51
08.13
environment
eMalahleni, which is a wetter area and where a lot of
the pollution has actually been diluted by the perma-
nently flowing rivers there.”
Air quality is another component of the overall
drive towards green mining and one of SRK’s experts
in this field is Vis Reddy, a Partner and Principal Sci-
entist, who has led numerous air quality and climate
impact assessment for ESIAs. He believes that an ap-
preciation of the need for air quality management is
gaining ground at mines. New emission standards are
due to be implemented in South Africa in 2015 with
a further tightening up scheduled for 2020 that will
increase the emphasis on air quality management at
mines. “The new standards are quite onerous and
mines will have to work hard to ensure that their
processing plants meet the required reductions in
emission levels,” he says. “The technologies required
to reduce emissions such as bag filters, electrostatic
precipitators and wet scrubbers are already widely
used but may need to be upgraded to bring plants into
alignment with the new emission standards.”
In respect of actual mining – as opposed to pro-
cessing – operations, Reddy says that there are very
few air quality regulations in place that mines have
to comply with (although air quality considerations
do have to be addressed in Environmental Manage-
ment Plans (EMPs). “In open-pit environments, the
main issue is dust control,” he notes. “The means to
tackle this are fairly straightforward and quite low
tech – it’s mainly a question of keeping haul roads
wet using water tankers or using various dust sup-
pressants which are commercially available. Mines
can also look at paving roads – though this would not
normally be applied to haul roads.
“Where there are conveyors and crushing instal-
lations, dust can be reduced by keeping the mois-
ture content of the ore up, by using enclosures over
conveyors and by giving close attention to transfer
points, where a great deal of dust is typically gener-
ated. Blasting, of course, is also a source of dust but
the impact is generally over very short periods – and
reduces, in any event, as a pit gets deeper. There’s not
An example of a more modern instrument used to monitor PM10 and PM2.5 dust particles.
SRK’s Peter Shepherd argues that water management is abso-
lutely critical to the concept of green mining.
a great deal to be done about blasting although there
are some measures that can be taken such as using a
water spray prior to blasting.”
Reddy makes the point that SRK’s clients tend to be
proactive on the issue of air quality. “There’s definite-
ly been a sea change in attitudes over the past couple
of decades,” he says. “Back in the 1990s – and even
into the early 2000s – we would write proposals and
people would ask, ‘Why do we need this?’ Nowadays
you don’t have to push clients to anywhere near the
same extent and we’re getting called in very early.
Their receptiveness to air quality, and indeed all en-
vironmental issues, is partly driven by legislation but
it also reflects the generally ‘greener’ mindset that
people now have, many of whom are now at manage-
ment level in the mining sector.”
Shepherd agrees with Reddy on this point and re-
marks that when he first started working in the en-
vironmental field on the environmental aspects of
mining projects, the environmental team tended to
