Liquid-liquid extraction of palladium(II) from nitric acid by bis(2-ethylhexyl) sulphoxide

✍ Scribed by J.P. Shukla; R.K. Singh; S.R. Sawant; N. Varadarajan

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 629 KB
• Volume: 276
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(93)85054-n

✦ Synopsis

The extraction of palladium(B) nitrate by bis(Zethylhexy1) sulphoxide (BBSO) was evaluated over a wide range of acidity, and BESO was shown to have a strong extraction ability toward this thiophilic "soft" metal. Essentially quantitative extraction of trace and macro amounts of palladium is easily accomplished from about 8 M HNO, down to pH 2 solutions by 0.2 M BESO into toluene. Optimum conditions such as aqueous phase acidity, solvent, period of equilibration, aqueous to organic phase ratios, reagent concentration and strippant were established for the selective and reversible extraction and separation of palladium. Slope analyses applied to Pd(II) distribution experiments from nitrate solutions showed a predominant formation of the solvated organic phase complex Pd(NO,),.2BESO. Recovery of the extractant from loaded palladium is easily accomplished by using sodium thiosulphate or a mixture of 2 M sodium carbonate + 0.5 M ammonia solution. The extracted complex was characterized by elemental analysis and IR and W-visible spectrometry, and its composition was confirmed to be Pd(NOsla .2BESO.