Rare Element Resources
Bear Lodge Project
Canadian NI 43-101 Technical Report
October 9
th
, 2014
10135-200-46 - Rev. 0
17-70
17.17.2.3
Rare Earths Oxalates Calcination Efficiency
The rare earths oxalates calcination reaction is a generic thermal
oxidation reaction with a typical efficiency of 100% for each oxalate
compound. The reaction extent is a function of the temperature of the
calcination, the excess oxygen and the residence time of the
equipment.
Thorium Removal Unit
17.17.3
17.17.3.1
Nitric Acid Leach Reaction Temperature
The nitric acid leach reaction temperature is established at 90
degrees Celsius.
17.17.3.2
Nitric Acid Leach Efficiency
The nitric acid leach reaction is a generic oxide acidic leach reaction
and is well documented in the literature. The leach efficiency was
established at 100% considering that enough residence time will be
maintained in the leach reactors.
17.17.3.3
Thorium Precipitation Reaction Stage 1 and 2 Temperature
The thorium precipitation stage 1 reaction temperature is established
at 25 degrees Celsius.
17.17.3.4
Thorium Precipitation Reaction Stage 1 and 2 Efficiency
Precipitation Efficiencies were established by SGS Lakefield Inc.
during pilot plant operation. In this process, thorium is precipitated as
thorium-hydroxide by neutralization of the nitric acid PLS using
ammonium hydroxide. Stage 1 pH is controlled to 3.7 and Stage 2 pH
is controlled to 4.8. The thorium precipitation efficiencies are
presented in Table 17.23.
