| 摘要 |
<p>A Process for the Preparation of Titanium Dioxide In the process for the preparation of titanium dioxide comprising decomposing titanium-containing raw materials with sulphuric acid, hydrolyzing the resulting titanyl sulphate, separating the metal sulphate-containing sulfuric acid from the titanium hydroxide formed by the hydrolysis, bleaching the titanium hydroxide by reductive treatment in the presence of sulphuric acid, calcining the bleached titanium hydroxide to titanium dioxide with the formation of exhaust gases, removing dust and H2SO4 from the exhaust gases of calcination, and desulphurizing the SO2-containing exhaust gases of calcination with the formation of 2 to 20% by weight sulphuric acid, the improvement comprising scrubbing and cooling the exhaust gases of calcination in a scrubber with 10 to 50% by weight of sulphuric acid feeding the 2 to 20% by weight sulphuric acid formed when SO2 is removed from the exhaust gases of calcination by desulphurization into the scrubber to maintain a predetermined sulphuric acid concentration, removing a suspension of titaniumcontaining dust in 10 to 50% by weight sulphuric acid from the scrubber and transferring that suspension to the titanium hydroxide bleach. Le A 27 182</p> |
