting essentially, of TiO2 coated by a uniform layer having a thickness up to 400 .ANG. consisting essentially of .alpha.or, .gamma. - Fe2O3, or magnetite, or mixtures thereof said particles, being prepared by a process consisting or consisting essen-, tially, in the precipitation of the oxide from Fe (III) salt solutions on the surface of solid pre-formed TiO2 particles having a narrow size distribution and a number average diameter below 1 µm or ? 3 µm, the Fe (III) concentration being ? 40% by weight calculated on TiO2, the pH of the suspension ranging from 1.0 to …