Impact of backmixing of the aqueous phase on two-component rare earth separation process  

作　　者：吴声 程福祥 廖春生 严纯华 

机构地区：[1]China Minmetals (Beijing) Research Institute of RE Co., Ltd. [2]Beijing National Laboratory for Molecular Sciences,State Key Laboratory of Rare Earth Materials Chemistry and Applications,PKU-HKU Joint Lab on Rare Earth Materials and Bioinorganic Chemistry, Peking University

出　　处：《Journal of Rare Earths》2013年第5期517-521,共5页稀土学报（英文版）

基　　金：supported by National High Technology Research and Development Program of China("863Plan",2010AA03A405);Major Project of Chinese National Programs for Fundamental Research and Development("973Program",2012CBA01200)

摘　　要：Solvent extraction based on mixer-settler is the major industrial method of rare earth （RE） separation. In the mixer-settler extraction process, due to the insufficient settling time in normal circumstances, backmixing of the aqueous phase could have signifi- cant impact on the process of RE extraction separation. Therefore on the basis of the extraction equilibrium and mass balance of the mixer-settler extraction process, here we developed a mathematic expression of the aqueous phase backmixing in a two-component separation process, and obtained a quantitative analysis of the backmixing effect on the purification process by the approximations according to certain hypotheses. Two extraction systems of La/Ce and Pr/Nd separation were chosen as the examples to analyze the backmixing effect, and the results showed that the aqueous backmixing had greater influence in the scrubbing segment than in the ex- traction segment, especially in the system with a high separation factor such as La/Ce separation. Therefore it was suggested that the aqueous backmixing effect should be well attended in the design and application of RE extraction separation.Solvent extraction based on mixer-settler is the major industrial method of rare earth （RE） separation. In the mixer-settler extraction process, due to the insufficient settling time in normal circumstances, backmixing of the aqueous phase could have signifi- cant impact on the process of RE extraction separation. Therefore on the basis of the extraction equilibrium and mass balance of the mixer-settler extraction process, here we developed a mathematic expression of the aqueous phase backmixing in a two-component separation process, and obtained a quantitative analysis of the backmixing effect on the purification process by the approximations according to certain hypotheses. Two extraction systems of La/Ce and Pr/Nd separation were chosen as the examples to analyze the backmixing effect, and the results showed that the aqueous backmixing had greater influence in the scrubbing segment than in the ex- traction segment, especially in the system with a high separation factor such as La/Ce separation. Therefore it was suggested that the aqueous backmixing effect should be well attended in the design and application of RE extraction separation.

关 键 词：BACKMIXING adjacent stage impurity ratio rare earth countercurrent extraction 

分 类 号：TF845[冶金工程—有色金属冶金]