Selective separation of thorium from rare earth elements liquor during the alkaline processing of Egyptian monazite concentrate

Abstract

Monazite ore processing is a complicated matrix which is mainly attributed to the presence of high phosphate (25% of P 2 O 5 ) and sulfate concentration, hence, complicate the extraction and separation of REEs and other elements. Therefore, this work developed technical systematic studies for monazite processing using alkali solution, resulting in the removal and recovery of phosphate as a valuable product. Moreover, solvent extraction technique was used for selective separation of Th(IV) followed by the chemical precipitation of REEs. According to the obtained results, it could be stated that the early washing step is more efficient for removal of 92.8% of P 2 O 5 hence; the separation of REEs from the matrix becomes more achievable. The subsequent extraction process of thorium (Th) revealed that secondary amine could be selectively and efficiently used for separation of Th and Fe with 100 and 98% efficiency respectively from U and REEs. In the residual aqueous solution, REEs were quantitatively precipitated as REEs-oxalate then separated from U.

Extraction of Thorium Oxide (ThO₂) from Malaysian Monazite through Alkali Digestion: Physical and Chemical Characterization Using X-Ray Analysis

“…Shahr El-Dina et al (2018) has successfully shown that 92.8% of P2O5 was removed from Egyption monazite using alkaline digestion. This high efficiency of phosphate removal may benefited the later rare earth and Th extraction process [13]. In this work, recent study are reported on the extraction of ThO2 from Malaysian monazite using alkaline digestion technique with caustic soda.…”