Process for manufacturing titanium dioxide

摘要

A process is provided for the manufacture of titanium dioxide pigment wherein excess ilmenite ore is reacted with dilute sulfuric acid having a concentration of between about 25% and about 60% by weight in the presence of an iron reductant, and in preferably at least two stages wherein the first stage is maintained at a temperature up to about 140 DEG C. and the second stage is conducted at a lower temperature (than the first stage) which is below about 100 DEG C. to provide a salt solution of titanium and iron. Thereafter, the titanium is hydrolyzed to provide titanium dioxide hydrate accompanied by recycling the spent acid from the hydrolysis for reaction with the ilmenite ore charged to the process. The titanium hydrate is calcined to provide titanium dioxide pigment.