A polluted tailings pond at the Kennecott Utah mine has sunk 20 feet or more, raising concerns that it has seeped contamination into the neighboring Great Salt Lake.

The salt at the Camp Verde Mine occurs as transparent crystalline cubes of halite, some weighing in excess of 20 pounds.

The expansion permits Signal Peak Energy to extract nearly 60 million tons of coal from the Bull Mountains mine north of Billings.

Compass Minerals International Inc.‘s board and top executives agreed to appoint a new chief accounting officer to end a ...