Sulphate process (titanium dioxide)

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Titanium dioxide
Production of titanium (IV) oxide using processes ( chloride process or sulphate process), with a distinction from Chinese production

The sulphate process was developed in 1915 by the Norwegians F. Farup and Dr. G. Jebsen developed process for the production of titanium dioxide . It has been in commercial use since 1916 and is still relevant today.

Procedural steps

The finely ground and enriched titanium iron ore ilmenite is digested with concentrated sulfuric acid . The iron oxide contained in the ore reacts to form iron sulfate , the titanium ore to titanium oxide sulfate TiOSO 4 .

The raw material ilmenite, formally FeTiO 3 , is converted with concentrated sulfuric acid to iron sulfate and titanium oxide sulfate. Since the iron is partially trivalent as Fe 3+ , the digestion solution must be mixed with pure iron scrap as a reducing agent in order to obtain exclusively bivalent iron Fe 2+ . This can then be crystallized out of the solution as so-called green salt .

The titanium oxide sulfate remaining in solution can be precipitated and separated off as a sparingly soluble titanium oxide hydrate by hydrolysis . After several filtration and washing processes, the titanium oxide hydrate has to be calcined at 800-950 ° C in order to obtain titanium dioxide.

By adding seed crystals and using the temperature, it is possible in this step to control the modification in which the TiO 2 is to be produced. The sulfate process is suitable for the production of both the anatase and rutile modifications, while the chloride process is generally only used for the production of pure rutile.

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