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Solvent impregnated silica gel material was prepared for thorium recovery from its aqueous nitrate solutions using the neutral phosphine oxide extractant, cyanex-923 in toluene. This was achieved by adsorption of the extractant onto the solid phase in three steps. The obtained adsorbent was characterized by means of Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The relevant factors of extraction such as influence of acid concentration, flow rate and impregnated cyanex 923 amount were optimized by equilibrium column experiments. The results revealed that thorium loaded on 0.5 g cyanex-silica achieved with about 99.6% efficiency. Selective elution of the loaded thorium was carried out in two steps using both sulfuric and hydrochloric acids after volume optimization. Based on the obtained optimum factors, validation of the studied impregnated solid phase occurred on three certified granite samples where the practical applicability was then examined upon two geological samples bearing Th(IV) collected from Abu Zeneima mineralization, South-Western Sinai.

A new reagent, 1,4-dihydroxyanthraquinone (1,4-DHA), is described for the spectrophotometric determination of thorium(IV). Optimization of the formed thorium−1,4-DHA complex was performed by studying several parameters such as methanol concentration, suitable pH, dye concentration, temporal stability of the formed complex and thorium concentration (calibration curve). The optimized method was applied to different rock types bearing thorium with good accuracy results. This reagent is highly sensitive toward thorium; thorium complex has a molar absorptivity of 1.82 × 104 L/(mol cm) at 600 nm and pH 3.25. Beer’s law was obeyed in the range from 0.9 to 20 µg/mL for Th(IV). The tolerance limits for several metal ions were calculated and gave high tolerance limit especially for uranium. Details are given for the estimation of thorium in standard reference and natural rocks.

A particular ion chromatographic method for yttrium determination after separation from dysprosium simultaneously with individual quantification of rare earth elements has been modified. Selective separation of yttrium from dysprosium plus the other thirteen rare earth elements was achieved by gradient elution using oxalic / diglycolic acid eluent mixture on IonPac CS5A separating column. The separated ions were then detected using 4-(2-pyridylazo)resorcinol (PAR) at 530 nm. The optimized method was subsequently validated by the analysis of a reference sample from Abu Rusheid area followed by its application on two geological materials from Wadi Khuda-Wadi Shut area and Abu Tartour phosphate deposits. Relative standard deviation (RSD) calculated for the analyzed samples were expressed with very low values the matter which confirms the precision of the developed method. The present work allowed the individual determination of lanthanide elements including yttrium and six heavy metal ions in an absolute time of about 110 minutes.

An ion chromatographic method for separation and determination of the sum of the rare earth elements in addition to the individual determination of some heavy metal ions has been developed. The separation has been performed on a mixed bed column, IonPac CS5A containing both anion and cation exchange sites. Selective separation of heavy metals was performed by isocratic elution using pyridine-(2,6)-dicarboxylic acid eluent followed by on-line elution of the total rare earth elements using oxalic acid eluent. Post-column spectrophotometric detection with 4-(2-pyridylazo) resorcinol was then coupled at 530 nm. The separation factors of the different ions were found to be dependent on the eluent concentration, the pH and to a much more extent on the flow rate. The optimized developed method has been validated by its application for the analysis of some heavy metals and the sum of the rare earth elements in a sample from Abu Rusheid mineralization that is considered as a reference material and has then been used for the analysis of two other samples represent two different localities one of which is from Gabal Gattar area while the other is from Abu Tartour phosphate deposits. The optimized method enabled the successful determination of both heavy metals and rare earth elements sum within a total analysis time of about 20 min with high reproducibility.

Polyacrylic acid/polyaniline composite (a three-dimensional cross-linked hydrophilic chelating polymeric sorbent) was improved for promoted recovery of uranium ions from nuclear industrial effluent. The obtained sorbent was physically characterized using scanning electron microscope and Fourier transform infrared spectrometer. The relevant factors were optimized by equilibrium batch experiments using a uranium synthetic nitrate solutions. Desorption of the loaded uranium was approved using 1 M sodium carbonate solution. The practical applicability of the polyacrylic acid/polyaniline composite was then examined upon a uranium nuclear industrial effluent. The experimental results have been studied by both kinetic and sorption isotherm models.

