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论文类型：期刊论文

发表时间：2016-12-15

发表刊物：JOURNAL OF MEMBRANE SCIENCE

收录刊物：Scopus、EI、SCIE

卷号：520

页面范围：596-606

ISSN号：0376-7388

关键字：Membrane extraction; Poly (ethylene-co-vinyl alcohol); Solvent resistant membrane; Lithium; Salt lake brine

摘要：Loss of organic extraction in membrane extraction process could be avoided by using an ion permeable, solvent stable barrier membrane. Development of solvent stable materials has been a key issue for liquid liquid membrane extraction. A new type of solvent resistant membrane, prepared from block copolymer poly (ethylene-co-vinyl alcohol) (EVAL) via immersion precipitation, is introduced as the barrier in membrane extraction of lithium from a real salt lake brine. The influence of EVAL concentration on the casting solution viscosity and the membrane properties was investigated. The membranes were characterized by scanning electron microscopy (SEM), water uptake, pure water flux, mechanical strength, and Li+ diffusion flux. Membrane phase separation was conducted at a temperature below the crystallization temperature of the polymer to ensure suitable membrane structure. The membrane prepared from 30 wt% EVAL content showed a Li+ flux of 2.7 x 10(-8) mol cm(-2) s(-1) at a Li+ feed concentration of 0.1 mol/L in a diffusion test. Using a tributylphosphate (TBP)/kerosene extractant, the lithium flux in a membrane extraction showed a linear relationship with the feed lithium concentration. In addition, long term stability tests showed a stable lithium extraction flux for about 1037 h. These results indicate that EVAL material is a promising stabilizing barrier membrane in liquid-liquid extraction of lithium. (C) 2016 Elsevier B.V. All rights reserved.