Solvent Extraction of Thorium From Rare Earth Elements in Monazite Thorium Concentrate

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...

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Highly proficient extraction separation of thorium(IV) from sulfuric acid solution using N-n-decylaniline: real sample analysis

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Separation of Thorium from Zirconium Carbide Waste by Liquid–Liquid Extraction Using Tri-n-octylamine Solvent after Selective Acid Leaching

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