The US Geological Survey (USGS) is now soliciting proposals for fiscal year 2024 cooperative agreements to collect data on mine waste. Mine waste represents a potentially valuable source of critical minerals and rare earth elements that were not targeted in prior mining operations and that can be developed without impacting sensitive and undeveloped lands.

This $5-million funding opportunity supports USGS efforts to build a national mine waste inventory and characterize mine waste at sites across the US. This competitive opportunity is supported by investments from the Bipartisan Infrastructure Law in the Earth Mapping Resources Initiative.

The USGS is investing $74 million per year in the Earth Mapping Resource Initiative to modernize the US’ mapping of potential mineral resources in the ground and in mine waste. Through collaboration between the USGS and state geological surveys across America, the initiative provides new geologic maps, geochemical sampling, and geophysical, topographic, and hyperspectral surveys.

This information will help the US more accurately identify critical minerals and rare earth elements contained in mine tailings and other mine waste.

Overall, the Bipartisan Infrastructure Law provides a $510.7-million investment in the USGS to advance scientific innovation and map critical minerals, including funding that has accelerated the Earth Mapping Resource Initiative program.

The Earth Mapping Resource Initiative provides science to evaluate the potential to extract valuable minerals from above-ground mine waste. It also supports partnering with state geological surveys to plan data acquisition by offering funding for state geological surveys to attend the annual Earth Mapping Resource Initiative planning workshop.

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, such as 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 investigated a legacy zinc mining district in Oklahoma to evaluate germanium and its mineralogical hosts in mine waste. Results indicated that weathering of mine waste at this site impacts germanium's mobility, bioaccessibility and potential for recovery.