2013

URANIUM evaluation AND ITS RECOVERY FROM MICRO GRANITE DIKE AT G. EL SELA AREA, SOUTH EASTERN DESERT, EGYPT

Abdel Gawad, A.E., Orabi, A.H. and Bayoumi, M.B.

Nuclear Materials Authority, P.O. Box: 530, Maadi, Cairo, Egypt

The present work aims at integrating detailed field studies to prospect for uranium ores associated with micro granite dike. The investigated area is mainly covered by medium to course- grained muscovite-biotite granites. They are injected by aplite, dolerite and bostonite dikes, quartz and jasperoid veins with pegmatite pockets. Uranium minerals are observed along ENE–WSW shear zone where quartz, jasperoid-bearing veins bounded the micro granite dike and dissected them in relation to the successive brecciation and fractures. Ferrugination, albitization, silicification, fluoritization, kaolinization and illitization are associated with the uranium-bearing zones in micro granite dike. The high fracture density of muscovite-biotite granite acted as good channels for the ascending hydrothermal fluids and the percolating meteoric water, that leached uranium from its bearing minerals disseminated all over the granitic host rocks and re-deposited them in micro granite dike along fractures trending ENE-WSW. Uranium was determined in the collected samples spectrophotometrically using arzenaso III as complexing agent. Utilizing statistical procedures for controlling and précising the ‘out put’ of the analytical data obtained in the uranium analysis. Uranium concentration measured by chemical analyses are higher than the ‘gamma-only’ radiometric grade of the same micro granite dike samples related to the series of uranium decay in the state of disequilibrium. Sulphuric acid was used, in the present work, for leaching uranium from a representative mineralized sample of highly ferruginated, silicified and albitized micro granite dike at El Sela area. Conditions were briefly studied to achieve uranium recovery optimum conditions. The acid leaching operating conditions allow us to obtain a uranium recovery rate of about 90 %. Ion exchange resin was used for the concentration- purification of our pregnant solution. A 75 % uranium concentration in final yellow cake product has been achieved.  

KEY WORDS

Micro granite dike, uranium evaluation, uranium minerals, alterations, shear zone, Eastern Desert, disequilibrium, leaching uranium, uranium recovery.