Commissariat a L'energie Atomique

Other

Commissariat &#xc0; L'&#xc9;nergie Atomique Et Aux &#xc9;nergies Alternatives

Areva Nc

Michael Lecomte

Pascal Baron

Charles Madic

Gilles Bernier

Christian Sorel

Binh Dinh

Xavier Heres

Michel Masson

Gerard Koehly

Jacques Bourges

Bernard Mauborgne

Alexandre Masslennikov

Vladimir Peretroukhine

The invention concerns a cyclic method for separating at least one chemical element Efrom at least one chemical element Efrom an aqueous solution containing said elements, which employs a mixture of two extractants operating in non-overlapping chemical fields. Each cycle of said method comprises: a) co-extracting elements Eand Eby means of an organic phase containing a first extractant suited to causing the migration of said elements into said organic phase; b) adding to the organic phase a second extractant suited to selectively retaining the element(s) Ein said organic phase during step c): c) selectively stripping the element(s) Efrom the organic phase; d) selectively stripping the element(s) Efrom the organic phase; e) separating the first and second extractants present in said organic phase at the end of step d).

Cyclic method for separating chemical elements present in an aqueous solution

The present invention relates to a process for separating technetium from a nitric solution of technetium through cathodic electrodeposition of said technetium by electrolysis. According to the process of the invention, the nitric solution of technetium is denitrified and its pH is adjusted to a value of approximately 5.5 to 7.5 before electrolysis. Electrolysis is conducted at galvanostatic rate, and the cathode potential is approximately &minus;1.36 V/SHE to &minus;1.16/SHE. The ratio of the cathode surface area (S) to the volume of the technetium solution to be electrolyzed may be in the region of 0.25 to 0.50 cm,.

Method for separating technetium from a nitric solution

The invention relates to a process for recovering the plutonium contained in the solid waste, such as process, technological and laboratory waste. The waste is contacted with aqueous nitric acid solution having a nitric acid concentration of 2 to 8 mole/l, which contains a compound of Ag.sup.2+ soluble in the solution, for oxidizing the plutonium present in the waste and for dissolving same in the nitric solution. Preferably, contacting takes place in an electrolytic cell having an anode and a cathode, by applying a potential difference between anode and cathode which is sufficient to continuously regenerate the Ag.sup.2+ ions used for oxidizing the elements present in said waste.

Process for the recovery of plutonium contained in solid waste

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Avignon, France

Michael Lecomte