EXTRACTION OF CESIUM AND STRONTIUM INTO HYDROCARBON SOLVENTS USING TETRA-C-ALKYL COBALT DICARBOLLIDE

Tetra-C-alkyl derivatives of cobalt dicarbollide, Co(C(2)R(2)B(9)H(9)) (2)(-) (CoB2-R4(-); R = CH3, C6H13) are examined as potential cesium a nd strontium extractants for acidic and alkaline solutions. The mechan ism of cobalt dicarbollide extraction is characterized, and extended i nto new non-toxic solvent systems. Extractions using 0.01 M H+CoB2-hex yl(4)(-) in mesitylene and diethylbenzene are compared to 0.01 M H+CoB 2- in nitrobenzene. H(+)CoB2(-)hexyl4(-) in diethylbenzene shows impro ved selectivity (10(4)) for Cs over Na in acidic solution. In dilute a lkaline solution (0.01 M NaOH), H+CoB2-hexyl(4)(-) extracts Cs less ef ficiently, but more effectively removes Sr at higher base concentratio ns (1.0 M NaOH). Other aspects of the H+CoB2-hexyl(4)(-)/hydrocarbon p erformace are comparable to the previously known H+CoB2-/nitrobenzene extractant.