EXTRACTION OF URANIUM(VI) WITH POLYURETHANE FOAM CONTAINING DI(2-ETHYLHEXYL) PHOSPHORIC-ACID

The extraction of uranium(VI) with free di(2-ethylhexyl) phosphoric acid (D2EHPA) and D2EHPA-loaded polyurethane (PU) foam were studied. For the extraction of uranium(VI) with free D2EPHA, the extraction efficiency of uranium(VI) was affected more significantly by the amount of D2EHPA than by the solution pH. The distribution coefficients of uranium between free D2EHPA and different nitrate solutions increased in the sequence Al(NO3)3<Ca(NO3)2<NH4NO3. For the extraction of uranium(VI) with D2EHPA-loaded PU foam, the appropriate amount of D2EHPA loaded in PU foam was found to be below 8-10% by weight. The D2EHPA loaded in PU foam had a higher extraction efficiency than the free D2EHPA, even in the absence of nitrate salt. This indicated that PU foam not only is a support but also promotes the extraction of uranium(VI). The percentage extraction for the extraction of uranium(VI) with D2EHPA-loaded PU foam from aqueous nitrate solution increased with increasing nitrate concentration. Also, the synergistic enhancement of the extraction of uranium(VI) in the presence of different nitrate salts increased in the sequence NH4NO3<Ca(NO3)2<Al(NO3)3.