Global Gold Mining and Processing: Environmental and Social Impacts
Review of publicly available academic, industry, and NGO research as well as first-hand personal accounts of the impacts of gold mining and processing.
Summary:
- Gold has high value in human society, as it has for thousands of years
- However, gold’s natural chemistry and geology results in gold ore being widely distributed in small quantities throughout the world
- The two primary processes for extracting gold, cyanidation (for large-scale mines), and mercury amalgamation (for small-scale mines), are highly toxic to the environment
- Gold ranks as one of the worst metals in terms of environmental impact
- While (uneconomic) better alternatives exist for these chemicals, the co-presence of other toxic heavy metals with gold ore means that tailings ponds unavoidably pose environmental risk
- Even in the most regulated countries, tailings dam failures occur (often due to natural events like earthquakes and flooding)
- In addition, gold is associated with armed conflict in various parts of the world, resulting in its regulated as a conflict mineral in the US and elsewhere
- Because many of the environmental impacts (including energy) of gold are during the initial stages of mining and processing, recycling—which avoids these stages—can be highly beneficial
- Gold is already highly recycled today, but with the increasing volumes of unrecycled electronics, e-waste can become an important source of recycled gold, with PCB “ore grades” 40-800 times higher than that of mined gold ore