Transactions of the Society for Mining, Metallurgy, and Exploration, Inc.
Transactions home

  SME FaceBook SME Twitter SME LinkedIn RSS Feed

Mineralogy, geochemistry and leaching characteristics of the high-grade Th-U-Y zone of altered syenite at El Garra El Hamra, SW Desert, Egypt

Minerals & Metallurgical Processing , 2018, Vol. 35, No. 4, pp. 230-240

Mahmoud, Soliman Abu Elatta A.; Abdellah, Waild M.; Abu Khoziem, Hanaa A.



The high-grade Th-U-Y zone is one of the numerous mineralized zones found in the El Garra El Hamra hydrothermally altered syenites in southwestern Egypt. It is characterized by the thorium minerals thorite and thorogummite, which are closely associated with xenotime-(Y). This zone of mineralization is localized in the eastern part of the El Garra El Hamra hydrothermally altered syenites. This zone does not relate to the first phase of syenites that appeared on the surface but is linked to the other, hidden phase of the syenitic body. Additionally, the fluids responsible for the mineralization of this zone belong to the late-stage hydrothermal event as well as the fault action due to the fact that it had continued reactivations for a long period of time. The studied mineralized zone also contains ceriopyrochlore-(Ce),(Ce,Ca,)2 (Nb,Ta)2 O6 (OH), fluorite (CaF2 ) and barite (BaSO4 ), which are found in considerable amounts, whereas apatite (Ca5 ( PO4 )3 F ) and chromite (FeCr2O4 ) are rarely found together with Fe-oxi-hydroxides (hematite and goethite) with a minor amount of jarosite (KFe33+(OH)6 (SO4 )2 ). Finally, the main constituent mineral in the zone is the pseudomorph perthite in addition to quartz, which is found as deformed crystals.

     A technological sample was collected from this zone and was found to assay 4.62 weight percent thorium (Th), 0.37 weight percent uranium (U) and 3.12 weight percent rare earth elements (REEs). From the chemical and mineralogical composition of the studied technological sample, the leachabilities of Th, U and REEs were investigated using sulfuric acid (H2SO4 ) agitation leaching and pug leaching methods. The latter was found to be preferred under the conditions of 0.54 ton H2SO4 per ton of altered syenite at 110 ºC for two hours.