33 / 60
DIAMONDS
March 2015
MODERN MINING
31
A
lthough Liqhobong has been
mined in the past, the new proj-
ect will see mining at the site on
a much larger scale. The new
US$185,4 mine is designed to
deliver 1,1 million carats a year over 15 years,
which is roughly 10 times what nearby Letšeng
– Lesotho’s best known mine – produces (al-
though the dollar price per carat of Letšeng’s
stones is the highest of any kimberlite mine in
the world).
The project is based on mining the main pipe
(there is also a satellite pipe) at the site down
to 393 m over 15 years, exploiting a reserve of
over 11 million carats at a grade of 32,07 cpht.
The anticipated average strip ratio of waste
to ore is 2,28. The ore will be treated in the
Main Treatment Plant (MTP) which utilises a
conventional flowsheet comprising scrubbing,
screening, crushing, concentration via DMS,
and final recovery using X-ray machines. The
plant will have 2 x 250 t/h streams.
According to Firestone Diamonds, the first
six months of the construction phase – which
started in late June 2014 – encountered both
winter and summer weather conditions. The
winter was relatively mild which enabled the
project to start well and the project team to get
ahead on a number of work streams before enter-
ing the start of the rainy season in November.
The above average rainfall experienced in
November and December and delays expe-
rienced in the issuing of work permits to the
civils and earthworks contractor had an initial
negative impact, necessitating a re-scheduling
of certain works and increased work load. The
project team also encountered areas where
excess top soil needed to be removed which, in
combination with the wet weather, caused days
to be lost through personnel not being able to
work safely. Additional crews were deployed to
ensure that development remains on schedule
and within budget.
Work on the residue tailings facility starter
wall and the accommodation terraces is also
progressing well. Overall, as at the end of
Liqhobong
off to a
strong start
View of the site in January
this year (photo: Firestone
Diamonds).
Firestone Diamonds, the AIM-quoted diamond development company
developing the Liqhobong mine in Lesotho, says that the project is currently
within budget and on schedule to achieve initial production at the end of H1
2016. In its recently released results for the six months ended 31 December 2014,
the company says achievements thus far include a safety record of zero lost time
injuries and the creation of approximately 1 000 jobs in Lesotho.
December, the project was marginally ahead of
schedule with significant progress being made
on the construction of the tailings dam wall, as
well as other earthworks and site preparations.
Design, engineering and procurement were set
as a priority by the development team and sig-
nificant progress has been made ahead of the
scheduled targets to ensure the smooth comple-
tion of the project.
The provision of electrical infrastructure
to connect the mine to grid power is a sepa-
rate undertaking which is also progressing
as planned. The total grid power project cost
is R165 million with Firestone funding R145
million and the balance of R20 million being
funded by the local company engaged to con-
struct the power infrastructure. All equipment
and long lead item orders have been placed
and site preparation for the substations is
well advanced. Connection to grid power is
expected to be achieved during the second half
of 2015, ahead of the initial schedule.
At the end of December, a total of R1,28 bil-
lion in orders out of the total budgeted R1,43
billion EPCM contract (being undertaken by
DRA) had been placed. The three largest sub-
contracts under the EPCM contract, totalling
R943 million, have been agreed on a fixed
price/cost basis to remove price escalation risk.
The grid power and Main Treatment Plant
projects combined have created over 1 000
local jobs, and it is expected that the level of
employment will continue to increase as con-
struction progresses.
Connection to
grid power is
expected to be
achieved during
the second half
of 2015, ahead
of the initial
schedule.