Four different analytical techniques were compared for their performance in direct determination of uranium in seven rock samples. These methods include: ion chromatography, laser fluorimetry, UV–Vis spectrophotometry and gamma spectrometry. The samples under study were six ore samples beside an international reference sample (GBWO4115). The results obtained from the comparison study reported a method accuracy of 98%, 90%, 65% and 86% for ion chromatography, laser fluorimetry, UV–Vis spectrophotometry and gamma spectrometry techniques respectively. Also, on the converse of the other three techniques, ion chromatography technique using DX-500 ion chromatograph achieves superior agreement with the certified sample with only 2% bias.

A new method is presented for measuring of uranium at low levels in crude phosphoric acid without preconcentration or complexing agents using Dionex DX-500 ion chromatograph. Two isocratic elutions namely; 7 mM PDCA (for eluting the interfering cations) and 0.3 M (NH4)2SO4/0.1 M HCl (for uranium separation) with flow rate of 0.9 and 0.7 ml/min respectively. The optimized developed method has been validated by its application for the analysis of uranium in a certified sample (GBW04115).The developed method has been successfully applied to the determination of uranium in the prepared synthetic orthophosphoric acid and the crude phosphoric acid.

This work concerned with the extraction of Th(IV) from aqueous solutions using natural cassitrite adsorbent natural tin oxide mineral (SnO2). The achieved maximum Th(IV) adsorption efficiency (99.2%) depends mainly on some effective parameters such as pH value, contact time, dose of cassiterite, concentration of Th(IV) and temperature. The Langmuir and Freundlich models are used to simulate the sorption isotherms, respectively. On the other hand, not less than 99.6% of the uptaken Th(IV) was regenerated using 0.005 mol L−1 HCl solution by stirring for 25 min to yeild Th(IV) concentrated solution. The concentrations of Th(IV) in all extraction process were spectrophotometric estimated using 1,4-di-hydroxy anthraquinone and Arsenazo(III) at λmax 600 and 655 nm, respectively.

Biosorption has gained important credibility during recent years because of its good performance and low cost. This work is concerned with studying the potentiality of the chitin component of the shrimp shells for uranium biosorption from nitric acid liquid solutions. The structural characteristics of the working chitin have been determined via Fourier Transform Infrared Spectroscopy (FTIR). The surface morphology was examined using Scanning Electron Microscopy (SEM). The adsorption capacity of biomass was investigated experimentally. The influence of contact time, pH, metal ion concentration, solution volume to mass ratio and temperature were evaluated and the results were fitted using adsorption isotherm models. The kinetic of uranium biosorption was also investigated as well as biosorption thermodynamic.

The extraction of uranium from sulfuric acid media using trioctylamine (TOA) impregnated activated carbon has been studied. The latter was prepared by direct adsorption of the extractant onto the solid phase (dry method) and its analysis by the Fourier Transform Infrared Spectroscopy (FTIR) and the Scanning Electron Microscopy (SEM) proved that TOA has successfully been grafted to the surface of the activated carbon with a loading capacity of 0.67 g TOA per 1 g activated carbon. Parameters affecting uranium extraction by the TOA impregnated activated carbon such as the contact time, the pH of the uranium solution, the initial uranium ion concentration, the volume of aqueous solution to the weight of the impregnated activated carbon ratio as well as the extraction temperature were investigated by batch experiments. Loaded uranium was eluted using 0.1 mol/l hydrochloric acid. The experimental results have been studied by both kinetic and sorption isotherm models.

Heavy rare earth (HRE) oxalate concentrates were prepared from the Egyptian crude monazite sand (graded about 47%). The concentrates were specified quantitatively for their constituents of individual rare earth elements using ion chromatograph (IC) and qualitatively by scanning electron microscope (SEM) for the other major constituents. The 1st concentrate was composed of 10.5% HREE where 7.25% of them represented yttrium. The 2nd concentrate contained about 41.7% LREE, 17.5% HREE and 13.6% Th. The LREE involved 18.3% Ce, 10.5% La and 8% Nd while the HREE were 8.7% Y, 3.5% Gd and 2.9% Dy. The 3rd concentrate was containing about 8.0% LREE (3.7% Ce, 2.0% La and 1.5% Nd), 10.2% HREE (6.4% yttrium and 2.0% Dy) and 2.1% uranium. The final concentrate comprised 0.84% uranium beside iron, chromium and traces of REE.