Extractant（2,3-dimethylbutyl）（2,4,40-trimethylpentyl） phosphinic acid（INET-3） impregnated onto XAD-16 and its extraction and separation performance for heavy rare earths from chloride media
来源期刊：JOURNAL OF RARE EARTHS2017年第12期
论文作者：Junlian Wang Meiying Xie Juanjuan Ma Huajun Wang Shengming Xu
文章页码：1239 - 1247
摘 要：(2,3-Dimethylbutyl)（2,4,40-trimethylpentyl）phosphinic acid（INET-3） was impregnated onto dry macroporous resins XAD-16 and pretreated XAD-16 with ethyl alcohol and HCl（Pre-XAD-16） to prepare the solvent impregnated resins SIRs-INET-3/XAD-16 and SIRs-INET-3/Pre-XAD-16. The molecular weight distribution of the low molecular weight（LMW） polymers washed off by ethyl alcohol during XAD-16 pretreatment was determined by gel permeation chromatography（GPC）. The macroporous resins（XAD-16 & Pre-XAD-16）, the corresponding solvent impregnated resins（SIRs-INET-3/XAD-16 &SIRs-INET-3/Pre-XAD-16） and the PVA coated SIRs-INET-3/Pre-XAD-16 with boric acid as cross-linking agent were characterized by FT-IR, SEM-EDS and TGA. The effects of XAD-16 pretreatment and PVA coating technology on RE（III） adsorption equilibrium time, INET-3 losses during extraction and adsorption capacity were investigated. The adsorption kinetics, selectivity and stripping behaviors of SIRs-INET-3/XAD-16 were further studied. The washed off LMW polymers had the Mn of 36,656, Mw of 40,310 and polydispersity coefficient of 1.10. The SIRs-INET-3/XAD-16 had shorter equilibrium time,less INET-3 loss and more Tm（III） adsorption capacity than the SIRs-INET-3/Pre-XAD-16. The PVA coated SIRs-INET-3/Pre-XAD-16 had less INET-3 loss and more Tm（III） adsorption capacity but longer equilibrium time than the uncoated SIRs-INET-3/Pre-XAD-16. The adsorption of RE（III） on the SIRsINET-3/XAD-16 followed the pseudo-second-order kinetic model. The Tm（III） accumulative adsorption amounts onto SIRs-INET-3/XAD-16 after eight extraction stages was 23.6 mg/g. The separation factors of adjacent heavy RE（III） βEr/Ho, βTm/Er, βYb/Tm and βLu/Yb values were 1.76, 2.59, 2.56 and 1.19,respectively. The adsorbed Lu（III） onto the SIRs-INET-3/XAD-16 can be stripped completely by 1.0 mol/L H2SO4.
Junlian Wang1，Meiying Xie1，Juanjuan Ma1，Huajun Wang1，Shengming Xu2
1. Civil and Resource Engineering School, University of Science and Technology Beijing2. Institute of Nuclear and New Energy Technology, Tsinghua University
摘 要：(2,3-Dimethylbutyl)（2,4,40-trimethylpentyl）phosphinic acid（INET-3） was impregnated onto dry macroporous resins XAD-16 and pretreated XAD-16 with ethyl alcohol and HCl（Pre-XAD-16） to prepare the solvent impregnated resins SIRs-INET-3/XAD-16 and SIRs-INET-3/Pre-XAD-16. The molecular weight distribution of the low molecular weight（LMW） polymers washed off by ethyl alcohol during XAD-16 pretreatment was determined by gel permeation chromatography（GPC）. The macroporous resins（XAD-16 & Pre-XAD-16）, the corresponding solvent impregnated resins（SIRs-INET-3/XAD-16 &SIRs-INET-3/Pre-XAD-16） and the PVA coated SIRs-INET-3/Pre-XAD-16 with boric acid as cross-linking agent were characterized by FT-IR, SEM-EDS and TGA. The effects of XAD-16 pretreatment and PVA coating technology on RE（III） adsorption equilibrium time, INET-3 losses during extraction and adsorption capacity were investigated. The adsorption kinetics, selectivity and stripping behaviors of SIRs-INET-3/XAD-16 were further studied. The washed off LMW polymers had the Mn of 36,656, Mw of 40,310 and polydispersity coefficient of 1.10. The SIRs-INET-3/XAD-16 had shorter equilibrium time,less INET-3 loss and more Tm（III） adsorption capacity than the SIRs-INET-3/Pre-XAD-16. The PVA coated SIRs-INET-3/Pre-XAD-16 had less INET-3 loss and more Tm（III） adsorption capacity but longer equilibrium time than the uncoated SIRs-INET-3/Pre-XAD-16. The adsorption of RE（III） on the SIRsINET-3/XAD-16 followed the pseudo-second-order kinetic model. The Tm（III） accumulative adsorption amounts onto SIRs-INET-3/XAD-16 after eight extraction stages was 23.6 mg/g. The separation factors of adjacent heavy RE（III） βEr/Ho, βTm/Er, βYb/Tm and βLu/Yb values were 1.76, 2.59, 2.56 and 1.19,respectively. The adsorbed Lu（III） onto the SIRs-INET-3/XAD-16 can be stripped completely by 1.0 mol/L H2SO4.
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