Sihayo reports N. Sumatra gold project update
Tuesday, November 1 2011 - 09:00 AM WIB
REVIEW OF OPERATIONS
1. Definitive Feasibility Study (?DFS?)
Metallurgical Testwork
The final phase of the DFS work related to the overall metallurgical gold recoveries is progressing well. Over 4,500 additional cyanide leach tests are being completed (2,750 completed to date) across the multiple mineralisation types that make up the Sihayo and Sambung Resources and the initial results suggest that some improvement in overall process gold recoveries is achievable.
Optimal Plant Capacity
Ongoing assessment of the ?optimal plant capacity? has confirmed that the project will be a 1.5Mtpa operation.
Key DFS Parameters at the 1.5Mtpa level
The Capex and Opex components of an expansion to 1.5 Mtpa have been completed to DFS standard and the key summary results are detailed in the table below. An additional scenario of improved recoveries over the initial mine life has also been included in the table below, however, it needs to be emphasised that this is merely for indicative purposes at this stage and any improvement in overall recoveries will be confirmed at the conclusion of the current metallurgical testwork program.
The Sambung Resource has been included in the mining schedule of the expanded 1.5 Mtpa throughput case, however, it must be noted that the Sambung Resource is currently in the Inferred Category and current infill drilling program is aiming to bring the resource up to the required Indicated Category for its ultimate inclusion in the DFS mining schedule.
| Sihayo Pungkut Gold Project | 1.25 Mtpa |
1.5 Mtpa |
1.5 Mtpa* |
|
| Capital Cost (pre contingency allowance) | USD mill | 80.4 | 87.1 | 87.1 |
| Pre-Production Mining | USD mill | Nil | 11.2 | 11.2 |
| Initial Mine Life | years | 7 | 7 | 7 |
| LOM Total Ore Processed** | Mt | 8.6 | 10.2 | 10.2 |
| LOM Average Annual Gold Production | Oz
|
72,000 | 88,000 | 93,000 |
| LOM Site Cash Costs (including royalties) | US$/oz
|
752 | 678 | 639 |
| LOM Average Gold Recoveries | % | 71.5 | 71.5 | 75* |
| LOM Average Strip Ratio | Waste: Ore | 5.4:1 | 4:1 | 4:1 |
| Note: 1.5 Mtpa* scenario assume a lift in LOM average gold recoveries to 75% from the base case 71.5% Note: LOM Total ore processed for the 1.5 Mtpa case includes 1.6 Mt currently classified as Inferred Resource Note: Inferred Resource material comprises 16% of the forecast total ore processed in the 1.5 Mtpa case |
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As part of the ongoing DFS work, two major Cost Optimisation Programs are underway, the first focused on project power supply and the second on a more efficient waste material movement process.
Cost Optimisation ? Biomass Power
Currently in the DFS, power production is based on diesel generators and at a basis of US$100/bbl oil, the unit cost of power is approximately US$0.25 kw/hr.
Our study of hydro power potential was unsuccessful due to the high Capex associated with the required infrastructure.
However, we have entered detailed discussions with a number of industry leading biomass power companies, including DP Cleantech, to determine the viability of an 8MW biomass power plant being the primary source of power.
DP Cleantech have designed, constructed and successfully commissioned over 40 biomass power plants across Asia and Europe with a combined installed capacity of 1,000MW.
The primary fuel source for the proposed power plant is Palm Kernel Shells (?PKS?) a waste product of the palm oil production process.
The PKS market is well established in Sumatra, Indonesia and export volumes of PKS to North Asia and Europe as a primary fuel for biomass power plants has been steadily increasing over the past five years.
Potential supply of PKS within trucking distance of the proposed power plant site exceeds 3 times the annual required supply and is available across multiple independent suppliers. Additionly, new palm oil plantations are being established within the area and will provide additional future supply of PKS.
From both an environmental and operating cost perspective, the potential to utilise proven biomass power supply is very material.
Biomass power would provide an approximate 70% operating cash cost saving compared to diesel generated power, excluding any carbon emission credits that maybe available.
DP Cleantech will provide DFS Capex and Opex estimates for the biomass power plant by the end of December 2011.
Cost Optimisation ? Overland Conveyor for Waste Material
The current waste material movement process is via haul trucks. Given the topography surrounding the proposed pits and waste dump areas, the required haulage distance from pits to waste dumps is up to 8km in the early years of operation.
We have entered detailed discussions with some of Europe?s leading manufacturers of conveyors for the mining industry, including Famur Group of Poland, for the installation of an overland conveyor to transport up to 8Mtpa of waste material from nearby the mining pits to the waste dump site.
The proposed conveyor will be between 1.2km and 2.0km in length and because the entire length of the conveyor will be downhill, the conveyor will generate excess power equivalent to approximately 10% of the total power requirement of the entire project.
Famur Group will provide DFS Capex and Opex estimates for the overland conveyor by the end of December 2011.
2. Sihayo Pungkut Gold Project (?SPGP?)
Drilling activities at SPGP resumed in October with a focus on the final phase of infill drilling. An infill program of approximately 3,000 meters is required to likely convert the limited amount of Inferred Resource contained within the overall JORC Compliant Resource of 16.3Mt at 2.7 g/t Au for 1.425 Moz into the higher Indicated Category. The program has begun with a single rig and a second rig shall arrive on site within 4 weeks. With two diamond drill rigs and the relatively shallow depth of the planned holes it is anticipated that the drilling will be completed within two or three months.
