Damang Gold Mine
Technical Short Form Report
This Technical Short Form Report reflects the latest Life of Mine plan, together with an updated
Mineral Resource and Mineral Reserve statement. The declared Mineral Reserve as at
30 June 2009 has increased by 466 koz of gold when reconciled against June 2008,
predominantly due to new discoveries, resource modelling and reduction in cut-off grade.
Abosso Goldfields Limited (AGL) is a Ghanaian registered company that owns and operates
the Damang Gold Mine. Gold Fields Ghana Holdings Limited holds a 71.1% interest in AGL,
IAMGold 18.9% and the Ghanaian Government the remaining 10%. Damang manages five
Prospecting Licences as well as two Mining Leases, namely the Damang Mining Lease and
the Lima South Mining Lease, which equate to 8,111 ha.
The mine exploits oxide and fresh hydrothermal mineralisation in addition to Witwatersrand
style palaeoplacer mineralisation. The hydrothermal mineralisation is located in Tarkwaian
sediments and is the only deposit of its kind, located on the eastern side of the Ashanti
Belt in southwest Ghana. Mineral Reserves for Damang are estimated using mine designs
generated from standard mine optimisation methods, current cost structures, and technical
assumptions derived from actual production history and/or feasibility studies.
The Damang Plant processes 5.1 Mt pa from a blend of proximately 37% oxide ore and
63% fresh ore, sourced from the open pit mining operations and existing surface stockpiles.
Process feed for the one-year period to 30 June 2009 comprised 5,0 Mt at a yield grade of
1.3 g/t Au for 200 koz.
All Mineral Resource and Mineral Reserve figures reported are managed unless otherwise
stated and Mineral Resources are inclusive of Mineral Reserves.
Salient Features
- Renewed focus on regional and near-mine exploration.
- Damang to accelerate its recent rate of discovery to maintain a pipeline of
quality projects.
- Mineral Resources of 4.3 Moz.
- Mineral Reserves of 1.8 Moz – 34% increase year-on-year.
- Life of Mine extends to F2019 (9 years).
The Abosso Mine operated from 1882 until 1956. From 1989, Ranger Exploration, initially with
other partners, firstly examined the feasibility of re-treating tailings from the Abosso Mine, and then
the northeast extension of the Banket Conglomerates towards Damang Village. Gold appeared to
be associated with both Banket Conglomerates and a flat lying quartz vein system.
Pitting and trenching carried out between 1990 and 1992 demonstrated near surface mineralisation
over a 3 km strike length and follow up drilling commenced in 1993. By early 1996, a 3 Moz
Mineral Resource had been estimated and a feasibility study demonstrated that open pit mining
would be viable to a depth of about 200 m. The current estimated depth for the Damang pit is
300 m following the approval of a cutback in 2005.
A mining lease was granted to AGL on 19 April 1995 and the mining operation commenced in
August 1997. |
Key Features
|
Independent Audit |
|
Figures reported in this declaration are as reviewed and approved by independent, external consultants as at
30 June 2009 |
|
Prepared by |
|
Gold Fields Limited |
|
Effective date |
|
30 June 2009 |
|
Source of Information |
|
This Technical Statement is a summary of the detailed internally sourced document entitled F2010 Damang Competent
Persons Report |
|
Personal Inspection |
|
Personal inspection is conducted by the Competent Persons as listed, who are full time employees of Gold Fields Limited
or ontracted external consultants |
|
General Location |
|
Damang is located in south-western Ghana, approximately 300 km by road, west of Accra, the capital, at a latitude
5° 11’ N and longitude 1° 57’ W. amang Gold Mine is located 30 km north of the town of Tarkwa with good access
roads and an established infrastructure. The Mine is served by a main road connecting to the port of Takoradi, some
90 km to the south-east |
|
Licence Status and Holdings |
|
The Damang concession covers a total area of 27,174 ha. All necessary statutory mining authorisations and permits are in
place for the Damang Mine Lease and AGL is entitled to mine all material falling within the lease. Abosso Goldfields holds
a mining lease in respect of the Damang Mine dated 19 April 1995, as amended by an agreement dated 4 April 1996.
This lease expires in 2025, but is renewable under its terms and the provisions of the Minerals and Mining Law, by
agreement between Abosso Goldfields and the Government of Ghana |
|
Operational Infrastructure |
|
The Damang plant processes oxide and fresh ore, which is sourced from the open pit mining operations and from existing
surface stockpiles, located on the Damang Mine Lease. The plant throughput is 5.1 Mtpa and comprises 37% oxide ore,
and 63% fresh ore blend |
|
Climate |
|
A tropical climate, with average monthly temperatures between 21°C and 32°C, is characterised by two distinct rainy
seasons from March-July and September-November. Average annual rainfall near the site is 2,030 mm. Although there
may be minor disruptions to operations during the wet season, there is no operating or long-term constraint on production
due to climate |
|
Deposit Type |
|
The Damang orebody is hosted by a north to north-westerly plunging antiform developed within Tarkwaian sediments.
