The present work was conducted in two stages of leaching processes, stage one, an
alkaline leaching of uranium and zinc from Alluga rock sample, Sinai area, using sodium
hydroxide solution. The leaching conditions, including sodium hydroxide concentration, stirring
time, temperature and liquid-solid ratio were studied. The optimum conditions were sodium
hydroxide concentration (5mol/L), stirring time (180 min), liquid-solid ratio (4/1) and
temperature (70oC), the leaching efficiency was about 91.2% for uranium and 93.5% for zinc.
 The second stage took place on the spent residue left behind for leaching the rare earth
elements using mixture of sulfuric acid and magnesium sulfate solution, the optimum conditions
were achieved at sulfuric acid concentration (1mol/L), magnesium sulfate concentration (0.8
mol/L), temperature (200o C), stirring time (120 min), and liquid-solid ratio (3/1), under these
conditions leaching efficiency of rare earth was 96.5%. The experimental leaching kinetic data
of uranium, zinc and rare earth elements were well identified by a shrinking core model with
diffusion control through a product layer, with apparent activation energies of 8.74 KJ/mol for
uranium, 21.3 KJ/mol for zinc and 18.26 KJ/mol for rare earth elements.