57 / 82
January 2015
MODERN MINING
55
DIAMONDS
Top projects
shipped tonnes of Karowe ore up to Europe and
did initial tests with graphite tracers, then – as
we gained confidence with the technology – we
introduced Karowe’s diamonds into the pro-
cess, including a +200 carat stone! TOMRA was
selected following a technical and commercial
adjudication. The net result of the selection
process is that we have a cost-effective technol-
ogy that can obtain high diamond recovery at
high throughput for all our ore types with mini-
mal need for further sorting.”
Once the upgrade is complete, Karowe will
be able to maintain its annual production in the
400 000 to 450 000 carat range through to 2026.
After that there is the possibility that the mine
could transform into an underground operation
and a preliminary desktop study on this option
is being undertaken.
Lucara is also embarking on an intensive pro-
gramme of exploration in the Karowe area with
the aim of identifying additional resources.
It recently put in some “aggressive applica-
tions” – as Dr John Armstrong, the company’s
VP, Mineral Resources, puts it – for prospec-
tive ground in the vicinity of the mine that was
‘on auction’ and was awarded two exploration
licences, both of which host known diamond-
iferous kimberlites, in September 2014. One of
the licences, Block A, is located 30 km to the
east of Karowe while the other, Block E, lies
15 km to the north of the mine.
According to Armstrong, all the kimberlites
were discovered by De Beers in the late 1960s,
with some having been subject to further explo-
ration in the intervening period since and others
almost totally neglected. “Our intention is to
bulk sample these kimberlites and – to this end
– we’ve contracted ADP Projects of Cape Town
to supply us with a 15 t/h bulk sample plant,
which we will install at Karowe. If all goes to
plan, we should be putting material through the
plant in the third quarter of 2015,” he says.
Karowe, of course, is not Lucara’s only asset
and it also owns the Mothae kimberlite pro
ject in Lesotho, which is just 6,5 km from the
Letšeng mine.
Lucara was considering expanding the
current bulk sampling plant on site to treat
Mothae’s significant resource of weathered ore
– as the first stage in developing a fully fledged
mining operation – but has recently announced
that it intends divesting itself of Mothae. In a
statement issued early this year (2015), Lucara
said that while it had evaluated multiple devel-
opment options for Mothae, it had concluded
that the project did not meet “the company’s
disciplined investment criteria for its targeted
return on capital”.
Summing up, Day says that with Karowe in
full production, Lucara is becoming a significant
player in the diamond market. “We’re a young
company but we’ve achieved a great deal over
our relatively short history,” he says. “Karowe is
our flagship and will underpin Lucara for years
to come but we will not necessarily remain
a ‘one-mine company’ and we remain on the
lookout for attractive opportunities, either in
Botswana or the wider Southern African region.”
Photos by Lucara Diamond Corp (unless otherwise credited)
Detailed planning the key to success
Leading the DRA teamon site on the Karowe upgrade as Construction Man-
ager is Clint Jennings, who told
Modern Mining
that the contract was pro-
gressing well.“The main challenge is that we’re having to handle some very
complex construction in and around an operating plant, at the same time
fitting in with the operational cycle,” he said. “The success of a ‘brownfield’
project is a function of how much planning goes into it at the beginning
and I spent four months coming up here from Johannesburg prior to the
project starting on site in March this year (2014) to ensure that we could
achieve a good alignment of construction with operation.”
DRA is managing a large contingent of sub-contractors and suppliers
who include Basil Read subsidiary Sladden International, responsible for
civils and earthworks, SMEI Projects, which is handling structural, mechani-
cal, piping and plating work, and HVC, the electrical instrumentation con-
tractor. The labour force deployed on site is due to peak at around 480.