rare earth elements in Wyoming

accessory aegirine, apatite, strontianite, barite, and
celestite (Rare Element Resources, 2011).
LREE dominate the Bear Lodge deposit. However,
a press release by Rare Element Resources on
August 4, 2011 describes high HREE grades in
the northern and western portion of their project
area. These localities are referred to as their Whitetail
Ridge, Taylor, and Carbon target areas (fig. 3).
These areas generally host grades greater than 3
percent REO and are also significantly enriched in
europium, terbium, dysprosium, and gadolinium,
as well as yttrium (Rare Element Resources, personal
communication, April 2013).
On March 18, 2013, Rare Element Resources
reported an NI 43-101-compliant 1 total high-grade
Measured and Indicated (M&I) mineral resource
of 13.3 million tonnes (14.7 million tons) grading
3.22 percent REO at a 1.5 percent cutoff grade,
which included M&I resources of 5 million tonnes
(6 million tons) grading 4.72 percent REO at 3
percent cutoff grade (Rare Element Resources,
2013b). In relative order of decreasing abundance
REOs include Ce 2 O 3 , La 2 O 3 , Nd 2 O 3 , Pr 2 O 3 ,
Sm 2 O 3 , Gd 2 O 3 , Y 2 O 3 , Eu 2 O 3 , Dy 2 O 3 , Tb 2 O 3 ,
and others (Rare Element Resources, 2012). The
continuing expansion of the identified Bear Lodge
REE deposit through drilling seems to confirm
Staatz’s 1983 claim that Bear Lodge may be the
largest resource of disseminated rare-earth elements
in North America.
Gold mineralization occurs within the same large
alkaline-igneous complex as the REE mineralization.
The Taylor target area was primarily a gold
exploration area until a thick FMR zone was intersected
in 2010. One hole intersected high-grade
1 National Instrument 43-101 is a Standards of Disclosure
for Mineral Projects rule issued by the Canadian
Securities Administrators, which governs the public disclosure
of scientific and technical information by publicly-traded
mining companies, including oral statements,
written documents, and websites. NI 43-101 requires
that all disclosure be based on advice by a “qualified person”
(engineer or geologist) who, in some cases, must be
independent of the mining company and the property.
Its purpose is to ensure public confidence in miningrelated
stocks by enhancing the accuracy and integrity of
public disclosure in the mining sector.
19
REE mineralization that also averaged 1.3 g/tonne
(0.038 oz/ton) gold 2 from the surface to a depth of
62.5 m (205 ft). On March 15, 2011, the company
released an NI 43-101-compliant inferred
mineral resource estimate of 26,850 kg (947,000
oz) of gold contained in 69.3 million tonnes (76.4
million tons) averaging 0.42 ppm (0.42 g/tonne;
0.122 oz/ton) using a 0.15 ppm (0.15 g/tonne;
0.004 oz/ton) cutoff grade. A February 27, 2012
news release reported some of Rare Element Resources’
best gold drilling assays that included 24.4
m (80 feet) of 4.5 ppm (4.5 g/tonne; 0.131 oz/
ton) in one hole (Rare Element Resources, 2012).
The 2011 gold drilling results will likely expand the
company’s gold resource.
Rare Element Resources’ REE project totals about
971.2 hectares (2,400 acres) that includes 90 unpatented
federal lode claims and one private section
of land. Between 2008 and the end of 2012, their
drill hole database included 216 core holes and
16,920 assay samples (Rare Element Resources,
2013b). On March 1, 2012, the company announced
positive economic results from a prefeasibility
study. Projections are for a conventional
open-pit mine and an on-site physical upgrade
plant using a gravity separation and screening and
wash process designed to produce up to 907 tonnes
(1,000 tons) of ore material per day. Their nominal
operating scenario addresses production of 20,970
tonnes (23,111 tons) per year of 45 percent REO
concentrate for a mine life of 19 years. However,
continued drilling in outlying areas indicates
potential for increased LREE and HREE enrichment
that could extend the life of the mine (Rare
Element Resources, 2012). In conjunction with a
feasibility study commencing in 2013, the company
plans to conduct pilot-scale metallurgical testing
on more than 19.1 tonnes (21 tons) of mineralized
material (Rare Element Resources, 2013b). Details
of Rare Element Resources, Ltd. recent activity can
be found on their website at http://www.rareelementresources.com.
2 By convention, ounces (oz) always means Troy ounces
when referring to gold or other precious metals.