Catalytic calcination process for making rutile pigments from aqueous titanium solutions

摘要

A low-temperature process for producing pigment-grade rutile titanium dioxide from an aqueous solution is disclosed, wherein the process comprises the following sequential steps: (a) preparing an aqueous feed solution comprising one or more titanium compounds; (b) adding a catalyzing salt selected from the group of alkali metal salts to the solution in an amount from 3 weight % of the equivalent amount of TiO2 present in the feed solution to the amount corresponding to the saturation point of the catalyzing salt in the feed solution; (c) evaporating the solution to produce a dry amorphous intermediate that includes a mixture of titanium compounds; and (d) calcining the intermediate at a temperature less than 500 Deg C to form TiO2 rutile pigment base.