Selective recovery of lanthanides,uranium and thorium from Rosetta monazite mineral concentrate

An innovative procedure for the selective recovery of lanthanides using (NH₄)₂SO₄ from hydrous oxide cake produced after the alkali breakdown of monazite mineral concentrate was proposed. By applying this procedure, 94.6% of the rare earth elements (REEs) content would be dissolved. In this context, partial precipitation of light rare earth elements (LREEs) as their double sulfate took place. To separate uranium completely from thorium and the remaining REEs (5.4%) from hydrous oxide cake, an alkaline leaching procedure has been carried out by using a mixture of 1/3 (Na₂CO₃/NaHCO₃) solution. Finally, the remaining hydrous oxide cake was then dissolved in 4M HCl to separate either Th or REEs contents.