Rare Element Resources
Bear Lodge Project
Canadian NI 43-101 Technical Report
October 9
th
, 2014
10135-200-46 - Rev. 0
17-1
Recovery Methods
17
17.1 Process Summary
The Rare Earth processing facility is designed with two distinct unit operations, a
Physical Upgrading (PUG) plant, which is designed to maximize the rare earth
recovery into a pre-concentrate; and a Hydrometallurgical plant (Hydromet), which is
designed to extract the rare earths and produce a pure mixed REO powder.
In order to defray capital and operating expenditures, most of the PUG plant will not
be constructed until year 9 of the project. The mine plan employs selective methods
to provide the Hydromet plant with higher grade ores in the first nine years of
operation that do not require pre-concentration. Therefore, the construction and
operation of the PUG and Hydromet plants will be conducted in two phases.
PHASE I - Years 1-9
Ore will be dry crushed and screened to 3” size at the PUG plant. Plus 3” material
will be stored in a low grade stockpile. Minus 3” material will be transported to the
Hydromet plant for wet crushing and screening to -48 mesh size, and then fed to the
Hydromet process (no pre-concentration).
PHASE II - Years 10+
Prior to production year 10, the PUG plant construction will be completed, and the
processing of lower & medium grade ores will begin.
The PUG process employs a series of crushing, washing, screening, and separation
steps to concentrate the REO minerals and reduce the physical mass of the ore sent
to the Hydromet plant. As discussed in Chapter 8, Deposit Types, there are four
major ore types, Bull Hill Oxide Carbonate (OxCa), Bull Hill Oxide (Ox), White Tail
Oxide Carbonate (OxCa) and White Tail Oxide (Ox). These ore types are further
classified as High-Grade (HG), Mid-Grade (MG), and Low-Grade (LG). Each of these
ore types has a different upgrade percentage and mass reduction in the PUG circuit.
Because the mining plan will encounter each of these ore types within any given
bench, the PUG circuit is designed with the flexibility to process each ore type with a
nominal capacity of 1,600 short tons (1,451 tonnes) per day.
The Hydromet plant is designed for a nominal capacity of approximately 9,000 short
tons per year REO product that will vary year to year depending on feed grades and
feed tonnage. The Hydromet process uses hydrochloric acid to leach the REE from
