SOLVENT-EXTRACTION OF PALLADIUM WITH BIS(2,4,4-TRIMETHYLPENTYL)DITHIOPHOSPHINIC ACID AND BIS(2,4,4-TRIMETHYLPENTYL)MONOTHIOPHOSPHINIC ACID

Solvent extraction of palladium(II) with bis(2,4,4,-trimethylpentyl) d ithiophosphinic acid (CYANEX 301) and bis(2,4,4,-trimethylpentyl) mono thiophosphinic acid (CYANEX 302) in n-heptane diluent was carried out. Measurement of palladium-loading capacity and stripping of palladium extracted by these extractants was also investigated. It was found tha t both CYANEX 301 and 302 have a high ability of palladium extraction and form the complexes of (palladium) 1 : (CYANEX 301) 1 or (palladium ) 1 : (CYANEX 302) 2, individually. The stripping of palladium extract ed was very difficult. But when thiourea was used as a stripping reage nt, the stripping of these palladium complexes was completely performe d.