Rare Earth Elements: A Review of Production, Processing ...

Rare Earth Elements Review Section 3 – Life-Cycle Stages of Rare Earth Elements Mines
As of the issuance of this report, the EPA is currently working on a methodology that will be used to
determine the level of financial responsibility requirements that will be imposed on the mine or mine
facility owner under Section 108(b) of CERCLA.
Current and Prospective Mine Development Activity
Rare earths are often a constituent in ores processed to recover other metal or mineral commodities. The
demand for rare earths may create opportunity for these mines to consider expanding their operations to
produce rare earths in addition to their primary commodity. Expansion of mining operations and changes
to milling and processing operations may require environmental review and additional permitting for
these active mining operations.
In addition to rare earth production from current mining sites, it could become profitable for operations to
resume at former mine locations. These may be mines with active permits that are currently not in
operation due to the current market value of the principal commodity mined, or closed mines where ore
remains but no mining is occurring, equipment has been removed, and possibly some level of reclamation
has been started or completed. Stockpiles of subeconomic ore, or potentially the waste tailings, may now
represent a rich source of ore for REEs that can help the mine transition back into production as the mine
site is re-developed. Most of the prospective REE mines in the United States include those that produced
REE ores in the past (e.g., Molycorp Mineral’s mine in Mountain Pass, California) or produced another
commodity from an ore containing REEs (e.g., Pea Ridge iron ore mine). Some exploration may be
required, or enough existing data may be available to begin planning the re-opening of the mine. Most of
the activities required for the mine development stage will be needed to reopen the mine. In some cases,
the environmental impacts from past mining activities and practices will need to be considered in
development of the new mining operation.
Development activity is currently occurring at two locations in the conterminous United States to reopen
idle mines. These include the Molycorp mine in California (as previously discussed) and the Pea Ridge
mine in Washington County, Missouri. Pea Ridge is a $1 billion dollar project that is underway in
Missouri to reopen the existing Pea Ridge mine and to begin construction of a processing plant for
magnetite iron ores (Baranyai, 2011). The iron ore processing plant will be located 1 mile from the mine,
and ore will be pumped through a pipeline to the plant. A St. Louis-based company (Wings Enterprises,
Inc.), with support from Glencore International AG of Baar, Switzerland, was developing plans around
the opening of the Pea Ridge Mine, and, in early 2012, had expected to start producing rare-earth minerals
from holding ponds left by previous mining activity and also from newly mined ores (Wings Enterprises,
2011). Wings Enterprises had estimated that underground mining may extract as much as 5,000 tons of
rare earths in 3 years. In addition to construction activities, planning and feasibility studies were under
way for the joint iron ore and REE mining operations in Missouri. However, Pea Ridge Resources, Inc.
recently purchased the mine from Upland Wings/Wings Enterprises. No additional information was
provided on the company’s website to determine when or if REE resource planning and/or production
will resume or continue (Pea Ridge Resources, 2012).
3.3.2.3 Construction and Mining (Mineral Extraction)
Once regulatory approvals have been acquired, construction can begin on waste management and
processing areas, followed by the commencement of mining activities. The mining methods that might be
used to recover REE ores are not different from hardrock or placer mining operations used for extracting
other metal ores. The EPA defines a hardrock mine in accordance to the BLM definition:
“(as extracting) Locatable minerals that are neither leasable minerals (oil, gas, coal, oil
shale, phosphate, sodium, potassium, sulfur, asphalt, or gilsonite) nor saleable mineral
materials (e.g., common variety sand and gravel). Hardrock minerals include, but are not
limited to, copper, lead, zinc, magnesium, nickel, tungsten, gold, silver, bentonite, barite,
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