Process for recovering titanium dioxide

A process for recovering titanium dioxide from a titanium-bearing material, the process including the steps of:

• leaching the titanium-bearing material in a first leaching step at atmospheric pressure and at a temperature of 70 to 97° C. with a first lixiviant to produce a first leach solution comprising undissolved first leach solids that include a titanium content and a first leach liquor, the first lixiviant comprising hydrochloric acid at a concentration of less than 23% w/w;
• separating the first leach liquor and the undissolved first leach solids;
• leaching the first leach solids in a second leaching step at atmospheric pressure and at a temperature of 60 to 80° C. with a second lixiviant in the presence of a Fe powder reductant to produce a second leach solution comprising undissolved second leach solids and a second leach liquor that includes a leached titanium content and iron content, the second lixiviant comprising a mixed chloride solution comprising less than 23% w/w hydrochloric acid and an additional chloride selected from alkali metal chlorides, magnesium chloride and calcium chloride, or mixtures thereof;
• separating the second leach liquor and the undissolved second leach solids;
• precipitating titanium dioxide from the second leach liquor by addition of heated or boiling water under an inert gas or nitrogen atmosphere to raise the temperature of the second leach liquor to 85 to 100° C. to produce a treated second leach liquor and a titanium dioxide containing solid;
• separating the titanium dioxide containing solid from the treated second leach liquor;
• precipitating the iron content from the treated second leach liquor by adding a neutralising agent and an oxidant to the treated second leach liquor at a temperature of 70 to 90° C. to raise the pH of the second leach liquor to 4 to 8 to produce an iron removed slurry comprising an iron removed second leach liquor and an iron precipitated solid;
• separating the iron removed second leach liquor from the iron precipitated solid;
• and
• regenerating the second lixiviant for recycle to the second leaching step,
• thereby recovering the titanium from the second leach solution as titanium dioxide.