不对称亚砜BSO萃取钯的性能及机理研究

Study on Behavior and Mechanism of Extraction of Palladium(Ⅱ)with Unsymmetrical Sulfoxide BSO

研究了不对称亚砜BSO从盐酸介质中萃取钯的性能和机理,结果表明:待萃液Pd(Ⅱ)浓度为1.0g.L-1,HCl浓度为0.1mol.L-1,用0.3mol.L-1BSO-煤油按相比1:1混合萃取Pd(Ⅱ),经过5min的萃取振荡时间,萃取率可达99.8%。通过斜率法和红外光谱分析表明,在低酸度([H+]≤0.3mol.L-1)下,亚砜主要以中性溶剂络合萃取机理萃取钯,萃合物组成为[PdCl2.2BSO](0);在高酸度(1.0≤[H+]≤4.0mol.L-1)下,亚砜以离子缔合萃取机理萃取钯,萃合物组成可能为[H+.hH2O.(BSO)2]2.[PdCl42-](0)。

The behavior and mechanism of extraction of Palladium（Ⅱ）with unsymmetrical sulfoxide BSO were studied.The results show that the percentage extraction of Pd（Ⅱ） achieves 99.8% from 0.1 mol.L-1 HCl media with 0.3 mol.L-1 BSO-kerosene（their phase ratio 1：1） as an extractant after 5 min extraction vibration.The structure of the complex was discussed by slope analysis method and FT-IR spectra.When HCl concentration is less than 0.3 mol.L-1,BSO acts as a neutral ligand coordinated with Pd（Ⅱ） and the composition of complex is [PdCl 2.2BSO]（0）.When HCl concentration ranges from 1.0 mol.L-1 to 4.0 mol.L-1,the reaction of extracting of Pd（Ⅱ） is acid ion association extraction and the composition of complex may be [H ＋.hH 2 O.（BSO） 2 ] 2.[PdCl 4 2]（0）.