(1. 东北大学 冶金资源与环境工程研究所，沈阳 110004；2. 北京有色金属研究总院 稀土材料国家工程研究中心，北京 100088；3. 有研稀土新材料股份有限公司，北京100088)
摘 要: 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。
关键字: P204；P507；硫酸介质；协同萃取；Sm3+；Nd3+
（1. Institute of Metallurgical Resources and Environmental Engineering, Northeastern University, Shenyang 110004, China;2. National Engineering Research Center for Rare Earth Materials, General Research Institute for Nonferrous Metals, Beijing 100088, China;3. GRIREM Advanced Material Co., Ltd, Beijing 100088, China）
Abstract:The mechanism and characteristics about synergistic extraction of Nd3+ and Sm3+ 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.
Key words: D2EHPA; HEHEHP; sulfuric acid; synergistic extraction; Sm3+; Nd3+
