Tailings
（重定向自Slickens）
![A panorama of Broken Hill, New South Wales, backed by the man-made tailings from the Line of Lode mine. The tailings heaps stretch across this image.](/Images/godic/202502/11/Broken_Hill_Town_&_Line_of_Lode_Pano,_NSW,_08.07.20072043.jpg")
![Yellow boy in a stream receiving acid mine drainage from surface coal mining.](/Images/godic/202502/11/Iron_hydroxide_precipitate_in_stream2043.jpg")
![Bauxite tailings near Stade (Germany)](/Images/godic/202502/11/Luftaufnahmen_Nordseekueste_2012-05-by-RaBoe-4782043.jpg")
![Emergency tailing ponds constructed in response to the 2015 Gold King Mine Spill in Colorado, pictured on August 7, 2015. The ponds were constructed to contain a spill created by EPA workers, while trying to install a cleanup system on the main tailing pond for the long closed mine.](/Images/godic/202502/11/Gold_King_Mine_Spill_Emergency_Retaining_Ponds2043.JPG")
Tailings, also called mine dumps, culm dumps, slimes, tails, refuse, leach residue or slickens, are the materials left over after the process of separating the valuable fraction from the uneconomic fraction (gangue) of an ore. Tailings are distinct from overburden, which is the waste rock or other material that overlies an ore or mineral body and is displaced during mining without being processed. The amount of tailings can be large, ranging from 90–98% for some copper ores to 20–50% of the other (less valuable) minerals.