RARE EARTH ELEMENTS (REEs)Looking for Critical Minerals in Mine Waste
Mine waste is the material left over after mining. It consists of tailings, the material that remains after mined ore is milled and concentrated, as well as the topsoil, waste rock and other materials that were removed to get to the ore. Some critical-mineral commodities, like rare earth elements, are known to occur alongside more commonly mined minerals like iron or nickel. Because of this, mine-waste sites are now being revisited.
The U.S. Geological Survey (USGS) is soliciting proposals for Fiscal Year (FY) 2023 grants to collect data on mine waste. This new competitive program is supported by investments from the Bipartisan Infrastructure Law in the Earth Mapping Resources Initiative (Earth MRI).
Earth MRI is a partnership between the USGS and state geological surveys across America to modernize our understanding of the U.S. fundamental geologic framework and mineral resources. Earth MRI is providing new geologic maps, geochemical sampling and geophysical, topographic, and hyperspectral surveys. The Bipartisan Infrastructure Law provided additional funding that has accelerated this new mapping in areas with potential for critical-mineral resources both still in the ground and in mine wastes.
With the new Bipartisan Infrastructure Law funding, Earth MRI will provide science to evaluate the potential to extract valuable minerals from above-ground mine waste. This $5 million funding opportunity supports USGS efforts to build a national mine-waste inventory and characterize mine waste at sites across the nation. It also supports partnering with state geological surveys to plan Earth MRI data acquisition.
Mine waste is the material left over after mining. It consists of tailings, the material that remains after mined ore is milled and concentrated, as well as the topsoil, waste rock and other materials that were removed to get to the ore.
Some critical-mineral commodities, like rare earth elements, are known to occur alongside more commonly mined minerals like iron or nickel. Because of this, mine-waste sites are now being revisited to see if the waste has potential for critical-mineral commodities that were not a primary product of the original mining. Understanding what is in these waste materials also helps identify potential hazards of reprocessing mine wastes and opportunities for remediation.
For example, the USGS revisited legacy iron mines in the Adirondack Mountains of New York to determine if rare earth elements might occur there. Results indicated significant potential that merits further exploration, especially for the less common heavy rare earth elements.
Earth MRI is investing $74 million per year to modernize the Nation’s mapping of the potential for mineral resources both still in the ground and in mine waste. Overall, the Bipartisan Infrastructure Law provides a $510.7 million investment to the USGS to advance scientific innovation and map critical minerals.
More information on Earth MRI can be found here.
