Mine excursion
The blasting teams have changed the blast design and
burden spacing and increased the bench height to
optimise the opencast operation.
Technology for the future
Although the Sishen mine’s
first-quarter production in 2018
decreased by 6% to 7.3 million
tonnes (Mt) compared to the last
quarter in 2017, it is certainly
recovering its losses. According to
Mapi Mobwano, general manager at
Sishen, these figures were primarily
driven by lower production in the
dense media separation (DMS) plant
due to short-term mining feedstock
constraints. These constraints,
however, were offset by higher yields
from both the DMS and JIG plants.
According to Glen McGavigan,
executive head of technical and
projects at Kumba Iron Ore, the
company is actively engaged in
exploration programmes at both
Sishen and Kumba’s newest mine,
Kolomela, about 90km south of
Sishen, in efforts to extend th e life
of both mines. The company’s oldest
mine, Thabazimbi, in the Limpopo
Province, is in closure phase, awaiting
a Section 11 approval from the
DMR to have the mine transferred
to Arcellor Mittal South Africa. “We
are looking at technology to improve
our recovery rates, especially at
Sishen, where we have the potential
to convert material currently regarded
as waste into valuable ore,” says
McGavigan.
Kumba has spent more than
R749-million on modern technology
between 2014 and 2017, hoping
to increase production at Sishen
and Kolomela. “For us, technology
really needs to improve safety and
productivity and reduce costs. If it
doesn’t tick one or all three of those
boxes, then we won’t implement it,”
says McGavigan.
Two of the 12 technology projects
implemented by Kumba over the past
three-and-a-half years that have had
a significant impact on the operations
in the pit, is the automated drilling
project and a fleet management
control system. Drill rigs are operated
from a remote command centre away
from the pit, using state-of-the-art
technology. Traditionally, the drill
operator will be seated inside the drill
rig, exposed to dust and unpredictable
weather conditions. “At present, six
rigs have been converted at Kolomela,
and this has improved efficiencies,
quality, and the results substantially,”
says McGavigan.
The automated drilling project
commenced at Sishen in 2015 with
the trialling of two automated drill
rigs, and the programme is set to be
rolled out to include the rest of the
Sishen drilling fleet on completion of
the pilot. The new fleet management
system known as Dispatch has
resulted, according to McGavigan,
in a reduction of haul truck cycle
AUGUST 2018 MINING MIRROR
[13]