高等学校化学研究 ›› 2015, Vol. 31 ›› Issue (4): 621-626.doi: 10.1007/s40242-015-4376-z
GAO Daolin1, YU Xiaoping1, GUO Yafei1, WANG Shiqiang1, LIU Mingming1, DENG Tianlong1, CHEN Yuwei1,2, BELZILE Nelson1,2
GAO Daolin1, YU Xiaoping1, GUO Yafei1, WANG Shiqiang1, LIU Mingming1, DENG Tianlong1, CHEN Yuwei1,2, BELZILE Nelson1,2
摘要:
Three ionic liquids(ILs), namely, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-me- thylimidazolium bis[(trifluoromethyl)sulfonyl]imide and 1-ethyl-3-methylimidazolium bis[(trifluoromethyl)sul- fonyl]imide with the triisobutyl phosphate(TIBP) and kerosene system were respectively used to extract lithium ion from salt lake brine with a high concentration ratio of magnesium and lithium experimentally. Results indicate that the highest extraction selectivity for lithium was obtained with IL 1-ethyl-3-methylimidazolium bis[(trifluoromethyl)- sulfonyl]imide. The effects of solution pH and phase ratio R(O/A) on the extractive step and the influence of acid concentration of the stripping solution and R(O/A) on the back extraction step were also investigated systematically. The single-step extraction efficiency of lithium ion was 83.71% under the optimal extraction conditions, and the single-step back extraction efficiency was 85.61% with a 1.0 mol/L HCl in 1.0 mol/L NaCl medium as stripping agent at R(O/A)=2. The liquid-liquid extraction mechanism and the complex of the ligand with lithium were proposed.