SOLVENT-EXTRACTION OF RHODIUM, RUTHENIUM, AND IRIDIUM WITH HDEHP

Solvent extraction of rhodium, ruthenium, and iridium with HDEHP from thioureachloride media was investigated. Under the conditions ([Cl-]=0 .50 M, [HDEHP]=1.0M, [SC(NH2)(2)]=0.50M, pH 4.50, phase contact time 1 min), Rh(III) is extracted 88.3%, Ru(III) and Ir(III) 40.8% and 28.5% respectively at phase ratio 1:1. The formation of rhodium-thiourea co mplexes in aqueous solutions, even at 5M chloride concentration with t he possible composition Rh[SC(NH2)(2)](3+)(6) is confirmed by the obse rved molar ratio of thiourea to rhodium and UV-spectra.