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Ilmenite
+ Sulphuric Acid-> Titanyl Sulphate -> |
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Travancore
Titanium Products Limited is currently producing TiO2, antase grade,
through the sulphate route. Ilmenite, a mixed oxide of titanium, ferrous
iron and ferric iron is the main raw material for the production of
titanium dioxide pigment.Ilmenite is reacted with sulfuric acid in reinforced
cement concrete tanks called Digesters, lined with lead and acid resistant
bricks. Exothermic reaction is initiated by the heat of dilution of
the acid with water and a porous cake is formed. The mass in the solid
form is dissolved in dilute sulphuric acid to get titanium in solution
as titanium oxy sulphate (TiOSO4) along with other metallic ingradients
in ilmenite as their sulphate. The liqour is reduced using scrap iron,
when the ferric iron gets completly reduced to the ferrous state.
The resulting black liquor is clarified, concentrated and boiled by injecting steam to precipitate the titanium content as hydrated titania. The hydrated titania is filterd over drum type rotary vacuum filters. Any ferric iron still present is reduced to ferrous iron by leaching the pulp with dilute sulphuric acid. It is washed free of iron and other impurities and calcined in a rotary kiln is cooled in rotating coolers and de-agglomerated in pendulum mills to very fine particles. The fine white powder is packed in 25kg HDPE bags. |
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