碱性氰化液中加表面活性剂用TBP萃取金的研究

Study on Gold(Ⅰ) Solvent Extraction from Alkaline Cyanide Solution by TBP with Addition of Surfactant

研究提出了在碱性氰化液中加入表面活性剂萃取金的新型萃取体系。考查了平衡pH值、有机相组成、CPB :Au(CN) 2 (摩尔 )、混相时间、相比、不同金初始浓度、温度、萃取剂类型及不同稀释剂、表面活性剂对萃取率的影响。控制表面活性剂用量 ,能使TBP选择性地定量萃取金 ;平衡pH值及稀释剂用量对萃取率影响不大 ;在优化实验条件下金的萃取率达 98%以上 ;用 30 %TBP +70 %磺化煤油的有机相 ,金的萃取容量达 380 4 2mg/L。讨论了萃取机理 ,推断了萃取反应式。

The new solvent extraction system for gold(Ⅰ) from alkaline cyanide solution by TBP with addition of surfactant in aqueous phase was studied. The effect of various factors, such as equilibrium pH, constitution of organic phase, CPB∶Au(CN) 2 - molar ratio, extraction time, aqueous/organic phase ratio, different initial gold concentration, equilibrium temperature, different diluent, different types of extractants and surfactants, etc ., was inspected. The results show that gold(Ⅰ) can be extracted quantitatively by controlling the quantity of surfactant (CPB); either the equilibrium pH and diluent can hardly influence percent extraction. Gold(Ⅰ) percent extraction reaches more than 98% under the optimal experimental conditions. 30% V/V TBP diluted by sulphonating kerosene can load gold(Ⅰ) to rather high levels. Loading capacity is more than 38 g/L. The extraction mechanism is discussed and the overall extraction reaction is deduced.