Mineralogical characterization and physical upgrading of radioactive and rare metal minerals from Wadi Al-Baroud granitic pegmatite at the Central Eastern Desert of Egypt

Abstract

Granitic pegmatites of Wadi Al-Baroud area in the Central Eastern Desert of Egypt have appreciated amounts of radioactive (U, Th) and rare metal- (Nb, Ta, Y, Zr, Hf, and rare earth elements—REEs) bearing minerals. A combination of both geochemical and physical methods has been used for investigation of Wadi Al-Baroud granitic pegmatites. The identification, imaging, and chemistry of rare metal-bearing minerals were conducted using the optical microscope, X-ray diffraction (XRD), scanning electron microscope (SEM), and electron microprobe analyzer (EMPA). The pegmatites host Nb-Ta oxides (euxenite-Y, fergusonite-Y, and yttrocolumbite-Y), REE minerals (xenotime-Y, monazite-Ce and allanite-Ce), U-Th minerals (thorite and uranothorite), and Hf-rich zircon. In addition, muscovite, quartz, feldspars, and some iron oxide minerals such as magnetite, goethite, and lepidocrocite represent the essential, gangue, and associated minerals. Physical upgrading of Wadi Al-Baroud-mineralized pegmatites was carried out using gravity and magnetic separation techniques. Applying the optimum conditions for both separation techniques, it is possible to attain a good concentrate with an acceptable recovery. Accordingly, the final concentrate contains ~ 0.25% U, 0.46% Th, and 0.31% REE with recovery of 91.17% U, 96.56% Th, and 86.19% REE in a weight of 6.58% out of the original sample assays 0.02% U, 0.04% Th, and 0.03% REE. Therefore, it is well-recommended that the final concentrate should subject to proper hydrometallurgical treatment to extract their valuable metal contents.