A comparision of the extraction of carrier-free 176,177W and 99Mo with that of U, Th, Am, Cm, La, Ce, Tm, Yb, Lu and Hf into Aliquat 336 in toluene from nitric, phosphoric, and sulphuric acid media

Abstract

Summary Carrier-free 176,177W and 99Mo have been extracted from 0.1-5.0M nitric, phosphoric and sulphuric acids into 0.22M Aliquat 336, CH3NR3Cl, in toluene. Their extraction properties have been compared to hafnium, to the lanthanides lanthanum, cerium, thulium, ytterbium and lutetium, and to the actinides americium, curium, thorium and uranium. From nitric acid solutions the extracted species of tungsten and molybdenum at low concentrations are probably CH3NR3· HMO4, where M=Mo or W. At higher nitric acid concentrations the extracted species are most likely similar to those of uranium, i.e. (CH3NR3)2·MO2(NO3)4 and possibly CH3NR3·MO2(NO3)3. For the extraction from phosphoric acid solutions the major extracted complex is most likely CH3NR3·MO2(H2PO4)3, while the minor extracted complex may be (CH3NR3)2·MO2(H2PO4)4 or even the more hydrolysed species CH3NR3·HMO4. From sulphuric acid solutions the extraction of molybdenum and tungsten has similarity with the extraction of uranium and thorium, although the decrease with acid concentration is slower.