The main Damang Pit is located close to the closure of the antiform, and all other known mineralisation is located on
the east and west limbs of the Damang Anticline. The concession covering the Damang Mine lies to the north of, and
joins the Tarkwa concession. The Damang Gold Mine exploits oxide and fresh hydrothermal mineralisation in addition to
Witwatersrand style, palaeoplacer mineralisation |
|
Life of Mine (LoM) |
|
It is estimated that the current Mineral Reserve will be depleted in 2019 |
|
Environmental |
|
Damang retained its ISO 14001:2004 (Environmental Management System) Certificate following an extended audit during
this year, and remains fully compliant to the ICMI Cyanide code |
|
Regulatory Codes |
|
Gold Fields reports its Mineral Resources and Mineral Reserves in accordance with the South African Code for The
Reporting of Exploration Results, Mineral Resources and Mineral Reserves (2007 SAMREC Code), and other relevant
international codes such as SEC Industry Guide 7, JORC Code and NI 43-101. The Mineral Resources and Mineral
Reserves are underpinned by a sufficient Mineral Resource Management process and protocol to ensure adequate
corporate governance in respect of the intent of the Sarbanes-Oxley Act |
Gold Fields has
stated that: “If we cannot mine
safely, we will not
mine”. This principle
is embedded at
Damang. |
Operating Statistics
|
Material Mined |
’000 tons |
|
19,459 |
|
31,422 |
|
31,250 |
|
24,735 |
|
11,586 |
|
|
Ore |
’000 tons |
|
4,402 |
|
4,092 |
|
3,141 |
|
3,172 |
|
3,370 |
|
|
Waste |
’000 tons |
|
15,057 |
|
27,330 |
|
28,109 |
|
21,563 |
|
8,216 |
|
|
Stripping ratio (Tons) |
Waste:Ore |
|
3.4 |
|
6.7 |
|
9.0 |
|
6.8 |
|
2.4 |
|
|
Ore Grade mined |
g/t |
|
1.6 |
|
1.6 |
|
1.4 |
|
1.7 |
|
1.5 |
|
|
Source of ore |
|
|
|
|
|
|
|
|
|
|
|
|
|
- Total tons milled |
’000 tons |
|
4,991 |
|
4,516 |
|
5,269 |
|
5,328 |
|
5,215 |
|
|
- Head grade |
g/t |
|
1.3 |
|
1.4 |
|
1.2 |
|
1.5 |
|
1.6 |
|
|
- Average yield |
g/t |
|
1.2 |
|
1.3 |
|
1.1 |
|
1.4 |
|
1.5 |
|
|
- Gold produced |
kg |
|
6,233 |
|
6,041 |
|
5,843 |
|
7,312 |
|
7,703 |
|
|
- Gold produced |
’000 oz |
|
200.4 |
|
194.2 |
|
187.9 |
|
235.1 |
|
247.7 |
|
|
Operating cost |
|
|
|
|
|
|
|
|
|
|
|
|
|
- Mining (Open Pit) |
US$ |
|
65.4 |
|
64.3 |
|
38.7 |
|
33.4 |
|
25.6 |
|
|
- Processing (Open Pit) |
US$ |
|
24.6 |
|
43.7 |
|
36.2 |
|
31.6 |
|
28.8 |
|
|
- Engineering |
US$ |
|
29.2 |
|
|
|
|
|
|
|
|
|
|
- Marketing/Overheads |
US$ |
|
13.3 |
|
10.1 |
|
13.1 |
|
12.6 |
|
12 |
|
|
Total |
US$ |
|
132.5 |
|
118.1 |
|
88.0 |
|
77.6 |
|
66.4 |
|
|
Notional Cash Expenditure |
US$/oz |
|
745 |
|
753 |
|
637 |
|
439 |
|
311 |
|
|
Capital expenditure |
US$ (million) |
|
16.9 |
|
28.1 |
|
31.7 |
|
25.6 |
|
10.6 |
|
|
General |
|
|
|
|
|
|
|
|
|
|
|
|
|
- Number of employees |
TEC’s |
|
1,649 |
|
1,146 |
|
899 |
|
913 |
|
861 |
|
|
- Expected Life-of-Mine |
years |
|
9 |
|
5 |
|
6 |
|
5 |
|
5 |
|
|
- Mineral Reserves |
Mt |
|
36.1 |
|
25.5 |
|
29.3 |
|
26.2 |
|
23.5 |
|
|
- Head Grade of Mineral Reserves |
g/t |
|
1.6 |
|
1.7 |
|
1.7 |
|
1.5 |
|
1.6 |
|
Rounding off of figures presented in this report may result in minor computational discrepancies. Where this occurs it
is not deemed significant.
