SYAMA
Re-development – Syama Gold Project
(Resolute 80%)
Work on the re-development of the Syama goldmine in Mali was completed during the year and the project is at the plant ramp up and optimisation phase, with all process areas operating. The majority of construction punch list items have been completed with only minor items remaining outstanding.
The total capital cost of the re-development was US$186m.
At 30 June 2009, US$3.0m of this is due for payment and
US$7.5m is still to be resolved.
Syama pre-production operating costs and inventory build-up,
net of
pre-production gold sales were A$77.6m for the year ended
30 June 2009.
Feasibility Study on Syama Free Milling Ore
The Feasibility Study of an expansion to the Syama Gold operations by processing free milling oxide ore resources, located near the existing Syama sulphide plant, continued into 2009. The study consists of:
- Drilling of deposits to define oxide, or non-refractory ores, located close to the Syama plant, and
- An engineering study into the capital and operating cost
of adding a circuit to the existing sulphide plant, to treat
non-refractory ore.
A review of exploration data has identified a number of
deposits within the Syama tenure that have the potential for
oxide ores. These deposits were A21, Tellem, Drag Queen,
Alpha and Syama Extension (figure 1). A21, Alpha and Syama
Extension have been partially mined for oxide ore by BHP and
Randgold. Other deposits which have oxide resources on tenure
adjacent to the SOMISY permit, such as the Tabakoroni deposit
on the Finkolo Joint Venture ground, would also be considered
for processing in this circuit.
During the resource definition work on A21, drill samples were collected for geotechnical and metallurgical evaluation to consolidate the conversion of resources to reserves. Metallurgical samples were submitted to Ammtec Ltd for comminution and CIL test work under guidance of the consultant firm Metallurgical Design.
The results from the metallurgical test work indicated the oxide and transition mineralisation could be processed via a gravity/CIL circuit with recoveries averaging + 90%. The sulphide (refractory) ore would require treatment via the existing flotation/roaster/CIL circuit.
Based on the results of the metallurgical, geotechnical test work, adopting a gold price of US$800/oz and costs related to the current Syama open pit mining, an open pit design was developed for the A21 deposit. The estimated reserve for this design using a 0.9g/t Au cut-off grade are, proven 724,000t @ 2.8g/t Au for 65,000ozs, probable 1,442,000t @ 2.7g/t Au for 125,000ozs, totalling 2,166,000t @ 2.7g/t Au for 190,000ozs. The oxide and transition ores constitutes 97% of this reserve, with the remainder being sulphide ore.
The engineering study for the free milling ore
commenced in the June 2009 quarter, with Abesque
Engineering commissioned to complete the study. The
study was based on the treating of 1.5Mtpa of oxide ore
from satellite deposits utilising common or redundant
components within the sulphide plant. Included in this
study is the construction of a water storage dam to hold
excess river water collected during the wet season for use
during the dry season. A new tailings storage facility to
store the oxide and calcined cyanide leached tails was
also included. The study is expected to be completed in
the September 2009 quarter.
Finkolo – Etruscan Resources JV
(Resolute 60%)
Activity on the Tabakoroni deposit within the
Finkolo Joint Venture tenure (figure 1) moved into
the development phase with commencement of infill
drilling, metallurgical, geotechnical and environmental
impact studies. This deposit is approximately 30kms
south of the Syama project treatment facilities which
could be used to process any ore delineated on the
joint venture tenure.
In the June quarter 2009 the resource for the Tabakoroni deposit was updated (refer Table 1). At 1g/t Au cut-off grade, the total estimated resource is 9.96Mt @ 2.59g/t Au for 829,000ozs. The quality of the resource improved with measured and indicated resources totalling 6.83Mt @ 2.78g/t Au for 610,000ozs, an increase of 228,000ozs. A further 3.13Mt @ 2.18g/t Au for 220,000ozs reports as an inferred resource.
