| 摘要 |
Waste sulphuric acid resulting from the titanium dioxide production is concentrated by evaporation followed by an aging process during which the metals, except chromium and vanadium, are precipitated. In order to sufficiently precipitate chromium and vanadium in a reasonably short time, the evaporated waste sulphuric acid is mixed with aluminum having an active surface, which may be achieved by comminution e.g. cutting or pulverization not more than 4 hours before adding it to the waste sulphuric acid. |
