论文部分内容阅读
以正十二烷作为稀释剂,研究了N,N’-二(2-乙基己基)二甘酰胺酸(HDEHDGA,简称HL)萃取剂对硝酸介质中Dy(Ⅲ)离子的萃取性能。结果表明:该萃取剂对Dy(Ⅲ)有良好的萃取性能,在硝酸浓度为0.3~4.0mol/L时,Dy(Ⅲ)的分配比(D(Dy))随水溶液中平衡酸度的增加先减小后增大,在HNO_3浓度大约为1.0mol/L时,分配比最小。萃取分配比随水相硝酸浓度变化的关系表明,HDEHDGA萃取Dy(Ⅲ)的机理随硝酸浓度变化而不同。从3.0mol/L HNO_3中萃取Dy(Ⅲ)的分配比与萃取剂浓度及硝酸根浓度的关系表明,萃取过程中HDEHDGA主要以中性萃取剂形式与Dy(Ⅲ)配位,萃取反应方程式可能为:Dy(Ⅲ)+2HL+3NO_3~-=Dy(Ⅲ))(HL)_2(NO_3)_3该反应为放热反应,反应的热焓为-63.38kJ/mol,降低萃取温度有利于HDEHDGA对Dy(Ⅲ)的萃取。
Using n-dodecane as a diluent, the extraction performance of Dy (Ⅲ) ions in nitric acid medium was investigated with HDEHDGA (HDEHDGA, abbreviated as HL) extractant. The results showed that the extractant had good extraction performance for Dy (Ⅲ). The distribution ratio (D (Dy)) of Dy (Ⅲ) increased with the increase of equilibrium acidity in aqueous solution when the concentration of nitric acid was 0.3 ~ 4.0mol / L Decrease and then increase, the distribution ratio is the smallest when the concentration of HNO 3 is about 1.0 mol / L. The relationship between extraction partition ratio and the concentration of nitric acid in aqueous phase showed that the mechanism of Dy (Ⅲ) extraction by HDEHDGA varied with the concentration of nitric acid. The extraction ratio of Dy (Ⅲ) from 3.0mol / L HNO_3 to the concentration of extractant and the concentration of nitrate showed that HDEHDGA mainly coordinated with Dy (Ⅲ) in the form of neutral extractant during the extraction process. The extraction reaction equation The reaction is an exothermic reaction, the enthalpy of reaction is -63.38kJ / mol, reducing the extraction temperature is conducive to the HDEHDGA (Dy3 +) 2HL + 3NO3 ~ = Dy (Ⅲ) Dy (Ⅲ) extraction.