季铵盐体系金的萃取与反萃

在碱性条件下研究了十六烷基三甲基溴化铵(CTAB)微乳液体系萃取KAu(CN)2. 实验考察了水相金浓度、反萃液中卤素离子、NH4SCN及羟乙基硫醚浓度对金萃取和反萃的影响及有机相中水含量与金萃取的关系. 结果表明：CTAB/己醇/庚烷微乳液体系可将绝大部分金从水相萃取到有机相；随着萃入金的增加，有机相水含量减少. 卤素离子的反萃能力顺序为：KI>KBr>KCl；高KI浓度(>2.0 mol/L)可将有机相中绝大部分(94%)的金反萃出来. 羟乙基硫醚及NH4SCN也是金的良好反萃剂，两者混合可以降低反萃液粘度，又可以减小NH4SCN浓度，而保持较高的金反萃率.

Solvent Extraction of KAu(CN)2 Using Quaternary Ammonium Salt

Solvent extraction and stripping of KAu(CN)2 from alkaline solution with cetyltrimethylammonium bromide (CTAB)/hexanol/heptane using 198Au tracer was investigated. Various parameters, such as Au(I) concentration in aqueous phase, concentrations of halogen ions, NH4SCH and thiodiethylene glycol in stripping solution as well as the relationship between water and Au(I) concentrations in organic phase, in the forward and backward extraction of Au(I) were studied. The results show that water content decreases significantly with the increase of Au(I) concentration in the organic phase. About 98% Au(I) extracted into organic phase can be back extracted with pure thiodiethylene glycol as the stripping agent. Most of Au(I) (~93%) in the organic phase can be stripped into the aqueous phase with high concentration of NH4SCN(>3.0 mol/L) or KI (>2.0 mol/L).