Petra Diamonds Limited
Annual Report and Accounts 2013
40
Performance Review
Operational Review continued
Performance in FY 2013
Koffiefontein is one of the world’s top kimberlite mines by average value
per carat, achieving US$471 for FY 2013, despite the fact that the overall
average has to some extent been reduced by the higher proportion of
lower value Ebenhaezer production in the total sales mix.
Diamond production for FY 2013 declined by 13% to 34,800 carats
(FY 2012: 40,117 carats). Underground production (239,161 tonnes in FY 2013
at a grade of 6.0 cpht) continues to be supplemented with production
from the Ebenhaezer satellite pipe (1,242,360 tonnes in FY 2013 at a grade
of 1.6 cpht), where pre-mining of initial lower grade areas progressed in
Q4 FY 2013, with the Company now having established access to higher
grade ore. Koffiefontein is now in a position to deliver improved
results for FY 2014.
Costs
Due to the high contribution from the lower-cost Ebenhaezer open pit,
the on-mine cash operating unit cost of R136/t remained relatively low
(FY 2012: R125/t), despite production constraints and cost pressures
associated with electricity and labour increases.
Development Plan
Petra’s expansion plan at Koffiefontein is expected to increase production
from 34,800 ctpa in FY 2013 to ca. 105,000 ctpa by FY 2017. Petra will therefore
be ramping up ROM production to 1.1 Mtpa by FY 2017. The current mine
plan has a life of 12 years, but the orebody remains open at depth so the
actual LOM could be considerably longer.
ROM throughput of 0.33 Mt is planned for FY 2014, consistent with H2 FY 2013
ROM production. ROM grade is guided at ca. 9 – 10 cpht, due to an increased
contribution of tonnages from higher grade areas.
Surface mining of the Ebenhaezer satellite pit will continue in FY 2014,
with ca. 1.2 Mt planned to be treated at a grade of ca. 2.7 cpht, and it is
expected to continue for two to three years (including FY 2014), whilst
mining of underground ROM tonnes is ramped up.
Petra’s mine plan involves the installation of a SLC between 560 mL and
580 mL, before installing a new block cave at 690mL. The revised mining
lay-out for the SLC (which will accelerate access to fresh kimberlite ore)
was finalised in FY 2013 and detailed design commenced. Development
work on the underground tunnel infrastructure is underway, while
ore-handling conveyor installations servicing the SLC are in the final
stages of commissioning.
In FY 2013, a revision to the mine design has led to ca. 450 Kt more tonnes
being accessible from the Koffiefontein SLC, as well as an expected increase
in the average grade from 8.7 cpht to ca. 9–10 cpht (due to the focus on
higher grade areas). The new targeted areas are expected to produce a
significant number of Type IIa diamonds (for which Koffiefontein is well
known), which should have a positive impact on the average US$/carat values.
Capex
Capex for the Year of US$20.4 million was primarily focused on underground
development and purchasing of plant, mining and surface equipment.
Koffiefontein
One of the world’s top kimberlite mines by average value per carat.
DELIVERING OUR STRATEGY
OUTPUT
Production supplemented
by Ebenhaezer satellite pipe until
development plan increases ROM
tonnage throughput.
RECOVERIES
High average value
per carat of US$471 for FY 2013,
despite lower value Ebenhaezer
carats in the mix.
EFFICIENCIES
Conveyor
ore-handling installations to service
SLC are in final commissioning.
AVERAGE PRICE PER CARAT
US$471
-3%
ROM GRADE
6.0 cpht
+22%
ON-MINE CASH COST PER TONNE
R136
+9%
REVENUE
US$16.6m
-12%
REVENUE CONTRIBUTION
4%
ROM TONNES
239,161
-52%
PRODUCTION (ROM +
EBENHAEZER + TAILINGS)
carats
34,800
-13%
1...,32,33,34,35,36,37,38,39,40,41 43,44,45,46,47,48,49,50,51,52,...142