摘要
本文采用萃取法测定了螯合萃取剂六氟乙酰丙酮(HHFAa)在1mol/LNaClO_4介质及甲苯中的分配常数logK_d=-1.80。并采用图解法求得HHFAa与Tm^(3+)萃取反应的累积配合常数:logβ_(110)=2.19、logβ_(120)=3.74、logβ_(130)=4.99。且得到加合物Tm(HFAa)_3(HHFAa)的配合常数logK_(add)=2.20。Tm^(3+)水解形成水合物Tm(OH)^(2+)、Tm(OH)_2^+、Tm(OH)_3和Tm(OH)_4^-的累积常数分别为logβ_(101)=8.23、logβ_(102)=13.97、logβ_(103)=18.05和logβ_(104)=21.73。其混合配合物Tm(HFAa)_2(OH)和Tm(HFAa)(OH)_2的累积常数logβ_(121)=7.68和logβ_(112)=11.93。
Hexafluoroacetyl-acetone has been shown as an excellent chelating agent based on its ability to ex tract thulium from the solution at pH higher than 9 without precipitate produced. The cumulative stabili ty constants of the following equations were determined.
According to Baes and Mesmer method the corresponding values were calculated, and then the plots logD versus pH were made from the equations logβ9 =logβp0 +n(n=1 ,2,3,4). The cumulative hydrolytic constants were got as follows:
Based on the assumption of Newman and Klotz,an equilibrium taking place in the organic phase, obeycs the rule of (MXY - logC )is suggested , where log C is estimated to be 0. 1 - 0. 7 from Newman and Klotz studies. According to the rule logβ121 =7. 68 and logβ112 = 11. 93 were obtained.
出处
《铀矿冶》
CAS
1991年第3期7-12,共6页
Uranium Mining and Metallurgy
关键词
六氟乙酰丙酮
TM^3+
配合
水解
Hexafluoroacetyl-acetone Thulium Cumulative complex constant Hydrolytic constant
