Rare Element Resources
Bear Lodge Project
Canadian NI 43-101 Technical Report
October 9
th
, 2014
10135-200-46 - Rev. 0
16-10
16.5 Waste Rock Facility Design
A preliminary design of a Waste Rock Facility (WRF) has been developed over the
eastern slope of the ridgeline that runs north-south between the WRF and the open
pit mine to the west. The proposed WRF layout has the capacity to store up to 133
million tons of mine waste and PUG reject material. Additionally, a low-grade ore
stockpile will be located in the northwest corner of the WRF with a capacity of
approximately 3 million tons of low-grade ore. The layout of the WRF and associated
sediment control features are within the Section 16 parcel to avoid disturbance of
USFS land. The crest of the waste rock dump is designed to an elevation of 6,260 ft.
above mean sea level (amsl). This elevation is equal to or less than the ridgeline
elevations that runs between the open pit mine and the WRF.
The WRF design capacity assumed a 30% swell factor for the waste material.
Construction of the WRF will be completed by benching the waste material in lifts up
to 50 ft. in height with bench face slopes being constructed at the angle of repose
(approximately 1.4H:1V). Benches will be constructed in such a manner as to
maintain an overall side slope of 3H:1V. Closure of the facility will include laying back
the bench face slopes to a 3H:1V angle. Concurrent reclamation will be incorporated
in areas where dumping activities have been completed and will be shaped to blend
the natural topography surrounding the WRF. Based on the existing topography
within Section 16 and a maximum height of the WRF set at 1650 ft., the southern
portion of the WRF will extend across Beaver Creek. Therefore, a permanent
diversion of Beaver Creek around the WRF is included in the WRF surface water
management plan.
Development of the WRF will be staged in a manner to delay the diversion of Beaver
Creek until after operation Year 15. Initially, the north area of the WRF will be
developed to keep surface water runoff and sediment control requirements out of the
Beaver Creek drainage. As the waste rock dump area expands and extends into the
Beaver Creek drainage area, temporary WRF runoff diversion ditches will be
constructed to route and collect runoff away from Beaver Creek. Progress maps
showing the staging of the WRF and surface water diversion/sediment control
structures over the LOM are shown in Figures 16.4 through 16.13.
The preliminary WRF design includes foundation preparation and surface water
management features. Foundation preparation will involve cutting and removing trees
and underbrush, removal of topsoil for reclamation, and removal of any unsuitable
