NI43-101Pre-Feasibility Study Report - page 489

Rare Element Resources
Bear Lodge Project
Canadian NI 43-101 Technical Report
October 9
th
, 2014
10135-200-46 - Rev. 0
18-33
should be sufficient for waste transport and deposition over the life of the facility,
assuming operations during dayshift hours only.
Deposition will generally be limited to an area commonly no more than 250 feet long
extending either into the TSF area from the main embankment and progress
southeastward or parallel to the TSF embankment alignment and progress
southwestward. The tailings will be placed and spread in lifts about four to seven feet
thick. In this way, the tailings dry stack will be developed using a bottom-up
construction approach that will cover the active footprint area prior to expanding
vertically by more than two or three lifts, pending detailed stacking plans. As the
tailings pile rises vertically and horizontally to cover the lined area with at least one lift
of material, tailings may be end-dumped near the crest of the working face and
pushed outward. Temporary operational side slopes are estimated to be 3.5H:1V for
operating stability purposes. The final design grade of permanent tailings slopes is
estimated to be no steeper than 5H:1V.
18.2.7.4.2TSF Cover
In order to minimize the potential for fugitive dust releases and/or erosion from runoff,
active tailings deposition operations at the TSF (i.e., areas operationally prepared to
receive tailings) will be limited to no more than 35 acres at any given time. Significant
dust and/or particulate matter, originating from winds, vehicular traffic, and
operational equipment, are not anticipated to be problematic due to the mineralogy
and crystallization of the tailings from the Hydromet plant. Additionally, some degree
of cementation is anticipated because of the neutralization of the tailings. Sections of
the active area that remains dormant for more than 60 days will receive a 6-inch soil
cover as needed to protect against wind and runoff erosion. This cover can remain in
place when operations resume in the area.
Once the TSF expands to the initial 35-acre active area, reclamation of completed
areas will begin concurrently with the TSF expansion. The completed areas will be
covered and reclaimed per guidelines in the LQD Non-coal Rules and Regulations
and approved TSF permit conditions. Once initial reclamation catches up to the active
TSF area, it is assumed that general TSF operations within the 35-acre active area
will include up to 10 acres of ongoing reclamation.
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