NI43-101Pre-Feasibility Study Report - page 487

Rare Element Resources
Bear Lodge Project
Canadian NI 43-101 Technical Report
October 9
th
, 2014
10135-200-46 - Rev. 0
18-31
year LOM TSF footprint, the pond area will be incorporated into the TSF grading plan
and liner footprint and replaced with a new collection pond down-gradient of the TSF
expansion. The conceptual pond layout and expansion sequence are shown on the
drawings.
The collection pond will function as an evaporation pond, where inflows from the TSF
from runoff and seepage approximately equal but do not exceed the potential
evaporation from the pond(s) on an annual basis. The pre-feasibility-level design
allows for operation and expansion plans for the TSF and assumes that no more than
35 acres of un-reclaimed areas will exist at any time within the TSF. A preliminary
water balance indicates that an un-reclaimed area of about 35 acres will require a
pond surface area of about 30 acres and an operating depth of about 2 feet to
prevent accumulation of inflows. Based on the water balance simulations, a pond size
of 30 acres will result in the pond drying up each fall, such that successive annual
accumulations are cyclic and do not accumulate. In addition, the collection pond will
have sufficient freeboard to store runoff from the 100-year, 24-hour design storm
event. Dissipation of the contact water inflows to the collection pond will be by
evaporation and reuse within the TSF for dust control.
18.2.7.4 TSF Operations
The Upton TSF is designed to operate as a dry stack facility and generally will include
the following activities:
Tailings transport, deposition, and management (including temporary cover
placement as needed);
TSF embankment and liner construction;
On-going TSF maintenance and reclamation
The operations at the TSF must ensure the following:
The basis of the design remains valid and design criteria are being achieved;
Changes in tailings production are accounted for;
Tailings geochemistry and physical properties are monitored and accounted for in
the event of changes from initial design criteria and values;
Tailings management and TSF construction planning takes into consideration the
availability of construction materials and seasonal constraints.
A) General Description
It is proposed to transport the neutralized waste material from the Hydromet plant to
the TSF using haul trucks. Waste blending and neutralization of the waste streams
will occur at the Plant prior to transport to the TSF. Active disposal areas and
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