Titanium dioxide (TiO ) is used extensively as a white pigment. It is produced from
Titanium dioxide (TiO ) is used extensively as a white pigment. It is produced from an ore that contains ilmenite (FeTiO ) and ferric oxide (Fe O ). The ore is digested with an aqueous sulfuric acid solution to produce an aqueous solution of titanyl sulfate [(TiO)SO ] and ferrous sulfate (FeSO ). Water is added to hydrolyze the titanyl sulfate to H TiO , which precipitates, and H SO . The precipitate is then roasted, driving off water and leaving a residue of pure titanium dioxide. (Several steps to remove iron from the intermediate solutions as iron sulfate have been omitted from this description.) Suppose an ore containing 24.3% Ti by mass is digested with an 80% H SO solution, supplied in 50% excess of the amount needed to convert all the ilmenite to titanyl sulfate and all the ferric oxide to ferric sulfate [Fe (SO ) ]. Further suppose that 89% of the ilmenite actually decomposes. Calculate the masses (kg) of ore and 80% sulfuric acid solution that must be fed to produce 1000 kg of pure TiO .