| 摘要 |
<p>The present invention relates to a method for eliminating halides, in particular chlorides and fluorides, from secondary zinc oxides, for example Waelz or Primus oxides, including the steps of (1) stripping the secondary zinc oxides with sodium carbonate and separating the dry matter from the base liquid, (2) leaching at least one portion of the dry matter from step 1 using HSO, preferably until reaching a pH of 2.5 to 4, and separating the dry matter from the acid liquid, and (3) treating the liquid from step 2 by adding Al ions and PO ions and a neutralising agent in order to eliminate the residual fluoride, preferably until reaching a pH of < 4, and separating the liquid from the dry matter containing the fluorides.</p> |
