Extracting performance of cesium by 25,27-bis(2-propyloxy) calix[4]-26,28-crown-6 (iPr-C[4]C-6) in n-octanol

In this work, the extraction of cesium(Cs+) in nitric acid and in a simulated high level liquid waste (HLLW) by iPr-C[4]C-6 was investigated in the diluent n-octanol. The slope of the extractant dependency equals 1, indicating that the complex has 11[Cs+ center dot iPr-C[4]C-6]Cs+ to ligand. 0.025 mol/L iPr-C[4]C-6 in n-octanol (abbreviated to iPr-C[4]C-6-n-octanol) has a stronger extracting ability to Cs when acidities are between 1.0 mol/L and 4.0 mol/L. The stripping properties of Cs loading in 0.025 mol/L iPr-C[4]C-6-n-octanol was studied. Cs loading in iPr-C[4]C-6-n-octanol can be stripped easily into the aqueous phase because the distribution ratios of Cs are lower than 0.5 when pH is between 2 and 10 in the aqueous phase. On the above basis, the better parameters were selected and the cold cascade test for removing Cs from the simulated HLLW was investigated on miniature centrifugal contactor. The results of the test are attractive. The removing ratio of Cs from the simulated HLLW is 99.5% and the stripping ratio of Cs loading in 0.025 mol/L iPr-C[4]C-6-n-octanol is 99.2%. The results show that 0.025 mol/L iPr-C[4]C-6-n-octanol is an effective process for removing Cs from HLLW.