Old coal mines' acid drainage could be used in batteries

New Yorker illustration by Leif Gann-Matzen

For decades, acid mine drainage from old coal mines, called "red dog" by locals, has polluted Appalachian creeks and rivers and killed or damaged their aquatic life. But recent research has found that this drainage "contains critical minerals and materials, including cobalt, manganese, and lithium, and rare-earth elements, such as neodymium," Eliza Griswold reports for The New Yorker. "These are essential to a wide range of high-tech products, including the magnets used in wind turbines and the ultra-lightweight batteries used in computers, smartphones, and a variety of modern weaponry."

These materials are mined in problematic places such as Congo, which is known to use forced child labor, and in China, which tightly controls production and exports. "This model is bad for the American economy, and it creates challenges for supply chains, as well as for national security, since it requires the U.S. to outsource the development and manufacturing of certain sensitive technologies to Chinese factories," Griswold reports. "In the past several years, however, American scientists have succeeded in extracting critical minerals and materials from coal waste. If this effort proves efficient and effective, we may be able to simultaneously clean up polluted places and secure access to rare resources. These resources could then be used to bring sensitive manufacturing back to the U.S., provide supplies used for military technologies, and help create more sustainable energy sources."