Geological Setting and Mineralisation
The Damang ore bodies are located within the
Tarkwaian Sediments, which form a significant
portion of the stratigraphy of the Ashanti Belt in
southwest Ghana. The Ashanti Belt is a north-easterly
striking, broadly synclinal structure
made up of Lower Proterozoic sediments
and volcanics underlain by the metavolcanics
and metasediments of the Birimian System.
The Tarkwaian unconformably overlies the
Birimian, and is characterised by lower intensity
metamorphism and the predominance of
coarse grained, immature sedimentary units.
 |
Local geology map |
Local geology
The stratigraphy at Damang is primarily
through the Tarkwaian Group and comprises a
large-scale fining upwards sequence of clastic
sediments interrupted by up to four major goldbearing
quartz pebble conglomerate horizons.
This sequence unconformably overlies a mixed
Birimian Supergroup basement comprising
volcaniclastic deposits and minor fine-grained
clastic sediments and black shales. The entire
region is intruded by a number of igneous
intrusions, the most common being dolerites
that occur as narrow dykes and sill-like bodies
along contacts on either side of the Tarkwa
Phyllite, a particularly fine-grained pelitic unit
in the upper Tarkwaian. A second intrusive
body, the so-called `Diorite Porphyry’ occurs
sporadically along the boundary between the
Birimian and the Tarkwaian.
Palaeoplacer mineralisation
There are three gold-bearing conglomerate
horizons recognised on the western limb of the
Damang Anticline. From footwall to hangingwall,
these are known as, the Star/Composite,
Malta/Breccia, and Gulder Reefs. There are
also three gold-bearing conglomerate horizons
recognised on the eastern limb, namely the
Lima, Kwesie-K1, and Kwesie-K2 Reefs.
These conglomerate horizons are separated
by poorly mineralised sandstone units.
 |
Local strategraphy |
 |
Siting exploration drillholes |
 |
Stratigraphic profiles showing proximal to distal setting across property |
The reefs are usually characterised by
a fining upwards sequence of poorly to
moderately sorted, clast supported polymictic
conglomerates. However, local variations are
observed where the conglomerate domain is
interbedded with fine to coarse grained, poorly
sorted sandstones. The Star/Composite,
Malta/Breccia, and Gulder Reefs on the west
limb and the Lima, Kwesie-K1 and Kwesie-K2
Reefs on the east limb of the Damang Anticline,
feature significantly higher gold grades than
the poorly mineralised sandstone units, which
separate the reefs. The conglomerate reefs
may contain between 1.3 to 1.5 g/t Au, and
the poorly mineralised sandstone units usually
contain between 0.2 to 0.1 g/t Au.
Hydrothermal mineralisation
Hydrothermal gold mineralisation at Damang
occurs in pyrite and pyrrhotite alteration
selvages, which are usually less than 1 m
wide and located immediately adjacent
to en-echelon quartz veins. Gold is also
associated with accessory vein minerals such
as carbonate, muscovite, tourmaline, ilmenite,
and apatite. These alteration zones are often
linked, and may result in significant volumes,
characterised by intense veining and gold
mineralisation.
Damang is unique in Ghana by virtue of
having hydrothermal mineralisation hosted
in the quartzites of the Tarkwaian Banket
Footwall as opposed to the Metavolcanics and
Metasediments of the Birimian Basement as
seen at Prestea, Bogoso, and Obuasi.
 |
Hydrothermal
mineralisation
model |
Exploration and drilling
The Exploration Strategy constitutes the
following:
- Aggressive five year exploration program to
extend Life of Mine to 2025;
- Mineral Resource extension drilling to assess
the magnitude and style of mineralisation;
- Infill and Mineral Resource conversion
drilling to increase the level of confidence in
the estimate;
- Geophysics survey to aid in target
generation; and
- Prospect development.
Exploration drill programmes are designed
to assess the magnitude and style of
mineralisation. Reverse circulation (RC) drilling
is usually employed for initial exploration drill
testing of both palaeoplacer and hydrothermal
styles of mineralisation. Diamond drilling is
usually minimised in the initial exploration
stages due to the higher cost, however, it is
common for a small component of core drilling
to be performed, to establish stratigraphic and
structural relationships and to enable samples
to be collected for metallurgical test work.
In general terms, it is aimed to achieve a
RC drill spacing of 100 m along strike by
100 m down dip, with confirmation core drilling
undertaken to resolve local complexities,
in both hydrothermal and palaeoplacer
mineralisation.
