The current study aimed at reducing concentrations of some toxic metal ions such as U, Cu and Zn in shale deposits of Abo-Thor area, south-western Sinai, Egypt. The improvement of some chemical properties of these shale deposits was taken in confederation to fulfill this target heap leaching of the used shale deposits was conducted at different concentrations of H2SO4 or solid : liquid ratios through out leaching columns with 331 cm diameter and 17.2 cm height of the ore.
The obtained results show that the leachability (leaching efficiency) reached the greatest percentage of U reached 86% by using 2% acid concentration and 1 : 3 solid : liquid ratio by using same solid liquid ratio of (1 : 3), but with acid concentration of 5%, there was almost favorable condition for extracting 84 and 55% for Cu and Zn, respectively. Moreover, the leaching process caused a pronounced reduction in the values of each EC, pH and soluble ions, lowering magnitudes depending on both acid concentration and solid: liquid ratios. As for the noticeable changes in clay minerals, data indicate that with increasing the acid concentrations and solid: liquid ratio the percentages in both kaolinite and illite mineral treated to decrease, reduce vs and increase in the percentage of quartz mineral.