Methods for purifying molybdenum-99
Methods for purifying the molybdenum-99 isotope are disclosed. Molybdenum-99 is loaded onto an anion exchange column and extracted. In some embodiments, the extraction solution may include nitric acid and nitrate salts. In other embodiments, a two stage elution is performed in which a nitric acid containing eluent and a hydroxide containing eluent are used in succession to extract molybdenum-99.
1. A method for purifying a molybdenum-99 feed stream comprising molybdenum-99, the method comprising:
contacting the molybdenum-99 feed stream with anion exchange media to adsorb molybdenum-99 onto the media; and
contacting the molybdenum-99 adsorbed media with an eluent solution comprising nitric acid and a nitrate salt.
2. The method as set forth in claim 1 wherein the molybdenum-99 feed stream comprises at least about 90 wt % molybdenum-99 on a dry basis.
3. The method as set forth in claim 1 wherein the nitrate salt is selected from the group consisting of alkali or alkaline earth-metal nitrate salts.
4. The method as set forth in claim 1 wherein the nitrate salt is selected from the group consisting of sodium nitrate and potassium nitrate.
5. The method as set forth in claim 1 wherein the molybdenum-99 feed stream comprises molybdenyl-99 ions.
6. The method as set forth in claim 1 wherein the molybdenum-99 feed stream is an aqueous hydroxide solution.
7. The method as set forth in claim 1 wherein the ratio of the mass of the eluent solution to the mass of molybdenum-99 in the molybdenum-99 feed stream is less than about 4:1.
8. A method for purifying a molybdenum-99 feed stream comprising molybdenum-99, the method comprising:
contacting the molybdenum-99 feed stream with anion exchange media to adsorb molybdenum-99 onto the media;
contacting the molybdenum-99 adsorbed media with a nitric acid-containing eluent solution; and
contacting the molybdenum-99 adsorbed media with a hydroxide-containing eluent solution containing hydroxide at a concentration of at least 0.1 M.
9. The method as set forth in claim 8 wherein the molybdenum-99 feed stream comprises at least about 90 wt % molybdenum-99 on a dry basis.
10. The method as set forth in claim 8 wherein the nitric acid-containing eluent comprises a nitrate salt selected from the group consisting of alkali or alkaline earth-metal nitrates.
11. The method as set forth in claim 8 wherein the nitric acid-containing eluent comprises a nitrate salt selected from the group consisting of sodium nitrate and potassium nitrate.
12. The method as set forth in claim 8 wherein the nitric acid-containing eluent solution is separate from the hydroxide-containing eluent solution, the nitic acid-containing eluent solution contacting the molybdenum-99 adsorbed media before the hydroxide-containing eluent solution.
13. The method as set forth in claim 8 wherein the nitric acid-containing eluent solution is separate from the hydroxide-containing eluent solution, the hydroxide-containing eluent solution contacting the molybdenum-99 adsorbed media before the nitic acid-containing eluent solution.
14. method as set forth in claim 8 wherein the molybdenum-99 feed stream comprises molybdenyl-99 ions.
15. The method as set forth in claim 8 wherein the molybdenum-99 feed stream is an aqueous hydroxide solution.
16. The method as set forth in claim 8 wherein the ratio of the mass of the nitric acid-containing eluent solution to the mass of molybdenum-99 in the molybdenum-99 feed stream is less than about 4:1.
17. The method as set forth in claim 8 wherein the ratio of the mass of the hydroxide-containing eluent solution to the mass of molybdenum-99 in the molybdenum-99 feed stream is less than about 4:1.
18. The method as set forth in claim 8 wherein the ratio of the mass of the sum of the nitric acid hydroxide-containing eluent solution and the hydroxide-containing eluent solution to the mass of molybdenum-99 in the molybdenum-99 feed stream is less than about 2:1.