Rare Element Resources
Bear Lodge Project
Canadian NI 43-101 Technical Report
October 9
th
, 2014
10135-200-46 - Rev. 0
18-23
density of 100 pcf. The TSF capacity can be increased as needed by placing the
tailings to a higher elevation and/ or extending the TSF footprint westward.
The major components of the proposed TSF are:
•
A perimeter containment berm;
•
A composite liner system over the impoundment area;
•
A collection pond for management of excess contact water (e.g., seepage
and runoff) from within the TSF
The perimeter containment berm is designed as a side-hill, homogeneous earthen
dam constructed of compacted clay soils excavated from within the TSF. The TSF
liner system will be a composite liner system consisting of a 12-inch thick low
permeability compacted soil liner directly overlain with an 80-mil HDPE liner. A
protective cover layer overlies the liner system. The collection pond will be composite
lined and will function as an evaporation pond to remove excess water from the
system. Should the Hydromet plant require makeup water, the collection pond
capacity can be reduced and excess water routed to the Hydromet plant for potential
reuse.
Construction of the TSF will be phased over the life of the project with start-up
facilities constructed at the north end of the TSF footprint and expanded southward.
The rate of dry tailings reporting to the TSF, including neutralization amendments, will
vary year to year with the minimum tonnage of 254,542 tons reporting in Year 45 and
the maximum tonnage of 422,449 tons reporting in Year 10. The average yearly
production of dry tailings, including neutralization amendments is 350,198 tons per
year (tpy). The start-up TSF configuration will allow for approximately 1.5 years of
operation of the Hydromet plant with a total dry tailings storage capacity of 464,158
tons. Expansions will occur in operating years 1 and 3 to provide sufficient space for
continued operations through Year 8 with vertical expansion of the tailings pile. The
next two expansions will be in operating years 7 and 16 and will provide storage
through Year 20. The estimated TSF capacity includes amendments added to the
tailings for neutralization prior to placement in the TSF. Starting in Year 20, it is
assumed that expansions will be required approximately every four (4) years for
preliminary planning and cost estimating purposes. It is estimated that in Year 7 plans
will be developed for reclamation of completed tailings slopes and will then continue
concurrently with tailings deposition operations. It is intended that the active area of
the TSF not exceed 35 acres to limit the contact water management from the TSF
and mitigate environmental concerns such as dust emissions from windblown tailings.
The start-up configuration and initial expansion schedules are not likely to change,
