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
Diserahkan: 2 Mac 2018/Diterima:
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