仲辛基苯氧基乙酸从稀土中萃取分离钪及其机理

Extraction Separation and Mechanism of Scandium by sec-Octylphenoxy Acetic Acid from Other Rare Earth Elements

首次研究了一种新型萃取剂仲辛基苯氧基乙酸 (CA 12 )萃取钪的性能及其机理。通过研究平衡水相酸度、萃取剂浓度和温度对萃取平衡的影响 ,用斜率法和等摩尔系列法确定了CA 12萃取钪的机理 ,并求得了CA 12萃取钪的热力学函数 ,计算了平衡反应的浓度平衡常数及钪同其它稀土离子的分离系数 ,指出CA 12是一种从稀土

The extraction behavior of Sc? using sec octylphenoxyl acetic acid (HA) as extractant from 0.2 mol/L ammonium chloride media has been investigated systematically. The extraction stoichiometry and the extraction constants was found by slope and constant molarity methods. It was demonstrated Sc? was extracted by CA 12 as a complex ScA 3·HA. The results also showed that the temperature affected the extraction and the equilibrium constant, the Gibbs energy change and the entropy change of the extraction reaction were calculated. The extraction phenomena and the separation factor between Sc? and other trivalent rare earths with sec octylphenoxyl acetic acid were better than those with naphthenic acid which is widely used in Sc? separation. It showed sec octylphenoxyl acetic acid was a valuable extractant which could be employed to replace naphthenic acid.