Rare Element Resources
Bear Lodge Project
Canadian NI 43-101 Technical Report
October 9
th
, 2014
10135-200-46 - Rev. 0
13-18
significantly lower than in the corresponding fine (-3”) fractions. The data showing the
upgrade that is attributed to screening is illustrated in Table 13.1.
13.6.2 Pilot PUG Test on COMP 1A
The pilot flowsheet for Composite 1A (BH oxide ore) required screening and gravity
separation. This flowsheet is illustrated in figure 13.5. High losses of REOs to gravity
tailings are mitigated by magnetic /gravity scavengers that are coupled to the tail end
of the flowsheets. For Comp 1A, the flowsheet comprises of primary screens, a
primary rougher gravity separator and a suitable primary magnetic scavenger. In
addition, the circuit also included secondary screens, a secondary rougher gravity
separator, and a secondary magnetic separator.
Table 13.13 presents the recovery data for each of the streams in the flowsheet. For
Comp 1 A, total REO recovery to combined concentrates was 94.8% to 80.5% of total
feed mass.
For Bull Hill high grade oxide ore, the mass pull was found to be too high to achieve
an acceptable upgrade factor. In the PFS, BH high-grade oxide ore is screened at a
3-inch size in years 1-9 and the minus 3 inch material is processed without gravity or
magnetic separators. In subsequent years, low-grade BH oxide ore will be subjected
to this flowsheet after screening at three inches.
(SGS Lakefield, 2013)
Table 13.13 - Comp 1A : PUG Concentrates and Tailings
