【摘要】 对4种金属离子[铜(Ⅱ),镧(Ⅲ),铀(Ⅵ)及铈(Ⅳ)]在双水相液-液萃取体系[聚乙二醇2000(PEG)-(NH4)2SO4-锌试剂]中的萃取行为,特别是影响萃取的条件(包括溶液的酸度,锌试剂用量;硫酸铵加入量及有无表面活性剂存在等)作了研究。结果表明,铜(Ⅱ)在pH 3～8的条件下,以锌试剂螯合物的形态被定量萃取进入PEG相,萃取率在95％以上;镧(Ⅲ)在pH 1～7之间不被萃取,仍以离子状态留在下层水相中;而铀(Ⅵ)及铈(Ⅳ)在pH 1～11范围内萃取不完全,萃取率在30％～65％之间。试验表明,在pH 6的条件下,铜(Ⅱ)可与共存的镧(Ⅲ)定量分离,铜(Ⅱ)进入PEG相的萃取率在95．6％～98．3％之间,而共存的镧(Ⅲ)仅有4．5％～5．1％进入PEG相中。对锌试剂作为螯合剂与上述4种金属离子在萃取过程的反应机理作了初步探讨。更多还原

【Abstract】 The extraction behavior of Cu(Ⅱ), La(Ⅲ), U(Ⅵ) and Ce(Ⅳ) in the bi-aqueous phase liquid-liquid extraction system of PEG-(NH4)2SO4-Zincon, especially the effects of acidity, the concentration of zincon, the amount of (NH4)2SO4, and the presence or absence of surfactants, were studied. Cupric ion, in the form of a chelate with zincon was found to be quantitatively extracted into the PEG phase in the pH range of 3-8, giving the extraction rate over 95%. Lanthanum(Ⅲ) was not extracted and remained as free ion in the lower aqueous phase in the pH range of 1 to 7. Incomplete extractions of U(Ⅵ) and Ce(Ⅳ) were observed in the range of pH 1-11, giving the extraction rates between 30%-65%. It was shown that at pH 6, Cu(Ⅱ) was separated quantitatively from co-existing La(Ⅲ), giving extraction rates in the range from 95. 6%-98. 3%, while the extraction rates of La(Ⅲ) were in the range from 4. 5% to 5. 1%. The reaction mechanism of the metal ions with zincon as a chelating agent during the course of extraction was also studied priliminarily.更多还原