EJMP&EP


Technical Note


Removal of Radioactive Elements from Niobium and Tantalum Ores

O.M. ELHusaini* and M.N. ELHazek

Nuclear Materials Authority, P.O. Box 530 El Maadi, Cairo, Egypt


Accepted 5 August 2004




ABSTRACT

The production of niobium and tantalum elements from their ores requires separating from the accompanying elements and purification. The ore material obtained from the Eastern-Desert of Egypt consists of euxenite, betafite, thorite and zircon. It was decomposed by sulfuric acid digestion and portions of its constituents were transferred to the leach liquor as given: 66.8% Nb2O5, 38.7% Ta2O5, 76% rare earths, 28.9% TiO2, 86.5% ThO2 and 91.1% U3O8; while ZrO2 remained in the unattacked residue. Liquid-liquid extraction was performed to remove the radioactive elements from the leach liquor, leaving niobium, tantalum and rare earths unextracted. The system sulfuric acid -diethylhexyl phosphoric acid / tributyl phosphate in kerosene was efficient to extract both thorium and uranium. The extraction was performed by contacting the sulfate leach liquor of pH =1.0 and 6.6M SO42- with 0.2M D2EHPA/TBP in the ratio A:O=3:1 for 15 minutes. The separation of thorium from uranium was performed by two different stripping steps to obtain recovery of 99.6% ThO2 and 91.2% U3O8. On the other hand zircon of 96% purity was separated from the unattacked residue by successive chemical treatments.


Keywords: Niobium; Tantalum; Rare earth elements; Leaching; Liquid-liquid extraction



* Corresponding author
   E-mail : omneya@link.net