Promontorio
Figure 1: Promontorio Project
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Figure 2: Deposit Plan
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Promontorio is an advanced stage project hosting a deposit with a JORC Code compliant resource which meets Azure’s strategic objective to secure a high quality, project with early cash flow potential.
The Promontorio project comprises the adjoining Hidalgo, Promontorio & Magistral mineral concessions (collectively Promontorio Central) and the surrounding 105km2 mineral concession (Promontorio Regional). Promontorio Central covers 187 hectares and is subject to an option to purchase agreement whereby Azure will pay US$4.0 million over four years to acquire the concessions, with no royalties payable to either vendors or government. Azure has 100% ownership of the surrounding Promontorio Regional concession.
Azure completed an initial diamond drilling program of 40 holes totaling 6,695m, and produced a JORC Code mineral resource of 502,000 tonnes @ 4.7% copper, 2.1g/t gold & 99g/t silver at a 1% copper cut off, containing a total of 23,400 tonnes of copper, 34,000 ounces of gold and 1.6 million ounces silver. Full details of the resources classification and estimation methodologies are detailed in Azure’s announcement to the ASX, released on 7th January 2009.
The deposit is a high sulphidation epithermal type consisting of multiple massive and semi-massive sulphide veins containing very high grades of copper, gold and silver. From west to east there are three main veins – Santiago, Mina Vieja and Veta Grande – interspersed with several other, un-named, mineralised veins. All veins have a north-south strike, dip steeply to the west, and possess good geological continuity.
The mineralised structure outcrops over at least a 1,000m strike length before becoming obscured by more recent cover rocks. The deposit has been drilled over a strike length of only 200m and to depths of about 150m, and remains open-ended along strike to the north and south and at depth. Wildcat drilling 340m to the north of the deposit intersected further high grade copper, gold, silver and molybdenum mineralisation, thereby demonstrating the opportunity for significant expansion of the resources in these areas.
Azure has commenced a pre-feasibility study with initial and follow-up metallurgical testwork completed on a bulk sample of Promontorio ore. The testing program included head grade analysis, mineralogical examination, comminution testing, sulphide flotation, a recommendation on the optimum process route to produce a copper concentrate, and preliminary evaluation of various downstream processing options for treatment of the copper concentrate. Details of metallurgical results are contained in Table 1.
| PRODUCT | MASS | COPPER | SILVER | GOLD | ARSENIC | ||||
|---|---|---|---|---|---|---|---|---|---|
| Recovery (%) |
Grade (%) |
Recovery (%) |
Grade (ppm) |
Recovery (%) |
Grade (ppm) |
Recovery (%) |
Grade (%) |
Recovery (%) |
|
| Concentrate | 15 | 40.1 | 94.2 | 773 | 88.2 | 9.6 | 52.4 | 9.7 | 97.0 |
| Comminution Testing Results | |||||||||
| Optimum Grind Size: P80 @ 75μm (medium) | |||||||||
| Rod Mill Work Index (kWh/t): 18.5 (moderate) | |||||||||
| Ball Mill Work Index (kWh/t): 17.2 (moderate) | |||||||||
| Abrasion Index: 0.6 (moderate) | |||||||||
| Indicative Processing Route | |||||||||
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Evaluation of the economic potential of Promontorio has found that:
- The project has the potential to be developed and operated at a significant profit.
- The high grade mineralisation provides a large positive margin over operating costs.
- Operating revenue is estimated at US$356 / tonne 1
- Operating costs estimated at US$96 / tonne
- Cash flow modelling shows additional resources result in a substantial increase in project value.
Also present at the project is the Cascada prospect which hosts a near surface zone of gold-silver mineralisation, with wide zones (>10m) of moderate grade gold (1-2g/t) indicating the potential for a bulk tonnage gold deposit. A best intercept of 7.6m @ 19.8g/t gold highlights the potential for bonanza-grade gold mineralisation.
Other major deposits in the district include the Ocampo Mine (reserves of 2.5Moz gold and 113Moz silver), the Pinos Altos Project (reserves of 2.5Moz gold and 73Moz silver), the Dolores Mine (reserves of 2.4Moz gold and 127Moz silver), and the Palmarejo Project (resources of 1.7Moz gold and 150Moz silver).
 Figure 3: Long Section View 85Kb PDF enlargement |
 Figure 4: Regional Magnetics and Project Outline View 110Kb PDF enlargement |
1 Metals prices used (at March 2010): Copper @ US$3.40/lb, Gold @ US$1,100/oz, Silver @ US$17.00/oz