Sulfide Mining - Acid Mine Drainage
Sulfide Mining
Sulfide Mines with Acid-Producing Waste Rock Piles
A second threat to the environment is the mining and processing of copper, nickel, platinum, palladium, rhodium, silver and gold found in low concentrations in rock with sulfides that turn to sulfuric acid (like what's in a car battery) when exposed to air and water — as they are when they are mined. The result is mountains of waste rock (99+% of mined rock would be waste) that are expected to leak acid for unknown decades. The acid kills aquatic life that feed fish and amphibians, leaving the rivers and downstream lakes barren and unsafe. Water draining from the waste rock also (with or without acid) will leach toxic metals such as cobalt into the waters.
After the mines play out, the perpetual costs of treating polluted drainage and tending toxic wastes could fall on taxpayers because sulfide mines are "reactive" or acid producing for thousands of years.
Processing the ore to increase the metal concentrations would use a mixture of new and old technologies. Air and water pollution are also concerns with the processing. As proposed, smelters would not be part of the processing. Asbestos-like fibers that cause lung damage are a concern for some of the mines.
Sierra Club is working with MCEA, NWF, Friends of the Boundary Waters, and MEP on protecting people and the environment from sulfide mining in Minnesota.
- Sulfide mining fact sheet (pdf 310k)
- Michigan Sierra Club on sulfide mining
Legislative Watchdog Update
Water Sentinels - volunteers begin water testing in the Yellow Dog Plains
Sulfide Mining Work Group is Successful
- Eagle Alliance on Sulfide Mining in Michigan's Upper Peninsula
There are three potential sulfide mines in Minnesota: PolyMet, Teck Cominco and Birch Lake Mining (Franconia Minerals).