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Fig. 1 - High-grade gold ore from a quartz vein near Alma, Colorado.
Small flecks of gold visible, but much more is hidden
microscopically within the rock requiring chemical extraction. |
Gold; arguably one of the most valuable metals on Earth. This yellow metal is soft, dense, malleable and ductile. Common uses include as jewelry (can be buffed to give off a bright luster), great investment potential, electronics, and even medicine. However, despite its useful characteristics, gold is very rare, and in small quantities (fig. 1). Because of this, the lengths some companies go to to obtain it is very extreme. Other than striking lucky and panning for gold in a river, the only way to economically obtain large amounts of gold is via mining, and one method of this process is using gold cyanidation (e.g.
Rees and Van Deventer, 1999). This process, while effective, can also be dangerous and affect the environment negatively.
While the methods we use to extract gold from ore is rather cost efficient and effective, it is not exactly the most environmentally friendly. The two biggest factors in this process that makes it harmful and potentially dangerous is the toxic nature of the chemical cyanide (e.g.
Cooper and Brown, 2008), and how the disposal of the byproducts can cause acid mine drainage (e.g.
Hoffert, 1947)
