Editing Open-pit mining (section)

==Typical open cut grades==
[[Gold]] is generally extracted in open-pit mines at 1 to 5&nbsp;ppm (parts per million) but in certain cases, 0.75&nbsp;ppm gold is economical. This was achieved by bulk [[heap leaching]] at the Peak Hill mine in western [[New South Wales]], near [[Dubbo]], [[Australia]].<ref>[http://www.dpi.nsw.gov.au/minerals/geological/initiatives/exploration/Minerals_program/major-metalic-mines "Peak Hill Gold Mine"] ''Major metallic mines, deposits & projects'' (2010) accessed 19 December 2011</ref>

[[Nickel]], generally as laterite, is extracted via open-pit down to 0.2%. [[Copper]] can be extracted at grades as low as 0.11% to 0.2%.