以酸性萃取劑萃取稀土元素釹(III)與釤(III)之平衡研究

The Extraction Equilibria of the Neodymium(III) and Samarium(III) with Acidic Extractants

許庭愷(Ting-Kai Hsu)

指導教授 ： 蔡德華

國立臺北科技大學/工程學院/化學工程研究所/碩士(2014年)

https://doi.org/10.6841/NTUT.2014.00713

摘要

本研究利用酸性萃取劑二(2-乙基己基)磷酸(D2EHPA)，在25 ℃定溫下以煤油(Kerosene)為稀釋劑，分別探討萃取氯化釹、氯化釤個別水溶液以及氯化釹、氯化釤混合水溶液中釹(III)和釤(III)之萃取平衡實驗，藉此所得的萃取平衡數據，探討反萃所需pH值、萃取劑濃度、陽離子濃度等因素對萃取反應的影響。
由實驗數據得知，以酸性萃取劑D2EHPA萃取氯化釹和氯化釤個別溶液以及氯化釹氯化釤混和溶液平衡實驗中，釹和釤在有機相和水溶液相間萃取分配比會隨酸性萃取劑濃度和pH值的增加而增大，且經圖解分析法得知萃合物組成。
在NdCl3/D2EHPA實驗中為NdA3和NdA3(HA)，其萃取平衡常數個別為KNd30 = 0.0061 (kmol/m3)1.5和KNd31 = 0.0027 (kmol/m3)；在SmCl3/D2EHPA實驗中為SmA3(HA)2和SmA3(HA)3，其萃取平衡常數個別為KSm32 = 0.22 (kmol/m3)0.5和KSm33 = 1.34。在NdCl3、SmCl3/D2EHPA實驗中為NdA3(HA)、NdA3(HA)2，以及SmA3(HA)、SmA3(HA)2，其萃取平衡常數分別為KNd31 = 0.00026 (kmol/m3)和KNd32 = 0.016 (kmol/m3)0.5；KSm31 = 0.031 (kmol/m3) 和KSm32 = 0.041 (kmol/m3)0.5；D2EHPA萃取釹(III)和釤(III)之分離係數：α=4.4[H2A2]-0.36。

關鍵字

萃取 ； 二(2-乙基己基)磷酸 ； 釹(III) ； 釤(III) ； 稀土元素 ； 萃取平衡 ； 酸性萃取劑

並列摘要

In this study, the equilibrium of the separation of Neodymium(III) and Samarium (III) by solvent extraction methods were investigated at 25°C；meanwhile, the acidic extractants D2EHPA was used. It began with the extraction equilibrium of Neodymium(III) and Samarium(III) in extractants-kerosene solution and extractants-aqueous solution, and eventually the mixed Neodymium(III) and Samarium(III) extractants-aqueous solution was studied.
The experimental results indicated that the distribution coefficients for the extraction of Neodymium(III) and Samarium(III) increased with either of rising concentrations of extractant in the organic phase or equilibrium pH values in the aqueous phase. Moreover we could realize the composition of the extractants through the graphical and numerical analysis.
The composition of NdCl3/D2EHPA complex formed in the organic phase were found to be NdA3、NdA3(HA), and at the same time the respective corresponding equilibrium constants were KNd30 = 0.0061 (kmol/m3)1.5、KNd31 = 0.0027 (kmol/m3) ; The composition of SmCl3/D2EHPA complex formed in the organic phase were found to be SmA3(HA)2、SmA3(HA)3, and furthermore the respective corresponding equilibrium constants were KSm32 = 0.22 (kmol/m3)0.5、KSm33 = 1.34.
The composition of NdCl3、SmCl3/D2EHPA complex formed in the organic phase were found to be NdA3(HA)、NdA3(HA)2、SmA3(HA)、SmA3(HA)2, and simultaneously the respective corresponding equilibrium constants were KNd31 = 0.00026 (kmol/m3)、KNd32 = 0.016 (kmol/m3)0.5；KSm31 = 0.031 (kmol/m3)、KSm32 = 0.041 (kmol/m3)0.5；separation factor：
α=4.4[H2A2]-0.36。

並列關鍵字

Extraction ； Di(2-ethylhexyl) phosphoric acid ； Neodymium(III) ； Samarium(III) ； Rare earth element ； Extraction equilibrium ； Acid extractant

參考文獻

3.Chang, H., M. Li, Z. Liu, Y. Hu, and F. Zhang, “Study on separation of rare earth elements in complex system”, Journal of Rare Earths. 28, Supplement 1(0), p. 116-119 (2010).

4.Liu, C., J. Liu, J. Wang, L. Yang, J. Wu, and L. Jia, “Geochemical characteristics of rare earth elements and their implications for the Huachanggou gold deposit in Shaanxi Province, China”, Journal of Rare Earths. 31(2), p. 215-226 (2013).

12.Schijf, J. and R. H. Byrne, “Determination of stability constants for the mono- and difluoro-complexes of Y and the REE, using a cation-exchange resin and ICP-MS”, Polyhedron. 18(22), p. 2839-2844 (1999).

14.Sun, Y., “Detailed study on simultaneous separation of rare earth elements by capillary electrophoresis”, Journal of Chromatography A. 1048(2), p. 245-251 (2004).

15.Hwang, H. S., G.W. Shin, H. J. Park, C. Y. Ryu, and G. Y. Jung, “Effect of temperature gradients on single-strand conformation polymorphism analysis in a capillary electrophoresis system using Pluronic polymer matrix”, Analytica Chimica Acta. 793(0), p. 114-118 (2013).