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本文研究了4-甲基苯并-15-冠-5三氯甲烷溶液从苦味酸水溶液中对某些镧系放射性核素(~(144)Ce、~(147)Nd、~(152+154)Eu、~(170)Tm和~(169)Yb)的萃取。从斜率分析得出,被萃取状态为1:2:3(金属离子/冠醚/苦味酸根)络合物。在25℃,测定了三价镧系元素的苹取常数(K_(ex)),得到下列次序:Nd~(3+)>Eu~(3+)>Ce~(3+)>Tm~(3+)>Yb~(3+)。结果表明,Nd~(3+)的离子大小(r=0.995)比其它镧系元素可能更接近4-甲基苯并-15-冠-5环孔的大小。 为了将镧系元素与锕系元素作比较,还测定了4-甲基苯并-15-冠-5对Th~(4+)、UO_2~(2+)和Am~(3+)的萃取率,所得到的萃取率次序为Th~(4+)>Am~(3+)》UO_2~(2+)。实验证明,4-甲基苯并-15-冠-5将可能是溶剂萃取法分离铀和钍的有用试剂。 溶剂和添加剂影响萃取实验表明,在有机相添加正丁醇或异戊醇,或者以高极性的溶剂(例如,硝基苯)替代三氯甲烷,都能显著地增加对镧系元素的萃取。
In this paper, the effects of 4-methylbenzo-15-crown-5 trichloromethane solution on some lanthanide radionuclides (~ 144 Ce, 147 Nd, 152 + 154 ) Eu, ~ (170) Tm and ~ (169) Yb). From the slope analysis, the extracted state was a 1: 2: 3 (metal ion / crown ether / picrate) complex. The extinction constant (K_ (ex)) of the trivalent lanthanide was measured at 25 ° C to obtain the following order: Nd ~ (3 +)> Eu ~ (3 +)> Ce ~ (3 +)> Tm ~ 3 +)> Yb ~ (3+). The results show that the ion size of Nd ~ (3+) (r = 0.995) may be closer to that of 4-methylbenzo-15-crown-5 ring than other lanthanides. In order to compare the lanthanides and actinides, we also measured the extraction of Th 4+, UO 2 2+ and Am 3+ by 4-methylbenzo-15-crown-5 The order of the extraction rate was Th ~ (4 +)> Am ~ (3 +) "UO_2 ~ (2+). Experiments show that 4-methyl-benzo-15-crown-5 may be solvent extraction of uranium and thorium useful reagents. Solvent and Additive Effects Extraction experiments show that the addition of n-butanol or isoamyl alcohol to the organic phase or the replacement of chloroform with a highly polar solvent (eg, nitrobenzene) can significantly increase the extraction of lanthanides .