Extraction behavior of cesium from nitric acid medium with calix[4]-bis[(4-tert-butyl-1,2-phenylene)-crown-6]

Cesium, one of the heat-emitting fission elements contained in high active liquid waste, deserved separation. Calixbiscrown is a class of chemical compounds, promising in the cesium extraction. In this study, calix[4]-bis[(4-tert-butyl-1,2-phenylene)-crown-6] (CalixBBC for short) was synthesized by a multi-step scheme. The cesium extraction study was carried out using CalixBBC in two organic diluents such as chloroform and o-nitroanisole, which were used as electron-deficient and electron-rich surrogate dilutions, respectively. The effects of HNO3 concentration, mixing time, temperature were investigated using a batch technique. Comparing with chloroform, o-nitroanisole was in favor of cesium extraction. Both extractions strongly relied on HNO3 concentration in the range of 0.4-6.0M. The pseudo-second-order model fitted the extractions well. Both extractions were spontaneous, exothermal processes. The foreigner metal ions showed little influence on the extraction. The stoichiometry of cesium and CalixBBC in the complex was 1:1.