The updated resource estimate was based upon results
from infill drilling carried out on the Tabakoroni deposit
over the past year. Highlights of this drill programme
include:
- 43m @ 7.0g/t Au (including 3m @ 26.7g/t Au)
- 22m @ 11.7g/t Au (including 2m @ 79.2g/t Au)
- 19m @ 8.8g/t Au (including 1m @ 106.0g/t Au)
- 17m @ 4.8g/t Au
- 14m @ 7.3g/t Au (including 1m @ 50.8g/t Au)
- 12m @ 9.4g/t Au (including 3m @ 25.6g/t Au)
Core and reverse circulation samples from the mineralised zone were sent to Ammtec in Australia for metallurgical test work which included comminution, gravity, leach and flotation plus acid mine drainage determinations. Gravity/CIL test work indicates recoveries of between 85% to 95% (24 hour period) for the oxide and transition mineralisation, while the sulphide zone indicated recoveries of approximately 42%. As organic carbon has been identified in the sulphide mineralisation test work is to be carried out on the sulphide material to determine if a flotation/ roaster/CIL process would improve the gold recovery.
Studies related to the final wall angles for open cut pit design, acid mine drainage and environmental geochemistry have been completed. These results will be incorporated into the Tabakoroni Feasibility Study. Pit optimisation will commence when all the metallurgical work has been finalised. Remaining field work to be completed for inclusion into the Feasibility Study is related to the environmental and community impact studies. A Malian consultancy firm has been retained to conduct this work in the later part of 2009. On completion of this work a full feasibility and environmental impact study will be submitted to the Malian government agencies for approval to mine this deposit.
Resource Development at Mt Wright, Australia
(Resolute 100%)
During 2008 and the early part of 2009 drilling continued at Mt Wright into the mineralised rhyolite breccia zone with a combination of infill and exploratory drill programmes. The majority of the drilling concentrated on upgrading the resource category to indicated and measured via underground infill drill holes. Highlights of the drilling include 43m @ 5.8g/t Au and 12m @ 3.7g/t Au and 36m @ 5.8g/t Au. A comparison of the original feasibility drill data against the underground resource drill results shows a high correlation.
Drilling of exploratory holes from underground positions to determine the depth extension of the mineralisation within the rhyolite and potential economic zones within the adjacent granite breccia was limited during the year as the available drill rigs were scheduled to drill areas for production. Two holes were drilled to test the extension of the high grade within rhyolite breccia. These holes deviated from the targeted zone and were terminated. However the data from the holes did indicate the continuity of the low grade mineralised halo within the rhyolite. Significant results from the drilling included drill intercept MTWR146W3 30m @ 1.0g/t Au and MTWR205 10m @ 2.1 g/t Au.
During the year test holes were drilled into the granite breccia to locate high grade zones within this unit. In 1992-3, 105,000t @ 5g/t Au was mined from this unit with a glory hole operation. In addition exploration holes drilled through the granite breccia show mineralisation occurs within this unit at depth. Initial intercepts MTWR148 5m @ 1.9g/t Au, MTWR167 10m @ 1.8g/t Au, and MTWR186 6m @ 12.1g/t Au were promising but only identified narrow discrete zones which were uneconomic to mine.
As the decline advances there exists the opportunity to further drill the granite breccia and to test the rhyolite breccia at depth for high grade gold zones.
Golden Pride, Tanzania
(Resolute 100%)
A review of adjacent mineralised zones at gold prices between US$850 to $950/oz has shown that several zones (Maji, Southern Oxides and Far East) have the potential to provide additional ore to the Golden Pride operations (see Figure 2). A study of the potential benefits and issues will be undertaken, and where required, further drilling will be carried out to provide information for mining studies.
The Maji zone, identified by artisanal workings and an early exploration programme, was tested with a shallow (20m) orientation drilling programme. Initial results were encouraging and this was followed up with drilling to a depth of 100m. Results from this second round of drilling are very promising with several high grade intercepts obtained that showed reasonable continuity between drill sections. Significant results included: 13m @ 2.8g/t Au from 41m, 22m @ 12.6g/t Au from 68m and 10m @ 6.9g/t Au from 110m. Further drilling is planned to provide enough data to upgrade an indicated resource to a potential reserve.
Drill programmes are planned on the Southern Oxides and Far East zones with work expected to commence in the later part of 2009. This drilling will allow an upgrade of the resource estimation to measured and indicated categories for potential mining studies.
