Process for the improvement of titanium dioxide pigments by post-treatment

Abstract From the Canadian patent

A process for the improvement of titanium dioxide pigments by a post-treatment, wherein the titanium dioxide pigment produced by any process, in the form of an aqueous suspension and in any order, is treated with an aqueous titanium oxide chloride solution resulting from the scrubbing of off-gases derived from the production of titanium tetrachloride and, optionally with one or more, other water-soluble metal salts which when neutralized form difficult-to-dissolve oxide hydrates and/or other difficult-to-dissolve compounds, and/or optionally with a water-soluble silicate, and where difficult-to-dissolve oxide hydrates and/or other difficult-to-dissolve compounds are precipitated onto the …