NEWS
The regular desilting of return water ponds and dams is becoming
increasingly important.
water than usual,” says Vine.
“It is therefore vital that they
operate optimally and do not
have their capacity constrained
by excess silt.”
He highlights the
environmental risk of tailings
spilling out of ponds and
perhaps even out of the
boundaries of the mining lease
area – something that mines
work hard to avoid due to the
stringent legal requirements.
“The regular desilting of
return water ponds and dams is
more and more important as we
begin to appreciate the proper
value of water on our planet,
and especially in relatively dry
countries like South Africa,” he
says. “Not only should mines
ensure there is enough capacity
to receive and retain excess water
during the rainy season, but there
is also the need to store as much
as possible for the dry season.”
He argues that purchasing
treated municipal water to ‘top
up’ their requirements is less
of an option for mines due to
the rising cost of water and
the growing competition for
water among stakeholders like
communities, industry and
agriculture.
Applying a regular dredging
programme need not be
onerous, he adds, and can avoid
a situation where silt or slimes
threaten the water retention and
water-holding capacity of ponds
and dams. Integrated Pump
Rental has locally designed,
engineered and manufactured
the SlurrySucker dredge unit for
precisely this purpose, and offers
the technology on a rental or
turnkey contract basis for mine
pond maintenance.
“There are even conditions
under which a mine may find it
worthwhile to procure its own
SlurrySucker for permanent
and ongoing use on desilting
operations,” says Vine. “The
equipment can be moved
easily by road trailer and
commissioned within a day.
The operation of the equipment
is conducted by just one
person, and we provide all the
necessary training, support and
maintenance required,” he adds.
During the rainy season in
South Africa’s mining regions,
checking the capacity of
process water return ponds to
monitor whether silt build-
up is jeopardising the dams’
performance, and this is
increasingly critical.
“Managing the water balance
on mines is more demanding
as mines work to be more self-
sufficient, and to draw less water
from municipal sources,” says
Lee Vine, managing director
at dredging and dewatering
specialist Integrated Pump
Rental. “Process water ponds
therefore need to be carefully
monitored and regularly
dredged to prevent too much
sediment from accumulating.”
More sediment means less
water storage capacity, which
can affect the efficient running
of the process plant as well as
create a potential environmental
hazard if heavy rainfall leads
to tailings over-topping the
pond. Exacerbating the risk
of insufficient water storage
capacity is the widely held
opinion that rainfall is becoming
increasingly variable due to
climate change factors.
“In many areas, this means
that summer rains will include
a higher number of heavy
downpours within relatively
short periods of time. And this
will place an increased load on
these ponds to contain more
Dredging the ponds
Process water ponds need to be carefully monitored and regularly
dredged to prevent too much sediment from accumulating.
QUARRY SA | MAY/JUNE 2018 _ 5