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

Rare Earth Elements Review Section 7 – Summary, Key Findings, and Next Steps
7. Summary, Key Findings from Literature Review, and Potential
Next Steps
The purpose of this report is to serve as a technical information resource to policy makers and other
stakeholders who are concerned with the potential environmental and health effects and impacts that can
be identified across the REE supply chain. RTI conducted a search of the technical literature and other
Internet sources related to each segment of the supply chain, including recent initiatives of U.S.
government agencies that document issues associated with REE production, processing, manufacturing,
end uses, recycling, and health/ecological effects. Information contained in this report also draws upon
past domestic and international experience, as appropriate. The vast majority of information in this report
is current. But, as noted in this report, mining and extraction of REEs is dynamic. Therefore, some
details regarding who is producing what and where may have changed between the time when: (1) data
collection as part of the literature search for this report was complete in July 2011, (2) the report’s
contract was completed in September 2011, and (3) its subsequent publication in 2012.
Although the current literature provides limited information specifically relating to REE mining,
processing, recycling, and environmental or health impacts, it is expected that more information will be
produced in the future as a result of the increased level of interest in REEs in the past few years.
7.1 Summary
REEs include the series of 15 lanthanide metals, plus scandium and yttrium. REEs have become
increasingly important in recent years because their unique chemical and physical properties have
contributed to technological advances in many areas, such as wind turbines, hybrid electric vehicles,
energy-efficient lighting, computers and electronics, and defense applications such as lasers.
In 1984, the Molycorp Minerals, Inc. mine in Mountain Pass, CA, supplied 100 percent of U.S. demand
and 33 percent of the world’s demand for rare earths. The mine was shut down in 2002 for a variety of
reasons, and since that time, China has become the world’s leading producer of REEs, handling
approximately 95 percent of worldwide production. Due to the increase in demand and the reduction in
supply of REEs, the cost of REEs has increased dramatically in recent years. Given the strategic
importance, supply concerns, and increasing cost of REEs, REE mines outside China are currently being
evaluated or are in development, including multiple sites in the United States. Past producers of rare
earths are re-opening idle or closed mines, and active mines that produce other metals that usually send
rare earths as waste are now considering recovery of rare earth oxides.
Molycorp Minerals, Inc. is at the forefront as one of the first companies to reinitiate mining operations at
their existing Mountain Pass mine. Molycorp also is attempting to find better mineral processing methods
that allow recovery of more rare earth oxides from the ore at a lower cost and with less environmental
impact.
Outside of direct mining operations, other sources of rare earths are being explored, such as recovery
from recycling or urban mining. Currently, commercial recycling of rare earths is very limited; however,
it is reported in the literature that, within the next year, several new commercial recycling operations will
begin operation, with the focus being on magnets, batteries, lighting and luminescence, and catalysts.
Mining and processing activities have the potential to create a number of environmental risks to human
health and the environment. The severity of these risks is highly variable between mine and mine plant
operations. The contaminants of concern will vary depending on the REE-mineral ore, the toxicity of the
contaminants from the waste rock, ore stockpiles, and process waste streams. The mobility of
contaminants will be controlled by the characteristics of the geologic, hydrologic, and hydrogeologic
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