Zirconium and hafnium tetrachloride separation by extractive distillation with molten zinc chloride calcium and/or magnesium chloride solvent
This patent describes an extractive distillation method for separating hafnim tetrachloride from zirconium tetrachloride of the type wherein a mixture of zirconium and hafnium tetrachlorides is introduced into an extractive distillation column, which distillation column has a reflux reboiler connected at the bottom and a reflux absorber connected at the top and wherein a molten salt solvent is circulated into the reflux absorber and through the column to provide a liquid phase. The molten salt solvent contains zirconium tetrachloride and is taken from the reboiler and run through a stripper to remove zirconium tetrachloride product from the molten salt solvent and the stripped molten salt solvent is returned to the reflux absorber and hafnium tetrachloride enriched vapor is taken as product from the reflux absorber. The improvement comprises: the molten salt solvent having a composition of at least 80 weight percent zinc chloride and at least 5 percent of a viscosity reducer, the viscosity reducer being chosen from the group consisting of magnesium chloride; and calcium chloride, and mixtures thereof.
- Assignee:
- Westinghouse Electric Corp., Pittsburgh, PA
- Patent Number(s):
- US 4749448
- OSTI ID:
- 7127166
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400201* -- Chemical & Physicochemical Properties
ABSORPTION
ADSORBENTS
ALKALINE EARTH METAL COMPOUNDS
CALCIUM CHLORIDES
CALCIUM COMPOUNDS
CALCIUM HALIDES
CHLORIDES
CHLORINE COMPOUNDS
DISPERSIONS
DISTILLATION
DISTILLATION EQUIPMENT
EQUIPMENT
HAFNIUM CHLORIDES
HAFNIUM COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
MAGNESIUM CHLORIDES
MAGNESIUM COMPOUNDS
MIXTURES
MOLTEN SALTS
PROCESS SOLUTIONS
REFRACTORY METAL COMPOUNDS
SALTS
SEPARATION PROCESSES
SOLUTIONS
SOLVENTS
TRANSITION ELEMENT COMPOUNDS
ZINC CHLORIDES
ZINC COMPOUNDS
ZINC HALIDES
ZIRCONIUM CHLORIDES
ZIRCONIUM COMPOUNDS