Initial, and follow-up exploration drilling, is
undertaken outside optimised pit shells and
is done to assess the magnitude, grade
distribution and continuity, engineering and
metallurgical character of the mineralisation.
Exploration objectives are specified in the
operation’s business plan and Mineral Reserve
Replacement Strategy.
Infill and Mineral Resource conversion drilling
is required to increase the level of confidence
in a resource estimate by more accurately
resolving mineralisation boundaries, grade
continuity and distribution and internal waste
boundaries. Resource models, which will be
generated following the completion of this
drilling, will be used to establish more robust
production schedules and will enable more
accurate and confident grade and tonnage
reconciliation to be undertaken.
Damang needs to accelerate its recent rate
of discovery to maintain a pipeline of quality
projects and to provide additional Mineral
Reserves to drive the LoM extension initiative
to F2025. On-Mine lease exploration activities
in F2010 will be assisted by the near mine
exploration initiative to ensure that the highest
potential targets are investigated as a priority.
Prime targets include Amoanda North,
Damang North (Huni) and Nohokoa.
 |
Air-core exploration drilling at Nohokoa |
Mining
Mining at Damang is carried out by conventional
open pit methods using a contractor-fleet
operated by African Mining Services (AMS).
AMS has held the earth-moving contract since
the commencement of operations in August
1997.
Load and haul is undertaken using a standard
truck-shovel operation, with excavators in
backhoe configuration (two Liebherr 994 and
five Liebherr 984s). The haulage fleet consists
of thirty-five (35) Caterpillar 777F dump
trucks, with an average payload capacity
of 100 t.
 |
Open pit mining in Tomento Pit 4 |
Off-highway trucks haul ore to interim
stockpiles near to the mining area. A fleet
of tipper trucks operated by Engineers and
Planners Ltd then reclaims the ore and
transports it to the treatment plant.
Mining methods
Consistent with the current production
schedule, mining is carried out seven days per
week, two shifts per day. Dayshift is 11 hours
duration and night shift is 10 hours duration.
Ancillary equipment includes bulldozers,
graders, water trucks, and service truck
vehicles, supporting the drill-and-blast and
haulage operations through vehicle, road, and
bench maintenance, dust and erosion control.
Fresh rock and transitional zones are drilled
and blasted in 6 m lifts, with excavation in
3 m flitches. To optimise ore fragmentation and
blast control, blasting in fresh rock utilises both
conventional (Nonel) and electronic detonators.
Oxide material, which cannot be ‘free-dug’, is
blasted using lower powder factors. Waste
material is hauled to planned dumps located
close to the pit exit. AGL has a progressive
reclamation plan, whereby, as areas become
inactive, they are immediately rehabilitated through contouring, and replacement of
topsoil, seeding, planting, and fertilisation.
Oxide ore is selectively mined to provide
incremental feed to the mill with Tomento North
and East pits, located at 5.3 km and 6.3 km
respectively from the treatment plant, currently
serving as the main oxide sources. During
2008 the Rex pit, located 15 km to the south of
the treatment plant was developed to replace
the nearly depleted Tomento North.
The haul roads are designed for CAT 777F
trucks. For double lane traffic, the minimum
width is 23 m, and includes a drainage ditch
and safety berm. For single lane traffic, a
minimum width of 15 m is used.
 |
Tomento Pit 3 |
Mine planning and scheduling
The Mineral Resource forms the basis for
subsequent design, planning, and extraction
scheduling, incorporated into the LoM plan.
In the majority of instances, this is completed
using a combination of commercial software
packages.
For all operational plans, a detailed (one-year)
operating and capital cost budget is produced
and where appropriate extended for the LoM
production schedule. The operational plan
is prepared on a monthly basis. Zero-based
costing is used to formulate the plan. Of critical
importance is the utilisation of historically
achieved data for productivity and operating
costs. All capital projects are ranked and
prioritised to maximise capital efficiency and
return on investment.
Open pit planning involves the input of
economic parameters and physical constraints
into optimisation software to generate a series
of nested pits from which an optimal shell is
selected. Detailed design is then undertaken to
confirm the mineability of the optimised shell.
The process is iterated until an acceptable
level of correlation is achieved between the
optimised shell and detailed design. The
relatively small dimension of the pits and the
characteristics of the ore bodies (i.e. narrow
and steeply dipping palaeoplacer reefs),
combined with the equipment size, make the
pit design exercise critical when it comes to
keeping strip ratios in line with optimisation
results.
Standard mine design software is used; Whittle
4X to derive the optimal pit shell and Datamine
or MineSight for the detailed engineering and
design work on the optimised pit shells.
