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US 7,708,962 B2Granted
Process for the separation and purification of hafnium and zirconium
AssigneeCompagnie Europeenne du Zirconium Cezus
InventorsLaurence Delons, Stéphane Lagarde, Alain Favre-Reguillon, Stéphane Pellet-Rostaing, Marc Lemaire, Ludovic Poriel
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Abstract
A process for the separation and purification of hafnium and zirconium.
Claims29
A process for separation of hafnium and zirconium from a mixture containing ZrCl4 and HfCl4, the process comprising:
- introducing the mixture of ZrCl4 and HfCl4 in vapour form into a continuous extractive distillation column;
- selective absorption of the ZrCl4 and HfCl4 vapours by an extraction solvent circulating in a counter-current to a stream of the vapours in the distillation column;
- drawing-off of one of a liquid and gaseous mixture of ZrCl4 and HfCl4 enriched with ZrCl4;
- drawing-off of one of a liquid and gaseous mixture of ZrCl4 and HfCl4 enriched with HfCl4;
- hydrolysis of one of the mixture obtained in the step of drawing-off of one of a liquid and gaseous mixture of ZrCl4 and HfCl4 enriched with HfCl4 in an aqueous solution of strong inorganic acid to form an aqueous solution having from 7 to 12 mol of acid per liter;
- passing the aqueous solution into an anion-exchange resin;
- and
- eluting and recovering a fraction enriched with hafnium.
5 more elements
Dependencies are inferred from the claim text.