Process for the separation of actinides from lanthanides by selective extraction of the actinides in an organic solvent containing propanediamide

摘要

The invention relates to a process for the separation of actinides from lanthanides by the selective extraction of the actinides in an organic solvent incorporating a propane diamide. This process consists of adding to the aqueous nitric solution containing the actinides and lanthanides a thiocyanate, e.g. ammonium thiocyanate, followed by the contacting of said solution with an organic solvent incorporating at least one propane diamide, e.g. 2-tetradecyl-N,N'-dimethyl-N,N'-dibutyl-propane diamide and optionally a quaternary ammonium salt such as trilauryl methyl ammonium (TMA) thiocyanate or a mixture of quaternary ammonium thiocyanates. This leads to distribution coefficients DM for the actinides (Am) and the lanthanides (Eu, Ce) making it possible to achieve high actinide/lanthanide separation factors.