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.
Ore Raththam 1987. N. Krishnaswamy of "The Indian Express" liked the film because "most of the characters get a say, the focus shifts to each of them one time or another". He also praised the narration, dialogue, background score, camera work, and editing. Ore Raththam Ore Raththam () is a 1987 Indian Tamil-language film directed by Swarnam and written by M. Karunanidhi. The film stars Karthik, BhagyalakshmiMadhuri, Kishmu, Manorama, Pandian, Seetha, M. K. Stalin and Radha Ravi. It is based on Karunanidhi's story of the same name, which was serialised in the magazine "Kungumam". "Ore Raththam" was a story which was serialised