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

Rare Earth Elements Review Section 1 – Introduction
1. Introduction
1.1 Background
Rare earth elements (REEs) are a group of 15 chemical elements in the periodic table, specifically the
lanthanides. Two other elements, scandium and yttrium, have a similar physiochemistry to the
lanthanides, are commonly found in the same mineral assemblages, and are often referred to as REEs.
Although relatively abundant in the earth’s crust, REEs rarely occur in concentrated forms, making them
economically challenging to obtain. These elements constitute critical components of many important
technologies and products, such as hybrid vehicles, wind turbines, and cell phones. Given this global
demand for green and sustainable products in energy, military, and manufacturing industries, REE
demand in the United States and throughout the world is projected to increase.
In recent years, China has been providing 95 to 97 percent of REEs worldwide. Because China has
demonstrated its ability to control and limit REE exports, it is crucial that the United States expand its
ability to obtain REE resources. Mining in the natural environment is the primary means of REE
acquisition; however, it results in a large quantity (greater than 90 percent) of excess and unused materials
and other environmental impacts. If the United States is to ensure a continuous supply of REEs,
responsible mining practices will need to be developed and enhanced. Additionally, effective recycling,
recovery, and reuse of spent consumer and industrial products may reduce the need to develop new
mineral resource areas.
To obtain up-to-date information on the environmental aspects and potential impacts of REE mining,
recovery, recycling, and reuse, the U.S. Environmental Protection Agency (EPA) Office of Research and
Development’s (ORD’s) Engineering Technical Support Center contracted with RTI International (RTI)
to conduct a literature review and to develop this report.
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. This document is not a life-cycle assessment or a risk
assessment. However, it does, to the extent possible based on anticipated, proposed, or past practices,
attempt to identify environmental compartments (i.e., aquatic environment, terrestrial environment, and
air) that may be at risk and the corresponding environmental loads (e.g., raw material consumption, air
emissions, water discharges, wastes), when that information is available in the literature or an association
can be made with anticipated, current, and past practices.
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 (i.e., U.S. Geological Survey
[USGS], U.S. Department of Energy [DOE], and the EPA) 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 (United Nations
Environment Programme [UNEP]), as appropriate.
1.2 Report Organization
This report is organized into eight sections and appendices, as follows:
� Section 1 provides the overall background for the project.
� Section 2 provides general background information on REEs, including information on their uses,
their reserves in the United States, and their current supplies and demand worldwide.
� Section 3 provides information on REE mining operations and potential environmental impacts.
1-1