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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. Source


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. Source


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. Source


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. Source


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. Source

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