中文摘要：

用二-2-乙基己基磷酸（HDEHP）做萃取剂,Na2CO3做反萃剂,^234Th为示踪剂,完成了从盐酸溶液中液-液萃取Th（IV）的实验研究。在不同萃取条件下（包括HDEHP和Na2CO3溶液浓度、震荡时间、有机相和水相比值等）对^234Th百分萃取（或反萃取）作了一系列实验。发现,随HDEHP浓度的增加,^234Th的萃取效率明显增加。当HDEHP的浓度≥20%时,^234Th的萃取效率〉97%;用Na2CO3溶液能有效地从有机相中反萃出^234Th,当Na2CO3溶液的浓度≥0.5mol/L时,^234Th的反萃效率〉96%;反萃时,震荡周期长于4min时,两相能达到反萃平衡;随有机相和水相比值的增加,^234Th的萃取效率也明显地增加,在合适的萃取条件下,有机相与水相比值≥4：1时,高达97%的234Th进入有机相。

英文摘要：

The solvent extraction investigations of Th（IV） from HC1 solution has been completed using di-2-ethyl hexyl orthophosphpric aicd （HDEHP） as an extractant and ^234Th as tracer. The condition experiments effecting of concentration of HDEHP and N2CO3 solutions, shaking period as well as ratios of the phases on ^234Th percent extractions （or back-extractions） were made. It has been found that the extraction efficiency of ^234Th is obviously increased with increase of concentration of HDEHP in kerosene and when the concentration of HDEHP in kerosene is ≥30%, the extraction efficiency for ^234Th is higher 98%. ^234Th can be striped from the organic phases with N2 CO3 solutions. The resuhsshow that when the concentration of Na2CO3 solutions is ≥1.25 mol/L, the stripping efficiency of ^234Th can attain to 96%. The data show that the back-extraction equilibrium of the two phases can achieved within the shaking period which is longer than 4.0 min.