Sains Malaysiana 47(8)(2018): 1873–1882

http://dx.doi.org/10.17576/jsm-2018-4708-28

 

Pengekstrakan dan Penulenan Torium Oksida (ThO₂) daripada Mineral Monazit

(Extraction and Purification of Thorium Oxide (ThO₂) from Monazite Mineral)

 

CHE NOR ANIZA CHE ZAINUL BAHRI, AZNAN FAZLI ISMAIL*, AMRAN AB. MAJID,

MOHD IZZAT FAHMI MOHD RUF & WADEE'AH MUTAHIR AL-AREQI

 

Nuclear Science Programme, School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan, Malaysia

 

Received: 2 March 2018/Accepted: 27 April 2018

 

ABSTRAK

Monazit merupakan mineral fosfat yang mengandungi unsur nadir bumi, torium dan uranium dalam kepekatan tertentu. Kepekatan torium dalam monazit di Malaysia dilaporkan sekitar 2,525.0 - 40,868 ppm dan berpotensi digunakan sebagai bahan api untuk kegunaan reaktor nuklear torium. Sehubungan dengan itu, kajian ini bertujuan mengkaji proses pengekstrakan dan penulenan torium oksida (ThO₂) daripada monazit tempatan. Proses pengekstrakan dan penulenan ThO₂ dibahagikan kepada empat peringkat iaitu proses penghadaman, pengasingan, pengekstrakan pelarut dan pengkalsinan. Pencirian sampel telah dilakukan melalui analisis spektrometri jisim gandingan plasma teraruh (ICP-MS), analisis termogravimetri (TGA), pembelauan sinar-X (XRD) dan mikroskopi pengimbas elektron dengan spektroskopi serakan tenaga sinar-X (SEM-EDS). Proses penghadaman telah menghasilkan larutan larut lesap monazit ((Th,REE,U)(SO₄)₂) yang mengandungi sehingga 99.77 ± 7.84 mg torium. Unsur nadir bumi (La, Ce, Nd, Pr, Sm, Eu dan Gd) telah diasingkan daripada torium pada peratusan 96.73%. Manakala larutan Th(NO₃)₄ dan ThO₂ yang dihasilkan masing- masing berketulenan 97.10 ± 0.74% dan 98.85 ± 0.69%. Sehubungan dengan itu, kajian ini menunjukkan bahawa pengekstrakan dan penulenan ThO₂ daripada monazit tempatan boleh dilakukan melalui proses pengekstrakan berperingkat.

 

Kata kunci: Monazit; pengekstrakan; penulenan; torium oksida

 

ABSTRACT

Monazite is a phosphate mineral containing rare earth elements (REEs), thorium and uranium at certain concentrations. The thorium concentration in Malaysian monazite was reported in the range of 2,525.0 - 40,868 ppm and potentially be used as fuel in thorium nuclear power reactor. Therefore, this study aimed to investigate the extraction and purification process of thorium oxide (ThO₂) from local monazite. The extraction and purification process of ThO₂ divided into four stages which are digestion, separation, solvent extraction and calcination. Sample characterizations were carried out via inductive coupled plasma-mass spectrometry (ICP-MS), thermogravimetric analysis (TGA), x-ray diffraction (XRD) and scanning electron microscope-energy dispersive x-ray spectroscopy (SEM-EDS). The digestion process produced monazite leach solution ((Th,REE,U)(SO₄)₂) containing up to 99.77 ± 7.84 mg of thorium. Rare earth elements (La, Ce, Nd, Pr, Sm, Eu and Gd) were separated from thorium at a percentage of 96.73%. Meanwhile, the produced Th(NO₃)₄ and ThO₂ has the purity of 97.10 ± 0.74% and 98.85 ± 0.69%, respectively. Therefore, this study showed that the extraction and purification of ThO₂ from local monazite are possible to achieve through the staggered extraction process.

 

Keywords: Extraction; monazite; purification; thorium oxide

 

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*Corresponding author; email: aznan@ukm.edu.my