用离心萃取器从罗布泊盐湖卤水中萃取硼的研究

Study of Extraction of Boron from the Lop Nur Salt Lake with Annular Centrifugal Extractors

中文关键词:  卤水  硼  2-乙基己醇  溶剂萃取  离心萃取器

英文关键词:Brine  Boron  2-ethyl-1-hexanol  Solvent extraction  Annular centrifugal extractor

中文摘要:

      研究了用2-乙基己醇作萃取剂从高浓度氯化镁卤水中萃取硼的工艺。先用分液漏斗通过单因素和正交实验优化了萃取与反萃取的工艺条件,作出了萃取与反萃等温线。结果表明,萃取最佳条件:pH=1.8,盐(MgCl₂)浓度28%以上；反萃pH大于2.3。由McCabe-Thiele图解法得到逆流萃取和反萃取级数分别为3和4级。然后用8台Ф20 mm离心萃取器进行了连续逆流萃取与反萃取硼的实验。结果表明,离心萃取器在较大的流比和转速范围内级效率达到99%以上；用4台离心萃取器进行连续逆流萃取,硼的总萃取率达到96.9%；负载有机相用4台离心萃取器进行连续逆流反萃取,硼的总反萃取率达到99.8%。

英文摘要:

      The solvent extraction and stripping of boron from the brine produced from saline lake of west region of China, using 2-ethyl-1-hexanol as an extractant, were studied. Firstly, optimizations of extraction conditions were conducted in separatory funnels using single factor method and orthogonal test. Results indicated the optimum conditions:pH=1.8, salt (MgCl₂) concentration higher than 28% for extraction; the stripping optimum pH higher than 2.3. The analysis of isothermal curves by McCabe-Thiele method indicated the stage numbers for countercurrent extraction and stripping were 3 and 4 respectively. Secondly, the continuously countercurrent extraction and stripping of boron were performed with 8 annular centrifugal extractors, with the aim to industrialization of this process. The results indicated that, the annular centrifugal extractors were suitable for extraction of boron from brine in a widely range of flow velocity ratio of two phases and rotating speed of rotator of extractor, and their stage-efficiencies were more than 99%. When 4 annular centrifugal extractors were used for successively countercurrent extraction, the total extraction percent of boron was more than 96.9%, while 4 annular centrifugal extractors were used for successively countercurrent stripping of loaded organic phase, the total stripping percent of boron was more than 99.8%.