P204-P507在酸性硫酸盐溶液中对Nd^3＋和Sm^3＋的协同萃取

Synergistic extraction of Nd^(3+) and Sm^(3+) from sulfuric acid medium with D_2EHPA-HEHEHP in kerosine

采用恒摩尔法、斜率法以及饱和容量法研究从硫酸介质中用P204(D2EHPA,用(HA)2表示)与P507(HEHEHP,用(HL)2表示)协同萃取Nd3+或Sm3+的性能与机理,并测定协萃反应的热力学平衡常数Ks.e,求得反应的焓变和熵变。结果表明,萃取反应呈现正协同效应,且协萃过程为放热反应,协萃配合物组成分别为Nd.(HA2)2.HL2和Sm.(HA2)2.HL2。因此,P204与P507混合使用可以改善硫酸介质下稀土的萃取分离效果。

The mechanism and characteristics about synergistic extraction of Nd^3＋ and Sm^3＋ by D2EHPA and HEHEHP from sulfuric acid medium were studied through the methods of slope, constant molecule and saturation extraction. The extraction equilibrium constants, enthalpy change and entropy change of the reaction were also calculated. The results show that the compositions of the extracted compound are identified as Nd·（HA2）2·HL2 and Sm. （HA2）2·HL2, the synergistic extractive effects are found, the extraction is an exothermic process. Consequently, the extraction and separation effect for rare earth can be improved with synergistic mixture of D2EHPA and HEHEHP.