Mine planning is based on three-dimensional
block models of in situ mineralisation, with
allowances made for minimum mining widths,
dilution and ore loss appropriate to the
mining method being considered. Historical
performance measures are considered in
determination of these modifying factors.
Infrastructure, waste disposal and ore stockpile
management requirements are incorporated
into the planning process.
Projects
Initial drilling projects for F2010 are as follows:
The Bonsa Hydrothermal project lies on the
Eastern Limb of the Damang anticline within
the north-south striking Banket Formation.
Birimian basement occurs to the west and
Tarkwaian Phyllite to the east. A number of
the important east-northeast trending faults
traverse the project area.
The Tomento Gap project just south of the
Tomento pits was identified as a possible
source of hydrothermal mineralisation and
needs to be explored. This is in line with the
view that Palaeoplacer orebodies should also
be tested for hydrothermal mineralisation.
The geological setting of the Chida East
project, just north of Rex, is very similar to
the Rex orebody and needs to be tested for
hydrothermal mineralisation.
The Rex South project borders the Rex orebody
and features an east-northeast structure with
north east striking magnetic lineaments across
the Banket, Kawere and Birimian contacts. Soil
sampling, trenching and pitting at Rex South
have identified hydrothermal mineralisation
along the Birimian – Tarkwaian contact.
A previous diamond drilling program, designed
to explore Rex South, was prematurely
stopped due to bad weather conditions and
the undulated terrain but work will continue
during the new financial year.
Nohokoa extends for over 3 km between
Amoanda in the north and Rex North in the
south. The area is located on the contact
between the Tarkwaian and Birimian
Basement, and has potential for Rex/
Amoanda – style hydrothermal mineralisation.
Previous exploration work was followed-up by
a diamond drilling program during F2009 and in view of the unexpected geology and
mineralized formations, a follow-up phase may
well be drilled in F2010 pending final assay
results.
 |
Amoanda block model (view to south-west) |
The Damang North and Koduakrom projects
lie to the north of the Damang (Huni) orebody
and on strike of the Damang Fault and have
potential hydrothermal mineralisation. These
areas received little attention in the past and
will be explored during the next financial year.
In order to locate concealed/sub-surface ore
bodies, geophysical exploration techniques
(Induced Polarization and Gravity surveys)
were employed during the fourth quarter of
F2009 and this work will be continued during
F2010.
The target area extends from the Damang
pit in the north to Rex in the south with the
Tarkwaian and Birimian as target Formations.
A secondary crusher is to be installed to
reduce the current dependency on oxide ore.
 |
Huni Pit design |
 |
Exploration project areas |
Mineral Processing
The Damang milling circuit was commissioned
in November 1997 at the design throughput
of 3 Mtpa. A number of modifications and
optimisations allowed an increase in the annual
throughput to about 5.2 Mtpa. The Plant is a
conventional two-stage grinding circuit using
SAG and Ball mill combination, with pebble
crusher and gravity concentration, followed
by a carbon-in-leach recovery process.
The average throughput of the Plant is currently
14,200 tpd, with an average availability
of 94.9%.
The ore being treated at Damang consists
of fresh rocks (siltstone, sandstone, phyllites
and dolerite) and weathered material (laterite,
saprolite). The blend requirement of the feed
to the plant is currently budgeted at 65% fresh
and 35% oxide. A high fresh rock proportion
up to about 65% is treated when new shell
liners are installed in the sag mill. However,
in order to sustain the mill throughput getting
to the end of the life of the liners, the blend is
made a little softer, with up to 55% fresh rocks.
The optimisations and modifications work
carried out on the Plant, has seen the Plant
throughput increasing from 450 tph to a
current 630 tph. This has reduced the total
residence time at the CIL circuit from 30 hours
to 17.8 hours. The reduction in the residence
time has affected the overall gold recovery on
the CIL Plant, with a reduction from an average of 93.6% (from 1998 to 2000) to 90.5% (from
2001 to 2006). However, since the successful
installation and commissioning of the seventh
tank in October 2008 and a second Knelson
concentrator, the recovery has increased by
1.6% to 93.8%. The plant will therefore be
in a better position to receive the high grade
material from the Damang cut back at the
current throughput.
Damang LoM Tailings Storage Facility Assessments
|
|
25.5 |
|
23.6 |
|
8 |
|
7.78 |
|
F2006-F2009 |
|
Sustainable Development
Damang aims to comply with established Gold
Fields Group Health and Safety Policy, which
subscribes to international best practices,
specifically in the context of World Bank
Policies and Guidelines, International Finance
Corporation Operational Policies, International
Labour Organisation Conventions and
OHSAS18001.
Damang has achieved an outstanding
health and safety performance through
the participation of all employees and the
application of safe, innovative processes
and technologies, within a framework of full
compliance. The Mine has set itself a target of
zero lost day injuries for the next financial year.
