RADIOCHEMICAL EXTRACTION AND SEPARATION OF CADMIUM(II) AND MERCURY(II) WITH BIS-2-ETHYLHEXYL SULFOXIDE

The extraction of cadmium(II) and mercury(II) from iodide solutions ha s been investigated by tracer techniques with bis-2-ethylhexyl sulphox ide (B2EHSO) in benzene as an extractant. For comparison, extraction s tudies also have been carried out with a well-known neutral organophos phorus extractant, trioctyl- phosphine oxide (TOPO). The extraction da ta have been analyzed by both graphical and theoretical methods taking into account aqueous phase speciation and all plausible complexes ext racted into the organic phase. The results demonstrate that Cd(II) is extracted as CdI2 . 2 B2EHSO with B2EHSO and CdI2 . 2 TOPO with TOPO. In the case of Hg(II) the extracted species are HgI2, HgI2 . B2EHSO/TO PO and HgI2 . 2 B2EHSO/2 TOPO. These results also demonstrate the mutu al separation possibility of cadmium and mercury from iodide solutions using B2EHSO or TOPO as an extractant.