| 摘要 |
<p>The present invention relates to employment of addition of zirconium and zirconyl compounds in an amount of 0.02 to 0.5 percent by weight of ZrOi2a, based on the weight TiOi2, into raw materials or arbitrary intermediates when preparing pigmentary titanium dioxide by employing sulfate process up to the calcining stage inclusive, in order to stabilize the calcining mode and enhancing optical properties of so prepared pigmentary titanium dioxide of either anatase and/or rutile type. Addition of ZrOi2 improves optical properties, particularly whiteness, tinge and colority, and considerably reduces pigment tendency towards over-calcining and consequently decrease of optical properties thereof. In case of titanium white of anatase type, the process reduces content of rutile being formed, what is very advantageous for products for fibers. Addition of zirconium and zirconyl compounds in an amount of 0.02 to 0.5 percent by weight of ZrOi2 during manufacture of pigmentary titanium dioxide by employing sulfate process up to the calcining stage inclusive, reduces in considerable manner deformations in the rutile crystal lattice to thereby also reducing undesirable phototropism and increasing light permanency of the pigment.</p> |
