| 摘要 |
<p>The approximately 23% waste sulphuric acid resulting from the digestion of raw titanium material is concentrated (CS) to approximately 70% by weight and completely, or at least for the most part, roasted (R) with the precipitated metal salts. whereas the metal oxides (MeO) resulting from the roasting are conveyed to a waste dump, the sulphur oxide gases which are produced are converted, with the addition of water, to highly concentrated, e.g. 98%, sulphuric acid (HCS), which is returned to the raw titanium material digestion process. As the proportion of recycled metal compounds is greatly reduced during recirculation, a titanium dioxide pigment of a better quality can be produced with little expenditure in terms of equipment and energy.</p> |
