Historical mercury losses from the gold mines of Victoria, Australia

Abstract

Health and ecological risks associated with the use of mercury in gold mining are well known, with much recent attention focussed on contemporary small-scale artisanal mining. Legacy tailings from historical gold mining may also present ongoing risks, as the industry used large quantities of mercury with minimal environmental regulation to limit its discharge. This occurred in both alluvial (placer) mining and in processing auriferous ores. Analysis of historical data on mercury use in the mining industry in Victoria, Australia, indicates that at least 131 tonnes of elemental mercury were discharged into the environment as mine tailings between 1868–1888, with the total amount lost over the historic mining period likely to be much higher. The processing of pyritic ores also concentrated mercury losses in a small number of mining centres, including Bendigo, Ballarat, Castlemaine, Clunes, Maldon and Walhalla. This analysis provides a basis for further research needed to support improved management of legacy mine tailings.

Characterising mine wastes as archaeological landscapes

“…Historically, miners in California also used large volumes of mercury, adding hundreds of kilograms of liquid mercury to hydraulic sluices each week (Alpers et al, 2005). There is little evidence for extensive mercury use by alluvial miners in Victoria during the artisanal phase of gold mining during the 1850s but at least 131 tonnes of mercury were discharged into the environment in tailings derived from hard rock mining between 1868 and 1888 (Davies et al, 2015; Lawrence & Davies, 2020).…”

Arsenic, cadmium, lead, antimony bioaccessibility and relative bioavailability in legacy gold mining waste

“…Victorian goldfields (Australia) hosted one of the world’s largest orogenic gold deposits, yielding at least 2,500 tons of gold between 1851–1914, which is ~30% of all Australian gold and ~2% of the world’s gold supply [ 6 , 7 ]. Nearly 40% of all gold from Victoria was alluvial, depositing in sand/gravel of streambeds due to the weathering of nearby orogenic deposits [ 7 ].…”

“…Nearly 40% of all gold from Victoria was alluvial, depositing in sand/gravel of streambeds due to the weathering of nearby orogenic deposits [ 7 ]. However, the majority of gold was recovered by crushing and processing subsurface quartz deposits [ 6 ]. Refuse materials from mining processes were generally discarded in waterways as sediment or ‘sludge’, causing substantial detriment to townships, industries and the environment downstream of mining activities [ 8 ].…”