Mineral dust properties at the Mt Lyell Cu-Au mine site, Australia

Abstract

Mine sites operating dust monitoring programs use a variety of techniques to comply with legislative constraints and maintain high standards of environmental and human health protection. One low cost option is the use of dust deposition gauges, which provide information on the total, soluble and insoluble dust fluxes. The aim of this study was to identify methods that could provide information on likely dust sources of samples, which were collected using dust deposition gauges at the Mt Lyell Cu-Au mine, Australia. Elemental analyses of archived dust samples combined with known dust deposition rates allowed quantification of annual metal fluxes. The highest annual metal fluxes were measured for Cu (1-33 g m-2 year-1) followed by Pb (8-343 mg m-2 year-1), Cr (3-59 mg m-2 year-1) and As (1-79 mg m-2 year-1). X-ray diffractometry and scanning electron microscopy permitted characterization of the mineralogical and morphological properties of dust samples. These analyses revealed that the analysed samples derived from at least four different dust sources. Consequently, geochemical and mineralogical characterization of mineral dust samples combined with a detailed site knowledge allows identification of dust sources at mine sites.