Single-particle analysis of atmospheric particulate matter using automated mineralogy: the potential for monitoring mine-derived emissions

Abstract

This article describes a new method for the analysis of fine (> 1 µm) atmospheric particulates using the Mineral Liberation Analyzer. After determining the optimum sampling technique, the accuracy and precision of the instrument were tested by repeat analysis and by comparison to certified reference materials, with relative standard deviations of less than 10% achieved. A pilot study using this method was applied to identify arsenic-bearing phases near a gold mine and to identify particulates near a large iron-ore mining operation. The results revealed the presence of only negligible amounts of the arsenic-bearing phases and sulfides typically associated with the gold deposit, with only 159 particles detected in the 22,511 particles analyzed. The presence of aluminum-enriched iron oxides in the particulates sampled near the iron-ore operation suggests that re-entrained soil is a significant source of particulates in this region. From the results of this study, the technique has been shown to have a significant potential for the rapid acquisition of reliable data for the characterization of airborne particulates, which is requisite for effective emissions management and for the monitoring of human and environmental health.