| 摘要 |
<p>The invention relates to a method of preparing microcrystalline titanium dioxide, in which a) the solid titanium dioxide hydrate is treated with a base, b) the precipitate treated with the base is treated with hydrochloric acid, and c) the precipitate treated with the base and the hydrochloric acid is neutralized. It has been noted that usable rutile crystals, a more appropriate crystal size and crystal size distribution and that chemicals can be saved if as the final hydrochloric acid content of the stage a) is adjusted a lower value than usually, being about 8 to 25g/liter, for the precipitation of microcrystalline titanium dioxide. Hereby the neutralization of the stage c) can also be carried out by raising the pH to a higher value than usually, i.e. the value about 4.0 to 6.0.</p> |
