Rare Element Resources
Bear Lodge Project
Canadian NI 43-101 Technical Report
October 9
th
, 2014
10135-200-46 - Rev. 0
13-11
Bull Hill Ore: Variability Screen Tests
Crushed ore (+¼ inch) was subjected to screening to assess recovery of REOs to
minus ¼ inch fraction. Figure 13.3 illustrates the behavior of crushed core samples
from the central zones of the BH deposits located near rare earth dikes. Rare earth
minerals (9.84%TREO and 3.33%TREO) were upgraded by a factor of 1.9. The mass
pull to minus ¼ inch was 52.3% and 36% with recoveries 96.9% and 94.9%,
respectively.
Figure 13.3 - Separation of REOs by Screening at ¼” Bull Hill High Grade
(Rare Element, 2014)
Low-grade ores from BH deposits were processed as illustrated in Figure 13.4. Rare
earth minerals (2.48% TREO and 2.07% TREO) were upgraded by a factor of 3.81
and 2.3, respectively. The mass pull to minus ¼ inch was 21.7% and 13.9% with
recoveries 82.7% and 31.7%, respectively. Upgrade factors are sufficiently high but
recoveries were on the low side and hence the need to improve recovery by
introducing gravity and magnetic separators. In general, drill core samples from
outlying zones of the deposit did not upgrade well after screening. However, all
samples leach well in chloride media.
3 inch - Drill PQ Core ( 9.82% REO )
Crushed and Screened at ¼ inch cut-off size
+ 1/4 inch
•
Oversize:
47.70 wt.%
•
Grade:
0.64 %
•
Distribution: 3.10 wt.%
Upgrade = 1.9
- 1/4 inch
•
Undersize:
52.3 wt.%
•
G rade:
18.2 %
•
Distribution:
96.9 wt.%
Ex. 1
3 inch - Drill PQ Core ( 3.33% REO )
Crushed and Screened at ¼ inch cut-off size
+ 1/4 inch
•
Oversize: 64.0 wt.%
•
Grade: 0.26%
•
Distribution: 5.1 wt.%
- 1/4 inch
•
Undersize:
36.0 wt.%
•
Grade:
6.34%
•
Distribution:
94.9 wt.%
Ex. 2
Upgrade = 1.9
