中空纤维膜萃取分离混合稀土中的钍

通过中空纤维膜逆流萃取，研究了伯胺Ｎ１９２３对Ｔｈ４＋和ＲＥ３＋的萃取分离过程。测定了水相料液硫酸浓度、水相与油相流量对传质系数的影响，并对包头矿硫酸分解浸出液进行中空纤维膜萃取实验。结果表明，Ｔｈ４＋的传质系数受水相流量影响，与酸度及油相流量无关，总传质速率受水相临界层传质步骤控制。ＲＥ３＋的传质系数不受水相流量影响，油相流量影响很小，但受硫酸浓度的影响，总传质速率受萃取反应速率控制。根据传质速率的不同，对包头矿硫酸浸出液进行萃取分离，在８ｈ内Ｔｈ４＋可基本萃取完全，而ＲＥ３＋及Ｆｅ３＋基本不被萃取，故可在密封条件下分离钍。

Separation of Th4+ and RE3+ with Hollow Fiber MembraneExtraction

Separation of Th 4 and RE 3 was investigated by hollow fiber membrane based extraction with N1923 in countercurrent recirculating operation. The effect of H concentration in water phase, flow rate of water phase and organic phase on mass transfer coefficient was tested. Then the extraction of Th 4 from RE sulfate gotten from Baotou ore was operated. The results show that the mass transfer coefficient of Th 4 changes with the flow rate of water phase, but does not change with the flow rate of organic phase and H concentration in water phase, which suggests that the mass transfer rate of Th 4 is controlled by these steps in the water critical layer. The mass transfer rate of RE 3 does not change with the flow rate of water phase, changes a little with the flow rate of organic phase, but change large with H concentration, which suggestes that the mass tranfer rate is controlled by the reaction rate. Th 4 can be extracted completely in 8 h from RE sulfate solution of Baotou ore with relatively less extraction of RE 3 . So the separation of Th 4 under the sealed condition can be done.