论文部分内容阅读
Rare earths are usually found together in ore.Their physical and chemical properties are very similar,so the separation coefficient of Ce3+/Pr3+ is fairly low in P507-HCl system[1].Pointing to this problem,we separated Ce3+/Pr3+ by the hollow fiber membrane contactor consisting of polypropylene membrane (PP) as the membrane support and saponified P507 dissolved in kerosene as the membrane solution[2-3].With P507-CeCl3/PrCl3-HCl as the experimental system,we investigated the effect of the feed liquid pH,P507 saponification rate and volume ratio of feed solution to organic phase on separation of Ce3+/ Pr3+ in detail.The result showed that the separation factor of Ce3+/Pr3+ by the hollow fiber membrane contactor was significantly higher than that provided from conventional solvent extraction.The suitable feed liquid pH=3.0 and P507 saponification rate (30%) were determined in order to overcome the emulsion of organic phase and pursuit a high extraction efficiency of Ce3+and Pr3+.Furthermore,the structural parameters (contactor length,contactor diameter and packing fraction) and operational schemes (cycle index,counter-current and co-current flow) of membrane contactor were analyzed in order to obtain the parameters in industrial production.This study indicates the hollow fiber membrane contactor extraction to separate Ce3+/ Pr3+ is a promising method,which not only produces high extraction efficiency but also reduces pollution brought by P507 saponification.