麻豆淫院

All the critical minerals the U.S. needs annually for energy, defense and technology applications are already being mined at existing U.S. facilities, according to a new analysis in the journal Science.

The catch? These minerals, such as cobalt, lithium, gallium and rare earth elements like neodymium and yttrium, are currently being discarded as tailings of other mineral streams like gold and zinc, said Elizabeth Holley, associate professor of mining engineering at Colorado School of Mines and lead author of the new paper.

"The challenge lies in recovery," Holley said. "It's like getting salt out of bread dough鈥攚e need to do a lot more research, development and policy to make the recovery of these critical minerals economically feasible."

To conduct the analysis, Holley and her team built a database of annual production from federally permitted metal mines in the U.S. They used a statistical resampling technique to pair these data with the geochemical concentrations of critical minerals in ores, recently compiled by the U.S. Geological Survey, Geoscience Australia and the Geologic Survey of Canada.

Using this approach, Holley's team was able to estimate the quantities of critical minerals being mined and processed every year at U.S. metal mines but not being recovered. Instead, these valuable minerals are ending up as discarded tailings that must be stored and monitored to prevent environmental contamination.

"This is a brand-new view of 'low hanging fruit'鈥攚e show where each critical mineral exists and the sites at which even 1% recovery of a particular critical mineral could make a huge difference, in many cases dramatically reducing or even eliminating the need to import that mineral," Holley said.

The analysis looks at a total of 70 elements used in applications ranging from consumer electronics like cell phones to medical devices to satellites to renewable energy to fighter jets and shows that unrecovered byproducts from other U.S. mines could meet the demand for all but two鈥攑latinum and palladium.

Among the elements included in the analysis are:

• Cobalt (Co): The lustrous bluish-gray metal, a key component in electric car batteries, is a byproduct of nickel and copper mining. Recovering less than 10% of the cobalt currently being mined and processed but not recovered would be more than enough to fuel the entire U.S. battery market.
• Germanium (Ge): The brittle silvery-white semi-metal used for electronics and infrared optics, including sensors on missiles and defense satellites, is present in zinc and molybdenum mines. If the U.S. recovered less than 1% of the germanium currently mined and processed but not recovered from U.S. mines, it would not have to import any germanium to meet industry needs.

The benefits of enhanced recovery are not only economic and geopolitical but also environmental, Holley said鈥攔ecovering these critical minerals instead of sending them to tailings piles would reduce the environmental impact of mine waste and open more opportunities for reuse in construction and other industries.

"Now that we know which sites are low-hanging fruit, we need to conduct detailed analyses of the minerals in which these chemical elements reside and then test the technologies suitable for recovery of those elements from those specific minerals," Holley said.

"We also need policies that incentivize mine operators to incorporate additional processing infrastructure. Although these elements are needed, their market value may not be sufficient to motivate operators to invest in new equipment and processes without the right policies in place."