"LEADVILLE, Colo. — Rust-colored piles of mine waste and sun-bleached wooden derricks loom above the historic Colorado mountain town of Leadville — a legacy of gold and silver mines polluting the Arkansas River basin more than a century after the city’s boom days.
Enter a fledgling company called CJK Milling that wants to “remine” some of the waste piles to squeeze more gold from ore discarded decades ago when it was less valuable. The waste would be trucked to a nearby mill, crushed to powder and bathed in cyanide to extract trace amounts of precious metals.
The proposal comes amid surging global interest in re-processing waste containing discarded minerals that have grown more valuable over time and can now be more readily removed. These include precious metals and minerals used for renewable energy that many countries including the U.S. are scrambling to secure."