Extraction of gold, palladium, and platinum from acidic media with cyclic sulfoxide derivative

The extraction of gold (III), palladium (II), and platinum (IV) from the acidic media with the cyclic sulfoxide derivative of alpha-dodecyl-tetrahydrothiophene I-oxide (dtmso) was investigated. Gold (III), palladium (II), and platinum (IV) could be separated from the acidic media with suitable sulfoxide concentration and acidity. The extraction reaction of gold (III), palladium (II) or platinum (IV) is exothermic when dtmso is used as an extracting reagent. The coordination number was studied by the slope method. The results indicate that, in high acidity, the dtmso coordination number for extracting gold (III) or palladium (II) is 3, and that for platinum (IV) is 2. UV and FT-IR spectra were used to analyze the structure of the complex. Gold (III) is coordinated with the oxygen atom in S=O group in dtmso, and palladium (II) or platinum (IV) is coordinated with the sulfur atom in S=O group in dtmso.