Che Nor Aniza Che Zainul Bahri

Pengekstrakan pelarut torium daripada unsur nadir bumi dalam pekatan torium monazit

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.

Characteristic of molten fluoride salt system LiF-BeF2 (Flibe) and LiF-NaF-KF (Flinak) as coolant and fuel carrier in molten salt reactor (MSR)

Interest of fluoride salts have recently revived due to the high temperature application in nuclear reactors. Molten Salt Reactor (MSR) was designed to operate at high temperature in range 700 - 800°C and its fuel is dissolved in a circulating molten fluoride salt mixture. Molten fluoride salts are stable at high temperature, have good heat transfer properties and can dissolve high concentration of actinides and fission product. The aim of this paper was to discuss the physical properties (melting temperature, density and heat capacity) of two systems fluoride salt mixtures i.e; LiF-BeF2 (Flibe) and LiF-NaF-KF (Flinak) in terms of their application as coolant and fuel solvent in MSR. Both of these salts showed almost same physical properties but different applications in MSR. The advantages and the disadvantages of these fluoride salt systems will be discussed in this paper.

Standardless EDXRF application for quantification of thorium (Th), uranium (U) and rare earth elements (REEs) in various Malaysian rare earth ores

Our local rare earth ores contained substantial amount of Thorium and Uranium which the level exceed permissible limit adopted by Malaysia and many importing nation. X-ray fluorescence technique has been applied for determination of thorium (Th), uranium (U) and rare earth elements (REEs) in Malaysian rare earth ores as it’s recognized as viable tool. XRF has been widely used in detecting elemental composition of unknown materials both qualitative and quantitatively because of its wide range of element detection alongside the non-destructive analytical technique with great accuracy and precision. Four types of minerals sample which is monazite, xenotime, ilmenite and zircon were collected from ‘amang’ factory located in famous city of mining, Ipoh and analyzed using EDXRF.

Advantages of Liquid Fluoride Thorium Reactor in comparison with Light Water Reactor

Liquid Fluoride Thorium Reactor (LFTR) is an innovative design for the thermal breeder reactor that has important potential benefits over the traditional reactor design. LFTR is fluoride based liquid fuel, that use the thorium dissolved in salt mixture of lithium fluoride and beryllium fluoride. Therefore, LFTR technology is fundamentally different from the solid fuel technology currently in use. Although the traditional nuclear reactor technology has been proven, it has perceptual problems with safety and nuclear waste products. The aim of this paper is to discuss the potential advantages of LFTR in three aspects such as safety, fuel efficiency and nuclear waste as an alternative energy generator in the future. Comparisons between LFTR and Light Water Reactor (LWR), on general principles of fuel cycle, resource availability, radiotoxicity and nuclear weapon proliferation shall be elaborated.

Thorium: Issues and prospects in Malaysia

In Malaysia, thorium exists in minerals and rare earth elements production residue. The average range of thorium content in Malaysian monazite and xenotime minerals was found about 70,000 and 15,000 ppm respectively. About 2,636 tonnes of Malaysian monazite was produced for a period of 5 years (2006-2010) and based on the above data, it can be estimated that Malaysian monazite contains about 184.5 tonnes of thorium. Although thorium can become a major radiological problem to our environment, but with the significant deposit of thorium in Malaysian monazite, it has a prospect as a future alternative fuel in nuclear technology. This paper will discuss the thorium issues in Malaysia especially its long term radiological risks to public health and environment at storage and disposal stages, the prospect of exploring and producing high purity thorium from our rare earth elements minerals for future thorium based reactor. This paper also highlights the holistic approach in thorium recovery from Malaysian rare earth element production residue to reduce its radioactivity and extraction of thorium and rare earth elements from the minerals with minimum radiological impact to health and environment.