Acid mine drainage, acid and metalliferous drainage (AMD), or acid rock drainage (ARD) is the outflow of acidic water from metal mines and coal mines.
Rio Tinto in Spain presents an acid drainage of both natural and artificial origin (mining)
Rocks stained by ferrous precipitate from acid mine drainage on Shamokin Creek in Northumberland County, Pennsylvania
In this case, the pyrite has dissolved away yielding a cube shape and residual gold. This break down is the main driver of acid mine drainage.
Yellow boy in a stream receiving acid drainage from surface coal mining
Coal mining is the process of extracting coal from the ground or from a mine. Coal is valued for its energy content and since the 1880s has been widely used to generate electricity. Steel and cement industries use coal as a fuel for extraction of iron from iron ore and for cement production. In the United Kingdom and South Africa, a coal mine and its structures are a colliery, a coal mine is called a "pit", and above-ground mining structures are referred to as a "pit head". In Australia, "colliery" generally refers to an underground coal mine.
A coal mine mantrip at Lackawanna Coal Mine in Scranton, Pennsylvania
Coal miners exiting a winder cage at a mine near Richlands, Virginia in 1974
Surface coal mining in Wyoming, U.S.
A coal mine in Frameries, Belgium
