VERFAHREN ZUR HERSTELLUNG VON TITANDIOXID.

摘要

Prodn. of TiO2 by the sulphate process involves lixiviating Ti raw materials with H2SO4, hydrolysis of the titanyl sulphate formed, sepn. of the dil. acid from the hydrolysate, concn. of the dil. acid by evapn. to a concn. such that a 60-70% H2SO4 is sepd. from the solid metal sulphates present and re-use of the conc. H2SO4 to lixiviation. The novel features are (a) the 60-70% H2SO4 is passed to second concn. stage, where it is conc. by evapn. to a concn. of 70-80% H2SO4; and (b) pt. of this H2SO4 is adjusted to a concn. of 98-99% H2SO4 by absorption of SO3 and then used with the remaining 70-80% H2SO4 in lixiviation.