| 摘要 |
<p>Pure TiO2 is prepd. from Ti-contg. core which contains TiO2, iron oxides and smaller amounts of other metal oxides as impurities, by (a) treating a bed of the ore in a reactor for gases and solids under reducing conditions at elevated temp. with chlorine gas, so that a partly chlorinated bed is formed, (b) removing the formed iron and other metal chlorides in vapour-form, (c) withdrawing a part of the partly chlorinated bed, (d) separating the withdrawn part into a first fraction of practically iron-free TiO2 pdt. and a second iron-contg. fraction, and (e) recycling the second fraction, opt. together with fresh ore, to the reactor. Gives practically iron-free TiO2 which is useful for prepn. of TiO2 pigments for paints, as a filler for rubber, as a pigment, and a flux for welding.</p> |
