以酸性萃取劑萃取鈥(III)及鉺(III)之平衡研究

A Study on the Extraction Equilibria of the Holmium(III) and Erbium(III) with Acidic Extractants

張詒鈞(Yi - Chun Chang)

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(2011年)

摘要

本研究是在探討利用酸性萃取劑二(2-乙基己基)磷酸(D2EHPA)及2-乙基己基膦酸單-2-乙基己基酯(PC-88A)，在25 ℃下以煤油(Kerosene)為稀釋劑，分別萃取氯化鈥和氯化鉺水溶液中鈥(III)和鉺(III)之萃取平衡實驗，藉此探討反萃所需酸度及pH值、萃取劑濃度、陰離子濃度等因素對萃取反應的影響。
由實驗數據得知，在酸性萃取劑D2EHPA、PC-88A萃取氯化鈥和氯化鉺平衡實驗中，鈥和鉺在有機相和水溶液相間萃取分配比隨酸性萃取劑濃度和pH值增加而增大，且經圖解分析法得知萃合物組成。在HoCl3/D2EHPA實驗中為HoA3(HA)和HoA3(HA)2，其萃取平衡常數個別為KHo31 = 2.514 kmol/m3和KHo32 = 33.541 (kmol/m3)0.5；在HoCl3/PC-88A實驗中為HoA3和HoA3(HA)，其萃取平衡常數個別為KHo30 = 0.036 (kmol/m3)1.5和KHo31 = 0.463 kmol/m3；在ErCl3/D2EHPA實驗中為ErA3(HA)和ErA3(HA)2，其萃取平衡常數個別為KEr32 = 7.876 kmol/m3和KEr33 = 45.98 (kmol/m3)0.5；在ErCl3/PC-88A實驗中為ErA3，其萃取平衡常數為KEr30 = 0.50 (kmol/m3)1.5。

關鍵字

萃取 ； 二(2-乙基己基)磷酸(D2EHPA) ； 2-乙基己基膦酸單-2-乙基己基(PC-88A) ； 鈥(III) ； 鉺(III)

並列摘要

In this study, the equilibrium of the separation of Holmium(III) and Erbium(III) by solvent extraction methods were investigated at 25°C. The acidic extractants D2EHPA and PC-88A were used. The extraction equilibria of Holmium(III) and Erbrium(III) in extractants-kerosene solution and extractants-aqueous solution were studied, respectively.
The extraction equilibria of Holmium(III) and Erbium(III) from an aqueous chlorate medium with D2EHPA and PC-88A as an acid extractant were studied. The experimental results indicated that the distribution coefficients for the extraction of Holmium(III) and Erbium(III) increased with increasing either concentrations of extractant in the organic phase or equilibrium pH values in the aqueous phase. Based on graphical and numerical analysis. The compositions of Ho/D2EHPA complex formed in the organic phase were found to be HoA3(HA) and HoA3(HA)2, and the respective corresponding equilibrium constants were KHo31 = 2.514 kmol/m3 and KHo32 = 33.541 (kmol/m3)0.5 ; The compositions of Ho/PC-88A complex formed in the organic phase were found to be HoA3 and HoA3(HA), and the respective corresponding equilibrium constants were KHo30 = 0.036 (kmol/m3)1.5 and KHo31 = 0.463 kmol/m3 ; The compositions of Er/D2EHPA complex formed in the organic phase were found to be ErA3(HA) and ErA3(HA)2, and the equilibrium constants were KEr31 = 7.876 kmol/m3 and KEr32 = 45.98 (kmol/m3)0.5 ; The compositions of Er/PC-88A complex formed in the organic phase were found to be ErA3, and the respective corresponding equilibrium constants were KEr30 = 0.50 (kmol/m3)1.5.

並列關鍵字

Extraction ； Di(2-ethylhexyl) phosphoric acid ； 2-Ethylhexyl phosphonic acid mono-2-ethylhexyl ester ； Holmium(III) ； Erbium(III)

參考文獻

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