The preparation of zirconium dioxide nanoparticles (ZrO2-NPs) as hard ceramics was accomplished from rosette zircon concentrate through two consecutive alkaline digestion reactions. The rosette zircon concentration in the Abu Khashaba area consists mainly of zircon and monazite minerals. Using different operating conditions, the hydrothermal digestion by autoclave and the conventional alkaline fusion methods was performed upon the non-magnetic concentrate of rosette in order to complete the removal of monazite firstly and to complete the purification of zircon metal secondly. All monazite content and undesirable impurities were removed by the hydrothermal method using optimal digestion conditions such as 4 mol/L NaOH solutions, 1/6 solid to liquid, 2 h dissolving time, and a temperature of 423 K. The residual zircon (84% Zr) was subjected to complete digestion using NaOH with a zircon-to-alkali ratio of 1/1.5 and a fusion temperature of 923 K. ZrO2-NPs were synthesized using the hydrothermal technique at 473 K for 7 h. The calcined ZrO2-NPs were characterized by X-ray diffraction, scan electron microscope, and transmittance electron microscope. Purified silica was also obtained as a by-product from washing solutions of fused zircon.

Leaching of uranium from a technological sample (680 mg/Kg U) in SW Sinai of Um Bogma Formation is carried out using a mix of sodium carbonte/sodium bicarbonate in presence of an oxidant (MnO 2 or H 2 O 2 ). The relevant factors e.g. (grain size = À 200 mesh, alkali concentration = 100 g/l (3 : 1) mixed Na 2 CO 3 / NaHCO 3 , time = 2 h, solid/liquid ratio = 1/3, T = 50°C and H 2 O 2 = 60 ml) of alkaline leaching of uranium have been optimized. This is followed by uranium recovery using an anion exchange resin, modified Dowex 1X8/TOA. Therefore, highly 92 % pure product of uranium has been obtained as sodium di-urinate Na 2 U 2 O 7 .