Editing Mining (section)

===Waste===
{{Further|Tailings}}[[File:Teghut Mine - waste rock storage.jpg|thumb|right| Location of waste rock storage (center) at Teghut (village) Copper-Molybdenum Mine in [[Armenia]]'s northern Lori province]]
Ore mills generate large amounts of waste, called [[tailings]].<ref>{{Cite journal |last1=Zvereva |first1=V. P. |last2=Frolov |first2=K. R. |last3=Lysenko |first3=A. I. |date=2021-10-13 |title=Chemical reactions and conditions of mineral formation at tailings storage facilities of the Russian Far East |url=https://mst.misis.ru/jour/article/view/289 |journal=Gornye Nauki I Tekhnologii = Mining Science and Technology (Russia) |volume=6 |issue=3 |pages=181–191 |doi=10.17073/2500-0632-2021-3-181-191 |s2cid=243263530 |issn=2500-0632 |doi-access=free |access-date=2022-11-03 |archive-date=2022-07-08 |archive-url=https://web.archive.org/web/20220708171644/https://mst.misis.ru/jour/article/view/289 |url-status=live }}</ref> For example, 99 tons of waste is generated per ton of [[copper]], with even higher ratios in [[gold mining]] – because only 5.3 g of gold is extracted per ton of ore, a ton of gold produces 200,000 tons of tailings.<ref>{{cite web|title = What is the Cost of Mining Gold?|url = http://www.visualcapitalist.com/what-is-the-cost-of-mining-gold/|website = Visual Capitalist|access-date = 2015-06-11|date = 2013-05-21|archive-date = 2015-06-12|archive-url = https://web.archive.org/web/20150612164752/http://www.visualcapitalist.com/what-is-the-cost-of-mining-gold/|url-status = live}}</ref> (As time goes on and richer deposits are exhausted – and technology improves – this number is going down to .5 g and less.) These tailings can be toxic. Tailings, which are usually produced as a [[slurry]], are most commonly dumped into ponds made from naturally existing valleys.<ref name=EPADesignDams>US EPA. (1994). [http://www.epa.gov/osw/nonhaz/industrial/special/mining/.../tailings.pdf Technical Report: Design and Evaluation of Tailings Dams]{{dead link|date=November 2016}}.</ref> These ponds are secured by impoundments ([[dam]]s or [[embankment dam]]s).<ref name=EPADesignDams/> In 2000 it was estimated that 3,500 tailings impoundments existed, and that every year, 2 to 5 major [[Tailings dam failure|failures]] and 35 minor failures occurred.<ref name="StewardDams" /> For example, in the [[Marcopper mining disaster]] at least 2 million tons of tailings were released into a local river.<ref name=StewardDams>TE Martin, MP Davies. (2000). [http://www.infomine.com/publications/docs/Martin2000.pdf Trends in the stewardship of tailings dams] {{Webarchive|url=https://web.archive.org/web/20160303193659/http://www.infomine.com/publications/docs/Martin2000.pdf |date=2016-03-03 }}.</ref> In 2015, [[Barrick Gold]] Corporation spilled over 1 million liters of [[cyanide]] into a total of five rivers in Argentina near their [[Veladero mine]].<ref>{{Cite news|url = https://www.reuters.com/article/us-barrick-gold-mine-argentina-exclusive/exclusive-barrick-faces-sanctions-for-argentina-cyanide-spills-judge-says-idUSKBN1841BK|title = Exclusive: Barrick faces sanctions for Argentina cyanide spills|newspaper = Reuters|date = 2017-05-08|access-date = 2019-06-21|archive-date = 2021-10-09|archive-url = https://web.archive.org/web/20211009182319/https://www.reuters.com/article/us-barrick-gold-mine-argentina-exclusive/exclusive-barrick-faces-sanctions-for-argentina-cyanide-spills-judge-says-idUSKBN1841BK|url-status = live}}</ref> Since 2007 in central Finland, the Talvivaara Terrafame polymetal mine's waste effluent and leaks of saline mine water have resulted in ecological collapse of a nearby lake.<ref>{{Cite journal|last1=Leppänen|first1=Jaakko Johannes|last2=Weckström|first2=Jan|last3=Korhola|first3=Atte|date=2017-09-05|title=Multiple mining impacts induce widespread changes in ecosystem dynamics in a boreal lake|journal=Scientific Reports|volume=7|issue=1|page=10581|doi=10.1038/s41598-017-11421-8|pmid=28874843|pmc=5585241|issn=2045-2322|bibcode=2017NatSR...710581L}}</ref> Subaqueous tailings disposal is another option.<ref name=EPADesignDams/> The mining industry has argued that submarine tailings disposal (STD), which disposes of tailings in the sea, is ideal because it avoids the risks of tailings ponds. The practice is illegal in the [[United States]] and [[Canada]], but it is used in the developing world.<ref>Coumans C. (2002). [http://www.bostgroup.com.au/images/mining/Submarine-Tailings-Disposal-Toolkit.pdf Mining's Problem with Waste] {{Webarchive|url=https://web.archive.org/web/20170706213221/https://www.bostgroup.com.au/images/mining/Submarine-Tailings-Disposal-Toolkit.pdf |date=2017-07-06 }}. MiningWatch Canada.</ref>

The waste is classified as either sterile or mineralized, with acid generating potential, and the movement and storage of this material form a major part of the mine planning process. When the mineralised package is determined by an economic cut-off, the near-grade mineralised waste is usually dumped separately with view to later treatment should market conditions change and it becomes economically viable. [[Civil engineering]] design parameters are used in the design of the waste dumps, and special conditions apply to high-rainfall areas and to seismically active areas. Waste dump designs must meet all regulatory requirements of the country in whose jurisdiction the mine is located. It is also common practice to rehabilitate dumps to an internationally acceptable standard, which in some cases means that higher standards than the local regulatory standard are applied.<ref name="StewardDams" />