Patent ID: 7157003

Claim:
A cyclic method for separating at least one chemical element E 1 from at least one chemical element E 2 present in an aqueous solution, each cycle of said method comprising successively: contacting said aqueous solution with an organic phase containing a first extractant in an organic diluent, wherein the first extractant coextracts E 1 and E 2 from the aqueous solution, and then separating the organic phase containing E 1 and E 2 from the aqueous solution; adding a second extractant to the organic phase containing E 1 and E 2 , wherein the second extractant is one that will selectively retain E 2 in the organic phase during the following stripping step; contacting the organic phase containing E 1 and E 2 with a first aqueous phase, wherein the first aqueous phase strips E 1 from the organic phase, and then separating said first aqueous phase containing E 1 from the organic phase; contacting the organic phase from which E 1 has been stripped with a second aqueous phase, wherein said second aqueous phase strips E 2 from the organic phase, and then separating said second aqueous phase containing E 2 from the organic phase; and separating the first and second extractants from each other and using said extractants in a subsequent cycle.