Refining and specification of the crude yellow cake produced from Abuzenima pilot plant, Sinai, Egypt / Eman Elsayed Abdelhalim Bayoumi ; Supervised Aida Lotfy Elansary , Wifky Elsayed Elnaggar , Galal Mahmoud Abdelwahab Dabbour

Thesis (M.Sc.) - Cairo University - Faculty of Science - Department of Inorganic Chemistry

Uranium is considered the main fuel for the nuclear electrical generation plants which explains the increased importance to improve each step in its production. Refining step is the main target in this thesis in which the concentrations of harmful impurities are minimized to acceptable levels, particularly to meet the international standard specification of nuclear purity ASTM C788-03 (2015). Foremost, the crude yellow cake produced from Abu-Zenima pilot plant (Sinai-Egypt) was specified qualitatively and quantitatively. The work is based on the selectivity of bicarbonate leaching to U(VI) which is attributed to formation of stable soluble carbonate complex. The leach liquor was then heated, acidified and followed by peroxide selective precipitation of pure uranium peroxide UO4.2H2O which is attributed to the formation of very stable, acid-insoluble peroxide. All leaching parameters as well as precipitation parameters were studied. The uranyl peroxide product was heated at 200 oC for 3 h to obtain uranium trioxide UO3.H2O of purity 97.2%. Further purification of crude yellow cake was achieved by using TBP solvent for extraction of pure uranyl nitrate crystals UO2(NO3)2.6H2O. The latter was heated at 300 oC for 3 h to obtain a uranium trioxide UO3.0.8H2O in purity of 98.1%.The purified products were specified qualitatively and quantitatively. Finally, uranium peroxide nanorods UO4.2H2O NR's were also produced by using ultrasonic technique in peroxide precipitation step. The nanoproduct was characterized using different techniques

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