Westinghouse Electric Corporation

Umesh P Nayak

Thomas S Snyder

Richard J Beleski

Steven H Peterson

Warren G Sisson

Timothy L Francis

Charles H Byers

A method and system for improved ion exchange chromatographic elemental separations of zirconium and hafnium elements and also, if desired, separations of the isotopes thereof from crude zirconium minerals by using improved crude aqueous zirconium (also containing hafnium) chloride feedstock solutions, aqueous chloride eluant solutions, cationic or anionic exchange resins, and reduced ion exchange chromatographic operating temperatures. The method and system of the invention provides improved crude aqueous zirconium chloride feedstock solutions by carbochlorinating zircon sand and hydrolyzing and dissolving the chlorination products under controlled conditions to substantially eliminate cross-polymerization of the carbochlorination products, which undesirably yield inseparable zirconium and hafnium co-polymers during hydrolysis, by inhibiting the hydrolysis exotherm and/or the free acid generation during hydrolysis.

Zirconium and hafnium separation in chloride solutions using continuous

A method and system for improved continuous ion exchange chromatographic elemental separations of zirconium and hafnium and also for isotopic separations thereof from crude zirconium minerals by using zirconium (also containing hafnium) sulfate feedstock solutions, sulfate eluant solutions, anionic exchange resins, and reduced ion exchange column operating temperatures. The method and system of the invention provides sulfate feedstock solutions by completely converting the carbochlorination products of zircon sand to sulfate solutions prior to feeding to the ion exchange chromatographic column. The method and system of the invention is performed in a continuously operating continuous annular chromatograph (CAC). Nuclear grade substantially purified zirconium and hafnium metals are produced.

Zirconium and hafnium separation in sulfate solutions using continuous

A method and apparatus for the partial or complete continuous separation of isotopes of gadolinium, especially high thermal neutron capture cross-section gadolinium isotopes, using continuous, steady-state, chromatography in which an ion exchange resin is the stationary phase, an aqueous solution of ions based on a mixture of gadolinium isotopes is the feed phase, and an aqueous acid eluant solution is the mobile phase. The method involves the mobile phase eluting or desorbing the gadolinium isotopic solute or ligand adsorbed on the stationary phase under conditions such that each of the various naturally occurring isotopes of gadolinium is primarily eluted in an elution volume distinct from the elution volumes of the other isotopes. In a preferred embodiment, the conditions are such that at least one of the elution volumes contains essentially only one isotope of gadolinium. The method is preferably conducted in a continuous, steady-state manner, and it is preferably conducted in a single operation in a continuous annular chromatograph (CAC).

Continuous, steady-state, chromatographic separation of gadolinium

A process for the partial or complete simultaneous separation of isotopes of erbium, especially high thermal neutron capture cross-section erbium isotopes, using continuous, steady-state, chromatography in which an ion exchange resin is the stationary phase, an aqueous solution of ions based on a mixture of erbium isotopes is the feed phase, and an aqueous acid eluant solution is the mobile phase. The process involves the mobile phase eluting or desorbing the erbium isotopic solute adsorbed on the stationary phase under conditions such that each of the various naturally occurring isotopes of erbium is primarily eluted in an elution volume distinct from the elution volumes of the other isotopes. In a preferred embodiment, the conditions are such that at least one of the elution volumes contains essentially only one isotope of erbium. The process is preferably conducted in a continuous, steady-state manner, and in particular is preferably conducted in a continuous annular chromatograph (CAC).

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Murrysville, PA, United States of America

Umesh P Nayak