Mineralogical, geochemical, and radiogeological studies of forty nine phosphorite samples from three main mining areas in Egypt, Abu Tartur (Western Desert), Sibaiya (Nile Valley), and Safaga (Red Sea) have been carried out and the results are incorporated in this dissertation. / X-ray diffraction studies of these Egyptian phosphorites show that carbonate-fluorapatite (francolite) is the major phosphorite mineral in these deposits, with partial substitution of Mg and Na for Ca, and (CO(,3)) for (PO(,4)). Other minerals identified using the x-ray diffraction and scanning electron microscope include calcite, dolomite, pyrite, quartz, gypsum, feldspars, micas and clay (smectite). Electron microprobe analysis of the apatite pellets was utilized for deducing the structural formula of the average phosphorites of Egypt. Francolites exhibit several systematic isomorphous substitutions including Na, Mg, Sr, and Cd for Ca; and SO(,4) and CO(,3) for PO(,4). These substitutions result in measurable variations in the unit cell dimensions. These variations in the chemical compositions and unit cell dimensions of the pelletal phosphorites in Egypt show some relation to their coloration. / The uranium content and U/P(,2)O(,5) ratio show low values in Abu Tartur phosphorite deposits relative to the Red Sea and Nile Valley deposits. Autoradiographic studies of the Egyptian phosphorites showed that the radioactivity is unequally distributed among its constituents. The opaque pellets are the most radioactive and the bone fragments are the least radioactive. / Geochemically, four distinct groups of minerals were identified in the Egyptian phosphorites according to the degree of correlation between the major apatite components and the trace elements. These mineral groups are apatite, clays, heavy minerals and leached group. The results showed that the phosphorites of Nile Valley are relatively rich in Co and Zn whereas the Red Sea phosphorites are relatively rich in Pb and U. The Western Desert phosphorites are much richer in Ti as compared to the other two areas. Relative to the world phosphorites, the Egyptian phosphorites are geochemically enriched in Co, Mn, and Ni and impoverished in Sr, Cr, U, Zn, Cu, Ti, and V. / Source: Dissertation Abstracts International, Volume: 42-10, Section: B, page: 3987. / Thesis (Ph.D.)--The Florida State University, 1981.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_74669 |
| Contributors | DABOUS, ADEL AHMED A., Florida State University |
| Source Sets | Florida State University |
| Detected Language | English |
| Type | Text |
| Format | 217 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
Page generated in 0.0032 seconds