TITLE:
Beneficiation Studies of a Rare Earth Ore from the Olserum Deposit
AUTHORS:
Xiaosheng Yang, Neea Heino, Lassi Pakkanen
KEYWORDS:
The Olserum Deposit, Rare Earth Minerals, Flotation
JOURNAL NAME:
Natural Resources,
Vol.10 No.9,
September
17,
2019
ABSTRACT: The Olserum deposit located in Sweden hosts an
indicated mineral resource of 4.5 million tonnes at 0.6% total rare earth
oxides (TREO), exhibiting a relatively high proportion of heavy rare earth
elements (HREE). The mineralogy and beneficiation of a composite drill core
sample from the Olserum deposit were studied. Monazite and xenotime were found
by the mineralogical analyses to be the target minerals for beneficiation of
REEs and most (96.9%) of REEs in the ore are carried by monazite (68.5%) and
xenotime (28.4%). Because xenotime carries 84.7% of heavy REEs (Y, Gd, Dy) in
the ore it is more valuable mineral than monazite. A beneficiation process was
developed which includes grinding, wet low intensity magnetic separation
(WLIMS) for removal of magnetite and REEs flotation consisting of one stage of
roughing and two stages of cleaning. Selective flotation collector of REE
minerals and suitable grinding size of feed material were determined by
testwork. The REE concentrate and tailings were chemically and mineralogically
characterized. The studies of process mineralogy showed that the REE-bearing
minerals, monazite and xenotime, and apatite were
successfully enriched from the concentrations of 0.6%, 0.31% and 2.6% in the
feed to those of 17.0%, 8.9% and 65.0% in the concentrate with the recoveries
of 79.0%, 81.3% and 71.0%, respectively.