The Mine’s progressive fatality free shifts is
currently in excess of 4 million. There have been
29 injuries recorded during F2009, comprising
2 lost day injuries, 5 medically treated injuries
and 22 minor injuries.
Analysis of incidents indicates that hand
injuries due to material handling and/or use
of equipment, are the major factors to be
addressed. Seventy percent of near miss and
dangerous occurrences were related to the
use of mobile equipment, particularly light
vehicles, and haul trucks.
Environmental management at Damang
is conducted within the framework of an
ISO14001 certified Environmental Management
System (EMS). Certification of the system
occurred first in July 2003 for a three-year
period and has since then been the subject
of annual third-party audits. Re-certification
of the EMS under the revised ISO14001:2004 standard was achieved in July 2006 for another
three-year period. The foundation of the EMS
is the Abosso Goldfields Limited Environmental
Policy, which is aligned with the Gold Fields
Limited Environmental Policy.
 |
Damang mine village |
F2009 |
|
|
Fatalities |
(No) |
|
0 |
|
0 |
|
0 |
|
0 |
|
0 |
|
|
Fatality rate |
(per Mmh) |
|
0 |
|
0 |
|
0 |
|
0 |
|
0 |
|
|
LDIFR |
(per Mmh) |
|
0.22 |
|
1.2 |
|
1.28 |
|
0.7 |
|
0.6 |
|
Mineral Resources and Mineral Reserves
The Damang Mineral Resource and Mineral
Reserve declarations are based on systematic
and sustainable mineral reporting practices.
Systematic RC and DD drilling and subsequent
core-logging, consistently updates the
geological structure and reef-pod models used
as the basis of each declaration. On-going
sampling of RC, DD and grade control core
is carried out to provide additional grade data
that is incorporated into a detailed evaluation
model.
Updated pit designs and schedules are then
compiled and evaluated based on the most
recent technical and economic parameters
to compile a LoM plan. Cognizance is taken
of pit limitations, haul road distance and plant
capacity. Detailed economic and scenario
models are subsequently compiled to ensure
validity of positive cash flow for Mineral Reserve
declaration purposes. Internal and external
audits as well as peer reviews are conducted
to ensure consistency and compliance to
regulatory practices.
Mineral Resources
Mineral Resources are quoted at an appropriate in-situ economic cut-off grade with tonnages and grades based on the resource block model.
They also include estimates of any material below the cut-off grade required to be mined to extract the complete pay portion of the Mineral Resource;
June 09 |
|
June 09 |
|
June 09 |
|
|
Open pit and underground |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Measured |
9.4 |
|
9.1 |
|
10.0 |
|
1.5 |
|
2.3 |
|
2.0 |
|
464 |
|
680 |
|
644 |
|
|
Indicated |
48.0 |
|
26.0 |
|
28.5 |
|
1.5 |
|
1.6 |
|
1.6 |
|
2,268 |
|
1,309 |
|
1,471 |
|
|
Inferred |
12.5 |
|
11.2 |
|
12.5 |
|
3.4 |
|
3.7 |
|
3.4 |
|
1,367 |
|
1,336 |
|
1,381 |
|
|
Total open pit and underground |
69.9 |
|
46.3 |
|
51.0 |
|
1.8 |
|
2.2 |
|
2.1 |
|
4,100 |
|
3,325 |
|
3,496 |
|
|
Surface |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Indicated low-grade stockpiles |
5.1 |
|
4.8 |
|
6.8 |
|
1.1 |
|
1.1 |
|
1.2 |
|
184 |
|
165 |
|
263 |
|
|
Grand Total |
74.9 |
|
51.1 |
|
57.8 |
|
1.8 |
|
2.1 |
|
2.0 |
|
4,283 |
|
3,490 |
|
3,759 |
|
Modifying factors
- The Measured and Indicated Mineral
Resources are inclusive of those Mineral
Resources modified to produce Mineral
Reserves;
- Unless otherwise stated, all Mineral
Resources and Mineral Reserves are quoted
as 100% and are not attributable with
respect to ownership;
- All Mineral Reserves are quoted in terms of
Run-of-Mine (RoM) grades and tonnages
as delivered to the metallurgical processing
facilities and are therefore fully diluted;
- Mineral Reserve statements include only
Measured and Indicated Mineral Resources,
modified to produce Mineral Reserves and
contained in the LoM plan; and
- Mineral Resources and Mineral Reserves
have undergone both internal and external
audits during the current year, and any issues
identified were rectified during the current
reporting cycle.
