Efficient enrichment and recovery of rare earth elements with low concentration by membrane dispersion micro-extractors

Publication date: Available online 16 March 2018 Source:Chemical Engineering and Processing - Process Intensification Author(s): Zhuo Chen, Fu-Ning Sang, Jian-Hong Xu, Guang-Sheng Luo, Yun-Dong Wang Membrane dispersion micro-extractors were used both in gas-liquid-liquid system to realize the intensification of REEs extraction at high phase ratio and also in stripping process to recover the rare earth elements (REEs) with low concentration (<100 mg/L) from industrial waste water. The effects of three phase (organic, aqueous, gas) flow rates on the extraction efficiency were investigated. The results indicated that 2 m of the out-let channel was required to reach 95% or above, and the overall volume mass transfer coefficient K L a was enhanced around 3.0-4.5 times compared with liquid-liquid system. The results of stripping process revealed that the stripping efficiency of Nd (III) could reach 98% and the total enrichment factor was 200. Finally, the mixture of REEs was employed as a model of industrial raffinate. The total enrichment factor was 150, which exhibited a potential method for the effective utilization of REEs from waste water. Graphical abstract

Source: Chemical Engineering and Processing: Process Intensification - March 17, 2018 Category: Chemistry Source Type: research