In their quest to secure critical mineral supply chains against the backdrop of surging demand and rising geopolitical pressures, stakeholders are leaving no stone unturned – quite literally — and have in fact begun turning the same stone twice.
As Australia’s Financial Post reports, the Australian government has completed a mapping project of sites containing mine waste with reprocessing potential.
The “Atlas of Australian Mine Waste“ was launched this week by Geoscience Australia in partnership with RMIT University, the University of Queensland, as well as geological surveys across the country.
As Minister for Resources and Northern Australia Madeleine King stated, “[s]ome of the minerals we need now, and into the future, may not just be in the ground—they’re also in rock piles and tailings on mine sites around the country.”
“These minerals might not have been of interest when first extracted but could now be in hot demand as the world seeks to decarbonize—for example, cobalt in the tailings of old copper mines.”
Acknowledging the potential held by mine waste and tailings, the U.S. Geological Survey (USGS) earlier this spring solicited proposals for FY2023 grants to collect data on mine waste, using funds from Bipartisan Infrastructure Act in the context of the Earth Mapping Resources Initiative (Earth MRI).
Earth MRI provides more than $74 million in new mapping funding each year to “modernize our understanding of the Nation’s fundamental geologic framework and improve knowledge of domestic critical-mineral resources both still in the ground and in mine waste.”
As announced this May, more than $5.8 million will go towards mapping critical-mineral resources in Alaska in partnership with the Alaska Division of Geological & Geophysical Surveys. Minerals included in the context of USGS and the Alaska Division of Geological & Geophysical Survey research projects Alaska are: Arsenic, antimony, bismuth, cobalt, graphite, indium, platinum group metals, rare earth elements tantalum, tellurium and tin.
Miners have long realized the potential of reprocessing tailings, and have already “made a business out of reprocessing old mine waste to extract metal, as part of a mine remediation process,” as the Financial Post reports. Many efforts have sprung up in recent years, and we’re featuring a few examples below:
In Australia, New Century Resources currently owns and runs the largest tailings retreatment operation at its zinc tailings retreatment operation in Queensland.
In the rare earths realm, Reuters lists six major projects outside of China aimed at extracting the critical minerals from waste or byproducts, including Iluka Resources Ltd’s and VHM Ltd’s operations in Australia, Rainbow Rare Earths Ltd’s endeavor in northeast South Africa, Swedish state-owned LKAB’s plans to extract REEs from two existing mines, and two U.S. operations:
Phoenix Tailings, a privately held U.S. company plans to launch operations using waste materials from a former iron ore mine in New York using its own processing technology.
U.S. Energy Fuels, originally focused on uranium production, started acquiring monazite, a byproduct of mineral sands, to extract REEs with plans to open its own separation plant by 2024.
Global miner Rio Tinto began producing tellurium at its Kennecott copper operation in Utah, where roughly 20 tons of the material are generated from by-product streams generated during the copper refining process. As America’s oldest copper mine, now in its 117th year of operations, there’s no telling how many critical minerals may reside in Kennecott’s historic waste piles.
In addition to recovering tellurium from Kennecott, after commencing production of battery-grade lithium from waste rock at a lithium demonstration site at its Boron mine site in California in 2021, the company last fall began partnering with CR Minerals Co. LLC in an effort to extract a material called pozzolans from the facility’s tailings, which can be substituted for or combined with cement to decarbonization construction materials. Meanwhile, in Canada, the miner is producing scandium from titanium waste, becoming the first North American producer of scandium in the process.
As the materials science revolution marches on and continues to unlock new technologies allowing for the safe and commercially viable recovery of mine waste tailings, harnessing this – to date largely untapped — potential could play a significant role in a comprehensive “all-of-the-above” approach to bolstering critical mineral supply chains.