| 摘要 |
Removal of aluminum and iron impurities is accomplished using an absorbing column containing potassium or sodium chloride, producing an aluminum and iron chloride-rich bottoms product and purified Zr(Hf)Cl4 vapor at the top of the column. This invention is a continuous process for removing impurities of iron or aluminum chloride or both from vaporous zirconium chloride (or hafnium chloride or a mixture thereof). When iron is being removed from zirconium tetrachloride using potassium chloride, the process comprises: introducing impure zirconium chloride vapor into a middle portion of an absorbing column containing a potassium chloride-containing molten salt phase, the molten salt phase absorbing the iron chloride impurity to produce a zirconium chloride vapor stripped of iron chloride in the top portion of the column; introducing potassium chloride into a top portion of the column; controlling the top portion of the column to between 300 DEG -375 DEG C.; heating a bottom portion of the column to 450 DEG -550 DEG C. to vaporize zirconium chloride from the molten salt; withdrawing molten salt substantially free of zirconium and hafnium chloride from the bottom portion of the column; and withdrawing zirconium chloride vapor substantially free of iron chloride impurity from the top of the column. Similarly, hafnium or hafnium-zirconium mixtures can be substituted for zirconium, or aluminum or iron-aluminum can removed rather than iron, or sodium chloride or sodium potassium chloride mixtures can be substituted for potassium chloride.
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