Chapter 4, Problem 4.59P

Titanium dioxide (TiCb) is used extensively as a white pigment. It is produced front an ore that contains ilmenite (FeTiO,) and ferric oxide (FejC^). The ore is digested w ith an aqueous sulfuric acid solution to produce an aqueous solution of titanyl sulfate [(TiO)SO₄] and ferrous sulfate (FeSO₄). Water is added to hydrolyze the titanyl sulfate to H2T1O3, which precipitates, and H2SO.4. The precipitate is then roasted, driv ing 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% H₂SO₄ 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 (Fe₂(SO₄)₃J. 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 TiO₂.