Mining in focus
mines. There is a lot of room for new
innovative products that can make
a mine manager’s life easier. It is
especially in the areas of monitoring
and communication where new
technology can add value. A mine
needs to continuously monitor the
underground environment in terms of
gases, dust, heat, radiation, moisture,
and fumes, and to achieve real-time
monitoring, sensors (in different forms)
are needed. “There is a strong need for
integrated communication systems to
be able to inform workers underground
about environmental changes, which
may need workers to be alerted about
the hazards,” says Mochubele.
Ventilation systems have to be
checked, monitored, and maintained
on a regular basis. This vital function
of an underground operation is often
not paid the necessary attention, which
could have disastrous consequences.
The most important component of the
system is the main fan, which has to
be maintained regularly according to
the original equipment manufacturer’s
(OEM’s) recommendations. Mochubele
says that air leakage is another thorny
issue, as this can be regarded as a
wasteful expenditure.
According to Michael De Angelis,
technical sales at WesTrac Cat, sealing
air leakages results in significant cost
savings and improves ventilation
and airflow systems. “The type of
manufacturing technology that is used
on mine ducting has an enormous
impact on the air quality underground.
It doesn’t really matter what brand is
used; what is important is the way the
duct has been made to seal the seams
and reduce leakage,” says De Angelis.
In Australia, there has been a
significant trend towards seam-welded
ducting rather than stitched-seam
ducting. This method ensures that
there is less leakage and that more air
reaches the face to help dilute harmful
gases and harmful diesel particulate
matter (DPM).
In a typical mining level that uses a
180kW fan at 30c/kWh (the average
cost for diesel-generated power in
West Africa), the cost of running
the fan continuously to ventilate the
level is more than USD450 000 per
year. “The purpose of the ducting is to
take the air from the fan outlet to the
mining working area, which could be
several hundred metres. Any air that is
lost in transit due to excessive leakage
and duct friction (duct roughness) is a
massive waste of this electricity spend,”
says De Angelis.
It was mentioned at a recent
conference in Australia that about
40% of deaths in underground mines
are in some way linked to ventilation.
Ventilation is often not paid enough
attention because the serious health
effects are not noticed immediately.
However, prolonged exposure to
respirable dust, DPM, fumes, and
gases can have a dramatic effect on
the quality of a worker’s life later on.
Lung cancer from DPMs is a slow
killer that is often overlooked, but it
highlights the importance of airflow in
an underground environment. Methods
have to be devised to reduce costs and
increase air at the same time, which will
ultimately result in healthier workers
and increased production. b
JULY 2018 MINING MIRROR
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