Studies on Separation of Actinides And Lanthanides by Extraction Chromatography Using 2,6-BisTriazinyl Pyridine P. Deepika, K. N. Sabharwal, T. G. Srinivasan and P. R. Vasudeva Rao Fuel Chemistry Division, Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, 603102 India
2 OECD 2008, Japan
THREE STAGE NUCLEAR POWER PROGRAM THREE STAGE NUCLEAR POWER PROGRAM 95 90 91 90 /Capacity Factor (%) -----> 86 84 84 90 85 81 79 85 80 75 82 72 80 75 69 75 70 71 65 Availability 67 60 60 55 50 1995-96 1996-97 1997-98 1998-99 1999-00 2000-01 2001-02 2002-03 2003-04 Stage - - II II Stage Stage - - III III Stage – – I PHWRs I PHWRs Stage Stage Fast Breeder Reactors Thorium Based Reactors Thorium Based Reactors Fast Breeder Reactors • 12 • 12- - Operating Operating • 6 • 6 - - Under construction Under construction • 40 MWth FBTR 40 MWth FBTR - - • • 30 kWth KAMINI 30 kWth KAMINI- - Operating Operating • • Several others planned • Several others planned Operating since 1985 Operating since 1985 • Scaling to 700 MWe Scaling to 700 MWe • Technology Objectives Technology Objectives • • 300 MWe AHWR 300 MWe AHWR- - • Gestation period being • Gestation period being realised realised Under Development Under Development reduced reduced • 500 MWe PFBR 500 MWe PFBR- - • POWER POTENTIAL ≅ ≅ • POWER POTENTIAL • Under Construction POWER POTENTIAL IS POWER POTENTIAL IS Under Construction 10,000 MWe 10,000 MWe VERY LARGE VERY LARGE ≅ POWER POTENTIAL ≅ • POWER POTENTIAL • Availability of ADS ADS Availability of LWRs LWRs 530,000 MWe 530,000 MWe can enable early can enable early • 2 BWRs Operating • 2 BWRs Operating introduction of Thorium on introduction of Thorium on • 2 VVERs under 2 VVERs under • a large scale a large scale construction construction DAE Presentation on 24-06-04 OECD 2008, Japan 3
Fast Breeder Test Reactor Kalpakkam OECD 2008, Japan 4
Radiochemistry Laboratory OECD 2008, Japan 5
6 Hot Cells OECD 2008, Japan
The Chemist's Playground Minor actinides H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba (Ln) Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn 104 105 106 107 108 109 Fr Ra (An) Rf Db Sg Bh Hs Mt 110 111 112 113 114 116 118 Minor Actinides 92 93 94 95 96 97 98 99 100 101 102 103 Man-made Radioactive Elements Naturally Radioactive Elements OECD 2008, Japan 7
S eparation of MINOR actinides by various techniques DIDPA HDEHP SASME Minor CYANEX TRUEX Actinides 301 TALSPEAK TPTZ TRPO OECD 2008, Japan 8
Extractants used in our Laboratory for Co extraction of lanthanides and actinides Truex process ---- CMPO ------ Solvent Extraction Diamides ----- DMDBMA ------- Solvent Extraction [Dimethyl Dibutyl Malonamide ] TEHDGA --- Tetraethyl Hexyl Diglycoamide -- Solvent Extraction DMDOHEMA ---- Solvent Extraction [ DimethylDioctylHexylEthoxyMAlonamide] OECD 2008, Japan 9
Other Techniques • Extraction Chromatography • Room Temperature Ionic Liquids • Supercritical Fluid Extraction • High Performance Liquid Chromatography OECD 2008, Japan 10
Actinide – Actinide – Lanthanide Lanthanide Separation Separation • Bis Bis Triazinyl riazinyl Pyridine Pyridine (BTP) (BTP) OECD 2008, Japan 11
12 OECD 2008, Japan
Outline • Introduction – Lanthanide-Actinide Separation. – Bis Triazinyl Pyridines (BTPs). – Advantages of Extraction Chromatography over Solvent Extraction. • Experimental Work – Synthesis of 2,6-bis(5,6-dipropyl-1,2,4-triazin-3- yl)pyridine. – Preparation of the Extraction Resin. – Extraction Studies of Am (III) and trivalent lanthanides by XAD-7 impregnated with 2,6- bis(5,6-dipropyl-1,2,4-triazin-3-yl)pyridine . • Conclusions OECD 2008, Japan 13
Introduction Lanthanide – Actinide Separation • Need – Partitioning and Transmutation ( to reduce long- term radiological risks to the environment by transmutation of the minor actinides). • Difficulty – Lanthanides and actinides have similar chemical properties due to similar ionic radii. OECD 2008, Japan 14
Bis Triazinyl Pyridines (BTPs) First reported in 1999 by Kolarik, Mullich and Gassner that 2,6-di(5,6-dialkyl-1,2,4-triazin-3-yl)pyridines extract and separate Am(III) and Eu(III) very efficiently as nitrates . (Solvent Extraction and Ion Exchange, 17(1), 23-22, 1999) OECD 2008, Japan 15
