N235支撑液膜分离页岩提钒酸浸液及传质机理

Separation and transfer mechanism of vanadium from black shale leaching solution by supported liquid membrane using N235

为强化钒与杂质离子的分离,研究以N235为载体的支撑液膜体系从钒页岩酸浸液中直接萃取钒时载体浓度、稀释剂种类、反萃剂种类及浓度、浸出液pH对钒传质过程的影响,以及钒与浸出液中主要杂质离子铁、磷、铝的分离规律。结果表明:当萃取剂的体积浓度10%、煤油为稀释剂、Na2CO3作反萃剂且浓度为0.6 mol/L、料液相pH=1.8、传质时间13 h时,钒的萃取率可达92%,同时硅的萃取率为6.1%,磷的萃取率为4.2%,铁、铝等金属离子的萃取率低于2%。采用一级动力学模型计算了传质过程的相关扩散参数。最后为考察支撑液膜的稳定性进行了循环试验,经过9次循环,萃取率仍能达到70%,膜经再生后萃取率为90.1%,仅比新膜的萃取率低1.9%。

To enhance the separation efficiency of vanadium from impurities,the highly selective separation of vanadium from multiple impurities and the transport mechanism of vanadium from a black shale leaching-solution,by a supported liquid membrane(SLM)using trialkylamine(N235)as the carrier,were investigated.The effects of parameters,such as feed-solution pH,carrier concentration,stripping-solution species,and diluent nature,were studied.The highest value of P is obtained at a feed solution pH of 1.8,at a carrier concentration of 10%(volume fraction),with a stripping solution of 0.6 mol/L Na2CO3,and with kerosene as the diluent.By enhancing the competition for extraction,92.0%of the vanadium,6.1%of the Si,4.2%of the P,and less than 2.0%of the Fe,Al,K,and Mg are transported through the membrane after 13 h.The diffusion parameters and facilitated transport mechanism are evaluated using a first-order kinetic model.In the membrane stability study,after nine runs using the same membrane,the vanadium extraction can still be about 70%.In addition,the membrane can be successfully regenerated through impregnation again and the vanadium extraction increases to be 90.1%,which is only 1.9%lower than the vanadium extraction at the first run.