Separation of Na3VO4 and Na2CrO4 from high alkalinity solutions by solvent extraction
Separation of Na3VO4 and Na2CrO4 from high alkalinity solutions by solvent extraction
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DOI：
10.1016/j.seppur.2020.117282
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发表时间：
2021-01
影响因子：
8.6
通讯作者：
M. Feng;Marco Wenzel;Shaona Wang;H. Du;Yi Zhang;J. Weigand
中科院分区：
文献类型：
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作者：
M. Feng;Marco Wenzel;Shaona Wang;H. Du;Yi Zhang;J. Weigand
通过去除铬化合物来纯化钒产品，特别是在高pH下，仍然是一项具有挑战性的任务。在这方面的贡献，钒酸钠溶液中的选择性溶剂萃取Cr（VI）从强碱性水溶液（初始pH值12以上）的净化进行了研究，和季铵盐Aliquat 336的选择性的机制进行了详细的研究和讨论。考察了料液pH值、添加的改性剂、稀释剂和接触时间等关键工艺参数的影响。实验结果表明，在TBP存在下，Aliquat 336对Cr（IV）有很高的萃取能力，在优化的条件下实现了V（V）的不萃取。进一步评价Cr（VI）从负载有机相中的汽提。本工作强调了一种新的方法，以高选择性的程度，使实现高纯度钒酸钠从强碱性溶液中分离铬（VI）。
Purification of vanadium products by removal of chromium compounds, especially at high pH, remains a challenging task. In this contribution, purification of sodium vanadate solutions by selective solvent extraction of Cr(VI) from strong alkaline aqueous solution (initial pH 12 and above) was investigated, and the mechanisms governing the selectivity of quaternary ammonium salt Aliquat 336 were studied and discussed in detail. The influence of critical technological parameters including pH of the feed solution, added modifier, diluent, and contact time were examined and analyzed systematically. The experiments reveal a high extraction power for Cr(IV) using Aliquat 336 in the presence of TBP, realizing no extraction of V(V) under optimized condition. Stripping of Cr(VI) from the loaded organic phase was furthermore evaluated. The present work highlights a new approach to separate Cr(VI) from strong alkaline solution with a high degree of selectivity which enables the achievement of a high purity sodium vanadate.