ROOM TEMPERATURE ELECTRODEPOSITION OF ACTINIDES FROM IONIC SOLUTIONS
Uranium metal can be electrochemical deposited from room temperature ionic liquid (RTIL), tri-methyl-n-butyl ammonium n-bis(trifluoromethansulfonylimide) [Me 3 N n Bu][TFSI] providing an alternative non-aqueous system for the extraction and reclamation of actinides from reprocessed fuel materials. Deposition of U metal is achieved using TFSI complexes of U(III) and U(IV) containing the anion common to the RTIL. TFSI complexes of uranium were produced to ensure solubility of the species in the ionic liquid. The methods provide a first measure of the thermodynamic properties of U metal deposition using Uranium complexes with different oxidation states from RTIL solution at room temperature.
1 . A method for the electrochemical deposition of an actinide or lanthanide comprising:
providing an actinide ion in a room temperature ionic liquid to form an actinide rich liquid composition;
providing an electrode and a cathode within the actinide rich liquid composition;
at temperatures below 30° C., applying a potential such that current passes between the electrode and cathode to deposit actinide metal on the cathode.
2 . The method of claim 1 wherein the actinide ion is provided by as a dissolved actinide ion or complexed actinide ion in the room temperature ionic liquid.
3 . The method of claim 1 wherein the ionic liquid comprises a tetra-alkyl group ammonium n-bis (perfluoroalkansulfonylimide.
4 . The method of claim 3 wherein each alkyl of the tetra-alkyl is selected from methyl ethyl, propyl, butyl and pentyl groups.
5 . The method of claim 3 wherein the tetra-alkyl group ammonium is a tri-methyl-n-butyl ammonium.
6 . The method of claim 5 wherein the n-bis(perfluoroalkansulfonylimide) is selected from the group consisting of n-bis(trifluoromethansulfonylimide and n-bis(pentafluoroethansulfonylimide.
7 . The method of claim 1 wherein the actinide deposited comprises uranium.
8 . The method of claim 1 wherein the actinide deposited comprises plutonium.
9 . The method of claim 3 wherein the actinide deposited comprises uranium.
10 . The method of claim 5 wherein the actinide deposited comprises uranium.
11 . The method of claim 3 wherein the actinide deposited comprises plutonium.
12 . The method of claim 5 wherein the actinide deposited comprises plutonium.
13 . The method of claim 6 wherein the actinide deposited comprises uranium.
14 . The method of claim 6 wherein the actinide deposited comprises plutonium.
15 . The method of claim 1 wherein at least some of the actinide deposited is selected from the group consisting of uranium, plutonium, americium, curium and samarium.
16 . The method of claim 3 wherein the current used during step c) to cause electrodeposition is in the range of between 10 μamps and 500 μamps /cm 2 .
17 . The method of claim 3 wherein the current used during step c) to cause electrodeposition is in the range of between 50 μamps and 150 μamps /cm 2 .
18 . The method of claim 3 wherein at least some of the actinide deposited is selected from the group consisting of uranium, plutonium, americium, curium and samarium.
19 . The method of claim 4 wherein at least some of the actinide deposited is selected from the group consisting of uranium, plutonium, americium, curium and samarium.
20 . The method of claim 16 wherein at least some of the actinide deposited is selected from the group consisting of uranium, plutonium, americium, curium and samarium.
21 . The method of claim 17 wherein at least some of the actinide deposited is selected from the group consisting of uranium, plutonium, americium, curium and samarium.