12
which leads to a decrease in airflow. The airflow quantity at
the Main Return is around 150 m3/s (317,000 cfm), and it
went up to around 180 m3/s (381,000 cfm) in the case of
the truck going into the mine. The airflow quantity went
down to around 110 m3/s (233,000 cfm). This change in
the airflow was not much observed at other locations. At
the Return 2 (Location 1), there was a slight increase in the
airflow quantity followed by its decrease.
SUMMARY
The ventilation of large-opening underground stone mines
has not been explored much, and it is challenging due to
the larger dimension of the mines. Research in the past has
suggested that having proper fan placement and movement
of a truck in the mine can help the ventilation of large-
opening mines. NIOSH investigators considered differ-
ent scenarios to model such as fan placement in the mine,
movement of a truck, and a combination of fan and truck
movement in the mine. The CFD modeling results pre-
sented in this paper show that placement of a fan can both
positively and negatively impact the ventilation of fresh air
at different locations in the mine. Simulation results from
the movement of a truck with no fan showed that a truck
going in the mine can lead to more airflow at the return
side but may not be able to ventilate other areas. A fan and
truck combination did show changes in the airflow at the
Main Return but did not have much impact on the air-
flow at other locations in the mine. Extending the model
domain beyond the mine opening did help in achieving
better modeling results in understanding the airflow with
fan and movement of a truck.
This study does demonstrate that CFD as tool can be
used to understand airflow in a large opening mine and has
potential to utilize complex airflow model such as move-
ment of body in fluid domain and play a part in decision
making for mine operators in terms of fan placement and
utilization of moving equipment operating in the mine to
improve ventilation.
LIMITATION OF THE STUDY
The current simulation study was based on the work done
in the past by NIOSH researchers and does offer some
insight on the impact of truck movement on airflow pat-
tern inside a large opening mine, however, the findings of
this work is limited to the movement of truck going in and
coming out of the mine. At the same time the results of
the simulation were not validated using data collected from
any current working mine and cannot be implemented to
a wide range of mining conditions. There are also factors
such as mine layout, release of DPM from trucks and other
equipment, influence of external and internal environment,
fan size, placement of fans among other not considered in
this study.
DISCLAIMER
The findings and conclusions in this report are those of
the author(s) and do not necessarily represent the official
position of the National Institute for Occupational Safety
and Health (NIOSH), Centers for Disease Control and
Prevention (CDC). Mention of any company or product
does not constitute endorsement by NIOSH.
REFERENCES
[1] NMA. Mine Safety &Health Administration’s Number
of Coal and Non- fuel Mineral Operations in the U.S.
2020 Available from: https://nma.org/wp-content
/uploads/2020/09/msha_number_operations_by
_sector_2020.pdf.
[2] Grau III, R.H., et al., NIOSH ventilation research
addressing diesel emissions and other air quality issues
in nonmetal mines, in SME Annual Meeting. 2002:
Phoenix, AZ. p. 1–7.
[3] Grau III, R.H., R.B. Krog, and S.B. Robertson,
Maximizing the Ventilation of Large-Opening Mines,
in Proceedings of the 11th U.S./North American Mine
Ventilation Symposium, J.M. Mutmansky and R.V.
Ramani, Editors. 2006, Taylor &Francis Group:
University Park, PA. p. 53–59.
[4] Grau III, R.H., et al., Raising the bar of ventilation
for large-opening stone mines, in Proceedings of the
10th US/North American Mine Ventilation System,
S. Bandopadhyay and R. Ganguli, Editors. 2004:
Anchorage, AK. p. 349–355.
[5] Krog, R.B., et al., Ventilation planning layouts for
large opening mines, in SME Annual Meeting. 2004:
Denver, CO. p. 1–9.
[6] Grau III, R.H. and G.M. Meighen, Novel stopping
designs for large-opening metal/nonmetal mines, in
Proceedings of the 11th U.S./North American Mine
Ventilation Symposium, J.M. Mutmansky and R.V.
Ramani, Editors. 2006, Taylor &Francis Group:
University Park, PA. p. 579–583.
[7] Grau III, R.H. and R.B. Krog, Ventilating large open-
ing mines. Journal of the Mine Ventilation Society of
South Africa, 2009. 62(1): p. 8–14.