Once the infill program is complete, ongoing exploration drilling shall target potential near-surface mineralisation along strike from the existing JORC Resources, which could potentially be included in the early years of the current proposed mine schedule as described within the DFS.
3. Regional Exploration
Hutabargot Julu Epithermal Gold Prospect
Exploration drilling re-commenced in September at the highly prospective Hutabargot Julu Epithermal Gold Prospect located 7km southeast, along strike, of the SPGP. Figure 2 below shows the location of the Hutabargot Julu Prospect within the wider Contract of Work (?COW?) area.
Ongoing exploration at Hutabargot Julu has defined an intermediate sulphidation epithermal gold complex that has a footprint of approximately 6km * 2km. Historic drilling yielded a best intercept of 5m @ 36.7 g/t Au and 198 g/t Ag from 47m within Quartz-Sulphide veining. The current drilling program will test multiple Epithermal Veins (high grade gold/moderate tonnage potential) and Hydrothermal Breccias (lower grade gold/high tonnage potential) and will consist of an initial 10,000m of drilling.
In addition to the drilling program, additional soil and IP surveys have been commenced and both programs extend the boundaries of the previous work area by moving to the north and the west.
Tambang Tinggi Gold Copper Prospect
The final holes of the first phase of drilling at Tambang Tinggi were completed during the quarter.
The next phase of drilling will require a larger capacity rig to test the porphyry copper gold potential at depth.
Highly anomalous Cu was intersected in drill holes TTDD008 and TTDD011:
TTDD008: 63m @ 0.55 g/t Au and 0.09% Cu from 196m
TTDD011: 46m @ 0.35 g/t Au and 0.13 % Cu from 116m
TTDD014 also intersected a potassium feldspar (Potassic alteration) zone. The combination of Potassic alteration and highly anomalous copper results at relatively shallow depth are potential vectors to a significant underlying Porphyry Copper Gold system.
Current surface exploraion work at the Tambang Tinggi area is focused on the Babisik Epithermal Gold Prospect.
Huta Pungkut Gold and Copper Skarn
The prospect is located 5km northwest and along trend of Tambang Tinggi. The area was identified from the regional stream geochemistry survey and confirmed by the recent aeromagnetic survey. The area comprises a broad zone (5.1 km strike length) of strong stream sediment gold anomalism (>10 ppb Au in 30 mesh BLEG). The prospect area is the most geochemically anomalous region within the COW with all drainages sampled along the trend returning anomalous values. The anomalous stream sediments appear to have a close relationship to magnetic anomalies suggestive of skarn type mineralisation.
The area presently has been divided into 3 prospects (Red Hill, Crown Hill and Blue Ridge) identified in reconnaissance exploration associated with small scale mining activity and possible vegetation anomalies similar to that at Tambang Tinggi.
Gold and copper skarn style mineralisation is hosted in limestones intruded by porphyry and the Mauri Sipongi granite.
Current exploration work includes geological mapping and soil sampling. Rock chips collected from skarn zones have yielded up to 44.6 g/t Au and up to 18% Cu. Soil sampling has delineated large areas (approximately 3km * 1km) of Cu-Au anomalism adjacent to mapped skarn zones. Scheduled ongoing work is an IP survey, further soil sampling, geological mapping and rock chip sampling. This work will be compiled and analysed to generate drill targets that are expected to be tested in 2012. Figure 6 below summarises the geology of the Huta Pungkut Prospect.
Community, Government and other Stakeholder Meetings
As previously reported, on Sunday 29th May, a group of demonstrators, believed to be supported by the representatives of illegal artisanal miners from the region, arrived and caused significant damage to Sihayo?s exploration camp.
Over the past five months, our community relations team has conducted over sixty meetings with the key SPGP stakeholders including; local community members, village heads, religious groups, NGO?s, local and provincial Government representatives, local and provincial Police and Army commanders, the newly elected Bupati of Mandailing Natal, North Sumatra and the Governor of North Sumatra.
The meetings have been focused on ensuring that the future activities of the Company are conducted in a safe and secure environment without the risk of any further unlawful acts. As with any mining project, our relationship with the local community is critical to our long term operational success. As part of our ongoing community program we took 15 local representatives on a site visit to a newly commissioned gold mine in North Sulawesi, Indonesia in mid-September, to show them first-hand the operational, environmental and community aspects of a mine of similar size to our planned SPGP.
In addition, community agriculture based programs have been initiated in four of the villages surrounding the SPGP and the aim is to establish similar programs in each of the 15 villages that are located in the project?s primary area of influence.
The agriculture programs work very well in these communities where over 90% of the local population are engaged in agriculture production as their primary source of income. The programs are built on the core philosophy of ?sustainability? and seek to improve the overall productivity of the local producers, add value to their existing products and ultimately facilitate better marketing of their products.
The response from within the initial four villages has been extremely encouraging and bodes well for the continued establishment of similar programs in the remaining 11 villages. (end of edited excerpt)