Ionic liquid (IL)-based extraction is a promising and environmentally benign separation technology. Processes for quaternary ammonium-based IL extraction of vanadium have been extensively studied, but the vanadium extraction mechanism has not been accurately confirmed. This study investigated vanadium extraction from sulphuric acid leachate of shale by solvent extraction with tri-n-octylmethylammonium chloride (TOMAC/CH3NClR3). The results indicated that 90.50 % of the vanadium extraction percentage comprised one stage under the optimal condition experiments. These experiments were carried out at pH 1.8; the IL phase consisted of 25 vol% TOMAC, 15 vol% TBP, and 60 vol% sulfonated kerosene; O/A phase ratio of 1:7.5; extraction time of 120 s. The forms of vanadium and impurities present were revealed by the solution chemistry, Medusa software simulation. The extraction mechanism of vanadium was investigated using ultraviolet spec-trophotometer (UV–Vis), fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (NMR), and hotometer matrix-assisted laser-resolved ionization time-of-flight mass spectra (MALDI-TOF-MS). Under extraction conditions at pH 1.8, vanadium was present as an anion in the form H2V10O4- 28 and HV10O5- 28. Since the extraction mechanism of TOMAC was anion exchange, the extracted vanadium was mainly present as the anionic complex [(CH3NR3)4·H2V10O4- 28]/[(CH3NR3)5·HV10O5- 28]. The ESP map of TOMAC and V (V) was calculated to confirm the reaction sites and was used to verify the anion exchange mechanism.

中文翻译：

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三正辛基甲基氯化铵对钒的选择性机制


基于离子液体 （IL） 的萃取是一种很有前途且对环境无害的分离技术。季铵基 IL 萃取钒的工艺已被广泛研究，但钒的萃取机制尚未得到准确证实。本研究研究了用三正辛基甲基氯化铵 （TOMAC/CH3NClR3） 溶剂萃取页岩硫酸渗滤液从页岩硫酸渗滤液中提取钒。结果表明，在最佳条件实验下，90.50% 的钒提取百分比包含一个阶段。这些实验在 pH 1.8 下进行;IL 相由 25 vol% TOMAC、15 vol% TBP 和 60 vol% 磺化煤油组成;O/A 相位比为 1：7.5;提取时间为 120 秒。存在的钒和杂质的形式通过溶液化学、Medusa 软件模拟揭示。使用紫外光谱仪 （UV-Vis）、傅里叶变换红外光谱 （FT-IR）、核磁共振光谱 （NMR） 和恒温仪基质辅助激光分辨电离飞行时间质谱 （MALDI-TOF-MS） 研究了钒的提取机制。在 pH 值为 1.8 的提取条件下，钒以阴离子形式存在，形式为 H2V10O4-28 和 HV10O5-28。由于TOMAC的提取机理是阴离子交换，因此提取的钒主要以阴离子络合物[（CH3NR3）4·H2V10O4- 28]/[（CH3NR3）5·HV10O5-28]。计算 TOMAC 和 V （V） 的 ESP 图以确认反应位点，并用于验证阴离子交换机制。