Sequential separation of the yttrium—heavy rare earths by fractional hydroxide precipitation

Characteristics of Precipitation of Rare Earth Elements with Various Precipitants

“…Such pretreated ores are then subjected to the leaching process of REEs. The leach liquor is frequently subjected to the removal of impurities such as iron, calcium, uranium, and thorium by going through stage-wise precipitation using various compounds such as hydroxide, carbonate, sulfate, and oxalate [7][8][9][10][11][12][13]. After the removal of these impurities by chemical precipitation, REEs in solution are then subjected to precipitation using various precipitants, which in general takes place at pH above 3−4, since most of these impurities are precipitated at around these pHs.…”

Raman characterisation of powder of cubic RE2O3 (RE=Nd, Gd, Dy, Tm, and Lu), Sc2O3 and Y2O3

“…They are recognised as highly active catalysts for a large number of organic reactions, like the oxidation coupling of methane to form higher hydrocarbon products [5,6] or the dehydration/dehydrogenation of alcohols [7,8]. Moreover, some of them are receiving attention in industry because of their potential use as control rods for nuclear reactors [9,10]. Yttrium oxide, Y 2 O 3 , and scandium oxide, Sc 2 O 3 , have a chemical behaviour similar to the RE 2 O 3 and so they are sometimes considered together.…”

Solubility behavior of rare earths with ammonium carbonate and ammonium carbonate plus ammonium hydroxide: Precipitation of their peroxicarbonates

“…More recently Abdel-Rehim [6] used ammonium carbonate-ammonium bicarbonate for the autoclave leaching and separation of thorium, uranium and rare earths. de Vasconcellos et al [7,8] exploited the selective dissolution of yttrium in ammonium carbonate starting from an industrial low cerium carbonate concentrate. Queiroz et al [9,10] reported that the addition of hydrogen peroxide to the carbonate rare earths complexes forms a precipitate, identified as rare earth peroxicarbonates.…”