Editing Open-pit mining (section)

===Waste===
Open-pit mines create a significant amount of waste. Almost one million tons of ore and waste rock can move from the largest mines per day, and a couple thousand tons moved from small mines per day.<ref name=eb /> There are generally four main operations in a mine that contribute to this load: [[drilling]], blasting, loading, and [[hauling]].

Waste rock is hauled to a waste dump. Waste dumps can be piled at the surface of the active pit, or in previously mined pits.

Leftover waste from processing the ore is called [[tailings]], and is generally in the form of a [[slurry]]. This is pumped to a [[tailings dam]] or settling pond, where the water is reused or evaporated. Tailings dams can be [[toxic]] due to the presence of unextracted [[sulfide]] [[minerals]], some forms of toxic minerals in the [[gangue]], and often [[cyanide]] which is used to treat [[gold]] ore via the [[Gold cyanidation|cyanide leach process]]. If proper environmental protections are not in place, this toxicity can harm the surrounding environment.<ref>[http://ec.europa.eu/environment/waste/mining/index.htm "Mining Waste"] ''European Commission Environment'' (17 November 2011) accessed 19 December 2011</ref>