Insight on uranium recovery valorization from El Sela highly altered granitic rocks, South Eastern Desert, Egypt

Abstract

One of the more difficult problems affecting leaching process is the presence of clayey materials. The latter act as natural adsorbent for dissolved uranium (U) from one hand, and a selling surface which complicate solid liquid separation from the other hand. The materials that are clay-like were created as a result of substantial weathering of the pre-formed granitic rocks. This is the case in the kaolinitized two mica mineralized granite of Gabal (G.) El Sela area, which is situated in the extreme southeastern part of Egypt. The present work is oriented towards solving the problems of low uranium leaching efficiency as well as poor filtration process. Agitation leaching process using H2SO4 was first applied upon mineralized raw sample assaying 850 ppm of U. Different leaching parameters include acid concentration, solid/liquid ratio, agitation time and temperature as well as the concentration of added NaCl were studied. About 89% of U content was dissolved using 15% H2SO4 at 90ºC for 2h in the presence of 0.25M of NaCl the purpose was to facilitate the permeability of the pulp. The experimental data were interpreted with a shrinking core model with diffusion control through a porous product layer for El Sela ore material. The leaching process follows the kinetic model: 1-3 (1-X) 2/3 + 2 (1-X) = k1t with an apparent activation energy of 19.49 kJ/mole.