| 摘要 |
<p>The approximately 23% strength waste sulphuric acid (DS) produced in the digestion of titanium raw materials is concentrated to about 70% by weight (CS) and is subjected together with precipitated metal salts completely or at least to a large extent to roasting (R). While the metal oxides (MeO) formed are deposited, the sulphur oxide gases produced are reacted with water to give highly concentrated, for example 98% strength, sulphuric acid (HCS), which is recycled into the digestion of titanium raw materials. Since the proportion of recycled metal compounds is substantially reduced in recirculation, a titanium dioxide pigment of higher quality can be produced with less complicated equipment and less energy. <IMAGE></p> |
