HPMBP与伯胺N_(1923)对希土元素(Ⅲ)的协同萃取

SYNERGISTIC EXTRACTION OF RARE EARTH IONS(Ⅲ) BY HPMBP AND PRIMARY AMINE N_(1923)

本文研究了HPMBP与伯胺N_(1923)的二甲苯溶液,从盐酸介质中协同萃取希土(Ⅲ)的机理。用斜率法、恒摩尔法确定了协萃配合物的组成为:RNH_3Ln(PMBP)_4。求得关于Pr(Ⅲ)协萃反应的平衡常数及协萃配合物的生成常数分别为:logK_(12)=-1.95;logβ_(12)=3.94。实验发现,协萃系数(R)随希土元素的原子序数(Z)递变而呈现“双峰效应”。还研究了协萃配合物的IR,NMR谱。

The synergistic extraction of rare earth ions (Ⅲ) (Ln3 + =La3+ ,Pr3+ ,Eu3+ , Gd3+, Tb3+, Er3+, Yb3+, and Y3+) from hydrochloric acid solution by mixtures of l-phenyl-3-methyl-4-benzoyl-pyrazolone-5 (HPMBP)and primary amine N1928,(R1R2 CHNH2, RNH2)have been investigated in xylene at 25±1℃. The resultsshow that Ln(Ⅲ) in the form of Ln(PMBP)3 in HPMBP solution alone arc extracted into organic phase under the experimental conditions.It is found that the synergistic coefficients vary with atomic number of rare earth elements and the 'double-peak effect' is demonstrated. The mechanism of the synergistic extraction with HPMBP-N1923 are determined by the methods of slope and constant mole. The synergistic species RNH3Ln(PMBP)4 is found to be extracted into the organic phase. The synergistic extraction reactions and addition reactions of the synergistic extracting complexes in organic phase are proposed as follows.Ln3+ + 4HPMBP(0)+RNH3Cl(0)RNH3Ln(PMBP)4(0)+H++Cl-Ln(PMBP)3(0)+HPMBP(0)+RNH3Cl(0) RNH3Ln(PMBP),2(0)+H++Cl-In addition, the equilibrium constants of the synergistic extraction reactions and addition reactions of praseodymium (Ⅲ) are calculated to be logK12= - 1.95, logβ12 = 3.94. The IR and NMR spectra of the synergistic extracting complexes of praseodymium(Ⅲ)are studied as well.