Pre-Development Work Program
Feasibility Study
The feasibility study for the full scale 20-25000 tpa cathode operation is running in parallel with the construction of the demonstration plant. Finders, on the basis of advice from metallurgical consultants, estimate that approximately 3-4 months of operating results from the demo plant will be required to finalise the feasibility study, particularly providing detailed information on rates of copper recovery and optimal heap height.
Detailed evaluation was undertaken on geotechnical aspects of the project including pit-wall stability studies and leach pad design (SRK Consulting), environmental management planning (HLA-ENSR) and an assessment of power options for the commercial scale project (Calder Projects). Finders submitted a KA-Andal to the Environment Impact Control Committee (BAPEDALDA) of the Maluku provincial government as the penultimate stage of the environmental permitting process for the planned full scale operation.
Calder Projects have been withdrawn as study managers for the Feasibility Study.
Ausenco Services Pty Ltd have been retained to:
o Review existing results and develop an implementation plan for the study as project managers
o review the development schedule in order to identify long lead time items required to achieve the late 2009 production target.
The Company has received a proposal from Ausenco to manage the remainder of the study with the option of advanced engineering studies to facilitate faster project timelines.
Demonstration Plant
A key component of the Wetar Feasibility Study is the construction and operation of a 5tpd copper cathode Demonstration Plant. This plant will replicate all aspects of the planned full scale 20-25,000 tpa cathode operation.
Progress includes the following:
• All major equipment items are now on site or in transit except for busbars; which are subject to fabrication delays and are due on site in late September.
• Earthworks are complete for the leach pad, crusher/stacker area and SX-EW plant and ponds.
• Concrete works complete for crusher circuit and installation underway
• Concrete footings underway for the SX-EW plant with installation scheduled for August
• Test pit mining pre-strip complete with ~4,000t stockpile.
Project Timing & Cost
The balance of equipment required for the demonstration plant will be mobilised by two further shipments in early August and early September. Commissioning of the demonstration plant is scheduled for end Sept 2008, subject to anticipated arrival of late equipment, particularly the truck busbars for the electro-winning plant. As a result of procurement delays for electrical equipment, the project is behind the original planned production schedule of mid-2008.
This has impacted the overall cost for the demonstration plant by means of carrying additional operating costs. Costs have also been impacted by higher fuel and freight charges in the past six months.
Overall, compared to the initial capital and pre-production operating costs estimate, on a like-for-like basis the current projection is that the demonstration plant will be approximately 20% over budget. Part of the overrun is due to larger than budgeted equipment costs and also the cost of engineering re-design work.
Finders also purchased significant capital items (previously unbudgeted) which can be utilised for the full scale project, namely:
• Primary, secondary and tertiary crushers purchased for approximately $1.2m with capacity of 120tph @ 6.5mm and 200tph @ 12mm.
• A 100DWT supply vessel capable of carrying 75,000l of fuel.
Metallurgical test work
Test work is continuing and results from ongoing laboratory scale leach test work being undertaken at HRL in Brisbane and Ammtec Ltd in Perth are being received. It should be noted that these progress results are based on extrapolation from solution assays, and that definitive recovery figures will require completion of solids assays and mass balances on completion of the tests.
At HRL, the four new 2m column tests at elevated (49°C) temperatures have commenced to further assess effects of crush-size on recovery rates.
Two of the six column tests using BioheapTM technology at the Ammtec Ltd laboratory have now been completed. Final copper recoveries from the 1m columns with Kali Kuning material after a 293 day leach cycle were 84.4% for the 6.3mm crush size and 88.4% for the 12mm crush size (after mass balance calculations). From the other tests, the Lerokis columns continue to show increasing copper recoveries.
