The solvent extraction of rare earths with bifuncional ionic liquids ( Bif-Ils ) [A336][CA-12]/[A336][CA-100] has been investigated in nitate medium. The extraction abilities for rare earths were compared with organic carboxylic acids CA-12/CA-100 and neutral organophos-phorus extractants TBP/P350. The results showed that they were in the descending order; [A336] [CA-12]/[A336][CA-100]>CA-12/CA-100>P350>TBP. The slope analysis method was used to determine the extraction stoichiometry. The extraction mechanisms of rare earths with Bif-Ils [A336][CA-12]/[A336][CA-100] were studied, and it was in accord with complexing mechanism. By studying the effect of extraction equilibration time and temperature on the extraction efficiencies, the results indicated that the extraction process of rare earths with Bif-Ils [A336][CA-12]/ [A336] [CA-100] was a fast equilibrium and exothermic reaction. The recycling and stripping experiments indicated that the Bif-Ils extractant has the advantages of high stability and easy stripping, and they are suitable for extracting rare earths.%研究了双功能离子液体萃取剂[A336][CA-12]/[A336][CA-100]在HNO3体系中对稀土的萃取性能.通过与有机羧酸类萃取剂CA- 12/CA- 100及中性有机膦(磷)类萃取剂TBP和P350的比较得知,在相同条件下,萃取能力按如下顺序降低:[A336] [CA- 12]/[A336] [CA- 100]＞CA- 12/CA- 100＞ P350＞ TBP.利用斜率法探讨了[A336][CA- 12]/[A336][CA- 100]萃取稀土的机理和反应方程式,表明双功能离子液体萃取剂[A336] [CA- 12]/[A336][CA- 100]在 HNO3体系中对稀土萃取符合离子络合机理.同时考察了萃取时间以及温度对萃取性能的影响.结果显示,双功能离子液体萃取剂[A336][CA-12]/[A336][CA-100]在HNO3体系中萃取稀土是快速平衡的放热反应.而循环和反萃实验说明双功能离子液体萃取剂[A336][CA-12]/[A336][CA-1oo]稳定性好,易反萃,是一种富集分离稀土的优良萃取剂.
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