Wharf (Foley Ridge) gold mine

Wharf is an open-pit mining operation located in the northern Black Hills region, a few kilometres south-east of the Homestake mine, in South Dakota.The mine utilises conventional truck-and-loader mining methods with the ore processed on five heap leach pads, prior to the pregnant leach solution reporting to the carbon-in-column circuit, the loaded carbon is then transferred to the elution circuit, the precious metals are then stripped from the loaded carbon using a modified Zadra process, before passing through the electrowinning circuit to produce an electrolytic sludge containing approximately 90-98% precious metals, this is then dewatered, packaged and shipped to a refinery for further processing. The current reserve estimates include the Green Mountain and Portland Ridgeline pits but numerous open pits have been mined at the deposit over more than 30 years, including Annie Creek, Juno, Foley, Portland, West Portland, Deep Portland, Trojan and American Eagle.