June 2014
MODERN MINING
11
MINING News
One of the longest-running opencast
mining contracts in recent company his-
tory has now been completed by Concor
Opencast Mining. The Impala Opencast
project, located on the Western Limb of
the Bushveld Complex near Rustenburg,
was awarded in 2002 by Impala Platinum
and mining commenced in the vicin-
ity of Impala No 6 shaft, with the Concor
Opencast Mining team tackling the
Merenksy orebody first. In 2005 the team
began mining the UG2 orebody.
The two Merensky faces were relatively
small scale, while the UG2 was present
on a much larger scale, with seven faces
mined. These reefs ranged over a 9 km
area and were mined to a depth of 35 m.
Lower down, the Impala Platinum under-
ground operation mined ore from its shaft
systems. The opencast contract included
crushing the material to less than 300 mm
and its delivery to the mine’s stockpile, as
well as rehabilitation of mined areas.
From inception in 2002 the contract
was renewed on an annual basis until
all opencast resources were depleted.
Between November 2009 and December
2013 Concor Opencast Mining mined
49 340 574 bm
3
of blasted overburden,
6 576 454 bm
3
of topsoil and 8 871 767
tons of reef.
“This project was tightly controlled
throughout its duration to mitigate the
associated challenges,” says Roger Hearne,
Acting GM of Concor Opencast Mining.
“For example, mining took place in close
proximity to both mine infrastructure
and housing occupied by members of
the local community. Great care had to be
taken not to impact these structures and
we achieved this by keeping the vibration
from blasting to a minimum. In addi-
tion, blasting was only carried out twice
a week out of consideration for the local
communities.
“At all times we also had to be careful
not to hole through to the mine’s under-
ground workings. For this, we depended
on existing surveys and worked closely
with the mine surveyor to ensure that
highwall positions were correct.”
At the end of the project, the team had
achievedmore than five million fatality free
hours and 1 196 LTI-free days, earning sev-
eral Impala Platinum and Concor Opencast
Mining safety awards along the way.
MDM to undertake study on Lofdal project
Namibia Rare Earths Inc, listed on the
TSX, has initiated a Preliminary Economic
Assessment (PEA) on the Area 4 heavy rare
earth deposit at Lofdal in north-western
Namibia. MDM Engineering of South Africa
has been engaged as the principal consul-
tant for the report, which will provide an
economic analysis of the potential viability
of the current resources at Lofdal.
Ongoing metallurgical test work
has achieved increased recoveries and
upgrades, indicating that the targeted min-
eral concentrate grade of 20 % total rare
earth oxides (TREO) can be attained from
low grade feed of 0,3 % TREO.
MDM Engineering will be assisted by
Mine Technics of Australia for pit opti-
misation, mine planning and operations,
Swinden Geoscience of Canada for geologi-
cal inputs, and Digby Wells Environmental
of South Africa for environmental manage-
ment and planning. The PEA , expected to
be completed before the end of Q3, will
utilise the NI 43-101 compliant resource
completed in 2012 by The MSA Group.
Namibia Rare Earths has also announced
that it has engaged the services of Cutfield
Freeman & Co Ltd (CF&Co) as a financial
advisor to assist in exploring strategic
options to maximise shareholder value for
its Lofdal asset. CF&Co is a global specialist
mining corporate finance house headquar-
tered in London with offices in Toronto and
Hong Kong.
Concor completes long-running opencast contract
A total of 240 people worked on the
project site. Equipment comprised five
bulk excavators for overburden removal;
six smaller excavators for cleaning the ore-
body and extraction of the ore; five dozers
for moving overburden and top soil; 25
trucks on site; three water carts and vari-
ous ancillary support plant. A static jaw
crusher serviced the southern pits during
the project while a mobile jaw crusher ser-
viced the northern pits.
Concor Opencast Mining applied
the strip mining method, with average
advances of 30 m wide. The team was also
responsible for the complete drilling and
blasting operation in all pits. The orebody
was exposed, extracted and transported
to a rail siding 5 km away, where it was
crushed and transported by rail to the
plant for further processing. Haul road
maintenance was critical to minimise wear
and tear on vehicles and ensure safety.
Overburden removal at Impala Platinum.
