Separation and recovery of molybdenum values from uranium process distillate
AssigneeHoneywell International Inc.
InventorsDavid Nalewajek, Kent Beckman
Life of this patent
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Abstract
A method for treating process distillate heavies produced during uranium fluoride purification is described. The heavies contain primarily uranium hexafluoride, UF6, and molybdenum oxytetrafluoride, MoOF4. The uranium hexafluoride is removed via distillation at reduced pressure leaving essentially MoOF4 containing <0.1% of residual uranium hexafluoride. This mixture is hydrolyzed in water, then treated with a solution of sodium hydroxide until a pH of at least 7.5 is reached. The precipitated sodium diuranate and sodium fluoride are removed by filtration. The filtrate is reacted with calcium chloride to precipitate the molybdenum values as calcium molybdate containing trace quantities of calcium fluoride.
Claims19
A method of manufacturing uranium hexafluoride comprising the steps of:
- feeding crude uranium hexafluoride comprising molybdenum impurities into a boiler still for processing;
- distilling at an elevated pressure greater than atmospheric pressure said crude uranium hexafluoride in said boiler still such that substantially pure uranium hexafluoride is recovered as a first light distillate product;
- and
- distilling a heavy distillate product from said elevated pressure distillation, the product including uranium hexafluoride and molybdenum oxytetrafluoride, at a reduced pressure lower than atmospheric pressure to recover substantially pure uranium hexafluoride as a second light distillate product.
A method of manufacturing uranium hexafluoride comprising the steps of:
- feeding crude uranium hexafluoride comprising molybdenum impurities into a boiler still for processing;
- distilling at an elevated pressure greater than atmospheric pressure the crude uranium hexafluoride in the boiler still such that substantially pure uranium hexafluoride is recovered as a first light distillate product;
- distilling a heavy distillate product from said elevated pressure distillation step, the product including uranium hexafluoride and molybdenum oxytetrafluoride, at a reduced pressure of less than about 50 kPa to recover substantially pure uranium hexafluoride as a second light distillate product;
- hydrolyzing a heavy distillate product from said reduced pressure distillation step with water to form a solution comprising hydrofluoric acid, hydrolyzed molybdenum, and uranyl fluoride;
- reacting the solution with sodium hydroxide to precipitate uranium as sodium diuranate and fluoride as sodium fluoride;
- and
- reacting a liquor from said sodium hydroxide treatment step with a calcium salt to precipitate molybdenum as calcium molybdate.
Dependencies are inferred from the claim text.