1 級アミンによる塩酸水溶液からのルテニウムの溶媒抽出特性

Ru(III) chlorocomplexes are poorly extracted into organic solvents, which is due to the charge of the complex as well as those inert character in chloride solutions, that is, formation of RuCl6-n(H2O)n(3-n)- (n=0-6). Therefore, it is difficult to extract Ru(III) by solvent extraction, and Ru(III) is currently separated and purified by the oxidative distillation method. If Ru can be separated and recovered from chloride solutions by solvent extraction, an efficient separation and recovery process for PGMs can be established. Therefore, it is important to investigate the solvent extraction of Ru(III) from chloride solutions. The authors have previously studied solvent extraction of Ru(III) with 2-ethylhexylamine (EHA), which is a primary amine extractant, from chloride solutions and shown that the extraction of Ru(III) with EHA from chloride solutions without the addition of Sn (II)was high. However, the stripping of Ru(III) was difficult. In the present study, extractions of Ru from hydrochloric acid solutions with EHA and octylamine (OA), which are primary amines, were tested to clarify the extraction of Ru and the stripping of Ru with various stripping solutions. The extraction efficiency of Ru with EHA and OA from hydrochloric acid solutions without the addition of Sn (II) was high. And also, it was found that Ru could be easily stripped from EHA with sodium sulfate solutions.