Rare Element Resources
Bear Lodge Project
Canadian NI 43-101 Technical Report
October 9
th
, 2014
10135-200-46 - Rev. 0
17-67
The Hydromet feed was defined based on the PUG mass balance for each year of
operation.
17.17 Model Parameters
Leach Unit
17.17.1
17.17.1.1
Total Hydrochloric Acid Addition
The total hydrochloric acid addition is adjusted to maintain a hydrochloric
acid concentration of 40 grams per liter in the PLS. A PLS free acid of
approximately 40 grams per liter is required to achieve optimal precipitation
in the Oxalate Precipitation Unit. This is representative of results shown by
the pilot plant PP6 operated by SGS Lakefield Inc..
17.17.1.2
Leach Reaction Temperature
The leach reaction temperature is established at 45 degrees Celsius as
presented in the pilot plants PP5, PP6 and PP7 operated by SGS Lakefield.
17.17.1.3
Leach Reactor Density
The pre-leach reactor density was established at 22 % solids. The pilot
plants PP5, PP6 and PP7 demonstrated that the leach reactor density was
not a critical parameter and that good leach efficiencies were achieved at
densities lower than 30% solids.
17.17.1.4
Leach Reaction Efficiency
Leach efficiencies were established by SGS Lakefield Inc. for five typical
feed composites. Each mine year composition was compared to the
composite composition and a leach efficiency dataset was attributed. The
assigned leach efficiency datasets are presented below:
1) Years 1 to 6: Composite D
2) Years 7 to14: Composite C
3) Years 15 to 19 and 23 to 26: Composite B
4) Years 20 to 22 and 27 to 45: Composite E
Leach efficiency datasets are presented in Table 17-21.
