Nuclear Materials Authority

Cairo, Egypt

Nuclear Materials Authority

Cairo, Egypt
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Eliwa A.A.,Nuclear Materials Authority
Journal of Radioanalytical and Nuclear Chemistry | Year: 2017

Various carbonate leaching studies were performed upon Abu-Zeniema uranium slurry concentrates of about 14% uranium and 71% moisture content to optimize the dissolution process and study the kinetics and thermodynamics of the process. Complete dissolution was performed by using 0.75 M of sodium carbonate, 60 min stirring time, at 70 °C and 60/1 solid to aqueous ratio. The carbonate leaching experimental data were well interpreted with shrinking core model with diffusion control through a porous product layer. The order of reaction was found to be pseudo first order with an apparent activation energy of 25.5 kJ/mole. © 2017, Akadémiai Kiadó, Budapest, Hungary.


Morsy A.M.A.,Nuclear Materials Authority
Environmental Technology and Innovation | Year: 2015

The purpose of this work is to take a closer look for the phosphorylation of chitosan and its potential applications for uranium removal from waste effluents. The synthesized P-chitosan has first been characterized using FTIR spectroscopy and scanning electron microscope before and after adsorption of uranium. From the former it is showed that the phosphate groups may be more responsible for the adsorption of uranium. The relevant factors that influence the uranium adsorption onto the phosphorylated chitosan namely solution pH, contact time, temperature, Co-ions, solid-liquid ratio and initial uranium concentration were studied in detail. The obtained results are fitted into the different adsorption isotherms and according to Langmuir adsorption model the uranium adsorption capacity of the synthesized P-chitosan is estimated as 54.6 mg/g. It was also observed from the obtained kinetic data that the pseudo-second order model is more suitable to explain the adsorption kinetics of uranium up on the P-chitosan. Finally the thermodynamic parameters show the adsorption reaction to be a spontaneous process and more favorable at room temperature. © 2015 Elsevier B.V.


Awadalla G.S.,Nuclear Materials Authority
Journal of African Earth Sciences | Year: 2010

Phosphorites in Egypt occur in the Eastern Desert, the Nile Valley and the Western Desert at Abu Tartur area and present in Duwi Formation as a part of the Middle Eastern to North African phosphogenic province of Late Cretaceous to Paleogene age (Campanian-Maastrichtian). The Maghrabi-Liffiya phosphorite sector is considered as the most important phosphorite deposits in the Abu Tartur area due to its large reserve thickness and high-grade of lower phosphorite bed beside high content of REE. Back scattered electron (BSE) images show framboidal pyrite filling the pores of the phosphatic grains, suggesting diagenetic reducing conditions during phosphorites formation.Electron Probe Micro Analyzer (EPMA) chemical mapping was conducted to examine the variation and distributions of selected elements (P,F,La,Fe,Yb,Si,Ce,W,Eu,S,Ca,Y and Er) within the shark teeth, coprolites and bone fragments. In the teeth W, S, Fe are concentrated along the axis of the teeth, the bone fragments show high concentration of W, Yb, Er and Eu, whereas coprolites are nearly homogenous in composition contains S, Er with some Si as micro-inclusions. Fluorapatite is considered as main phosphate mineral whereas pyrite occurs as pore-filling within the phosphatic grains and cement materials. Maghrabi-Liffiya samples show a wide range in the P2O5 content, between 19.8wt.% and 29.8wt.% with an average of 24.6 wt.% and shows low U content ranging from 15ppm to 34ppm with an average of 22ppm. The total REE content in nine samples representing the Maghrabi-Liffiya ranges from 519 to 1139ppm with an average of about 879ppm. The calculation of LREE (La-Gd) show indeed a marked enrichment relative to the HREE (Tb-Lu) where LREE/HREE ratio attains 8.4 indicating a strong fractionation between the LREE and HREE. Chondrite-normalized REE patterns of the studied phosphorite samples show a negative Eu anomaly. © 2009 Elsevier Ltd.


