摘要
研究了中性萃取剂三烷基氧膦混合物Cyanex923对稀土元素Yb（Ⅲ）的萃取和反萃性能。考察了振荡时间、金属离子浓度、Cyanex923浓度、硝酸根浓度对Yb（Ⅲ）萃取的影响,由斜率分析法确定了反应机理,获得了萃取平衡方程。并探讨了温度对Cyanex923萃取Yb（Ⅲ）的影响,由vant′Hoff方程计算出298~323 K温度范围内的热力学参数值（△H、△S和△G）,△H为正值,表明整个反应为吸热反应;△S为正值,表明反应很容易发生。通过反萃实验发现,负载了Yb（Ⅲ）的Cyanex923很容易被反萃,当硝酸浓度大于1.2 mol·L-1时,反萃率可达100%,表明Cyanex923利于循环使用。
In the present work,the extraction performance for the rare earth element Yb（Ⅲ） of a kind of neutral extractant named Cyanex923,a mixture of straight chain triakylphosphine oxide had been investigated.The effects of oscillation time,Yb（Ⅲ）,Cyanex923 and NO-3 concentration on Yb（Ⅲ） extraction were studied,respestively.The extraction mechanism was suggested based on the slope analysis and the extraction equilibrium equation was obtained.Then,the effect of temperature on Yb（Ⅲ） extraction was studied.From the temperature dependent data,values of the thermodynamic parameters（ΔH,ΔS and ΔG） were calculated by van′t Hoff equation during temperature range of 298323 K and the thermodynamic properties were discussed.Positive ΔH indicated the reaction belonged to endothermic reaction,positive ΔS indicated the reaction was achieved ensily.The stripping behavior of loaded Cyanex923 was investigated by different concentration of nitric acid.The stripping rate reached 100% when the concentration of nitric acid was above 1.2 mol·L-1.The result showed that the loaded Cyanex923 was easy to be stripped for recycle.
出处
《化学与生物工程》
CAS
2011年第7期58-60,共3页
Chemistry & Bioengineering
