共查询到17条相似文献,搜索用时 93 毫秒
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研究新型萃取剂从硝酸盐介质中萃取分离稀土元素对于后处理工艺具有重要意义。本文报道以甲苯为稀释剂,N,N,N′,N′-四丁基丙二酰胺(TBMA)从硝酸盐介质中萃取铈(Ⅲ)、镝(Ⅲ)、铒(Ⅲ)、镨(Ⅲ)、钐(Ⅲ)、铽(Ⅲ)、铥(Ⅲ)、镱(Ⅲ)的机理。考察了硝酸浓度、TBMA浓度、盐析剂浓度以及温度对上述三价镧系离子分配比的影响。得出萃合物的组成主要是三配体配合物M(NO3)3·3TBMA;计算出萃取反应的条件平衡常数、萃取平衡常数。温度效应研究表明萃取反应主要是焓驱动的。对萃取分离系数以及TBMA萃取三价镧系离子的规律进行了初步研究。 相似文献
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Sun Guoxin Cui Yu Xu Rongqi Jiang Runtian Sun Sixiu 《Journal of Radioanalytical and Nuclear Chemistry》2003,258(1):181-184
The extraction behavior of N,N,N',N'-tetrabutylmalonamide (TBMA) employing toluene as diluent toward Dy(III) has been investigated. The effect of the concentrations of nitric acid, lithium nitrate and extractant and also of the temperature on the distribution ratio has been studied. The stoichiometry found for the Dy(III) extracted species suggests a structure such as Dy(NO3)3
.3TBMA. An attempt has been made to establish the structure of the isolated extracted species recurring to the data of IR. 相似文献
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N,N,N‘,N’—四己基丙二酰胺从硝酸介质中萃取铀(Ⅵ) 总被引:2,自引:1,他引:2
以甲苯为稀释剂研究了N,N,N',N'-四己基两二酰胺从硝酸介质中萃取硝酸和铀(Ⅵ)的性能.考察了水相硝酸浓度、李取剂浓度、硝酸钠浓度以及温度对萃取分配比的影响,确定了萃合物的组成.借助红外光谱分析了萃合物的结构.求得了萃取硝酸和硝酸铀酰的平衡常数及反应的热力学焓变.与N,N,N',N'-四丁基丙二酰胺萃取铀的性能比较,发现烷基链长的增加减少了三相生成的倾向,但酰胺的萃取能力却下降. 相似文献
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Tom Vander Hoogerstraete Ernesto Rezende Souza Bieke Onghena Dipanjan Banerjee Koen Binnemans 《Journal of solution chemistry》2018,47(8):1351-1372
The solvent extraction of lanthanides from chloride media to an organic phase containing an anion exchanger in the chloride form is known to show low extraction percentages and small separation factors. The coordination chemistry of the lanthanides in combination with this kind of extractant is poorly understood. Previous work has mainly used solvent extraction based techniques (slope analysis, fittings of the extraction curves) to derive the extraction mechanism of lanthanides from chloride media. In this paper, EXAFS spectra, luminescence lifetimes, excitation and emission spectra, and organic phase loadings of lanthanides in dry, water-saturated and diluted Aliquat 336 chloride or Cyphos IL 101 have been measured. The data show the formation of the hydrated lanthanide ion [Ln(H2O)8–9]3+ in undiluted and diluted Aliquat 336 and the complex [LnCl6]3? in dry Aliquat 336. The presence of the same species [Ln(H2O)8–9]3+ in the aqueous and in the organic phase explains the small separation factors and the poor selectivities for the separation of mixtures of lanthanides. Changes in separation factors with increasing chloride concentrations can be explained by changes in stability of the lanthanide chloro complexes in the aqueous phase, in combination with the extraction of the hydrated lanthanide ion to the organic phase. Finally, it is shown that the organic phase can be loaded with 107 g·L?1 of Nd(III) under the optimal conditions. 相似文献
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