الفهرس | Only 14 pages are availabe for public view |
Abstract The Rare Earth Elements (REEs) are relatively abundant in the earth’s crust, but discovered economic concentrations are less common than for most other ores. They consist of a coherent group of elements (lantha-nide series) with similar chemical properties. They play an important role in various fields ranging from geology to electronics, which demand their determination from percentage to ultra-trace levels. The naturally existing actinides or radio nuclides like Uranium (238U) and Thorium (232Th) are present everywhere in the Earth’s crust. The Egyp-tian black sands along the Mediterranean coast consist of massive assets of several common economic minerals. This study consists of three chapters:- Chapter 1 : Introduction This chapter includes introduction, aim of the work, an overview of pre-vious researches for REEs, U, Th and the isotopic ratios of U / Th. Chapter 2 : Experimental Work This chapter contains the chemicals, methods and applied measure-ment techniques as follow: 1) The chemicals, Calibration standards and its concentrations. 2) Methods of digestion for black Sand samples. 3) Chemical treatment for sea water samples 4) Chemical treatment for phosphate samples. 5) Instrumental set up and calibration of ICP-MS. Chapter 3 : Results and discussions This chapter describes and discusses the results of different analyses car-ried out in this study and included: 1- Results of black sand samples analysis a- U and Th contents and concentrations b- U/Th isotopic ratios. c- REEs content and concentrations 2- Results of sea water samples analysis a- U and Th contents and concentrations b- U/Th isotopic ratios. c- REEs content .and concentrations 3- Results phosphate samples analysis a- U and Th contents and concentrations b- U/Th isotopic ratios. c- REEs content .and concentrations. |