Separation of rare earth elements

Patent metadata

Field	Value
Publication number	US-12157930-B2
Application number	US-202017778257-A
Country	US
Kind code	B2
Filing date	Nov 19, 2020
Priority date	Nov 20, 2019
Publication date	Dec 3, 2024
Grant date	Dec 3, 2024

Abstract

A method for purifying lutetium includes providing a solid composition comprising ytterbium and lutetium and subliming or distilling ytterbium from the solid composition at a temperature of about 1196° C. to about 3000° C. to leave a lutetium composition comprising a higher weight percentage of lutetium than was present in the solid composition.

First claim

What is claimed is:

1. A method for purifying lutetium, the method comprising:
subliming or distilling ytterbium from a solid composition in an inert or reduced pressure environment and at a temperature of about 400° C. to about 3000° C. to leave a lutetium composition comprising a higher weight percentage of lutetium than was present in the solid composition.

2. The method of claim 1 , wherein the temperature is about 450° C. to about 1500° C.

3. The method of claim 1 , wherein the temperature is about 450° C. to about 1200° C.

4. The method of claim 1 , further comprising collecting the ytterbium for reuse.

5. The method of claim 4 , wherein the ytterbium is collected in an amount that is about 90 wt % to about 99.999 wt % of the ytterbium present in the solid composition.

6. The method of claim 1 , wherein the reduced pressure is about 1×10 −8 to about 2000 torr.

7. The method of claim 1 , wherein the temperature is about 450° C. to about 1500° C., and the reduced pressure is about 2000 torr to about 1×10 −8 torr.

8. The method of claim 1 , wherein the temperature is about 450° C. to about 1200° C., and the reduced pressure is about 1000 torr to about 1×10 −8 torr.

9. The method of claim 1 , wherein the reduced pressure is about 100 torr to about 1×10 −7 torr.

10. The method of claim 1 , comprising subliming the ytterbium, wherein the reduced pressure is about 10 torr to about 1×10 −6 torr and the temperature is about 450° C. to about 800° C.

11. The method of claim 1 , comprising distilling the ytterbium, wherein the reduced pressure is about 1×10 −3 torr to about 2000 torr and the temperature is about 600° C. to about 1500° C.

12. The method of claim 1 , wherein the subliming or distilling is conducted for a period of about 1 second to about 1 week.

13. The method of claim 1 , wherein the subliming or distilling is conducted at a rate of about 10 min/g to about 100 min/g of solid composition.

14. The method of claim 13 , wherein the subliming or distilling is conducted at a rate of about 20 min/g to about 60 min/g of solid composition.

15. The method of claim 14 , wherein the subliming or distilling is conducted at a rate of about 40 min/g of solid composition.

16. The method of claim 1 , wherein the process yields a ytterbium mass reduction of the solid composition from 1000:1 to 10,000:1.

17. The method of claim 1 , wherein the lutetium composition comprises about 1 wt % to 90 wt % of ytterbium.

18. The method of claim 1 , wherein the solid composition further comprises metals, oxides, or ions of K, Na, Ca, Fe, Al, Si, Ni, Cu, Pb, La, Ce, Lu (non-radioactive), Eu, Sn, Er, and Tm.

19. The method of claim 1 , wherein the ytterbium comprises Yb-176 and the lutetium comprises Lu-177.

20. The method of claim 1 , wherein the providing comprises reducing ytterbium oxide to ytterbium metal, and irradiating the ytterbium metal to generate lutetium.

21. The method of claim 1 , wherein the ytterbium is Yb-176 and the lutetium is Lu-177, and a neutron capture reaction with Yb-176 forms the composition comprising solid Yb-176, solid Yb-177, and solid Lu-177.

22. The method of claim 21 , further comprising prior to subliming, contacting a solid comprising Yb-176 with a neutron source to convert at least a portion of the Yb-176 to Lu-177 to form the solid composition.

23. The method of claim 1 , wherein the temperature is about 400° C. to less than 700° C. and the reduced pressure is 1×10 −5 torr or less.

24. The method of claim 23 , wherein the reduced pressure is 1×10 −6 torr or less.

25. The method of claim 1 , wherein the temperature is about 400° C. to about 650° C.

26. The method of claim 1 , wherein the temperature is about 450° C. to about 650° C.

27. The method of claim 1 , wherein the temperature is about 470° C. to about 630° C.

28. The method of claim 1 , wherein the temperature is greater than 800° C. to about 3000° C.

29. The method of claim 1 , wherein the temperature is about 1000° C. to about 3000° C.

30. The method of claim 1 , wherein the temperature is about 1200° C. to about 3000° C.

31. The method of claim 1 , wherein the temperature is about 1500° C. to about 3000° C.

32. The method of claim 1 , wherein the solid composition is contained in a crucible of a sublimation/distillation apparatus and subliming or distilling ytterbium from the solid composition comprises heating the crucible such that the ytterbium sublimes, distills, or both sublimes and distills from the solid composition and collects on a collection substrate of the sublimation/distillation apparatus.

33. The method of claim 32 , wherein the subliming or distilling comprises establishing the reduced pressure environment, thereby degassing the crucible of the sublimation/distillation apparatus, and thereafter heating the solid composition to the temperature of about 400° C. to about 3000° C.

34. The method of claim 32 , wherein the collection substrate is movable to selectively seal the collection substrate onto the crucible.

35. The method of claim 34 , wherein a cool finger extends from the collection substrate toward the crucible such that the cool finger extends into the crucible when the collection substrate is sealed onto the crucible.

36. The method of claim 32 , wherein the collection substrate is actively cooled when subliming or distilling ytterbium from the solid composition such that the ytterbium collects on the collection substrate.

37. The method of claim 32 , wherein a cool finger extends from the collection substrate toward the crucible and the cool finger is actively cooled when subliming or distilling ytterbium from the solid composition such that the ytterbium collects on the cool finger.

38. The method of claim 1 , wherein the inert or reduced pressure environment comprises an inert environment.

39. A method comprising:
heating a solid composition of ytterbium and lutetium to a first temperature in an inert or reduced pressure environment;
retaining the solid composition at the first temperature in the inert or reduced pressure environment such that ytterbium sublimes, distills, or both sublimes and distills from the solid composition; and
heating the solid composition to a second temperature that is greater than the first temperature in the inert or reduced pressure environment such that a lutetium composition comprising a higher weight percentage of lutetium than was present in the solid composition remains, wherein the first temperature and the second temperature are both within a range of about 400° C. to about 3000° C.

40. The method of claim 39 , wherein the reduced pressure is 1×10 −5 torr or less and the first temperature is about 400° C. to less than 700° C.

41. The method of claim 40 , wherein the reduced pressure is 1×10 −6 torr or less.

42. The method of claim 39 , wherein the first temperature and the second temperature are both within a range of about 400° C. to about 650° C.

43. The method of claim 39 , wherein the inert or reduced pressure environment comprises an inert environment.

Assignees

• Shine Technologies Llc

Inventors

• Piefer Gregory
• Van Abel Eric
• Sisson Richard

Classifications

• Y02P10/20

  Recycling · CPC title

• C22B9/04

  Refining by applying a vacuum · CPC title

• C22B9/02

  Refining by liquating, filtering, centrifuging, distilling, or supersonic wave action {including acoustic waves; (C22B9/003, C22B9/006, C22B9/05, C22B9/22 take precedence)} · CPC title

• G21G2001/0094

  Other isotopes not provided for in the groups listed above · CPC title

• C22B3/205

  using adducts or inclusion complexes · CPC title