A new extraction system based on polyethylene glycol 1500 and NaNO3 was proposed for the recovery of light rare-earth elements (Ce, La, Nd, Pr, and Sm) from aqueous solutions. The equilibrium distribution coefficients and degrees of extraction of CeIII, LaIII, NdIII, PrIII, and SmIII in the proposed aqueous two-phase system were found. The dependences of the quantitative characteristics of rare-earth element extraction on the temperature, initial metal concentration, and acidity of the medium were obtained. The degree of extraction of the metal ions within one step was shown to exceed 60% at the phase ratio 1:1 without introducing additional complexation agents.

中文翻译：

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使用聚乙二醇 1500 从硝酸盐溶液中回收稀土元素

提出了一种基于聚乙二醇 1500 和 NaNO3 的新萃取系统，用于从水溶液中回收轻稀土元素（Ce、La、Nd、Pr 和 Sm）。发现了所提出的含水两相系统中 CeIII、LaIII、NdIII、PrIII 和 SmIII 的平衡分配系数和萃取度。获得了稀土元素提取的定量特征对温度、初始金属浓度和介质酸度的依赖性。在没有引入额外的络合剂的情况下，一步中金属离子的萃取度在 1:1 的相比下超过 60%。