17 / 128
Annual Report 2016 15
BACKGROUND
IGO targeted and pegged the area
containing the current gold reserves in
2001. AngloGold Ashanti farmed into
the project in 2002, discovering the
Tropicana, Havana and Boston Shaker
gold deposits respectively in 2005, 2006
and 2010. Mining of the Havana deposit
commenced in 2012 with the first gold
being produced in September 2013. In
October 2016, the Tropicana Gold Mine
achieved its 1 million ounce milestone,
in line with expectations outlined in the
2010 Bankable Feasibility Study.
FY16 PRODUCTION
Tropicana gold production for FY16 was
in line with expectation at 448,116oz (on
a 100% basis) and cash costs and All-in
Sustaining Costs (AISC) were $730/oz
produced and $918/oz sold respectively.
During the year, a total of 24.6M bank
cubic metres of material were mined and
hauled ex-pit. This material comprised
of 7.3Mt of full grade ore (>0.6g/t), 1.2Mt
of marginal ore (grading between 0.4 &
0.6g/t Au) and 50.3Mt of waste material.
Full grade ore sources were the Havana
Pit (4.47Mt), the Boston Shaker Pit
(0.82Mt) and Tropicana (2.0Mt) with the
average run-of-mine grade for full grade
ore (>0.6g/t Au) being 2.13g/t Au for the
year.
A total of 6.53Mt of ore at an average
grade of 2.39g/t Au was processed
during the year. Average metallurgical
recovery was 89% for 448,116oz of gold
produced.
The reduction in gold production for the
year compared to the FY15 (496,413oz)
is a result of the cessation of grade
streaming in December 2015. Gold
production is forecast to trend to long
term guidance of 400,000oz/pa once
expansion of the process plant to 7.5Mtpa
is achieved.
ATTRIBUTABLE PRODUCTION
IGO’s attributable gold production
during FY16 was 134,435oz and IGO’s
attributable share of gold refined and
sold was 135,864oz. IGO’s attributable
average cash costs for FY16 were $730/
oz Au produced and AISC were $918/oz
Au refined.
TROPICANA OPTIMISATION PROJECT
Business improvement initiatives
within the mining operation include the
implementation of priority road rules,
which have improved mining costs
and efficiencies by reducing haul truck
stoppage time.
Optimisation and upgrade of the process
plant due for completion in September
2016 is targeted to achieve a throughput
rate of 7.5Mtpa. This project involves
optimisation and upgrade of existing
equipment including:-
•
Upgrades to the conveyor systems in
the secondary crushing, High Pressure
Grinding Rolls (HPGR), and grinding
circuits
•
Optimising screens in the secondary
and HPGR circuits
•
Upgrade to the lime storage
•
Upgrade to the oxygen plant
•
Upgrade to the air water and elution
systems
•
Upgrade to the emergency fine ore
stockpile
•
Improved utilisation of the HPGR circuit
The progress of these works enabled the
process plant to achieve an annualised
rate of 6.88Mtpa in the June 2016 quarter
at a 95% availability with May and June
achieving an annualised rate of 7.3Mtpa.
GAS PIPELINE PROJECT UPDATE
The gas pipeline project including the
installation of the gas fired generators is
complete with the commissioning of the
17 gas fired generating units. Further cost
savings resulting from this project will
be achieved as site equipment requiring
LNG as fuel is progressively upgraded to
operate on natural gas.
LONG ISLAND STUDY
The Long Island study is looking at
alternative lower cost mining methods
to enable the mining of ore below the
currently planned pits.
This approach is considering strip mining
mine design techniques, more commonly
used in the coal mining industry which
has the effect of reducing haulage of
waste as the open pit mining progresses
at depth. The concept involves the
existing Tropicana pit, once its resources
are depleted, being backfilled with waste
from the strip mining of the Havana,
Havana South, and Boston Shaker ore
zones. This approach would reduce
waste removal costs as a result of in
pit dumping of waste and shorter haul
distances which would, in turn, facilitate
the extension of mine life.
The study is supported by data from a
substantial framework drilling program
targeting extensions beneath and along
strike of the existing pits completed
during FY16.
OPERATIONS - TROPICANA GOLD MINE
IGO 30%, ANGLOGOLD ASHANTI 70% (MANAGER)