Malaysian Journal of Analytical Sciences Vol 21 No 6 (2017): 1250 - 1256

DOI: 10.17576/mjas-2017-2106-06

 

 

 

SOLVENT EXTRACTION OF THORIUM FROM RARE EARTH ELEMENTS IN MONAZITE THORIUM CONCENTRATE

 

(Pengekstrakan Pelarut Torium daripada Unsur Nadir Bumi dalam Pekatan Torium Monazit)

 

Wadeeah M. Al-Areqi*, Che Nor Aniza Che Zainul Bahri, Amran Ab. Majid, Sukiman Sarmani

 

Nuclear Science Programme, School of Applied Physics,

Faculty of Science and Technology,

Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia

 

*Corresponding author:  walareqi@yahoo.com

 

 

Received: 6 April 2017; Accepted: 20 August 2017

 

 

Abstract

Solvent extraction is a powerful separation technique in the preparation of nuclear grade thorium. In this study, monazite thorium concentrates produced from Malaysian monazite were used. Thorium was extracted from an aqueous nitric acid medium with TBP (30%) in kerosene and Aliquat-336 (10%) in kerosene, respectively. Constant experimental conditions were used for the extraction in terms of the molarity of nitric acid, concentration of extractants in kerosene, organic/aqueous volumetric ratio, mixing time, and contact time between phases. The stripping process was carried out with distilled water. The determination of thorium and rare earth elements (REEs) in the monazite thorium concentrates and aqueous solutions were performed by using inductively coupled plasma mass spectrometry (ICP-MS). The concentrations of thorium in the thorium concentrate samples were in the range of 11.58 – 83.56%. Three stages of extraction and three stages of stripping were carried out for the extraction of thorium from the REEs in the nitrate solution. The results of the study showed that the thorium extraction efficiency was in the range of 60.96 – 99.75% using TBP (30%) in kerosene and Aliquat-336 (10%) in kerosene. Thorium was stripped from the loaded TBP (30%) in kerosene and Aliquat-336 (10%) in kerosene at an average stripping percentage of 89.04% and 75.75%, respectively. The stripped aqueous solutions were analysed, and it was shown that the thorium content was in the range of 29.49 – 91.28%. This study indicated that both extractants can be successfully used to recover thorium from REEs, but in order to increase the purification of thorium, the extraction and stripping process cycle should be increased.

 

Keywords:  thorium, rare earth elements, solvent extraction, monazite thorium concentrate

 

Abstrak

Pengekstrakan pelarut adalah teknik pengasingan yang kuat digunakan untuk mengasingkan torium bergred nuklear. Dalam kajian ini, pekatan torium monazit yang dihasilkan daripada monazit Malaysia telah digunakan. Torium diekstrak daripada medium akues asid nitrik dengan TBP (30%) dalam kerosin dan Aliquat-336 (10%) dalam kerosin. Kondisi eksperimen digunakan iaitu molariti asid nitrik, kepekatan pengekstrak dalam kerosin, nisbah isipadu organik/akues, masa percampuran dan masa sentuhan antara fasa dikekalkan. Proses pelucutan dilakukan menggunakan air suling. Torium dan unsur nadir bumi (REEs) dalam pekatan torium monazit dan larutan akues ditentukan menggunakan spektrometri jisim plasma gandingan teraruh (ICP-MS). Kepekatan torium dalam sampel pekatan torium ditentukan adalah dalam julat 11.58 – 83.56%. Tiga peringkat pengekstrakan dan pelucutan dilakukan untuk mendapatkan torium dari REEs dalam larutan nitrat. Hasil kajian menunjukkan kecekapan pengekstrakan torium adalah dalam julat 60.96 – 99.75% menggunakan TBP (30%) dalam kerosin dan Aliquat-336 (10%) dalam kerosin. Torium telah dilucutkan daripada muatan TBP (30%) dalam kerosin dan Aliquat-336 (10%) dalam kerosin dengan purata peratus pelucutan masing – masing adalah 89.04% dan 75.75%. Larutan akues yang dilucutkan telah dianalisis dan menunjukkan bahawa kandungan torium adalah dalam julat 29.49 – 91.28%. Kajian ini menunjukkan bahawa kedua – dua pengekstrak boleh digunakan dengan berkesan untuk mendapatkan torium daripada REEs tetapi untuk meningkatkan kemurnian torium, pengekstrakan dan kitaran proses pelucutan harus dipertingkatkan.

