Rare Earth Element Phases in Bauxite Residue

Vind, Johannes
Malfliet, Annelies
Blanpain, Bart
Tsakiridis, Petros E.
Tkaczyk, Alan H.
Vassiliadou, Vicky
Panias, Dimitrios

Publication date

February 2018

DOI

10.3390/min8020077

Abstract

Abstract: The purpose of present work was to provide mineralogical insight into the rare earth element (REE) phases in bauxite residue to improve REE recovering technologies. Experimental work was performed by electron probe microanalysis with energy dispersive as well as wavelength dispersive spectroscopy and transmission electron microscopy. REEs are found as discrete mineral particles in bauxite residue. Their sizes range from <1 µm to about 40 µm. In bauxite residue, the most abundant REE bearing phases are light REE (LREE) ferrotitanates that form a solid solution between the phases with major compositions (REE,Ca,Na)(Ti,Fe)O3 and (Ca,Na)(Ti,Fe)O3. These are secondary phases formed during the Bayer process by an in-situ transformation ...