SYNERGETIC EXTRACTION IN SYSTEMS WITH DICARBOLLIDE AND BIDENTATE PHOSPHONATE

A process for the extraction of tervalent metal cations from 3 M HNO3 highly radioactive waste based on synergetic mixtures of dicarbollide with neutral organophosphonate (dibutyl diethylcarbamoylmethylene phos phonate) is proposed. Due to the great hydrophobicity of dicarbollide anion, the species ML(n)(3+).3BCl(-) is extracted and the extraction i n this TRUDIC process decreases with aqueous acidity, contrary to TRUE X process. HL(+) BCl- is the main particle in the organic phase. The e xtraction of Cs+, Sr2+, Ba2+ and Ru is low, and the extraction of Zr c an be suppressed by citric acid. Possible advantages of the system are discussed.