物理化学学报
物理化學學報
물이화학학보
ACTA PHYSICO-CHIMICA SINICA
2015年
5期
843-851
,共9页
铀%离子液体%萃取三相%萃取选择性%萃取机理
鈾%離子液體%萃取三相%萃取選擇性%萃取機理
유%리자액체%췌취삼상%췌취선택성%췌취궤리
Uranium%Ionic liquid%Extraction third phase%Extraction selectivity%Extraction mechanism
研究了三辛基氧化膦(TOPO)和三丁基氧化膦(TBPO)在离子液体(ILs)1-烷基-3-甲基咪唑双三氟甲基磺酰亚胺盐(CnmimNTf2, n=2,4,6,8)中萃取分离UO2(NO3)2. TOPO-C2mimNTf2和TOPO-C4mimNTf2体系萃取UO2(NO3)2时会出现三相,而TBPO萃取UO2(NO3)2的萃合物可以很好地溶解在所有离子液体中.论文也考察了萃取过程中的萃取剂浓度效应、酸效应、盐效应.水相加入HNO3会降低萃取效率.盐效应证明了萃取是一种阳离子交换机理.水相中加入NO3-能够提高U的萃取,这说明NO3-参与萃取.选择性研究表明：除了在高酸度下对Zr的显著萃取, TBPO-C4mimNTf2萃取体系在低酸度下对U呈现较好的选择性；去除U后,在低酸度下该体系对三价Nd仍保持较好的选择性.通过定量比较离子液体中NO3-进入量,电喷雾质谱(ESI-MS)和紫外光谱表征确定了TBPO-CnmimNTf2中萃取机理的差异性.萃取中存在两种萃合物,即UO2(TBPO)3(NO3)+和UO2(TBPO)32+,其中UO2(TBPO)3(NO3)+的比例从C2mimNTf2体系到C8mimNTf2体系逐渐增加.
研究瞭三辛基氧化膦(TOPO)和三丁基氧化膦(TBPO)在離子液體(ILs)1-烷基-3-甲基咪唑雙三氟甲基磺酰亞胺鹽(CnmimNTf2, n=2,4,6,8)中萃取分離UO2(NO3)2. TOPO-C2mimNTf2和TOPO-C4mimNTf2體繫萃取UO2(NO3)2時會齣現三相,而TBPO萃取UO2(NO3)2的萃閤物可以很好地溶解在所有離子液體中.論文也攷察瞭萃取過程中的萃取劑濃度效應、痠效應、鹽效應.水相加入HNO3會降低萃取效率.鹽效應證明瞭萃取是一種暘離子交換機理.水相中加入NO3-能夠提高U的萃取,這說明NO3-參與萃取.選擇性研究錶明：除瞭在高痠度下對Zr的顯著萃取, TBPO-C4mimNTf2萃取體繫在低痠度下對U呈現較好的選擇性；去除U後,在低痠度下該體繫對三價Nd仍保持較好的選擇性.通過定量比較離子液體中NO3-進入量,電噴霧質譜(ESI-MS)和紫外光譜錶徵確定瞭TBPO-CnmimNTf2中萃取機理的差異性.萃取中存在兩種萃閤物,即UO2(TBPO)3(NO3)+和UO2(TBPO)32+,其中UO2(TBPO)3(NO3)+的比例從C2mimNTf2體繫到C8mimNTf2體繫逐漸增加.
연구료삼신기양화련(TOPO)화삼정기양화련(TBPO)재리자액체(ILs)1-완기-3-갑기미서쌍삼불갑기광선아알염(CnmimNTf2, n=2,4,6,8)중췌취분리UO2(NO3)2. TOPO-C2mimNTf2화TOPO-C4mimNTf2체계췌취UO2(NO3)2시회출현삼상,이TBPO췌취UO2(NO3)2적췌합물가이흔호지용해재소유리자액체중.논문야고찰료췌취과정중적췌취제농도효응、산효응、염효응.수상가입HNO3회강저췌취효솔.염효응증명료췌취시일충양리자교환궤리.수상중가입NO3-능구제고U적췌취,저설명NO3-삼여췌취.선택성연구표명：제료재고산도하대Zr적현저췌취, TBPO-C4mimNTf2췌취체계재저산도하대U정현교호적선택성；거제U후,재저산도하해체계대삼개Nd잉보지교호적선택성.통과정량비교리자액체중NO3-진입량,전분무질보(ESI-MS)화자외광보표정학정료TBPO-CnmimNTf2중췌취궤리적차이성.췌취중존재량충췌합물,즉UO2(TBPO)3(NO3)+화UO2(TBPO)32+,기중UO2(TBPO)3(NO3)+적비례종C2mimNTf2체계도C8mimNTf2체계축점증가.
The extraction of UO2(NO3)2 from aqueous solution was investigated using trioctylphosphine oxide (TOPO) and tributylphosphine oxide (TBPO) in ionic liquids (ILs) (CnmimNTf2, n=2, 4, 6, 8). A third phase was formed in the TOPO-C2mimNTf2 and TOPO-C4mimNTf2 extraction systems, whereas the extracted species of TBPO-CnmimNTf2 (n=2, 4, 6, 8) were wel soluble in al ILs. The influence of the concentrations of the extractant, nitric acid, and salt on the extraction efficiency was also investigated. Adding HNO3 to the aqueous phase decreased the extraction efficiency. The effect of salt indicates the presence of a cation-exchange mechanism in the extraction. The addition of NO3-in the aqueous phase increased the extraction efficiency of U, which indicates that NO3-participates in the extraction. Selective extraction research indicates that TBPO-C4mimNTf2 exhibits good selectivity for U at low acid concentration despite the significant extraction efficiency on Zr at high acid concentration. After removing U, TBPO-C4mimNTf2 still showed high selectivity for Nd at low acid concentration. We also confirmed the difference of the extraction mechanisms among TBPO-CnmimNTf2 by quantitative measurement of NNO3- in ILs, electrospray ionization mass spectroscopy (ESI-MS), and UV spectroscopy. There are two extraction species (UO2(TBPO)3(NO3)+and UO2(TBPO)32+) and the proportion of UO2(TBPO)3(NO3)+increases from C2mimNTf2 to C8mimNTf2.
