Instrumental Neutron Activation Analysis of Egyptian Phosphate Samples and Adsorption Studies of Their Elemental Contents

Samples of Egyptian phosphate ore obtained from Om Salmah mine at El-Sibaiya, Nile valley, were analyzed for some lanthanides and concomitant elements by instrumental neutron activation analysis. The use of a high-resolution HPGe detector connected to a PC-based multichannel analyzer enabled simultaneous nondestructive multielement analysis in a single irradiation run with good accuracy. The following elements were determined after relatively short cooling time (5 days): lanthanides (La, Ce, Eu, Nd, Sm, Gd, Tb, Yb), concomitant elements (Ba, Br, Ca, Co, Cr, Fe, Hf, Na, Rb, Sb, Sc, Se, Sr, Zn, Zr), and actinides (Th, U). After longer cooling time, the following elements were determined: La, Ce, Nd, Eu, Gd, Tb, Yb, and the concomitant elements: Cr, Fe, Hf, Nb, Sc, Th, Co, Zn, and Zr. Adsorption experiments were performed on synthesized inorganic ion exchangers: zirconium titanium phosphate (ZTP) with different Zr : Ti molar ratios and ceric tungstate (CeW), as well as on organic cation and anion exchangers: Dowex-50x8 and Dowex-1x8, respectively. The adsorption was performed from solutions containing dilute HCl and HNO3, formed by dissolving the irradiated phosphate samples in aqua regia, diluting, and cooling for a certain time. The effect of some factors on the adsorption was studied. Some options for separating the elements were suggested.