STUDY THE EFFECT OF CHEMICAL AND PHYSICAL PROCESSES ON THE DISTRIBUTION OF RADIONUCLIDES IN SOME ALTERED ROCK TYPES FROM SINAI AND EASTEREN DESERT- EGYPT

Abstract

The aim of this study has been to clarify the behavior and distribution of radionuclides in different rock types, different locations, different degrees of alterations and its effects by the chemical and physical properties prevailing during formation and processing of these rocks in Sinai and Eastern Desert. In the first part, to study the radionuclides transfer from the solid material (ore) to the liquid phase (acid and/or alkali solutions), sixteen samples of different rock types from Sinai and Eastern Desert were collected and prepared for different analyses. These samples have been characterized by different analyses such as gamma-ray spectrometry by high purity germanium (HPGe), X-Ray Diffraction (XRD), and wet chemical analysis. The collected samples are chemically categorized under the following types; high silica, mainly silicates, high carbonates and high organic matter. It is necessary to consider briefly the features which affect chemical composition, such as degree of source weathering. So, the chemical index of alteration was calculated for different rock types in Allouga and Eastern Desert. Sedimentary rock samples of Allouga and granites from Gattar have slightly to moderately weathered source terrain while El Sela samples have strongly weathered source terrain. 232Th/238U concentration ratios of Allouga and Eastern Desert (< 2) are highly suggestive of relative uranium enrichment, and implicate reducing conditions.