Patent ID: 7429364

Claim:
A sulfate process for producing titania from a titaniferous material which includes the steps of: (a) leaching the titaniferous material with a leach solution containing sulfuric acid and forming a leach liquor that includes an acidic solution of titanyl sulfate (TiOSO 4 ) and iron sulfate (FeSO 4 ); (b) separating the leach liquor and a residual solid phase from the leach step (a); (c) precipitating iron sulfate from the leach liquor from step (b) and separating precipitated iron sulfate from the leach liquor; (d) extracting titanyl sulfate from the leach liquor from step (c) with a suitable solvent and thereafter stripping titanyl sulfate from the solvent and forming a raffinate having an acid concentration of at least 250 g/L sulphuric acid and a solution that contains titanyl sulfate; (e) using at least part of the raffinate from solvent extraction step (d) as at least part of the leach solution in the leach step (a); (f) hydrolysing the solution that contains titanyl sulfate and forming hydrated titanium oxides from the titanyl sulfate; (g) separating a solid phase containing hydrated titanium oxides and a liquid phase that are produced in the hydrolysis step (f); and (h) calcining the solid phase from step (g) and forming titania.