 

Kata kunci:  torium, unsur nadir bumi, pengekstrakan pelarut, pekatan torium monazit

 

References

1.       Navratil, J. D. (1986). Solvent extraction in nuclear technology. Pure & Applied Chemistry, 58(6): 885 – 888.

2.       Patil, C. B., Mohapatra, P. K. and Manchanda, V. K. (2008). Transport of thorium from nitric acid solution by non-dispersive solvent extraction using a hollow fibre contactor. Desalination, 232: 272 –280.

3.       Abrao, A., Alves de Freitas, A. and Sequeira de Carvalho, F. M. (2001). Preparation of highly pure thorium nitrate via thorium sulfate and thorium Peroxide. Journal of Alloys and Compounds, 323: 53 – 56.

4.       EUR 17771en. (1997). A present review of the thorium nuclear fuel. Final report, European commission.

5.       Hughes, K. C. and Singh, R. (1980). The isolation of thorium from monazite by solvent extraction. Hydrometallurgy, 6: 25 – 33.

6.       Ali, A. M. I. El-Nadi, Y. A. Daoud, J. A. and Aly, H.F. (2007). Recovery of thorium (IV) from leached monazite solutions using counter-current extraction. International Journal of Mineral Processing, 81: 217 – 223.

7.       Nasab, M. E., Sam, A. and Milani, S. A. (2011). Determination of optimum process conditions for the separation of thorium and rare earth elements by solvent extraction. Hydrometallurgy, 106: 141 – 147.

8.       Amaral, J. C. B. S. and Morais, C. A. (2010). Thorium and uranium extraction from rare earth elements in monazite sulphuric acid liquor through solvent extraction. Minerals Engineering, 23: 498 – 503.

9.       Sato, T. (1965). The extraction of thorium from sulphuric acid solutions by di-(2-ethylhexyl)-phosphoric acid. Inorganic Nuclear Chemistry, 27: 1395 – 1403.

10.    Sato, T. (1970). The extraction of thorium(IV) from sulphuric acid solutions by long-chain aliphatic amines. Inorganic Nuclear Chemistry, 32: 1341 – 1349.

11.    AL-Areqi, W. M., Majid, A. A. and Sarmani, S. (2016). Separation and radiological impact assessment of thorium in Malaysian monazite processing. Malaysian Journal of Analytical Sciences, 20(4): 770 – 776.

12.    Bahri, C. N.A. C. Z., AL-Areqi, W. M., Majid, A. A. and Ruf, M. I. F. M. (2016). Production of rare earth elements from Malaysian monazite by selective precipitation. Malaysian Journal of Analytical Sciences, 20(1): 44 – 50.

13.    Academy of Sciences Malaysia (2013). Revitalising of rare earth mineral programme in Peninsula Malaysia as a strategic industry. The Academy of Sciences Malaysia (ASM) study report 1/2013.

14.    Ayranov, M., Cobos, J., Popa, K. and Rondinella, V. V. (2009). Determination of REE, U, Th, Ba, and Zr in simulated hydrogeological leachates by ICP-AES after matrix solvent extraction. Journal of Rare Earths, 27(1): 123 – 127.

15.    Cordier, D. J. (2012). Mineral commodity summaries. U.S. Geological Survey, 703: 648 – 772.

16.    Kabata-Pendias, A. and Mukherjee, A. B. (2007). Trace elements of group 15 (Previously Group Va). Trace Elements from Soil to Human, 15: 381 – 399.

17.    Gupta, C. K. and Krishnamurthy, N. (1992). Extractive metallurgy of rare earths. International Materials Reviews, 37(5): 197 – 248.

 




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