Editing Ore (section)

== Gangue and tailings ==
In most cases, an ore does not consist entirely of a single mineral, but it is mixed with other valuable minerals and with unwanted or valueless rocks and minerals. The part of an ore that is not economically desirable and that cannot be avoided in mining is known as [[gangue]].<ref name="Brit_Ore23"/><ref name="AGI" /> The valuable ore minerals are separated from the gangue minerals by [[froth flotation]], gravity concentration, electric or magnetic methods, and other operations known collectively as [[mineral processing]]<ref name="Wills-2015" /><ref>{{cite book |last1=Drzymała |first1=Jan |url=https://www.dbc.wroc.pl/Content/2070/Drzymala_mineral.pdf |title=Mineral processing : foundations of theory and practice of minerallurgy |date=2007 |publisher=University of Technology |isbn=978-83-7493-362-9 |edition=1st eng. |location=Wroclaw |access-date=24 September 2021}}</ref> or [[ore dressing]].<ref>{{cite book |last1=Petruk |first1=William |title=Mineral Processing Design |chapter=Applied Mineralogy in Ore Dressing |date=1987 |pages=2–36 |doi=10.1007/978-94-009-3549-5_2 |isbn=978-94-010-8087-3}}</ref>

Mineral processing consists of first liberation, to free the ore from the gangue, and concentration to separate the desired mineral(s) from it.<ref name="Wills-2015" /> Once processed, the gangue is known as [[tailings]], which are useless but potentially harmful materials produced in great quantity, especially from lower grade deposits.<ref name="Wills-2015" />