In-mine evaluation of catalyzed diesel particulate filters at two underground metal mines

The US Bureau of Mines evaluated the performance of a catalyzed diesel particulate fiber (CDPF) and a CDPF combined with a diesel oxidation catalyst (DOC) at two metal mines. This report describes the results from the two field evaluations. The CDPF-DOC was installed on a load-haul-dump (LHD) powered by a 175-kW, prechambered, turbocharged engine. This system reduced diesel particulate matter (DPM) concentrations by 71 {plus_minus} 28%, as determined by size-selective sampling with gravimetric analysis, and by 71 {plus_minus} 29%, as determined by respirable combustible dust (RCD) analysis at the vehicle operator`s location. The CDPF was installed on a diesel-hydraulic, roof-bolting jumbo, powered by a 172-kW engine. The CDPF reduced DPM concentrations by 72 {plus_minus} 21%, as determined by size-selective sampling with gravimetric analysis, and by 62 {plus_minus} 25%, as determined RCD analysis at the vehicle operator`s location. Underground evaluation was more difficult because of frequent movement by the roof-bolting jumbo, variation in daily workload, tremendous fluctuation in ventilation airflow rates, and use of a high sulfur diesel fuel, which promotes the formation of sulfate particles, decreases filtration efficiency, and hastens the deterioration of the catalyst.