Published online by Cambridge University Press: 10 February 2011
Acidic salts of polyvalent metal antimonates(M-antimonates(M-Sb); M=Cerium, Tin, Titanium and Silicon) have been synthesized under different conditions( 1,2). The products were characterized by powdered X-ray diffraction patterns, Differential Thermal Analysis(DTA) and infrared spectrometry. Chemical stability of the product materials were studied by mixing 50 mg of the prepared materials with 50 ml of the desired medium(H20, HNO3 and HCI) with determination for the concentration of the metalions dissolved(Sb, Ce, Sn, Ti and Si) which showed high chemical stabilities in water and acid media up to I OM HNO 3 and 6M HCI.The data of the distribution coefficients showed that the selectivity decrease in the order; Eu3+> Co2+> Sr2+> Cs+ for cerium(IV) antimonate(CeSb), tin(IV) antimonate(SnSb) and silicon(IV) antimonate(SiSb), while the selectivity decrease in the order UO22+>Th4+ for titanium(IV) antimonate(TiSb). Besides, the effect of EDTA, citric acid, ferric nitrate and sodium nitrate as interfering ions in solution on the distribution coefficient of the studied cations for CeSb and SnSb were studied under certain conditions. The results showed that, the Kj values of CS+, Co2+ and Eu3+ are decreases with increasing the concentrations of ferric and sodium nitrates in the feed solutions for both materials and also Kd values are effected to some extent in case of EDTA and citric acid. Based on the obtained results, practical separation experiments on column were performed(3).
The following figures represents the break-through curves for CeSb and SnSb columns for some radionuclides 60Co (10-3M ) as example. From the above studies we conclude that, CeSb and SnSb have been successfully used for the quantitative separation of cesium which suggests its use in the treatment of radioactive liquid waste.