Lekouara,Fatima. Sari,Meriem Chabane .Chebouki , Dallal . Study of the elaboration of U3O8 by the Modified Direct Denitration process (MDD)

Abstract

Analysis of impurities in uranium materials is crucial for quality control or the purity required by standards in the nuclear industry. This study involves the analysis of impurities in a sample of uranium ore concentrate produced from Tahaggart ore. The instrumental techniques used for the analysis are highly sensitive and susceptible to much interference following the uranium spectrum. Different processes for separating uranium from impurities for comparison were used to quantify them. The uranium sample is an Algerian yellow cake that was digested in nitric acid, separated by solvent extraction using the TBP/CHCl3 system, by extraction chromatography method using tributyl phosphate (TBP) impregnated on the Amberlite XAD-7 resin and by precipitation of uranium with hydrogen peroxide. The raffinate from each process is then analyzed by flame atomic absorption spectroscopy and flame photometry. The concentration of uranium is determined by the Potassium Bichromate method in concentrated solutions and by the Arsenazo III method in raffinates and eluates. Uranium extraction yields are 99.65% using TBP-CHCl3 and exceed 99% using TBP-impregnated XAD-7 resin. The results of the analysis of impurities in Algerian yellow cake after the separation of uranium using different processes show that the contents meet the ASTM C967-13 standard for the elements analyzed except for the iron element. A comparison of the results of the impurities analysis values in Algerian yellow cake by the three separation processes (liquid-liquid extraction (ASTM C761-11), extraction chromatography column, and precipitation) shows the absence of cadmium, titanium, lead, and chromium and the values of the manganese, zinc, and lithium are quite close. The analysis results for the solvent extraction and chromatographic column extraction processes showed that the values of magnesium, copper, and nickel are very close and identical for cobalt. The values of aluminium and iron are close.