|
Resource gold price |
US$/ oz |
1,000 |
|
|
Cut off for fresh ore |
g/t |
0.55 |
|
|
Cut off for oxide |
g/t |
0.35 |
|
|
Reserve gold price |
US$/ oz |
800 |
|
|
Cut off for mill feed open |
g/t |
0.62 |
|
|
Cut off for fresh ore |
g/t |
0.62 |
|
|
Cut off for oxide |
g/t |
0.43 |
|
|
Stripping |
waste:ore |
3.33 |
|
|
Dilution (hydrothermal) |
% |
15 |
|
|
Dilution |
cm |
40 |
|
|
Mine call |
% |
100 |
|
|
Plant recovery factor fresh ore |
% |
92.5 |
|
|
Plant recovery factor oxide |
% |
93.5 |
|
|
Processing |
Mtpa |
5.2 |
|
Grade tonnage curves
Open pits

Underground

Mineral Reserves
The Mineral Reserves are derived following the production of a LoM plan, by incorporating modifying factors into the Mineral Resource model. Optimal
pit shells are used as a basis for pit design. Bench Mineral Reserves are generated from the pit designs for scheduling and comprise four scheduling
categories, oxide and fresh ore plus oxide and fresh waste. The oxide and fresh ore categories are based on confidence intervals, weathering codes
and cut-offs, whilst the oxide and fresh waste categories include all materials that are not considered as ore.
In general, Proved Mineral Reserves are derived from Measured Mineral Resources, and the Probable Mineral Reserves are derived from Indicated
Mineral Resources, except where confidence levels of modifying factors leads to Measured Mineral Resources converting to lower confidence
Probable Mineral Reserves.
The stockpiles included in the Mineral Reserve comprise mostly lower grade mineralisation that has been accumulated since the start of mining of the
Damang Pit. The stockpile material comprises about 10% of the Mineral Reserve ounces and 14% of the Mineral Reserve tons.
June 09 |
|
June 09 |
|
June 09 |
|
|
Open pit |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Proved |
3.5 |
|
4.6 |
|
6.0 |
|
1.8 |
|
2.6 |
|
2.2 |
|
207 |
|
388 |
|
434 |
|
|
Probable |
27.5 |
|
16.1 |
|
16.5 |
|
1.6 |
|
1.6 |
|
1.7 |
|
1,429 |
|
800 |
|
902 |
|
|
Total open pit |
31.0 |
|
20.7 |
|
22.6 |
|
1.7 |
|
1.8 |
|
1.8 |
|
1,636 |
|
1,189 |
|
1,336 |
|
|
Surface stockpiles |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Probable |
5.1 |
|
4.8 |
|
6.8 |
|
1.1 |
|
1.1 |
|
1.2 |
|
184 |
|
165 |
|
263 |
|
|
Grand Total |
36.1 |
|
25.5 |
|
29.3 |
|
1.6 |
|
1.7 |
|
1.7 |
|
1,820 |
|
1,354 |
|
1,599 |
|
Mineral Reserve by deposit
|
DPCB |
2.4 |
|
1.9 |
|
148 |
|
6.8 |
|
1.9 |
|
407 |
|
|
Juno 3 |
1.1 |
|
1.7 |
|
59 |
|
0.5 |
|
2.0 |
|
33 |
|
|
Huni |
– |
|
– |
|
– |
|
11.4 |
|
1.7 |
|
630 |
|
|
Tomento North |
– |
|
– |
|
– |
|
0.2 |
|
1.7 |
|
12 |
|
|
Tomento East |
– |
|
– |
|
– |
|
1.3 |
|
1.0 |
|
41 |
|
|
Lima Gap |
– |
|
– |
|
– |
|
0.4 |
|
1.2 |
|
16 |
|
|
Lima South |
– |
|
– |
|
– |
|
2.4 |
|
1.0 |
|
78 |
|
|
Rex |
– |
|
– |
|
– |
|
2.4 |
|
1.8 |
|
140 |
|
|
Abosso Tails |
– |
|
– |
|
– |
|
1.9 |
|
1.2 |
|
73 |
|
|
Stockpiles |
– |
|
– |
|
– |
|
5.1 |
|
1.1 |
|
184 |
|
|
Total |
3.5 |
|
1.8 |
|
207 |
|
32.6 |
|
1.5 |
|
1,614 |
|
Mineral Resources and Mineral Reserve Reconciliation year-on-year
Mineral Resource
Factors that affected Mineral Resource reconciliation:
- Growth due to discovery, resource modelling and Gold
Price.
- Decrease only as a result of depletion.
Change in Mineral Resource F2009 to F2010

Mineral Reserve
Factors that affected Mineral Reserve reconciliation:
- Growth largely as a result of discovery and increase in Gold Price.
- Decrease mainly due to production depletion.
