Implementing the latest engine and exhaust aftertreatment technologies is one of the major strategies used by the mining industry to control exposures of underground miners to gases and aerosols emitted by diesel-powered vehicles. Due to the rapid development of engine and aftertreatment technologies, limited information is available in the literature on their potential impact on concentrations of carbon monoxide (CO), nitric oxide (NO), nitrogen dioxide (NO₂), ammonia (NH₃), and submicron aerosols in underground mines.
This study was conducted to develop a better understanding of how the recently introduced Tier 4i Mercedes Benz OM926 engines equipped with a selective catalyst reduction (SCR) catalyst system might alter concentrations of criteria gases and aerosols in mine air. To provide a reference for the comparison with engines currently used by the industry, the effects of a vehicle powered by the Tier 4i engine were qualitatively compared with the effects of a similar vehicle powered by the comparably rated Tier 3 engine from the same manufacturer, which for testing purposes was equipped with a diesel oxidation catalyst (DOC) or diesel particulate filter (DPF) system.
Both engines were fueled with a 50 percent biodiesel blend (B50). Under prevailing test conditions, the Tier 4i engine was found to contribute less than the Tier 3 engine retrofitted with the DOC to concentrations of NO, elemental carbon (EC), organic carbon (OC), total carbon (TC), and total number of aerosols; but more to concentrations of CO, NO₂, and NH₃. The Tier 4i engine contributed more than the Tier 3 engine equipped with the DPF to concentrations of CO, NO₂, EC, TC, and total number concentrations of aerosols, but less to the concentrations of NO and OC; and similarly to NH₃ concentrations.
Last Updated: 19/05/2020 01:14:14pm