Youssef M.A.S.,Nuclear Materials Authority
Journal of Environmental Radioactivity | Year: 2016

In the last decades of years, there was considerable growth in the use of airborne gamma-ray spectrometry. With this growth, there was an increasing need to standardize airborne measurements, so that they can be independent of survey parameters. Acceptable procedures were developed for converting airborne to ground gamma-ray spectrometric measurements of total-count intensity as well as, potassium, equivalent uranium and equivalent thorium concentrations, due to natural sources of radiation.The present study aims mainly to establish relationships between ground and airborne gamma-ray spectrometric data, North Ras Millan, Southern Sinai Peninsula, Egypt. The relationships between airborne and ground gamma-ray spectrometric data were deduced for the original and separated rock units in the study area. Various rocks in the study area, represented by Quaternary Wadi sediments, Cambro-Ordovician sandstones, basic dykes and granites, are shown on the detailed geologic map. The structures are displayed, which located on the detailed geologic map, are compiled from the integration of previous geophysical and surface geological studies. © 2015 Elsevier Ltd.


Morsy A.M.A.,Nuclear Materials Authority | Hussein A.E.M.,Nuclear Materials Authority
Journal of Radioanalytical and Nuclear Chemistry | Year: 2011

The adsorption of uranium from crude phosphoric acid has been investigated using conventional activated carbons. It was found that treatment with nitric acid oxidized the surface of activated carbon and significantly increased the adsorption capacity for uranium in acidic solutions. The parameters that affect the uranium(VI) adsorption, such as contact time, solution pH, initial uranium(VI) concentration, and temperature, have been investigated. Equilibrium data were fitted to a simplified Langmuir and Freundlich isotherms for the oxidized samples which indicate that the uranium adsorption onto the activated carbon fitted well with Langmuir isotherm than Freundlich isotherm. Equilibrium studies evaluate the theoretical capacity of activated carbon to be 45.24 g kg-1. © 2011 Akadémiai Kiadó, Budapest, Hungary.


Hussein A.E.M.,Nuclear Materials Authority
Journal of Radioanalytical and Nuclear Chemistry | Year: 2011

The present work deals with uranium and thorium recovery from the Egyptian monazite sulfate leach liquor using the extraction chromatography technique (solvent impregnated material), where tributylamine (TBA) and di-n-octylamine (DOA) solvents were impregnated onto foam uranium and thorium separate recovery. The calculated theoretical capacities of the latter solvents were about 1.4 gU/g foam and 1.6 gTh/g foam, respectively. The attained uranium and thorium adsorption efficiencies (using ion-exchange columnar technique) were about 75 and 70% of its theoretical capacities, respectively. Using 1 M NaCl-0.1 M H 2SO4 and 2 M H2SO4 as eluent solutions for uranium and thorium from the loaded solvents impregnated foam gave 95.8 and 98.7% elution efficiencies, respectively. © 2011 Akadémiai Kiadó, Budapest, Hungary.


El Dabe M.M.,Nuclear Materials Authority
Arabian Journal of Geosciences | Year: 2013

The two anorogenic (EA), (A1) and (AA), and postorogenic (PO), (A2) and (PA), alkaline groups, Bonin (1990), Eby (1992), and Hong et al. (1996), alternatively, can be further distinguished into hotspot, rift and post-continent-continent collision, post-subduction magma varieties, respectively, by using some binary and ternary elements relation diagrams. The hotspot varieties have the highest differentiated index values, while the rift varieties have a moderate to low differentiated index values compared to the post-continent-continent collision and the subduction varieties which have low differentiated index values. The hotspot and the post-continent-continent subgroups generated sodic, peralkaline magma type, and are characterized by oxidized tectonic setting regime, while the rift and the post-subduction alkaline varieties have both a sodic and potassic nature characterizing the peralkaline, the metaluminous, and the peraluminous magma types that are generated in both oxidized and reduced conditions. © 2013 Saudi Society for Geosciences.


