Historical mercury losses from the gold mines of Victoria, Australia

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.

Arsenic Precipitation from Solutions in Autoclave-Hydrometallurgical Technology of Processing Sulphide Concentrates

Currently, the share of gold extracted from technologically simple gold ores is steadily decreasing, which determines the involvement in the processing of refractory gold ores containing finely disseminated gold and silver in sulfides, mainly in pyrites and arsenopyrites. Autoclave oxidation is a promising method of pretreatment of the refractory sulfide-arsenic gold-bearing raw materials before cyanidation. A serious problem of auriferous ores autoclave-hydrometallurgical processing is the removal of contained arsenic into relatively harmless and capable of being kept forms. This article shows the results of behavior of arsenic during the neutralization of solid after autoclave oxidative leaching of refractory gold-containing materials.