تازه های تحقیق
2. International Atomic Energy Agency; Thorium fuel cycles: potential benefits and challenges, IAEA Report, Vienna (2005).
3. O. Tickell, The promise and peril of Thorium, The Nonproliferation Review (2012).
4. Molycorp, Inc, A lanthanide, Part II, M-Z. Mountain Pass, Library of Congress Card Number 94-75361, CA, U.S.A (1997).
5. R. Vijayalakshmi, S.L. Mishra, H. Singh, C.K. Gupta, Processing of Xenotime concen-trate by sulphuric acid digestion and selective thorium precipitation for separation of rare earths, Hydro-metallurgy, 61 (2001) 75-80.
6. C.K. Gupta, N. Krishnamurthy, Extractive metallurgy of rare earths, Taylor and Francis, CRC. Press Ltd., Online book, New York (2004).
7. A.M. Eyal, R. Canari, pH dependence of carboxylic and mineral acid extraction by amine-based extractants: Effects of pKa, amine basicity, and diluent properties, Ind. Eng. Chem. Res. 34 (1995) 1789–1798.
8. J. Stary, The Extraction of Metal Chelates, Pergamon, Oxford (1964).
9. J. Stary, H. Freiser, Equilibrium Constants of Liquid-Liquid Distribution Reactions, Part 4. Chelating Extractants, Pergamon, Oxford (IUPAC Chem. Data Series No. 18) (1978).
10.S.P. Mohanty, I. Mohanty, S. Mishra, V. Chakravortty, Extraction of uranium(VI) with a binary mixture of LIX-860 and Versatic-10, J. Radioanal. Nucl. Chem. 227 (1998) 99–103.
11.G.R. Howells, T.G. Hughes, D.R. Mackey, K. Saddington, Proceedings of 2nd Peaceful Uses of Atomic Energy, United Nations, Geneva, 17 (1958) 3.
12.S. Lawroski, M. Levenson, USAEC Report, TID 7534 (1957).
13.N.A. Yatsenko, A.A. Palant, Micelle formation in liquid-liquid extraction of tungsten(VI), molybdenum(VI), and rhenium(VII) by diisododecylamine, dioctylamine, and trioctylamine from sulfuric acid solutions, Russ. J. Inorg. Chem. 45 (2000) 1460-1464.
14.V.K. Manchanda, P.N. Pathak, P.K. Mohapatra, Ion Exchange and Solvent Extraction Series (New Developments in Thorium, Uranium, and Plutonium Extraction), 19, CRC Press, Chap. 2 (2009).
15.Y. Toker, M. Eral, Ümran Hiçsönmez, Recovery of uranium from aqueous solutions by trioctylamine impregnated polyurethane foam, Analyst, 123 (1998) 51-53.
16.C.K. Gupta, T.K. Mukherjee, Hydrometallurgy in Extraction Processes, CRC Press, Boca Raton, FL (1990).
17.Uranium Extraction Technology, Technical Reports Series No. 359, International Atomic Energy Agency (IAEA), Vienna (1993).
18.G.M. Ritcey, A.W. Ashbrook, Solvent extraction principles and applications to process metallurgy, Vol 2, Elsevier Scientific Publishing Company, Amsterdam (1982).
19.Uranium ore processing-proceeding of an Advisory Group Meeting, IAEA (1975).
20.M. Eskandari Nasab, A. Sam, S.A. Milani, Determination of optimum process conditions for the separation of thorium and rare earth elements by solvent extraction, Hydrometallurgy, 106 (3-4) (2011) 141-147.
21.M. Kiaie, Uranium and thorium processing investigation in Saghand-Anomaly 5, Master Degree Thesis, Bahonar Uni, (2000) 26-36.
22.M. Eskandari Nasab1, S. Alamdar Milani, A. Sam, Thorium-Uranium Processing with Gravity, Magnetic and Electrical Separation in Zarigan Ore Deposit, J. of Nuc. Sci. and Tech, 54 (2011) 37-43.
23.C. Eleni, P. Ioannis, Thorium determination in water samples by liquid scintillation counting after its separation by cloud point extraction, J Radioanal Nucl Chem, 287 (2011) 261–265.
24.D. Alamelu, S.K. Aggarwal, Determination of 235U/238U atom ratio in uranium samples using liquid scintillation counting (LSC), Talanta, 15; 77(3) (2009) 991-994.
