High Selective Extraction Ability for Platinum-group Metals Based on Thiacalix[6]arene Derivatives

Abstract

Two kinds of new thiacalix[6]arene (TC6A) derivatives, TC6A-CH₂COOH (1) and TC6A-CSN(CH₃)₂ (2), were synthesized through modify at the lower rims of TC6A. The extraction of 1 or 2 for rare metal ions from platinum-group metals (PGM) solution containing eight rare metals (Rh, Pd, Pt, Zr, Ce, Ba, La, Y) and one base metal (Al) were investigated. Compound 1 showed selective extractability for Pd and Zr ions, which the extraction rates were 70% and 91%, respectively. The extraction rates of the other metal ions were below 5% by using 1 and 2. Compound 1 also showed stripping extraction ability of Pd ion by 7N HCl where the stripping ratio was ca. 70%. On the other hand, compound 2 indicated high selectivity of almost 100% Pd ion extraction from PGM solution.