Targeted Crystallization of Rare Earth Carbonate Polymorphs at Hydrothermal Conditions via Mineral Replacement Reactions.

ABSTRACT: The interaction between rare earth element (REE)-rich (La, Pr, Nd, Dy) aqueous solutions, dolomite (CaMg(CO₃)₂), and aragonite (CaCO₃) at low temperature hydrothermal conditions (25-220 °C) is studied. The experiments result in the solvent-mediated surface precipitation and subsequent pseudomorphic mineral replacement of the dolomite and aragonite seeds by newly formed REE-carbonates. The host grains are replaced from periphery inward. The newly formed REE-bearing carbonates in La-, Pr-, and Nd-doped systems follow the crystallization sequence: lanthanite [REE₂(CO₃)₃·8H₂O] → kozoite [orthorhombic REECO₃(OH)] → hydroxylbastnasite [hexagonal REECO₃(OH)]. The interaction of Dy-bearing solutions

SUBMITTER: Szucs AM 

PROVIDER: S-EPMC9900722 | biostudies-literature | 2023 Feb

REPOSITORIES: biostudies-literature