Particulate Matter Dispersion in Indian Non-coal Opencast Mines

Abstract

Exposure of mine workers to particulate matter (PM) in opencast mines is of major concern because of associated adverse health impacts. Dispersion studies of PM generated during opencast mining until now have mostly been confined to estimation of emissions from individual mining operations as well as total emission from an opencast mine. No literature could be found on PM dispersion inside the mine since its generation until it escapes the mine. However, this is important particularly for deep mines where mine workings are confined to bottom benches and emission from it passes across all benches before it reaches surface, thus affecting the exposure level of workers at higher benches. The proposed research works have been conducted in three non-coal opencast mines in India: (i) Kiriburu Iron Ore Mine (KIOM), (ii) Meghahatuburu Iron Ore Mine (MIOM), and (iii) Malanjkhand Copper Project (MCP). Mining at KIOM and MIOM was carried out at 9–10 m depths. At MCP, mining activities at 168–180 m depth were the source of PM. The aims were to investigate: (i) vertical PM concentration profiles at different depths during mining operations, (ii) particle travel time and its relationship with mine depth, (iii) particle retention time and fraction at workplace, (iv) particle mass balance in terms of the dispersion and settling proportion, and (v) the relationship of particle concentration with depth. For a deep mine, this is of significant interest. The authors propose more studies in different seasons of the year in deeper mines and mines with varying pit geometry for better understanding of the influence of depth of mine. To assess role of particle density on PM dispersion, similar studies should be carried out in coal mines.