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U.S. Department of Energy
Office of Scientific and Technical Information

Recovery of hafnium values from loaded extraction solvent

Patent ·
OSTI ID:7008042
This patent describes an improvement in a process for recovering high purity hafnium hydroxide from a methyl isobutyl ketone organic solvent that is substantially free of sulfate ions and contains hafnium thiocyanate and thiocyanic acid. The improvement comprising reacting the organic solvent with ammonia to produce a reaction product in the form of a methyl isobutyl ketone organic solvent that is substantially free of sulfate ions and contains ammonium thiocyanite solution and hafnium hydroxide; separating the constituents of the reaction product in accordance with their respective specific gravities to produce a hafnium hydroxide sludge as one of the separation products; and removing the liquid component of the sludge to yield a high purity hafnium hydroxide ready for calcination to hafnium oxide.
Assignee:
Westinghouse Electric Corp., Pittsburgh, PA
Patent Number(s):
US 4873072
Application Number:
PPN: US 7240184A
OSTI ID:
7008042
Country of Publication:
United States
Language:
English