Hassanien Gomaa Abdien Gomaa (H. Gomaa), Mohamed Farid Mohamed Cheira (M. Farid), Mohamed Abd-Elmottaleb Abd-Elraheem (M. A. Abd-Elraheem), Tarek Ahmed Saef El-Naser (T. A. Seaf El-Naser), Ibrahim Hashem Zidan (I. H. Zidan)
Abstract: In this work, the recovery of uranium from phosphate ore (El Sibaiya area, Egypt) requires applying some hydrometallurgical processes, leaching and extraction. To study the leaching of uranium ions from its ores, the ore material was first crushed and grinded to the liberation size (200 mesh ≡ 0.075 mm), amenable for U dissolution. The acid leaching process depends largely on a number of factors; these factors include acid type and its concentration, oxidizing agent concentration, leaching time, temperature, and solid/liquid ratio (S/L). These parameters have been investigated and optimized conditions was determined (1g of phosphate ore contact with 4ml of H2SO4 (200g/l) and H2O2 (5%) for 90min. at 70◦C. The adsorption of uranium(VI) from acidic leach liquor onto activated carbon (AC) and impregnated AC by tributyl phosphate (TBP) have been studied using a batch adsorber. The parameters that affect the uranium(VI) adsorption, such as contact time, solution pH, initial uranium(VI) concentration, concentration of TBP, amount of AC and modified AC, and temperature, have been investigated and optimized conditions was determined (0.03g of AC, modified AC contact with 50 ml of leach liquor for 45min. at pH 4 and at room temperature). The maximum loading of uranium ions on AC and TBP/AC are 24.3 mg/g (243 mg/l), and 58.2 mg/g (582 mg/l), respectively. And it was analyzed by the Fourier Transform Infrared Spectroscopy (FTIR) and the Scanning Electron Microscopy (SEM). Both the kinetic and the sorption isotherm modeling have been applied upon the obtained data. Thus, it was found that the uranium sorption obeys a pseudo-second order reaction while the Freundlich sorption isotherm model is most suitable to describe the studied sorption reaction.
Keywords: Standard uranium solution, El Sibaiya phosphate ore, Activated carbon (AC) and Tri butyl phosphate (TBP).
Pages: 313 – 340 | Full PDF Paper