用分配法研究铀（VI）与硫氰酸盐配合物的稳定性常数测定

DETERMINATION OF STABILITY CONSTANTS OF THE COMPLEXES OF URANIUM(VI) WITH THIOCYANATE BY PARTITION METHOD

用单烷基磷酸酯（Ｐ５３８）的环己烷溶液，萃取铀（ＶＩ），改变水相硫氰酸铵的浓度，使分配比不断降低的实验方法，用水相不存在硫氰酸铵测得的分配比（Ｄ０）与存在硫氰酸铵时测得的分配比（Ｄ）之比与水相中硫氰酸根的平衡浓度的函数关系Ｄ０Ｄ＝１＋∑βｉ［ＳＣＮ－］ｉ研究铀（ＶＩ）与硫氰酸根形成配合物的稳定性，在温度２５℃，离子强度Ｉ＝２．８时，得到ＵＯ２ＳＣＮ＋（β１＝０．６４）、ＵＯ２（ＳＣＮ）２（β２＝１．１６）

Uranium(VI) is extracted by P 538 extractant in cyclohexane solution.The stability of complexes of uranium(VI) with sulfocyan is studied by changing the concentration of ammonium sulfocyanate in aqueous phase to graduelly reduce the pontition ratio and by making use of relation between.The ratio of D 0 (when sulfocyanate is not in aqueous phase) to D (when sulfocyanate is in aqueous phase) with equilibrium concentration of sulfocyanate,i.e, D 0D=1+∑β i i The measured stability constants of UO 2(SCN) - and UO 2(SCN) 2 are β 1 =0.64 and β 2=1.16 respectively.(Ion strength=2.8,Temperature=25℃) D calculation is almost the same as D experiment .