[8] Grau III, R.H. and R.B. krog, Using mine planning
and other techniques to improve ventilation in large-
opening mines, in SME Annual Meeting. 2008, SME:
Salt Lake City, UT. p. 1–4.
which leads to a decrease in airflow. The airflow quantity at
the Main Return is around 150 m3/s (317,000 cfm), and it
went up to around 180 m3/s (381,000 cfm) in the case of
the truck going into the mine. The airflow quantity went
down to around 110 m3/s (233,000 cfm). This change in
the airflow was not much observed at other locations. At
the Return 2 (Location 1), there was a slight increase in the
airflow quantity followed by its decrease.
SUMMARY
The ventilation of large-opening underground stone mines
has not been explored much, and it is challenging due to
the larger dimension of the mines. Research in the past has
suggested that having proper fan placement and movement
of a truck in the mine can help the ventilation of large-
opening mines. NIOSH investigators considered differ-
ent scenarios to model such as fan placement in the mine,
movement of a truck, and a combination of fan and truck
movement in the mine. The CFD modeling results pre-
sented in this paper show that placement of a fan can both
positively and negatively impact the ventilation of fresh air
at different locations in the mine. Simulation results from
the movement of a truck with no fan showed that a truck
going in the mine can lead to more airflow at the return
side but may not be able to ventilate other areas. A fan and
truck combination did show changes in the airflow at the
Main Return but did not have much impact on the air-
flow at other locations in the mine. Extending the model
domain beyond the mine opening did help in achieving
better modeling results in understanding the airflow with
fan and movement of a truck.
This study does demonstrate that CFD as tool can be
used to understand airflow in a large opening mine and has
potential to utilize complex airflow model such as move-
ment of body in fluid domain and play a part in decision
making for mine operators in terms of fan placement and
utilization of moving equipment operating in the mine to
improve ventilation.
LIMITATION OF THE STUDY
The current simulation study was based on the work done
in the past by NIOSH researchers and does offer some
insight on the impact of truck movement on airflow pat-
tern inside a large opening mine, however, the findings of
this work is limited to the movement of truck going in and
coming out of the mine. At the same time the results of
the simulation were not validated using data collected from
any current working mine and cannot be implemented to
a wide range of mining conditions. There are also factors
such as mine layout, release of DPM from trucks and other
equipment, influence of external and internal environment,
fan size, placement of fans among other not considered in
this study.
DISCLAIMER
The findings and conclusions in this report are those of
the author(s) and do not necessarily represent the official
position of the National Institute for Occupational Safety
and Health (NIOSH), Centers for Disease Control and
Prevention (CDC). Mention of any company or product
does not constitute endorsement by NIOSH.
REFERENCES
[1] NMA. Mine Safety &Health Administration’s Number
of Coal and Non- fuel Mineral Operations in the U.S.
2020 Available from: https://nma.org/wp-content
/uploads/2020/09/msha_number_operations_by
_sector_2020.pdf.
[2] Grau III, R.H., et al., NIOSH ventilation research
addressing diesel emissions and other air quality issues
in nonmetal mines, in SME Annual Meeting. 2002:
Phoenix, AZ. p. 1–7.
[3] Grau III, R.H., R.B. Krog, and S.B. Robertson,
Maximizing the Ventilation of Large-Opening Mines,
in Proceedings of the 11th U.S./North American Mine
Ventilation Symposium, J.M. Mutmansky and R.V.
Ramani, Editors. 2006, Taylor &Francis Group:
University Park, PA. p. 53–59.
[4] Grau III, R.H., et al., Raising the bar of ventilation
for large-opening stone mines, in Proceedings of the
10th US/North American Mine Ventilation System,
S. Bandopadhyay and R. Ganguli, Editors. 2004:
Anchorage, AK. p. 349–355.
[5] Krog, R.B., et al., Ventilation planning layouts for
large opening mines, in SME Annual Meeting. 2004:
Denver, CO. p. 1–9.
[6] Grau III, R.H. and G.M. Meighen, Novel stopping
designs for large-opening metal/nonmetal mines, in
Proceedings of the 11th U.S./North American Mine
Ventilation Symposium, J.M. Mutmansky and R.V.
Ramani, Editors. 2006, Taylor &Francis Group:
University Park, PA. p. 579–583.
[7] Grau III, R.H. and R.B. Krog, Ventilating large open-
ing mines. Journal of the Mine Ventilation Society of
South Africa, 2009. 62(1): p. 8–14.
[8] Grau III, R.H. and R.B. krog, Using mine planning
and other techniques to improve ventilation in large-
opening mines, in SME Annual Meeting. 2008, SME:
Salt Lake City, UT. p. 1–4.