A method for preparing aqueous titanium dioxide hydrate - suspensions by pressure filtration

摘要

In the recovery of titanium dioxide by subjecting an aqueous titanium dioxide hydrate suspension to at least one stage of filtering and washing to form a washed filter cake, adjusting the composition and calcining the adjusted and washed filter cake, the improvement which comprises filtering the aqueous titanium dioxide hydrate suspension under a pressure of about 1 bar to 16 bars to form a homogeneous substantially crack-free filter cake of a thickness of about 10 to 25 mm. Advantageously a membrane filter is employed, and washing is effected under a pressure of 1 to 16 bars and a liquid flow rate of 0.1 to 1 m/h to produce a filter cake having a solids content of at least 45 % by weight.