Rare Element Resources
Bear Lodge Project
Canadian NI 43-101
Technical
Report
October 9
th
, 2014
10135-200-46 - Rev. 0
17-24
The nitrate reactors will operate at 90
o
C. Most of the energy to maintain this
temperature will come from heat transfer loop #2. Heat transfer loop #2 recovers
heat by cooling the REO solids in the rotary cooler (300-CLR-001). Heating coils
inside the mix tank (600-TAK-001) and reactor tanks (600-REA-010, 011) will be used
to heat the slurry. The nitrate tanks will also be equipped with steam coils to pre-heat
the reactors on start-up and maintain temperature as needed during operation.
Nitrate Leach Chemistry
Typical Rare Earth Nitrate reaction
RE
2
O
3
+ 6*HNO
3
→ 2*RE(NO
3
)
3
+ 3*H
2
O
Reaction Extent: 100%
In the above reaction, RE is a rare earth element or Yttrium.
Thorium Removal
17.8.2
Thorium precipitation is accomplished in two stages by the addition of ammonium
hydroxide. The REE nitrate solution is combined with a limited amount of 20%
ammonium hydroxide solution in reactor (600-REA-020). Thorium hydroxide is
precipitated along with small amounts of REE hydroxides. The precipitate is filtered
in filter press (600-PFT-001) and placed in containers for disposal. The REE nitrate
solution from filter (600-PFT-001) is combined a second time with a limited amount of
20% ammonium hydroxide solution to complete the precipitation of thorium from the
REE nitrate solution. This precipitate is filtered in filter press (600-PFT-002) and
recycled back to the nitric acid leach reactor #1 (600-REA-010). The second
precipitate is recycled back into the process because it contains a significant
percentage of REE hydroxides. The thorium removal process is unique and a patent
application titled:
“Extraction of Metals from Metallic Compounds” was filed by Rare
Element Resources Ltd. on January 18, 2014. Dr. Henry Kasaini, Director of Science and
Technology for Rare Element Resources, is named as inventor on the patent. This patent
combines an initial provisional patent on the “Rare Earth Element Extraction” process
technology, filed in January 2013, with another patent titled: “Extraction of Thorium from
Rare Earth Compounds and Related Methods” provisional patent, filed in November
2013.
Thorium Precipitation Chemistry
Thorium hydroxide precipitation
Th(NO
3
)
4
+ 4*NH
4
(OH) → Th(OH)
4
+ 4* NH
4
NO
3
Reaction Extent: 100%
The reaction extent is for both stages.
