Mining Publication: Diesel Aftertreatment Control Technologies in Underground Mines: The NO2 Issue

Extensive use of diesel-powered equipment makes reduction of underground miner exposure to diesel particulate matter and gaseous emissions from diesel-powered equipment a major challenge for the mining industry in the U.S. and worldwide. Improvements in mine ventilation are a commonly used remedy to meet more stringent emission limit for all pollutants. However, mine operators have other options to reduce diesel particulate matter emissions including the adoption of more advanced engine technologies, aftertreatment control strategies, and the use of biodiesel fuels. These strategies have been found to be effective in reducing the mass concentration of diesel particulate matter (DPM) but, as a side effect, they can modify the tailpipe emission of another pollutant, nitrogen dioxide (NO₂). If the concentration of NO₂ exceeds the regulatory enforced limit, an increase in ventilation rate becomes necessary with related increased power demand and/or the cost of supplemental air shafts. This paper provides an overview of what effects the different exhaust aftertreatment technologies and control strategies available to the mining industry have on the NO₂ emissions. Specific focus is given to their effect on the ventilation strategy in an underground mine environment.