Isolation of Transplutonium Elements by Tertiary Amine Extraction

The Tramex Process for separating the transplutonium elements from ionic impurities and fission products, including the rare earths, was developed and tested in laboratory scale experiments. This process is based on tertiary amine extraction of transplutonium elements from concentrated lithium chloride solutions. Single-stage separation factors between the transplutonium and the lanthanide elements were found to be ≧100. Extraction positions were found to be Cf > Fm > Es > Bk > Am > Cm ≫; lanthanides. Extraction coefficients were directly proportional to the square of the amine concentration in the solvent, directly proportional to the 17th power of the LiCl concentration in the aqueous phase, and inversely proportional to the 1.3 to 2.0 power of the acid concentration in the aqueous phase. Extraction coefficients were affected by the presence of various contaminant anions and were also dependent upon the solvent used to dilute the amine.