Abstract: A process is provided for removing impurities from a slurry of titanyl hydrate. The titanyl hydrate is separated from the slurry, washed, and reslurried with water to make the resulting titanyl hydrate slurry fluid. The reslurried titanyl hydrate slurry is then treated by the addition of a trivalent titanium compound in an amount between about 0.01 grams and about 0.7 grams trivalent titanium compound measured as TiO.sub.2 per 100 grams titanyl hydrate as calcined TiO.sub.2 in the absence of additional acid values. The titanyl hydrate is then separated from the treated slurry, washed and recovered.

Abstract: A process is provided for the manufacture of titanium compounds and particularly titanium dioxide wherein excess titaniferous bearing material is reacted with dilute sulfuric acid having a concentration of between about 25% and about 60% by weight at a temperature below about 140.degree. C., and in the presence of a reducing agent which affects the reduction of ferric iron to ferrous iron. Thereafter, the titanium sulfate may be recovered or further processed to provide titanium dioxide hydrate accompanied by recycling the spent acid for reaction with the titaniferous bearing material charged to the process. The titanium hydrate may be calcined to provide titanium dioxide.

Abstract: A process is provided for the manufacture of titanium compounds and particularly titanium dioxide wherein excess titaniferous bearing material is reacted with dilute sulfuric acid having a concentration of between about 25% and about 60% by weight at a temperature below about 140.degree. C. Thereafter, the titanium sulphate may be recovered or processed to provide titanium dioxide hydrate accompanied by recycling the spent acid for reaction with the titaniferous bearing material charged to the process. The titanium hydrate may be calcined to provide titanium dioxide pigment.

Abstract: 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 and in preferably at least two stages wherein the first stage is maintained at a temperature up to about 140.degree. C. and the second stage is conducted at a lower temperature (than the first stage) which is below about 100.degree. 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.

Abstract: 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.degree. C. and the second stage is conducted at a lower temperature (than the first stage) which is below about 100.degree. 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.

Abstract: A process is provided for the manufacture of a stable titanyl sulfate solution by diluting a reaction mixture containing iron sulfate and titanyl sulfate with a material selected from water, a titanyl sulfate solution, and mixtures thereof. The titanyl sulfate solution may be recovered or processed to provide titanium dioxide hydrate which may be calcined to provide titanium dioxide pigment.