25.V. Gomez Escobar, F. Vera Tomé, J.C. Lozano, A. Martín Sánchez, Extractive procedure for uranium determination in water samples by liquid scintillation counting, Appl Radiat Isot, 49(7) (1998) 875-883.
26.S.A. Milani, M. Kiaei, M. Akbari, Processing of metasomatite deposit of Saghand Anomaly No. 5 by Sulphuric Acid Digestion, Journal of Nuclear Science and Technology, Article in Press.
27.Z. Chenglong, Z. Youcai, Mechanochemical leaching of sphalerite in an alkaline solution containing lead carbonate, Hydrometallurgy, 100 (2009) 56–59.
28.A. Azad, The recovery of rare earth elements by solvent extraction method in saghand area (anomali 5), Master Degree Thesis, Amir Kabir Uni., (2006) 62-66.
29.S. Ölmez and M. Eral, Extraction of Uranium from Acidic Solutions by TBP, Impregnated Polyurethane Foam, J. Biol. Trace Element Res, 43/45 (1994) 731-735.
30.Chul-Joo Kim, Jyothi Rajesh Kumar, Joon-Soo Kim, Jin-Young Lee, Ho-Sung Yoon, Solvent extraction studies on uranium using amine based extractants and recovery from low grade ore leach liquors, J. Braz. Chem. Soc. 23(7) (2012) 1254-1264.
32.S. Gueu, B. Yao, K. Adouby, G. Ado, Kinetics and thermodynamics study of lead adsorption on to activated carbons from coconut and seed hull of the plam tree, Int. J. Env. Sci. Tech. 4 (2007) 11-17.
33.Fathi Habashi, A Textbook of Hydrometallurgy, 2nd edition, Quebec City, Canada: Métallurgie Extractive Québec (1999).
34.M. Eskandari Nasab, A. Sam, S.A. Milani, Determination of optimum process conditions for solvent extraction of thorium using Taguchi method, J Radioanal Nucl Chem, 287 (2011) 239-245.
35.I.S. El-Yamani, E.I. Shabana, Studies on extraction of thorium(IV) from sulfate media with mixtures of long-chain primary amines and tributyl phosphate, Journal of Radioanalytical and Nuclear Chemistry, Articles, 88/2 (1985) 273-280.
36.Hung-Sheng Tsai and Teh-Hua Tsai, Extraction Equilibrium of Indium(III) from Nitric Acid Solutions by Di(2-ethylhexyl)phosphoric Acid Dissolved in Kerosene, Molecules, 17 (2012) 408-419.
37.A. Haggag, S.A. El-Fekey, M. El-Mamoon Yehia, W. Sanad, Solvent extraction studies on thorium sulphate and halides, J. Radioanal. Chem. 33 (1976) 139-152.
38.Marcelo Borges Mansur, Solvent extraction for metal and water recovery from industrial wastes and effluents, Rem: Revista Escola de Minas, 64(1) (2011).
39.K.B. Brown and C.F. Coleman, Solvent Extraction in ore Processing, Progress in Nuclear Energy, Series III. 2, Pub: Pergamon Press )1978( 3-34.
عنوان مقاله [English]
نویسندگان [English]چکیده [English]
The present work deals with successive uranium and thorium recovery from the sulfate leach liquor of the ore deposit of the 5th Anomaly of Saghand using liquid-liquid extraction technique, where trioctylamine (TOA) and di-(2-ethylhexyl) phosphoric acid (D2EHPA) were used. The solvent extraction of uranium by trioctylamine in kerosene was investigated using Taguchi method. The extraction parameters were pH, extractant concentration, contact time and aqueous/organic volume ratio. The optimum conditions were determined as the extractant concentration of 5%, aqueous/organic volume ratio of 1, pH=1.6 and the contact time of 3 minutes. Under these conditions, the uranium extraction percent was 98.7% in a single step extraction process. For a deeper investigation of the achieved results by Taguchi method, the effect of different parameters such as contact time, temperature, concentration of extractant, and pH were considered. Thorium extraction from uranium extraction raffinate was performed by D2EHPA 4% in kerosene at pH=1.5-2 in a three step extraction process. The kinetic studies showed that the extraction follows a second order kinetics. The optimium conditions for the selective stripping (back extraction) of uranium and thorium from the loaded organic phases were obtained when 5.0 M nitric acid and 1 M sulfuric acide were used, respectively.