Determination of Rare Earth Elements in Clay Samples Using k0-NAA Method
Lylia Hamidatou
Nuclear Research Centre of Draria, Alger, ALGERIA
This work deal with the determination of REE in Mag and Mos bentonites by k0-NAA method for which many results are obtained about the content of LREE and HREE and their proportion. The study was carried out on two Algerian sodium bentonites obtained from western Algeria and delivered by the Algerian Company ENOF. The samples were collected from Maghnia and Mostaganem areas in the western of Algeria. To apply the k0-NAA method for the determination of REE the samples and flux monitors together were irradiated during 4 h into a vertical channel of Es-Salam research reactor in Nuclear Research Centre of Birine (Algeria) with a thermal neutron flux of 4.7 10+12 n/cm2s. This channel is characterized by a = 0.027 (the correction of epithermal neutron flux factor) and f = 28.83 (the ratio of the thermal to epithermal neutron flux). In addition, two standards reference materials were analyzed for quality control purpose although the statistical assessment parameters such as Z-score and U-score. The results revealed that the total LREE in Mos (168 ppm) is higher than in Mag (68.5 ppm). In addition, the ratio of SLREE/SHREE was found 6.40 in Mag and 27.6 in Mos which indicate that Mos is highly rich with REE than Mag. Cerium and europium correspond to the highest and lower trace rare earth elements in both bentonites, respectively. Also, the concentration of Sc, Tb and Ho are comparable in two materials.
Keywords: Bentonite of Magnhia, Bentonite of Mostaganem, k0-NAA method, rare earth elements.