Page 229 - Advances In Productive, Safe, and Responsible Coal Mining

208 Advances in Productive, Safe, and Responsible Coal Mining

and air conditioning systems usually rely on mechanical means. Total airflow require-
ments in a mine depend upon the mine’s total diesel operating power, types of engines
in use, and the airflow distribution system. Dilution of DPM concentrations by ventilation
is the most important and common way to control DPM in mines. A proper ventilation
system should be present in any mine to direct the airflow in the mine. Short circuiting
of the mine air should be avoided and leakage of mine air through stoppings and mine
doors should be kept to a minimum level. A number of metal-nonmetal mines use booster
and auxiliary fans to circulate air in different parts of their mines. These fans, if not utilized
with proper distribution systems, can be a big contributor to mine air recirculation. As a
result, miners assume that air is moving appropriately; whereas in reality, the airflow is
simply being recirculated and fresh air is not being supplied to working areas of the mine
properly. Recirculation can cause a significant increase in pollutant concentrations in cer-
tain parts of mines.
l Environmental cabs: Environmental cabs are effective in order to reduce a worker’s expo-
sure to DPM. Environmental cabs can reduce DPM exposure from 60% to 80% and reduce
miners’ exposure to noise and dust. Environmental cabs are useful only for workers who stay
inside the cab; those workers involved in mine activities that are executed from outside the
cab are not protected by environmental cabs. Studies showed that DPM removal efficiency
of environmental cabs can be over 90% if the cab is used properly [68]. The environmental
cab’s benefits largely depends upon its proper use.

11.7.4 Administrative controls

Various administrative controls can be implemented in order to control DPM emis-
sions in underground mines and to reduce miners’ exposure to DPM. Some adminis-
trative controls are described as follows:
l Downsizing diesel fleet: If possible, downsizing the present diesel fleet by removing under-
utilized, unnecessary, and high-emitting diesel engines in the mine can help in controlling
DPM. This approach can be most effective for LD vehicles, as HD diesel vehicles are usually
a necessary component of mine production and other operations.
l Workers’ training: Training of all parties involved in DPM control efforts is essential. They
should have a clear understanding of all possible health hazards and other risks associated
with DPM exposure. Everyone involved in this process should be well aware of all factors
associated with implementation of DPM control technologies and other strategies. Since
aggressive driving tendencies normally result in over fueling of engines, high DPM emis-
sions, and lower engine efficiency; operators should be trained to avoid aggressive driving
or operating practices.
l Limiting engine idling: Engine idling refers to equipment that is running, but not working.
DPM emissions from diesel-powered equipment can be reduced by limiting unnecessary
engine idling. In mining operations, engine idling is common. Workers should be educated
and well informed about potential impacts on mine air quality from idling diesel equipment.
Diesel equipment operators should turn off engines to avoid unnecessary idling.
Scheduling: Scheduling of work activities is another important and effective way to control
l
miners’ exposure to DPM. Mine management should try to schedule work activities in such a
way that they do not concentrate all HD diesel equipment in a single working stope. In case
of difficulty in scheduling, management can consider the use of vehicles operated by remote
control as this can reduce operator exposure to diesel pollutants by removing them from the
source.