Gold Mining: Processing Tonnes of Rock for Grams of Metal
Modern gold mining processes enormous volumes of low-grade ore through cyanide leaching, a real, tightly regulated chemical process, not simple panning.
Modern industrial gold mining bears almost no resemblance to a prospector’s pan. Typical ore grades run a few grams of gold per tonne of rock, sometimes less, which makes gold mining, like copper, fundamentally a bulk-processing operation.
Cyanide leaching: the dominant extraction chemistry
Crushed ore is treated with a dilute cyanide solution, which dissolves gold as a soluble complex that can then be separated and recovered, the dominant large-scale gold extraction method for over a century precisely because cyanide, among practical reagents, dissolves gold efficiently at low concentrations. This is a real, tightly regulated industrial process, subject to strict containment and water-treatment requirements in most jurisdictions because of cyanide’s toxicity, not an incidental detail.
Artisanal and small-scale mining, a real and separate supply stream
As with cobalt, a meaningful share of global gold production comes from artisanal and small-scale mining, often using mercury amalgamation instead of cyanide, a cheaper but more environmentally and health-hazardous method, a real, documented issue in several gold-producing regions that runs alongside, not instead of, the large-scale industrial sector.
Sources: cyanide leaching and ore grade figures draw on standard extractive metallurgy references (USGS, World Gold Council); production figures reference the production data elsewhere on this site.