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Separating the valuable elements from the gangue requires mining, crushing and grinding and concentration using heavy, robust, energy-gobbling machinery plus considerable water and/or exotic chemicals that may or may not perform safely or efficiently in outer space.

These elements generally occur, combined physically or chemically, as a tiny, tiny, tiny fraction of heavy, bulky, relatively worthless but intimately associated rock material known as gangue.

The coastal city of Gangue will be used for the figure skating, curling, ice hockey, speed and short-track skating events, while the alpine town of Pyeongchang will stage mountain events such as skiing, sliding and Nordic events.

China is the only country apart from Russia to use raw coal production rather than sales to calculate overall output, which fails to account for the losses that accrue during processing and transportation and also ignores waste products like gangue, which could account for around 18 percent of raw coal output.

When the vein-stuff has been raised it is reduced to a pulverulent condition, to liberate the gold from the gangue.