Change in Mineral Reserve F2009 to F2010

Mineral Reserve sensitivity
The Mineral Reserve sensitivity has been derived from the
application of the relevant cut-off grades to individual gradetonnage
curves of the optimised pit shells for the open-pits. The
Mineral Reserve sensitivities are not based on detailed depletion
schedules and should be considered on a relative and indicative
basis only.
The following graph indicates the Managed Reserve sensitivity at
–10%, -5%, base, +5%, +10% and +25% to the gold price.
Managed Mineral Reserve Sensitivity

Regulatory Codes
SAMREC
This Technical Statement has been prepared
in Compliance with the South Africa Code for
the Reporting of Exploration Results, Mineral
Resources and Mineral Reserves (2007
SAMREC Code).
JSE
This Technical Statement has been prepared in
compliance with the listing requirements of the
JSE Securities Exchange, South Africa (JSE),
specifically Section 12 – Issue 11.
Sarbanes-Oxley Act
The Mineral Resource and Mineral Reserve is
underpinned by an adequate Mineral Resource
Management process and protocol to ensure
adequate corporate governance in respect of
the intent of the Sarbanes-Oxley Act.
Environmental
Damang has an environmental management
team who are supported by specialist
assistance from the South Africa regional
office in Johannesburg. The systems,
procedures, training etc. are at international
best practice levels. Gold Fields has produced
a Sustainability Report in 2009 and intends
reporting annually in accordance with the
Global Reporting Initiative.
Competent Persons
Arnand van Heerden: Mineral Resources Manager
BSc (Hons) Economic Geology, BSc Geology, SACNASP (No. 400106/02), MAusIMM (No. 990525). Arnand has 11 years experience in mining and
exploration in South Africa and Ghana and is jointly responsible for the overall correctness, standard and compliance of this declaration.
Chris Murray: Chief Mine Geologist
MSc (Sedimentology), SACNASP (No. 400046/04). Chris has 30 years experience in mining and exploration in South Africa and Ghana and is
responsible for Grade Control, Reserve Reconciliation and Resource Modelling.
Sean Kelly: Geostatistics and Evaluation Manager
National Higher Diploma (Mineral Resource Management), GDE (Mining Engineering), Mine Surveyors Certificate of Competency, Member of PLATO
(No. MS0095). Sean has 27 years experience in the mining industry and is responsible for the Resource Modelling and Estimation.
Deon Steenkamp: Chief Exploration Geologist
BSc (Hons.) Economic Geology, BSc (Geology), MBA, MAusIMM (Membership pending). Deon has 27 years experience in mining and exploration in
Ghana and South Africa and is responsible for Exploration Programme Planning and Implementation.
David Lee: Consulting Mining Engineer
B.Eng (Hons) (Mining Engineering), MAusIMM (No. 106796). David has 22 years experience in the mining industry in Australia, Ghana and Tanzania
and is responsible for Mine Planning, Optimisation and Scheduling.
Key Technical Staff
|
Post |
Incumbent |
|
Qualifications |
Years |
Key Responsibilities |
|
|
General Manager |
Alfred Baku |
|
MSc (Mining Engineering), MAusIMM
(Membership No. 226333) |
13 |
Responsible for the overall
strategic direction, leadership &
management |
|
|
Mine
Manager |
Gareth Phillips |
|
National Higher Diploma
(Metalliferous Mining) |
22 |
Mine planning optimisation and
scheduling |
|
|
Metallurgy Manager |
Charles Amoah |
|
BSc Metallurgy |
15 |
Mineral Processing and
Metallurgy |
|
|
Environmental Manager |
Ben Addo |
|
BSc (Chemistry),
MSc (Environmental management) |
4.5 |
Environmental management
Monitoring and compliance
with regulatory requirements
Conformance with ISO14001
systems |
|
|
Finance Manager |
Gabriele Decina |
|
B.Comm (Hons), CCISA Surveyors Certificate
of Competency |
13 |
Financial management,
reporting and compliance |
|
|
Engineering Manager |
Manfred Hildebrandt |
|
EECC. (Mines & Works) EECC. (Factories)
PG Dip, MDP |
24 |
Engineering, logistics and
infrastructure management |
|
|
Human Resources Manager |
Charles Klutse |
|
BSc (Human Resources)
MSc (Human Resources) |
5 |
Human Resources
Training & development, Social
responsibility |
|
|
Safety Superintendent |
Andre von Solms |
|
COMSOC 1&2
CoM adv Cert
(Mine environmental control) |
23 |
Management of safety risk
exposure occupational hygiene
monitoring programmes |
|
|
Local Affairs Manager |
Robert Siaw |
|
M.A. (Urban management)
BSc. (Hons) (Planning) |
12 |
Community Relations
Crop compensation
resettlement and livelihood
programmes Promotion of
positive corporate image |
|
Damang History
at a Glance
|