High efficiency extractants play a necessary role in the selective removal of uranium from rare earth minerals. In this paper, a novel cyclic bidentate diamine extractant, 1, 4-dioctyl-1, 4-dihydroquinoxaline-2, 3-dione (DODQ), was synthesized, and the complexation and extraction of UO in nitric acid medium were systematically studied. The results indicate that DODQ exhibits a unique combination of properties in removing UO, with an extraction capacity 132 times higher than that of DODPhOA (acyclic structure). Extraction isotherm experiments and slope analyses illustrate the formation of a 1:1 DODQ/UO regime during the extraction process. Electrospray mass spectrometry, fluorescence spectroscopy, and X-ray crystal diffraction analyses further corroborated its stoichiometric properties. In addition, DODQ can remove UO from rare earth solutions containing UO with high selectivity. This study provides an alternative method to separate uranium from the leaching solution of rare earth ore and has a new understanding of the coordination and complexing behavior of UO with bidentate oxygen-containing ligands.

中文翻译：

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一种新型双齿二酰胺配体 DODQ 用于分离硝酸介质中的铀和稀土离子


高效萃取剂在稀土矿物选择性脱铀中发挥着必要的作用。本文合成了一种新型环状二齿二胺萃取剂1, 4-二辛基-1, 4-二氢喹喔啉-2, 3-二酮（DODQ），并系统研究了硝酸介质中UO的络合和萃取。结果表明，DODQ 在去除 UO 方面表现出独特的综合性能，其萃取能力比 DODPhOA（无环结构）高 132 倍。萃取等温线实验和斜率分析说明了萃取过程中 1:1 DODQ/UO 体系的形成。电喷雾质谱、荧光光谱和X射线晶体衍射分析进一步证实了其化学计量特性。此外，DODQ可以高选择性地从含有UO的稀土溶液中去除UO。该研究提供了一种从稀土矿浸出液中分离铀的替代方法，并对UO与二齿含氧配体的配位络合行为有了新的认识。