Limitations of solvent extraction – • Third Phase formation, • Need for phase-modifiers, • Disposal of large volumes of extractants and diluents, • Tedious multi-stage extraction procedures. Advantages of Extraction Chromatography • No third phase formation, • No need for a modifier, • Reusability of the synthesized resin, • Simple and compact equipment, • Minimal loss of organic solvent. OECD 2008, Japan 16
Experimental Work Synthesis of 2,6-bis(5,6-dipropyl-1,2,4-triazine-3-yl)-pyridine O N H 2 H 2 N N C C + N N N H 2 H 2 N O 2 , 6 - p y r id in e d ic a r b o x a m id e O c t a n e - 4 , 5 - d io n e d ih y d r a z o n e N N N N N N N 2 , 6 - b is ( 5 , 6 - d ip r o p y l- 1 , 2 , 4 - t r ia z in e - 3 - y l) p y r id in e OECD 2008, Japan 17
Preparation of the Extraction Resin Resin Impregnation XAD-7 particles Washing Air-drying (Methanol, Acetone) Extractant: nPr-BTP Impregnation in rotary evaporator Diluent: dichloromethane (298K, 2h) Extraction resin Air-drying Removing Diluent (nPr-BTP/XAD-7) (323K) OECD 2008, Japan 18
“ Extraction Studies of Am (III) and trivalent lanthanides by XAD-7 impregnated with 2,6- bis(5,6-dipropyl-1,2,4-triazin-3-yl)pyridine” OECD 2008, Japan 19
1 4 0 0 1 2 0 0 1 0 0 0 8 0 0 d K 6 0 0 4 0 0 2 0 0 0 5 1 0 1 5 2 0 2 5 T i m e , h r Figure : Kinetics of the uptake of Am (III) by nPr-BTP/XAD-7 resin (0.25g nPr- BTP/XAD-7, 0.1M HNO 3 , 2M NH 4 NO 3 , 303K) • Distribution coefficient (K d ) values increased with increasing time of equilibration and equilibrium is reached in 24 hours. • For K d measurements, we have equilibrated for 3 hours . OECD 2008, Japan 20
8 0 0 7 0 0 W ith o u t N H 4 N O 3 6 0 0 W ith N H 4 N O 3 5 0 0 4 0 0 d K 3 0 0 2 0 0 1 0 0 0 0 .0 0 .5 1 .0 1 .5 2 .0 2 .5 3 .0 [H N O 3 ], M Figure : Effect of nitric acid concentration on the uptake of Am(III) by nPr-BTP/XAD-7 resin with and without 2M NH4NO3 (0.25g nPr-BTP/XAD-7, 303K, 3h). • K d values for the extraction of Am(III) from nitric acid with ammonium nitrate are significantly higher. • The increase of Am(III) adsorption with increasing nitrate concentration can be explained by the following adsorption equilibrium represented by Equation (1), - + n (nPr-BTP) = M(NO 3 ) 3 (nPr-BTP) n M 3+ + 3NO 3 (1) OECD 2008, Japan 21
2 0 L a ( I I I ) 8 0 0 A m ( I I I ) C e ( I I I ) 1 8 N d ( I I I ) 1 6 E u ( I I I ) 7 0 0 G d ( I I I ) 1 4 1 2 6 0 0 1 0 d d K K 5 0 0 8 6 4 0 0 4 2 3 0 0 0 0 1 2 3 4 0 1 2 3 4 [ H N O 3 ] , M [ H N O 3 ] , M Figure : Effect of nitric acid concentration on the uptake of Am(III) and lanthanides by nPr-BTP/XAD-7 resin (0.25g nPr-BTP/XAD-7, 2 M NH 4 NO 3 , 303K, 3h) • The lanthanides are not extracted by the resin at any acidity. • K d value for the extraction of Am(III) is maximum at 0.1M nitric acid in the presence of ammonium nitrate. OECD 2008, Japan 22
1 4 0 1 0 0 0 L a ( I II ) G d ( I II ) 1 2 0 N d ( I I I ) 8 0 0 C e ( I I I ) 1 0 0 A m ( I I I ) E u ( I I I ) 8 0 6 0 0 d d 6 0 K K 4 0 0 4 0 2 0 0 2 0 0 0 - 2 0 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 [ N H 4 N O 3 ] , M [ N H 4 N O 3 ] , M Figure : Effect of nitrate concentration on the uptake of Am(III) and Lanthanides by nPr-BTP/XAD-7 resin (0.25g nPr-BTP/XAD-7, 0.1M HNO 3 , 303K, 3h) The distribution coefficient (K d ) value of Am (III) increases with increase in NH 4 NO 3 concentration, which can be explained by equation (1), - + n (nPr-BTP) = M(NO 3 ) 3 (nPr-BTP) n M 3+ + 3NO 3 (1) OECD 2008, Japan 23
Separation Factor (K d Am / K d Ln) [NH 4 NO 3 ] M La Ce Nd Eu Gd 0 192 173 173 173 173 1 2730 5187 5187 66 451 2 2471 7638 1400 43 296 3 8925 8926 8926 27 246 4 1412 937 347 14 92 6 770 465 117 7 52 Table: Separation Factors for Americium-Lanthanide Separations ( 0.25g nPr- BTP/XAD-7, 0.1M HNO3, 303K, 3h) OECD 2008, Japan 24
1 .0 0 .8 E u ( III) A m ( III) 0 .6 0 C/C 0 .4 0 .2 0 .0 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 V o lu m e , m L Figure : Loading of Am (III) and Eu (III) on to a column of nPr-BTP/XAD-7 resin. Europium was not retained in the column and up to 99.4% of it was recovered at the loading stage itself. Up to 90% of the Am was retained in the column. OECD 2008, Japan 25
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