Zl. Zhu et al., The extraction of Fe3+ and La3+ by synergetic effects of TBP and p-tert-butylcalix[8]arene octacarboxylic acid, SEP SCI TEC, 36(12), 2001, pp. 2761-2772
The extraction of Fe3(+) and La3(+) with p-tert-butylcalix[8]arene octacarb
oxylic acid (H8L) and tributyl phosphate (TBP) was studied at 30 +/- 1 degr
eesC and ionic strength of 0.1. Fe3+ and La3+ are highly extractible with H
8L; Fe3+ > La3+. The results showed that TBP had a significant synergetic e
ffect on the extraction of Fe3+ by H8L. By the slope method, the extraction
mechanism is given as Fe3+ + H8L(O) + 2TBP((O)) = (TBP)(2)Fe H5L(O) + 3H(). The equilibrium constant of the extraction reaction was log Kex((S)) = 4
.68 +/- 0.12. However, TBP showed no synergetic effect on the extraction of
La3+ with H8L.