Acid mine drainage where the ore is a sulfide mineral or is associated with pyrite. In these cases the predominant metal ion may not be iron but rather zinc, copper, or nickel. The most commonly mined ore of copper, chalcopyrite, is itself a copper-iron-sulfide and occurs with a range of other sulfides. Thus, copper mines are often major culprits of acid mine drainage. At some mines, acidic drainage is detected within 2–5 years after mining begins, whereas at other mines, it is not detected for several decades. In addition, acidic drainage may be generated for decades or centuries after it is first detected.
Western Ore Mountains Western Ore Mountains The Western Ore Mountains () is a natural region that forms the westernmost part of the Ore Mountains in the German federal state of Saxony. It is also part of the major landscape unit known as the Saxon Highlands and Uplands. It extends eastwards to include the valley of the Schwarzwasser, and, below its mouth, that of the Zwickauer Mulde, and incorporates the western parts of the former major units known as the Lower and Upper Western Ore Mountains ("Unteres und Oberes Westerzgebirge"), no. 423, as well as the Southern Slopes of the Ore Mountains ("Südabdachung des