Nouh E.S.A.,Nuclear Materials Authority
Journal of Industrial and Engineering Chemistry | Year: 2015

Cloud point extraction (CPE) was used for Eu(III) determination in water samples using flame atomic absorption spectrometry (FAAS). Complex of Eu(III) with alizarin red S was extracted into the surfactant-rich phase of octylphenoxypolyethoxyethanol (Triton X-114) from samples at room temperature in presence of an amount of NaNO3. The parameters affecting CPE such as sample pH and concentrations of NaNO3, complexing agent and Triton X-114 were studied. Under the optimized conditions, the limit of detection (3σ) was 6 ng mL-1 and the relative standard deviation (RSD) was 1.95%. The method was successfully applied to Eu(III) determination in water samples. © 2014 The Korean Society of Industrial and Engineering Chemistry.


Ali K.G.,Nuclear Materials Authority
Arabian Journal of Geosciences | Year: 2013

The El Sela area is a part of the basement complex of the Eastern Desert of Egypt and the Pan-African Shield. The area comprises outcrops of dismembered ophiolites thrust over arc volcano-sedimentary sequence and intruded by different syn- to post-tectonic granitoids. Structural analysis of the area enabled the separation and definition of four structural episodes: (E1) folding-thrusting episode associated with the cratonization of the arc/inter-arc rock association and the intrusion of the syntectonic (Older) granites. (E2) Upright folding episode associated with the compression and shortening to the ENE-WSW direction which is different from the NNW-SSE shortening direction during E1; at the end of E2, late tectonic granites were intruded. (E3) Post-tectonic granitic intrusion episode: two mica granite and granitic dikes were intruded during this episode. (E4) Fracturing, faulting, and post-granitic dike extrusion episodes caused different faults that took place after cratonization until the present. There are three generations of folds during ductile deformation (E1 and E2). The F2 folds are nearly coaxial (along ENE-WSW trend) with the F1 folds. The F3 folding is displayed by folds generally trending NNW-SSE. Therefore, the ENE-WSW and NNW-SSE trends can considered as preexisting discontinuities and mechanical anisotropy of the crust in the following structure episodes. Brittle deformation (E3 and E4) reveals the importance of those trends which control the multi-injections and many alteration features in the study area. During reactivation, a simple shear parallel to the inherited ductile fabrics was responsible for the development of mineralized structures along the ENE-WSW and NNW-SSE trends. So they can be considered as paleochannel trends for deep-seated structures and can act as a good trap for uranium and/or other mineral resources. Most of the uranium anomalies are delineated along ENE-WSW and NNW-SSE shear zones where quartz-bearing veins bounded the lamprophyre dike and microgranites and dissected them in relation to the successive fracturation and brecciation corresponding to the repeated rejuvenation of the structures. Therefore, the structural controls of the uranium mineralizations in the El Sela area appear to be related to the interaction between inherited ductile fabrics and overprinting brittle structures. © 2011 Saudi Society for Geosciences.


Optical microscopy, X-ray diffraction (XRD), and back-scattered electron imaging (BSE) have been used to determine the mineralogical composition of the uraniferous iron and manganese oxides and the associated U-minerals hosted in biotite granite that occurred north east Gabal El Sela area south Eastern Desert, Egypt. These mineralizations were found as veinlets fractures filling associated with strongly kaolinitic alteration of the coarse-grained biotite granite. XRD determined that the geothite mineral form the main constituent of uraniferous iron oxide in addition to tapiolite, and kaolinite minerals, where as uraniferous manganese oxide composed of pyrolusite, ramsdellite, and cryptomelane. BSE confirmed that the associated uranium minerals represented by uranothorite, kazolite, and zentime in addition to columbite-bearing minerals. Uranothorite and columbite-bearing minerals are the most abundant minerals in this mineralization. Petrographically, biotite granite is composed mainly of quartz, in addition to K-feldspars, biotite and muscovite with minor zircon, garnet, apatite, uranium-rich thorite and iron oxide. Petrochemical studies and tectonic discrimination diagrams for this granite reveal that they are classified as granite to alkali feldspar granite, originated from calc-alkaline magma having peraluminous nature and developed in within-plate tectonic environment. Field radiometric measurements revealed the localization of two high radiometric anomalies associated with iron and manganese oxides, within this anomaly uranium content range from 65 to 85 ppm. Alpha Track-etch Detectors of radon gas registrations revealed high track density reach up to 15,448.7 Bq/m3. © 2011 Saudi Society for Geosciences.

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