Rare Element Resources
Bear Lodge Project
Canadian NI 43-101 Technical Report
October 9
th
, 2014
10135-200-46 - Rev. 0
17-56
Transportation delays are expected from bad weather during the winter.
Control and Automation
17.9.6
The PUG and Hydromet Plants will be semi-automated. All equipment and stream
flows will be automated and primarily controlled from the control room. Local
controls will also be installed where required. Laboratory technicians will manually
perform chemical analyses such as rare earth product element distribution and
tailings elemental distribution.
Measurements such as pH will be automated, but a constant manual validation of
the instruments will be required to ensure the proper processing of the rare earths.
A data historian system connected to the DCS will enable the collection of data
centrally from across the plant.
Radionuclides
17.9.7
There are two main sources of radionuclides (thorium and uranium) the Bull Hill and
Whitetail mine mineralization. These radionuclides are closely associated with rare
earths and therefore will be transferred to the pre-concentrate together with REO
minerals
At the acid digestion step, most of the radionuclides will be leached out of the solids
and transferred to into the leach solution such that less than 0.05%Th+U will remain
in the leach residue. Subsequently, all the thorium isotopes in the leach solution will
be co-precipitated with rare earths into the final oxalate precipitate. The average
assay of Th+U in the oxalates will vary from 0.4 to 1.9%Th+U.
A thorium removal step is incorporated in the Hydromet process. Thorium recovery
from rare earth oxalate precipitates and handling of isolate thorium hydroxide will
occur in a restricted access area of the plant and will be packaged and sealed in B-
12 size containers and shipped to the Richland, WA radioactive disposal site.
Once processed in the Hydromet, the acidic tailings containing combined
radionuclides will be neutralized with limestone and quick lime, and report to the
tailings storage facility. The radionuclide content will be below 0.05%.
The radionuclide content reporting to the rare earth oxide concentrate is at levels
below 0.0065%.
