Rare Element Resources
Bear Lodge Project
Canadian NI 43-101 Technical Report
October 9
th
, 2014
10135-200-46 - Rev. 0
15-4
(northwestern) area. The tenth sector is for all material within approximately 150 ft. of
the topographic surface. Table 15.2 summarizes the overall slope angles used in the
LG evaluation, which include provisions for internal haul roads.
Table 15.2 - Overall Slope Angles for Pit Optimization
Sector
Pit Area & Wall Location
OSA
Degrees
1
Bull Hill NW wall
32
2
Bull Hill N wall
34
3
Bull Hill NE-E wall
34
4
Bull Hill S wall
37
5
Bull Hill W wall
29
6
Whitetail W wall
30
7
Whitetail N wall
34
8
Whitetail E wall
30
9
Whitetail S wall
34
10
All areas, 150 ft. depth
30
(WLRC, 2014)
A restriction was made on the south side of Bull Hill to prevent the LG pit shell from
crossing into Section 20 of T52N, R63W (Sixth Principal Meridian). Mining
excavations are not permitted in Section 20 at this time. Restrictions were also
placed on sulfide material, including a 100-ft buffer zone above the sulfide contact, to
prevent exposure of sulfides in the pit walls for environmental reasons.
In the pit design, walls were smoothed from the basic LG shell to minimize noses and
notches that could affect slope stability. Internal 70-ft-wide haulage ramps were
included to allow for truck access to working faces. Figure 15-1 illustrates the
resulting ultimate pit design; the red line marks the northern edge of Section 20. Grid
lines are shown on 1000-ft intervals. The pit length is approximately 4700 ft. along
the NW-SE trending long axis, with a maximum width of about 2800 ft. along an
orthogonal SW-NE direction.
Mineral reserves are reported inside the designed pit using a cutoff grade of 1.5%
TREO for Bull Hill oxide, 1.75% TREO for Bull Hill OxCa and 1.0% for all Whitetail
material. These TREO cutoffs vary according to the anticipated performance of the
physical upgrade plant for the different ore types and are equal to or higher than the
computed breakeven cutoffs.
