氯化亚锡活化-TOPO溶剂萃取分离铑铱及机理研究  

Extraction Separation of Rhodium and Iridium from the Stannous Chloride Medium with Trioctylphosphine Oxide and Its Mechanism

作　　者：马亮帮[1] 宁丽荣[1] 范必威[2] 沈洪久[3] 

机构地区：[1]中国石化石油勘探开发研究院无锡石油地质研究所,江苏无锡214151 [2]成都理工大学材料与化学化工学院,四川成都610059 [3]中国石油天然气股份有限公司辽宁销售分公司,辽宁沈阳110014

出　　处：《分析测试学报》2009年第4期483-488,共6页Journal of Instrumental Analysis

摘　　要：在三正辛基氧化膦(TOPO)-乙酸乙酯体系中,应用氯化亚锡活化-溶剂萃取技术选择性分离Rh(Ⅲ)和Ir(Ⅳ),通过萃取铑实现铑铱的分离。考察了nSn/nIr、盐酸浓度对铱萃取率的影响。在相比为1∶1,nSn/nIr(nSn/nRh)=4,3 mol.L-1盐酸浓度的条件下,通过对含不同浓度铑、铱的料液进行萃取,铑的萃取率达到98%以上,铱的萃取率低于4%。在萃取过程中未能完全分离的铑铱通过HCl与KClO3的混合溶液以及硝酸的反萃实现分离。研究了贱金属的萃取行为,考察了贱金属及金对铑铱萃取分离的影响。将饱和萃取有机相减压蒸馏,通过红外光谱表征,探讨了萃取机理。The separation of Rh（ Ⅲ） and Ir（Ⅳ） from the stannous chloride medium by extraction of rhodium with trioctylphosphine oxide （TOPO） was studied. It is based on the fact that a bi-nuclei bridged complex anions of the form [ Rh2 Cl6-n （ SnCl3 ） n ]^4- （ n = 2 - 4） could be extracted rapidly by TOPO, while IRCl^2-6 remained in the organic phase. The effects of Sn/Ir molar ratio and hydrochlo- ride concentration on the extraction of iridium were studied. The optimal conditions were as follows： phase ratio, 1 ： 1; Sn ： RhandSn ： Ir molar ratios, 4; CHCl, 3mol.L^-1. Under the optimal extraction conditions, the percent extractions of Rh and Ir were more than 98% and less than 4% , respectively. The rhodium and the iridium which were not separated in the extraction process could be stripped by a mixed solution of HCl with KClO3 and nitric acid, respectively. The extraction behavior of base metal was studied and the result indicated that the effect of base metal must be taken into consideration in the separation process. Extraction complex obtained from the saturated organic phase was analyzed by FT- IR spectra and the extraction mechanism was discussed.

关 键 词：铑 铱 溶剂萃取 氯化亚锡 红外光谱 机理 

分 类 号：O652.62[理学—分析化学] O643.12[理学—化学]