Impact of backmixing of the aqueous phase on two-component rare earth separation process
来源期刊：JOURNAL OF RARE EARTHS2013年第5期
论文作者：吴声 程福祥 廖春生 严纯华
文章页码：517 - 521
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 significant 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 extraction 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.
吴声1,2，程福祥1,2，廖春生1,2，严纯华2
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
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 significant 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 extraction 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.
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